Hot Water vSupply 
 
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 Kitchen Boiler Connections 
 
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 Hot Water Supply 
 
 and Kitchen Boiler 
 
 Connections 
 
 A Text Book on the Installation 
 of Hot Water Service in Resi- 
 dences and Other Buildings and 
 Methods of Connecting Range 
 Boilers, Steam and Gas Water 
 Heaters 
 
 By William Hutton 
 
 Based on Articles from 
 
 Metal Worker, Plumber & Steam Fitter 
 
 with Addenda and Useful Tables 
 
 New York 
 
 David Williams Company 
 
 231-241 West 39th Street 
 1913 
 
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 Copyrighted, 1894 
 By DAVID WILLIAMS. 
 
 Copyrighted, 1899 
 By DAVID WILLIAMS COMPANY. 
 
 Copyrighted, 1913 
 By DAVID WILLIAMS COMPANY. 
 
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 ©CU350288 
 
PEEFACE. 
 
 Every man who lias been engaged in the plumbing business 
 or who has had to do with the design and construction of build- 
 ings requiring a supply of hot water at the various sanitary fix- 
 tures, will concede that there is no other branch of building 
 
 construction in which trouble is easier to find by a departure 
 
 » 
 
 from correct design or by improper construction. 
 
 Those who do not admit it need only study the columns of 
 trade papers devoted to plumbing topics to find that more 
 problems are presented for solution in this line than in any 
 other branch of plumbing, and the same can be said of all coun- 
 tries possessing trade papers. There need be no reflection on 
 the plumber in admitting this. The subject is one that requires 
 more study of principles than practical experience in construc- 
 tion, and it is generally found that when unsatisfactory systems 
 are constructed the mistake is in design through an improper 
 understanding of principle, and not because of poor workman- 
 ship. 
 
 The popular hand-book ** Kitchen Boiler Connections" — 
 dealt principally with piping problems and with the connec- 
 tions to boilers in the smaller type of residence. While the 
 examples shown in the book which is designed to replace it 
 cover the larger buildings as well, it has been recognized that the 
 former are the more important by reason of their far greater 
 number and therefore the examples of piping construction and 
 connections for small buildings 'are shown in greater variety. 
 This is considered all the more necessary, as the opportunity for 
 departure from certain standard types of construction are more 
 in small buildings than in large ones, as a rule, owing to greater 
 variety in architectural design. 
 
 All of the methods of connecting heating appliances 
 of various types have come under the author's personal observa- 
 tion, and it has been his intention to show as nearly as possible 
 such connections as may be considered standard and which are 
 likely to become necessary at some time in the practice of others, 
 while eliminating examples which might be considered freakish 
 or exceptional. Much of the material in the book has appeared 
 
PREFACE. 
 
 in the pages of ''Metal Worker, Plumber and Steam Fitter,'' 
 and snch parts of the previous book on this subject as applied 
 to up-to-date practice have been retained. 
 
 While it is not to be expected that every combination that 
 can be satisfactorily used is shown, it is hoped that the examples 
 which have been selected are varied enough to serve the purpose 
 of guiding the inexperienced mechanic to the selection of a form 
 of construction which will give satisfactory service for the special 
 conditions he may have to work to, and it is hoped that these 
 have been set forth in such a manner that a little study will 
 enable him to grasp the principles which have to be kept in mind 
 in selecting them. If this is done and each problem carefully 
 considered with these principles in mind, there will be less need 
 for the services of the ** trouble man" in hot water installations. 
 
 Wm. Hutton. 
 
TABLE OF CONTENTS. 
 
 Chapter I. Principles of Heating, Combustion, Transmission 
 OF Heat, Etc. 
 
 The principles of circulation. Density of water. Tempera- 
 ture of maximum density. Effect of density in causing circula- 
 tion. Motive force of water in a circulating system. Heat. 
 Definition of standard of measurement of heat. Combustion. 
 Heat of combustion. Production of heat by combustion of fuel. 
 Transmission of heat. Radiation. Convection. Conduction. 
 Improper combustion. Heat available from various fuels. 
 Necessity of ample air supply to fuel. Strains and stresses. 
 Definition of terms used in practice of hot water pipe fitting. 
 
 Chapter II. Corrosion of Water Fronts, Boilers and Pipes, 
 Deposit of Sediment, Etc. 
 
 Difference between corrosion and sedimentation. Cause of 
 more active corrosion of hot water pipes than of cold. 
 Amount of oxygen dissolved by water. How corrosive effect 
 may be lessened. Stoppage of pipes and water fronts by 
 sediment. Hardness of water. Measurement of degree of hard- 
 ness. Permanent and temporary hardness. Method of softening 
 water. Appliances for neutralising effect of heating on hard 
 water. Prevention of deposits by proportioning heating appara- 
 tus. Method of removing deposits of lime. Avoidance of pre- 
 cipitation by indirect heating of water. Construction of indirect 
 heating plant. Sediment collecting chambers. Heat losses 
 from boilers and pipes. Effect of various pigments and metallic 
 paints on radiation. Table of heat loss,es from cast iron 
 radiators with various paints. 
 
 Chapter III. Water Fronts, Coils and Heaters. 
 
 Construction of various types of water fronts. Position of 
 flow and return connections. Partitions in water fronts. Results 
 of accumulation of air in water fronts. Effect of sediment in 
 water fronts. Indication of overheating of walls of water 
 fronts. Vertical partition in v»'^ater fronts. Relation of size 
 of firebox to efficiency of ranges. Setting water fronts with 
 cement. Necessity of setting stove properly. Extending heat- 
 
 1 
 
2 TABLE OP CONTENTS. 
 
 • 
 
 ing surface of water fronts. Various methods of constructing 
 heating coils. Estimating capacity of water fronts and coils. 
 Time and size of coils and water fronts required to heat given 
 quantities of water. 
 
 Chapter IV. Examples of Range Conditions for Various Con- 
 ditions. 
 
 Common type of range connection. Common type with allow- 
 ance for expansion. Cause of pounding and snapping sounds 
 in boilers. Connection designed to avoid such noises. Insuf- 
 ficient circulation and its cause. Quick heating connections. 
 Combination of quick heating and side opening connection. 
 Connection for boiler with door intervening. Connection for 
 gas heater. Gas heater connection to avoid stoppage with sedi- 
 ment. Connection for boilers under low static head. Preven- 
 tion of siphonage with intermittent supply. Connection for 
 standard vertical boilers in horizontal position. Connections 
 for regular horizontal boilers. Example of installation of 
 steam heated boiler set at too low level. 
 
 Chapter V. Variations in Connections to Suit Special Con- 
 ditions. 
 
 Setting boiler on floor below heater. Connecting branches 
 to fixtures to prevent drawing water below level of water 
 front. Danger of siphonage of water in coil or water front 
 when boiler is below its level. Connecting boiler on lower 
 level with overhead tank supply. Connections for boilers on 
 floors above heaters. Connections for coil in furnace and gas 
 heater in kitchen. Continuous flow connection for coil and 
 gas heater. Connection of coil and gas heater to provide less 
 storage from gas heater. Providing additional storage capa- 
 city. Connections for additional horizontal boiler. Connections 
 for additional vertical boiler, Equalization of flow from two 
 boilers. Connections for two vertical boilers on same level 
 to one heater. Connections for two boilers on different levels. 
 Connections for two heaters to one boiler on same level. Con- 
 nections for boilers with two heaters on same level and one 
 on floor below. 
 
 Chapter VI. Multiple Connections With Tank and Pressure 
 Supply. 
 
 Connections for boiler with heater on same level and one 
 on floor below. Example of connections to boiler from heater 
 
TABLE OF CONTENTS. 3 
 
 on same level and one on floor above that show conflicting 
 currents. Connections to same system to avoid retarding of 
 circulation to fixtures. Connecting horizontal boiler with 
 heater on same floor and OEe on floor above. Connections for 
 two boilers with individual heaters to a common maiji pipe. 
 Probability of drawing tepid water and connections to avoid 
 it. Connections for two boilers with individual heaters for two 
 flats. Two boilers heated from either heater at option. 
 Example of unusual connection of two boilers to heaters on 
 different levels. Connections of two boilers to common supply 
 line to equalize flow. Circulation of water between two boilers 
 on same level. 
 
 Chapter VII. Supply Connections and Distribution. 
 
 Objections to customary methods of running supply pipes in 
 small houses. Advantages of providing stopcocks on each 
 branch. Method of distribution from water tables. Construc- 
 tion of distributing headers. Solid nipples. Draining horizontal 
 lines. Circulation of hot water to fixtures. Primary and 
 secondary circulation loops. Important features of design in 
 circulating systems. Continuous loop circulationt System with 
 independent circulating loops. Danger of drawing cold water 
 at fixtures. Making connections to fixtures at point which will 
 prevent drawing cold water. Avoiding stoppage of circulation 
 by sagging pipes. Setting check valves. Hot water and ice 
 water in one piping system. Circulating hot water to cottage 
 plumbing. Circulation system for a five-story building, with 
 boiler for each apartment. Circulating system with overhead 
 tank supply for large residence. Example of English system 
 of hot water distribution. Circulating system to fixtures on 
 same floor as boiler. Circulating water to fixtures below boiler 
 level. 
 
 Chapter VIII. Hot Water Circlt.ation in Large Buildings* 
 
 Disadvantage of carrying high pressures in boilers heated by- 
 steam coils. Drop feed system of circulation* Provision for 
 expansion of risers. Circulating system with supply branches 
 from rising lines. Circulation in long lateral branches. 
 Equalization of temperature. Sectional system of distribution. 
 Hot water supply to shower baths. Proportioning supplies 
 and apparatus for showers in large institutions. Resultant 
 temperature of mixing hot and cold water. Anti-scalding valves 
 and mixers. Mixing tank controlled by attendants. Mixing 
 tube suitable for factory washroom showers. 
 
4 TABLE OF CONTENTS. 
 
 Chapter IX. Double Boilers, Connections and Distributing 
 Pipes. 
 
 Use of the double boiler. Selection of system to suit con- 
 ditions. Use of two boilers and two water backs. Regular 
 double boiler system. Difference in capacity of inner and 
 outer boilers. Strength of boiler shells. Correct methods of 
 making connections. Connections to admit filling of inner 
 boiler from street supply as well as tank. System with reverse 
 cocks to allow quick change from street to tank supply and 
 vice versa. Example of double tank system and connections. 
 Horizontal double boilers. Double water backs. Use of two 
 boilers with separate heaters. Necessity of safety valve when 
 check valve is used on supply pip,e. 
 
 Chapter X. Heating Water by Gas. 
 
 Calculation of capacity and efficiency of gas heaters. Effect 
 of vent flues on gas heaters. Efficiency of various systems 
 compared. Constructive features of gas heaters. Instantaneous 
 bath heaters. Supplying more than one fixture from a bath 
 heater. Kitchen boiler heaters. Kitchen boiler heater with 
 thermostatic control. Instantaneous heater with pressure con- 
 trol. Instantaneous heater with pressure and thermostatic 
 control. Operation of thermostats. Storage type of heater 
 thermostatically controlled. Rules for installation of heaters 
 and satisfactory maintainance. Distribution of water from 
 heaters to fixtures in apartment. Connection of heaters as 
 auxiliaries. Heater connected as auxiliary to coil in furnace. 
 Continuous flow connection of heater and water front in stove. 
 Departure from usual method of setting kitchen boiler heater 
 to economize space. 
 
 Chapter XI. Heating Water by Steam Coils and by Inject- 
 ing Steam, and by Coils in Heating Apparatus. 
 
 Finding of heat necessary to raise water to desired tempera- 
 ture. Transmission of heat through steam coils. Results 
 of tests by French engineer. Tables of transmission of heat 
 by steam through copper pipe. Heating water by exhaust 
 steam. Proportion of heating surface in coils. Construction 
 of coils in boilers. Control of steam supply by thermostatic 
 valves. Heating kitchen boilers by steam. Heating water by 
 injecting live steam. Amount of water heated by one pound 
 of steam. Proportioning steam supply pipes. Table of B.t.u. 
 in steam at various temperatures. Equivalent of calories 
 in B.tu. Method of injecting live steam without noise. Inject- 
 
TABLE OF CONTENTS. 5 
 
 ing live steam to closed boilers. Apparatus for mixing steam 
 with water outside of boiler. Example of tank heated by 
 steam coils and tank heater. Auxiliary heaters in furnaces. 
 Cast iron heaters and coils. Method of making coils for fire- 
 box of steam heater. Capacity of cast iron heaters suspended 
 over and in contact with fire. Capacity of coils. Heater con- 
 structed from radiator sections. Heater combined with 
 laundry stove. 
 
 Chapter XII. Utilizing Excess Heat in "Warming Rooms and 
 Domestic Appliances. 
 
 Heating coils and radiators from water fronts. Heating wall 
 coil on same level as boiler. Two methods of connecting 
 radiator on floor above boiler. Length of pipe required to equal 
 1 ft. of radiating surface. Using an additional boiler as a 
 radiator. Connecting a radiator to domestic water supply lines. 
 Room warmed by hot air from kitchen stove. Connecting 
 radiators to stoves when water front is not used for domestic 
 supply. Heating a plate warming closet or table. Heating 
 towel rails by hot water. Utilization of waste heat. Warming 
 supply water from heat of wastes. Water heating by garbage 
 burning. Warming boilers in bakeries by heat of oven. 
 
 Chapter XIII. Air Locking, Expansion of Water, Relief 
 Pipes and Valves. 
 
 Cause of air locking in hot water supply systems. Examples 
 of piping installations leading to air locking. Methods of pip- 
 ing to .eliminate air locking. Causes of spattering and inter- 
 mittent flow at fixtures. Unique remedy for air bound circulat- 
 ing system. Expansion of water through relief pipes. Increase 
 in volume of water at different temperatures. Continuous flow 
 of hot water through relief pipe to tank. Method of overcom- 
 ing excessive relief flow. Advantage of safety valves on boilers. 
 Vacuum valves. Method of fitting vacuum valves. Collapse of 
 copper boilers. Cause and prevention of collapse. Method of 
 making range connection? to double boiler to guard against 
 collapse by siphonage. Method of avoiding excessive pressure 
 in system by expansion when check valves are used. 
 
 Chapter XIY. Common Complaints and Their Remedy. Re- 
 pair Kinks. 
 
 Unsatisfactory service from kitchen ranges. Causes of 
 unsatisfactory heating of water. Construction of stoves cause 
 of poor service. Fire-box overtaxed. Stoppages in water front 
 
I 
 
 Q TABLE OF CONTENTS. 
 
 causing faulty circulation. Pipe sizes and pitch of boiler con- 
 nections. Boiler supply rusted off. Repairing leaks in boilers. 
 Fitting plugs in corrosion holes. Milky appearance of water. 
 Water hammer in boiler connection. Lukewarm water only 
 drawn. Rusty water. Making a new connection to boiler. Hot 
 water supply to a barber shop. Comparative value of lead and 
 brass for range connections. Annealed and semi-annealed brass 
 pipe. Use of copper pipe. Cutting threads on brass pipe. 
 
 Typical Examination Questions on the Theory and Practice 
 OF Hot Water Supply Installation. 
 
 Pages 190 to 201. 
 
CHAPTER I. 
 
 Principles of Heating, Combustion, Transmission of Heat. 
 
 Is there any single branch of the plumbing business which 
 provides so much food for discussion, so many knotty problems 
 to solve or so many possibilities of failure as that branch of work 
 which comes under the heading of Hot Water Supply and 
 Kitchen Boiler Connections? 
 
 Take up the current number of any one of the trade journals 
 and an enquiry will be found from some member of the craft 
 who is '*up against it.'* Look back over a year of your own 
 experience and see if you cannot recollect some instances when 
 you found it very hard to decide on the proper, or at least the 
 most advantageous, method of installing a hot-water generator 
 or system of distribution. 
 
 It is precisely this choice of methods, the uncertainty of gain- 
 ing the results expected and the difficulty of deciding which of 
 several plans is best suited to a particular problem that lead to 
 the troubles experienced by most plumbers at one time or an- 
 other, and in many cases to loss of patronage through unsatis- 
 factory working of the apparatus he has installed. In practically 
 all of the other branches of our business, the methods are well 
 defined, and the results of a failure to comply with established 
 practice so obvious that difficulties are encountered only by the 
 less experienced or incompetent men. 
 
 But in this business of Hot-Water Supply, it is not only the 
 young mechanic, but often the old and presumably much ex- 
 perienced craftsman who ** falls down" on some point or other 
 with the attendant failure to secure satisfactory results from his 
 work. And the only possible explanation is lack of compre- 
 hension of the principles governing the movement of water in 
 a heating and distributing system. 
 
 The purpose of this book is to present to such as are in- 
 terested in the subject a few of the chief factors which make 
 for success, or failure, in a hot-water installation, a few of the 
 
 7 
 
8 . HOT WATER SUPPLY. 
 
 facts known to most experienced men, but possibly new to the 
 young journeyman or apprentice, and examples of the applica- 
 tion of these principles and methods which have come under the 
 writer's observation or been submitted to him for opinion by 
 others from time to time. 
 
 For the benefit of the new boy who wants to know "how 
 the hot water gets into the boiler, anyhow/' it is necessary to 
 explain what causes circulation. 
 
 Circulation. 
 
 Circulation, as understood in its application to a hot-water 
 heating or domestic hot-water supply system, is the movement 
 of bodies of water from the primary heating appliance, which 
 may be a kitchen stove, a regular hot-water heater, an automatic 
 gas or a steam-heating contrivance, to the storage tank or boiler, 
 and the return of water from thence to the source of heat again. 
 It is also applied to the movement of hot water through a circuit 
 of pipe to some point near the fixtures to be supplied with hot 
 water for heating purposes or for bathing and similar purposes, 
 and its return from that point to the tank or boiler to be re- 
 heated and again returned to the point of discharge for im- 
 mediate service when wanted. 
 
 What causes circulation ? Briefly, the difference in density 
 or weight per given volume of two columns of water at different 
 temperatures. 
 
 And now to explain the meaning of Density. Density has 
 been defined as the ** Ratio of mass to volume.'* 
 
 Water has a maximum density at a temperature of about 40 
 deg. F. That means that a given quantity of water will weigh 
 more at 40 deg. than at 35 deg. or at 110 deg., for a rise in 
 temperature causes the molecules to expand in volume, thereby 
 taking up more space, with the obvious result that our ''given 
 quantity" is larger, while its weight has remained as it was. 
 A decrease in temperature has the same effect, but at 32 deg. 
 the water solidifies and takes the form of ice. 
 
 We take advantage of this natural law in causing circulation 
 to take place in heating systems, and its application to practical 
 problems is as follows: 
 
PRINCIPLES OF HEATING, ETC. 
 
 Fig. 1. Applian«e Used to Demonstrate 
 Circulation of Water. 
 
 When heat is applied to a vessel containing water, the mole- 
 <cules at the point to which heat is applied expand and, being 
 lighter for the same space occupied than the cooler particles sur- 
 rounding them, are pushed upward; those taking their place 
 pass through an identical 
 process, follow, and immedi- 
 ately a constant upward 
 current is established. 
 
 Suppose, then, we take 
 two vessels and connect them 
 together with two tubes, one 
 close to the bottom and one 
 near the top of the vessels. 
 We now have an apparatus 
 which represents approxi- 
 mately the usual heater and 
 boiler combination. 
 
 Apply heat to the lower part of the vessel, representing the 
 heater, and the local circulation just described begins im- 
 mediately. Very soon the water will begin to pass through the 
 upper tube into the second vessel, while a corresponding 
 quantity will pass from that vessel through the lower tube into 
 the first, where it will become heated and rise until it reaches 
 the upper part, then through the tube back into the lower part 
 of the original vessel again. 
 
 Thus complete circulation has been established and will be 
 maintained as long as heat is applied. It will be obvious that 
 the temperature will not be the same in all parts of the vessel, 
 owing to the cooling effect of its walls, but the local 
 circulation induced through this is so slight as to be almost 
 imperceptible and has no effect on the circulation through 
 the tubes to the other vessel. 
 
 The force that causes the water in a hot-water heating or 
 supply system to flow is sometimes termed the ** Motive 
 Colmnn,'* and is the pressure due to the head of water gained 
 by expansion over the head at the temperature before heating. 
 It must always be borne in mind that hot water will move, 
 or ** circulate, ' ' only when there is a heavier or cooler body of 
 water to displace it, and the motive force is proportional to 
 
10 HOT WATER SUPPLY. 
 
 the difference in temperatures of the ascending and descending- 
 columns and also to the height. Thus the motive force in a 
 circuit 30 ft. high is twice as great as in one 15 ft. high, and 
 this is the reason why circulation to a radiator or other fixture 
 on an upper floor is generally faster than to some other on the 
 same or on a lower level. 
 
 But even with a considerable difference in temperature 
 in the two columns, and a considerable height of circuit, the 
 force is very slight and circulation comparatively easily held 
 back or entirely stopped. 
 
 A pitch in the wrong direction, causing a pocket where air 
 may form, is often enough to entirely prevent satisfactory 
 circulation and horizontal runs of circulation pipe must be 
 carefully laid so that these pockets are impossible. 
 
 If lead pipe is used every precaution to prevent sagging 
 must be taken or trouble will surely come to the fitter. 
 
 We have given some consideration to the matter of ''Cir- 
 culation" and its cause. Let us enumerate and try to define 
 some of the properties and natural forces which we bring into 
 operation in promoting it, or which may act to retard it, in 
 any system of hot-water heating or supply. 
 
 Heat. 
 
 Heat is a phenomenon hard to define. 
 
 Briefly: Heat is not matter, but a form of energy requir- 
 ing matter to act through. It has no weight. The addi- 
 tion of heat to any substance, liquid or solid, makes no 
 difference whatever to its total weight, although it may change 
 its nature to a very considerable degree. 
 
 Heat is measured by a standard unit known as the British 
 thermal unit, or shortly, B.t.u., which is the amount of heat re- 
 quired to raise the temperature of 1 lb. of water at 39 deg. 1 
 deg. F. and also by a standard termed a calorie, which is roughly 
 equal to 4 B.t.u. 
 
 It cannot be destroyed or created ; it can simply be trans- 
 mitted from one substance to another, from one form of matter 
 to another form, or transformed into work from which it may 
 be again recovered. 
 
 The temperature at which oxygen goes into rapid combus- 
 tion — that is, causes what we call fire to take place — differs 
 
PRINCIPLES OF HEATING, ETC. 11 
 
 with different bodies. Thus phosphorus ignites at 150 degrees 
 F., sulphur at 480 degrees, while the hydrocarbons require a 
 temperature of nearly 1000 degrees to kindle them. 
 
 Development of Heat and Fire. 
 
 Fire is visible heat or light. Luminous heat, light, is 
 motion; heat is motion. The more intense the motion the 
 greater the heat and light. Whenever motion is arrested heat 
 is liberated, and whenever motion is set in action heat is ex- 
 pended. The same amount of heat that it took to start the 
 train is given out when the train is stopped, whether 
 it be slowly or suddenly. If it be suddenly, the heat is 
 more intense, brakes are very much heated, and sparks are 
 produced at the point of friction. 
 
 The heat of ordinary combustion is generated by the im- 
 pact of the particles or atoms of oxygen with those of the com- 
 bustible. The greater the affinity of oxygen for any substances 
 or the greater the facilities for their union the more intense 
 the action and the greater the heat. 
 
 The kindling of a fire is an art that has grown with the 
 intelligence of the race. First, the rubbing of two sticks ; then 
 the flint and tinder, and last the phosphorized match — the per- 
 fection of convenience. In each instance the cause of the fire 
 is the same, friction or arrested motion. Phosphorus has the 
 lowest ignition point of any substance that would be safe to 
 use, a slight stroke producing sufficient heat to ignite it. After 
 ignition the energetic union of the elements is sufficient to 
 maintain the fire. Two requirements, therefore, are necessary 
 for a fire. First, elevation of temperature to the ignition point ; 
 second, a supply of air to the fuel. 
 
 On the other hand, only two things are necessary to ex- 
 tinguish it — lower the temperature or cut off the supply of air. 
 The best results are obtained when both expedients can be 
 employed. Chemical extinguishers are mostly carbon dioxide 
 generators, and their extinguishing properties are due more to 
 the water projected at a lower temperature and at the base of 
 the flame than to the gas, although it is a perfect extinguisher, 
 could it be provided in sufficient quantity economically. 
 
12 HOT WATER SUPPLY. 
 
 The Production of Heat by Combustion. 
 
 Combustion may be defined as a rapid chemical combina- 
 tion, resulting in heat and light. The combining elements are: 
 
 (a) Oxygen, which is usually derived from atmospheric air; 
 
 (b) either carbon or hydrogen, or a compound of the two. 
 Sulphur sometimes appears with carbon and hydrogen, and 
 also combines with oxygen. The substance that is formed by 
 the chemical union is called the product of combustion; and 
 the heat that is produced by the combustion of a unit weight 
 (1 lb.) of the fuel is called the heat of combustion. 
 
 When hydrogen burns it combines with the oxygen of the 
 air and forms water and gives off 62,000 heat units per pound 
 of hydrogen burned. When carbon is burned one atom of carbon 
 may take up one atom of oxygen, forming carbon monoxide and 
 developing 4,400 B.t.u. per pound. When the combustion pro- 
 cess is carried to its limit; in other words, when two atoms of 
 oxygen combine with one atom of carbon, carbon dioxide is 
 formed, developing 14,500 B.t.u. per pound of carbon. The 
 difference in the amount of heat developed shows how important 
 it is to have a sufficient draft and supply of air. 
 
 Heat may be transmitted to the water in a heating system 
 from the fire-box or gas burners in three different ways— by 
 radiation, by convection and by conduction. 
 
 Radiation. 
 
 Radiant heat possesses the remarkable property of passing 
 through the atmosphere without perceptibly raising its tempera- 
 ture. These heat rays, whether emanating from a glowing or 
 dark hot body, are transmitted through the air at right angles 
 to the point of emanation until they are absorbed or reflected 
 by another body; in this particular case the walls of the fire- 
 box, the exposed portions of the boiler or the coils. 
 
 Radiant heat passes away from hot-water pipes, boilers, 
 radiators, etc., so long as the temperature of these is higher 
 than that of any objects within its sphere of influence. The 
 amount of radiant heat emitted and received varies with the 
 nature of the surface affected, but in the same surface the power 
 of absorption and radiation is equal. Different metals have 
 
PRINCIPLES OP HEATING, ETC. 13 
 
 different powers of radiation, and it is important to bear this 
 in mind in designing or installing heating appliances. 
 
 Convection. 
 
 The conductivity of liquids for heat is very slight. Never- 
 theless, heat is rapidly transferred throughout their volume, 
 owing to their qualities of expansion and mobility, by direct 
 transport of the heated particles. In describing the action set 
 up by heat and the cause of circulation, it was shown that the 
 particles expanding on the application of heat, and becoming 
 lighter, volume for volume, than those surrounding them, were 
 rapidly carried upward and displaced by the heavier and cooler 
 particles in regular sequence. 
 
 These particles in their upward passage transmit a portion 
 of their heat by convection, until in the regular rotation of 
 heating, expanding, rising, loss by convection, sinking and re- 
 heating, a complete circulation is maintained, and eventually a 
 more or less uniform temperature obtained through the whole 
 body of water in the system. 
 
 Heat applied near the bottom of any vessel or apparatus 
 designed for the purpose of heating water is therefore the most 
 effective ; as the particles being driven away from contact with 
 the heated bottom surface, rise through the longest section of 
 cold water in the boiler, transferring a proportionately larger 
 amount of heat by convection to the descending particles. That 
 applied at the sides, as in the side flues of a hot-water boiler, 
 causes the currents of heated particles to start only from that 
 point where the heat is applied; while heat applied at the top 
 is almost useless except as a means of checking loss by radiation 
 from the boiler or its connections. 
 
 Conduction. 
 
 The power of transmission of heat by conduction 
 varies in different metals to a considerable extent, and a knowl- 
 edge of the relative coefficiencies is of considerable value, as it 
 enables the mechanic to select the material best suited to pre- 
 vent waste and diffusion of heat, or to convey it with the best 
 hopes of successful results. 
 
 The expansion of various metals with a rise in temperature 
 must always be kept in mind and an acquaintance with the 
 
14 HOT WATER SUPPLY. 
 
 relative amount of expansion of various metals is important. 
 Tables showing coefficiencies of expansion and conductivity are 
 available and are likely to be of considerable assistance to the 
 student in obtaining reliable design. 
 
 Imperfect Combustion. 
 
 From the foregoing data it will be seen that imperfect 
 combustion of fuel is not only a nuisance through the produc- 
 tion of excessive smoke but is really wasteful. This explains 
 the economy shown in the operation of a stove or water heater 
 with a well designed firebox and grate. If the supply of oxygen 
 is sufficient to effect the higher and more complete combustion 
 the total heat available from 1 lb. of anthracite may be 14,500 
 B.t.u., but making due allowance for the loss in flues and by 
 radiation to the plates of the heater and so to the air a total 
 transmission of 8,000 heat units to the water in the coil or water 
 front may be looked for. Under the same conditions one 
 authority has calculated the heat available from soft or bitu- 
 minous coal as 6,500 B.t.u.^ from coke as 9,350 B.t.u., from 
 hickory wood as 4,300 B.t.u. from 1 cu. ft. of coal gas as 650 
 B.t.u. and from natural gas 950 B.t.u. 
 
 These are the figures that may be taken as a basis on which 
 to estimate heating capacities of fireboxes or heating surfaces, 
 allowances having been made for losses in stoves of average M 
 
 design and construction. 
 
 To secure satisfactory combustion of fuel in the ordinary 
 kitchen stove or tank heater the oxygen supplied should be in 
 sufficient quantity to reach all parts of the fuel. If properly 
 proportioned the two atoms of oxygen necessary to combine 
 with each atom of carbon and hydrogen in the fuel will be pro- 
 vided and not only will there be an absence of smoke but the 
 efficiency of the heater will be higher. 
 
 Strains and Stresses. 
 ^ The various strains and stresses in materials such as metals 
 engendered by expansion or by methods of construction of the 
 appliances the student is interested in should also be the subject 
 of his consideration, as he will be better able to judge of the 
 efficiency of his work, if he has some knowledge of the breaking 
 or tensile str^rigths and the stresses that can safely be withstood. 
 
PRINCIPLES OF HEATING, ETC. 15 
 
 Stresses may be classified as follows: ** Tensile/' or pull- 
 ing, ''compressive," ''transverse," or bending, "shearing" and 
 "torsional," or twisting stress. 
 
 Strain is deformation, or change of shape of a body as the 
 result of a stress. 
 
 Elasticity is the power a body has of returning to its 
 original form after a stress on it is withdrawn. 
 
 Elastic limit is the unit stress under which the body be- 
 comes permanently strained or deformed. 
 
 In the practice of hot-water pipe fitting these terms are 
 met with frequently. For example: 
 
 Lead pipe has little elasticity. Under the stresses set up 
 by repeated contraction and expansion, it becomes strained or 
 permanently elongated, causing sagging ; or where movement of 
 the body is prevented, as at a junction with another pipe, the 
 low tensile strength of the material causes it to rupture by re- 
 peated stress and distortion of the component particles at some 
 particular point. 
 
 Then there are the bursting and shearing stresses and 
 strengths, as exemplified in the amount of pressure a boiler 
 will stand without a failure of its plates or pulling apart from 
 its rivets, or that various kinds of pipe will withstand under 
 heavy pressures or sudden shocks. 
 
CHAPTER II. 
 
 Corrosion of Water Fronts, Boilers and Pipes. 
 
 Most plumbers who have had an opportunity of observing 
 the effect of corrosion in pipes have noticed the fact that pipes 
 conveying hot water have been more affected than those in 
 which cold water is conveyed. While this has been known in 
 the trade for a long time it is only within recent years that 
 any attempt has been made to ascertain the conditions which 
 would tend to hasten the process with the object of avoiding 
 them if that is at all possible. 
 
 In this ease corrosion must not be confounded with sedi- 
 mentation or precipitation of insoluble matter. 
 
 In all waters brought from lakes or open reservoirs there 
 is as a rule a fair proportion of matter in suspension which will 
 be precipitated on boiling and the same is true as regards 
 water impregnated with lime and other impurities of a mineral 
 nature. It is a common thing to find galvanized iron and even 
 brass or lead pipe which has become coated with a deposit from 
 the water which has gradually built in on the walls of the pipe 
 until its bore has become almost closed. This cannot be called 
 corrosion as there has been no deterioration of the pipe, no 
 eating away and weakening of its walls. Occasionally, how- 
 ever, this latter condition becomes evident and this is what is 
 referred to as true corrosion and to be seen more frequently 
 in hot water pipes than in cold. Investigations of the cause 
 of rapid corrosion of hot water pipes in recent years have 
 brought out the statement that rusting tests at varying tem- 
 peratures show that corrosion is most active between 140 and 
 180 deg. Fahr. and that above that temperature there is com- 
 paratively little action on the pipe. 
 
 This has been explained as being due to excess of oxygen. 
 Pure water at normal pressure will dissolve 14.7 parts per mil- 
 lion of oxygen at 32 deg. Fahr. and 7.60 parts per million at 
 86 deg. Fahr. At 210 deg. oxygen is practically insoluble so 
 that as the water is heated the solubility at normal pressure 
 
 16 
 
CORROSION OF WATER FRONTS, ETC. 17 
 
 becomes less. In the conditions in which water is heated for 
 domestic hot water supply the oxygen must remain in solution 
 owing to the fact that the water is heated under pressure and 
 in a closed vessel. Thus the water may be said to be super- 
 saturated with oxygen and judging from the effects noted in 
 different tests its rapid passage over the surface of iron or steel 
 pipes in circulation through the system hastens corrosion 
 entirely because of the presence of an excessive supply of 
 oxygen in a condition favorable for this action. 
 
 The obvious remedy for this state is to reduce the tempera- 
 ture of the water passing through the pipes and where this 
 has been possible and has been put into effect the results are 
 said to have been satisfactory. In ordinary kitchen range; 
 water heating systems, however, 4;his is not so easily arranged. 
 A temperature of only 110 deg. at the water front would neces- 
 sitate a larger storage tank than is easily found room for and 
 even with that it would be hard to circulate the water quickly 
 enough to prevent its reaching a much higher temperature when 
 a strong fire was maintained in the range. Where a tank heater 
 is employed this latter objection does not apply and it is possible 
 by using a heater of ample proportions together with a storage 
 tank of more than the actual size required under the present 
 conditions to maintain a larger supply of water at the lower 
 temperature and so obtain a satisfactory service while reducing 
 the effect of corrosion considerably. Where the water front 
 must be used a compromise can be effected by using brass 
 pipe for the connections between boiler and water front 
 as the average temperature in the boiler will seldom rise 
 above 110 and the water passing into the secondary cir- 
 culation will therefore have a less harmful effect on the 
 piping than that circulating between the water front and the 
 boiler where the temperature is higher. 
 
 Stoppage of Pipes and Water Fronts by Lime. 
 
 Filling of pipes and water front passages by sediment de- 
 posited as the result of precipitation of matter in solution, 
 such as sulphates and carbonates of lime, is frequent in districts 
 where the water supply is obtained from springs or wells 
 drilled in rock of a limestone or chalky formation. Such water 
 
18 HOT WATER SUPPLY. 
 
 is always hard, its hardness being measured by degrees based 
 upon the amount of carbonates or sulphates the water contains. 
 One degree of hardness would thus mean that one gallon of 
 water contained one grain of carbonate of lime or chalk and 
 as every grain of chalk in the water will curdle eight grains 
 of soap before a lather is produced the degrees of hardness in 
 the water may be very accurately estimated by a careful test 
 using soap as the medium. 
 
 Waters which contain sulphates of lime are classed as per- 
 manently hard and their mineral contents are not precipitated 
 to any extent by boiling. If, however, the hardness be caused 
 by the presence of carbonates then the water is classed as tem- 
 porarily hard and the chalk will be deposited in any vessel 
 in which the water is boiled vigorously. This is the white 
 and hard deposit which builds up on the walls of pipes between 
 the water front and the boiler, which chokes up the water 
 ways of the water front also and which manifests its presence 
 by poor heating and by snapping sounds in the tank. It can 
 be softened to some extent before it enters the water front by 
 adding to the water a little lime water, which will absorb the 
 carbonic acid which holds the salts in solution and so precipitate 
 both the lime in the water added and that in the water. A 
 modification of this process is seen in the water softening ap- 
 pliances known as injectors, shown in Fig. 2, and which are 
 intended to be placed in the return connections of water fronts 
 so that all water passing through them will be subjected to a 
 treatment which will neutralize the action of the heat upon 
 the contents of the water. 
 
 The deposit of the carbonates will also be accompanied by 
 the precipitation of a certain amount of calcic sulphate should 
 that be present. When water of known hardness must be used 
 for domestic purposes the means of heating should be such that 
 the water will never reach boiling point. This can be effected 
 either by the use of a tank heater and storage tank of such 
 generous proportions that a low fire may be run and the supply 
 of water make up in quantity what is lost in temperature or 
 by shielding the surface of the water front or coil which is 
 exposed to the fire by inserting a brick in front of it and by 
 using large pipes with easy bends so that the water will circu- 
 
CORROSION OF WATER FRONTS, ETC. 
 
 19 
 
 late freely and will have little tendency to deposit any matter 
 in suspension at the elbows or sharp turns. The effect of such 
 deposits on the plates of a water front or the pipes in a coil 
 has already been commented upon and the danger that may 
 arise from this building up process is too great to neglect. 
 
 Removal of Lime From Waterbacks. 
 
 Where it is known to exist the water front and coil connec- 
 tions should be made in such a manner that they can be readily 
 
 Fig. 2. Water Softening Apparatus. 
 The Component Parts. The Parts Assembled. 
 
 removed and the deposit cleaned out at frequent intervals. There 
 are several methods of removing a deposit of this character 
 among which may be mentioned that of pouring into the water 
 front a solution of one part hydrochloric acid and five parts 
 water, which has been recommended by many who have had 
 occasion to try it. The water front should be heated until the 
 solution boils gently, when the water back is to be removed 
 from the range and the ordinary impurities washed out by 
 being thoroughly flushed. Then the solution can be poured 
 in and the water back placed on top of the stove or any other 
 place where it can be brought to a boiling point. The incrusta- 
 tion, it is said, will be dissolved within the course of an hour 
 or two and can be flushed out with water. If there is a thick 
 incrustation and the first treatment fails to remove it the treat- 
 ment should be repeated until it takes effect. 
 
20 
 
 HOT WATER SUPPLY. 
 
 Instead of using the acid a solution of common washing 
 soda may be tried. This is commonly used for the removal of 
 scale from boilers and according to the nature of the deposit 
 and the amount of it may give satisfactory results in water 
 fronts also. The water front should be allowed to soak in the 
 solution and the process of removing the incrustation will be 
 hastened by heating. The incrustation should leave 
 the metal and when dry form a powder which is not 
 difficult to remove. When the deposit is very heavy 
 
 the water front should be al- 
 
 Q*--Safety Valve 
 
 Air 
 
 s 
 
 Wafer, line 
 
 ^ 
 
 Wafer 
 Back 
 
 Fig. 3. Method of Connecting 
 Using Alkaline Water. 
 
 Boiler 
 
 lowed to soak in it for several 
 days and an extra quantity of 
 soda should be used. 
 
 Another method of avoid- 
 ing the precipitation of the 
 mineral contents of water in 
 water fronts, pipes and boil- 
 ers is that illustrated in Fig. 
 3. This is said to have been 
 very satisfactory in many 
 places whore the water is of 
 an alkaline nature and where 
 the usual method of piping the 
 range connections is not satisfactory through the excessive deposit 
 which is made in the system and which necessitates constant 
 changing of water fronts and cleaning of pipes and boilers. 
 From the illustration it will be seen that the flow pipe from the 
 water front does not connect with the boiler proper, but with a 
 coil that is placed inside it. This coil is kept filled with pure 
 rain water from a small reservoir shown connected to the upper 
 pipe connection to the water front. 
 
 If the reservoir is covered at the top and a safety valve 
 fitted a pressure can be maintained on the coil which will allow 
 of carrying a much higher temperature than would be possible 
 were it open, while the evaporation will be much reduced and 
 thus necessitate less frequent filling. One of the boilers 
 ordinarily used for heating water by steam is quite suitable for 
 connecting to the water front in this manner as it requires 
 about 1 sq. ft. of heating surface for each 5 gall, of water 
 
CORROSION OF WATER FRONTS, ETC. 
 
 21 
 
 Wafer- 
 Back 
 
 heated. The reservoir may be made out of 3 in. iron pipe 
 about 18 in. long, the top being closed by a cap drilled and 
 tapped to fit the safety valve and having a plug for easy filling 
 as often as is necessary. "While this system is one requiring at- 
 tention it is efficacious as the alkaline water in the boiler which, 
 is fed from the main pipe in the usual manner is heated by 
 conduction and does not become heated to the high temperature 
 that it would when passed through 
 a water front or coil in the firebox in ^ IflD 
 
 the usual manner. Thus the pre- 
 cipitation of the mineral contents is ^ 
 almost entirely avoided as there is 
 very little effect on the water until 
 boiling point has been reached. It is 
 a good plan when using water that 
 carries sediment or that is likely to 
 precipitate lime to use tees at all 
 bends or turns instead of ells and to 
 plug one outlet. Thus the pipes 
 can be easily cleaned with a wire 
 when the sediment begins to fill up the pipe. 
 
 Sediment 
 Cook 
 
 Fig. 4. A Sediment Chamber. 
 
 Sediment Collecting Chambers. 
 
 A sediment chamber which collects mud and other matter 
 precipitated in the heating system is shown at Fig. 4. A clean- 
 out screw on the bottom allows of the easy removal of the sedi- 
 ment and its flushing with a hose. 
 
 This appliance can be fitted on the return connection of the 
 water front or immediately under the lower tapping of the 
 boiler as found desirable and convenient. 
 
 A sediment chamber of a little different design and intended 
 to be fitted to the lower tapping of a vertical boiler is shown 
 in Fig. 5. From the illustration it will be seen than an inner 
 tube extends through the connection into the boiler, thus keep- 
 ing the inlet to the water front above the level at which sediment 
 will be likely to stand. A hose bibb or a pipe connection \vith a 
 valve screwed into the outer chamber enables the sediment to be 
 flushed out at intervals. 
 
22 
 
 HOT WATER SUPPLY. 
 
 Heat Losses From Boilers and Pipes. 
 
 "While the heat losses from an ordinary kitchen boiler with 
 a connection from a water front heated by a coal fire may be 
 comparatively unimportant, there are other conditions which 
 
 make such losses a matter worth 
 consideration. In tanks of larger 
 capacity than those used in the 
 average household, such losses by 
 radiation become important and 
 the usual method of avoiding them 
 is to cover the tank with a non- 
 conducting covering of asbestos 
 or some such substance. Smaller 
 boilers may have a covering of 
 similar nature if desired and spe- 
 
 "Sedimenf Chamber 
 
 To Water F ront 
 Fig. 5, 
 
 A Sediment Chamber for cial Coverings of sheet asbestos and 
 
 a Kitchen Boiler. -■ x,- x, i, 
 
 canvas are made which can be 
 readily laced into place with hooks provided for the pur- 
 pose. Another method is to use a lagging of closely fitted 
 boards bound with metal bands. Where the boiler is heated by 
 gas and a thermostatic control of the valves is used such pro- 
 visions are economical, as the constant radiation from the boiler 
 when uncovered will cool off the contents and cause the gas 
 valve to open more frequently than the ordinary demand of the 
 building would call for. Where such coverings are dispensed 
 wdth, however, it is possible to retard to some extent the radia- 
 tion by using the proper paint to finish the boiler with and a 
 knowledge of the effects of different pigments and bronzes on 
 the radiation from substances coated with them is of some value 
 in this connection and may be applied with profit. 
 
 In an extensive series of tests made several years ago it was 
 found that the use of the bronzes, paints and enamels commonly 
 used for painting radiators and other metal surfaces affected the 
 rate of transmission of heat from the surfaces by as much as 
 27 per cent. Applying two coats of copper bronze reduced the 
 heat transmission from a radiator by 26 per cent, while the addi- 
 tion of two coats of terra cotta enamel on the top of the bronze 
 not only reversed this effect but gave a higher rate of trans- 
 
CORROSION OF WATER FRONTS, ETC. 
 
 23 
 
 mission than the bare metal gave. The effect of adding these 
 two coats was to increase the transmission of heat 28.6 above 
 the transmission when the bronze only was used and to check 
 this two more coats of copper bronze were applied on the top of 
 the terra cotta enamel when the conducting capacity of the 
 surface fell 26.5 per cent., bringing back the rate of transmis- 
 sion to about the same as it was with the two coats of copper 
 bronze. Following out the tests it was found that the loss of 
 heat was nearly the same with 14 coats of paint as it was with 
 2 coats and that the effect depended apparently on the nature 
 of the last coat applied. The tests also showed that the color 
 of the paints and enamels applied had some effect on the rate 
 of transmission and the final conclusion was that copper or 
 aluminum bronze offered the greatest resistance to the passage 
 
 HEAT LOSSES IN B.t.u. 
 Pe" sq. ft. 
 
 
 
 
 «-"t3s 
 
 0. 
 
 
 0.S.2 
 
 E 
 
 0) 
 
 
 TS*- . 
 
 ■4^ 
 
 
 VOV 
 
 s 
 
 
 rt^TS 
 
 
 
 "S" j 
 
 o 
 
 ■w 
 
 '■^^-S 
 
 do 
 
 
 3 0) U 
 
 
 o 
 
 ■w P.O. 
 
 > 
 
 o 
 
 ca 
 
 < 
 
 ^ 
 
 9. 
 Ju. 
 11. 
 12. 
 \b. 
 
 14 
 
 lo. 
 16 
 17. 
 18. 
 19. 
 20 
 21. 
 
 22. 
 
 23. 
 
 Rad. plain as received from factory 
 Rad. plain as received from factory 
 Rad. painted witli copper bronze 
 Rad. painted with copper bronze 
 Rad. painted with terra cotta enamel 
 Rad. painted with copper bronz3 
 Rad. painted with light brown varnish 
 Rad. painted with oak brown varnish 
 Rad. painted with aluminura bronze 
 Rad painted with aluminum bronze 
 Rad. painted with silver gray enamel 
 Rad. painted witn snow-white enamel 
 Rad. painted with bronze green 
 
 enamel 
 Rad. painted with no luster green 
 
 enamel 
 Rad. painted with naaroon gloss japan. 
 Rad. painted with shellac and copper bronze powder 
 Rad. painted with copper bronze powder and linseed oil 
 Rad. painted with white paint 
 Rad. painted with terra cotta paint 
 Rad. painted with light green paint 
 Rad. painted with liglit green paint 
 
 zinc 
 Rad. painted with terra cotta paint 
 
 zinc 
 Rad. painted with white paint zinc 
 
 These paints of 
 two coats each 
 were painted 
 over one an- 
 other in the 
 order given. 
 
 This series fol- 
 lows one an- 
 other. 
 
 Painted over 
 one another 
 
 3.82 
 
 74.4 
 
 1 
 
 2.925 
 
 76 
 
 2 
 
 2.8:35 
 
 63.1 
 
 3 
 
 278 
 
 72.3 
 
 4 
 
 2.78 
 
 74.5 
 
 5 
 
 3.05 
 
 66.3 
 
 6 
 
 2.74 
 
 74.1 
 
 1 
 
 ^.74 
 
 72.9 
 
 8 
 
 2.70 
 
 71.8 
 
 9 
 
 2.77 
 
 70 5 
 
 10 
 
 2.77 
 
 66.7 
 
 n 
 
 2.72 
 
 67.6 
 
 12 
 
 2.67 
 
 64.3 
 
 13 
 
 2.67 
 
 64.0 
 
 14 
 
 2.63 
 
 70.6 
 
 15 
 
 2.61 
 
 68.5 
 
 16 
 
 2.66 
 
 67.0 
 
 17 
 
 2.66 
 
 86 9 
 
 18 
 
 2.64 
 
 83.4 
 
 19 
 
 2.62 
 
 86.8 
 
 20 
 
 2.72 
 
 77.2 
 
 21 
 
 2.77 
 
 77.7 
 
 22 
 
 268 
 
 76.0 
 
 2} 
 
 0.997 
 1.005 
 0.761 
 0.752 
 1.038 
 735 
 0.977 
 0.977 
 0.730 
 0.724 
 0.970 
 1.01 
 
 0.997 
 
 0.956 
 
 0.997 
 
 0.850 
 
 0.760 
 
 0.987 
 
 1.00 
 
 0.989 
 
 1.00 
 
 0.964 
 1.01 
 
 Table of Heat Losses Through Painted Iron Surfaces. 
 
 of heat and therefore is the best material that can be used to 
 paint boilers or pipes which are in such a position that it is not 
 practicable to cover them with the ordinary form of covering. 
 
24 
 
 HOT WATER SUPPLY. 
 
 The foregoing table shows the rate of heat transmission per 
 sq. ft. per deg. difference in temperature in a cast iron radiator 
 with steam at an average temperature of 224 deg., and the losses 
 from a boiler containing water at 180 to 200 deg. Fahr. may be 
 estimated from this, making due allowance for the difference in 
 outside and inside temperatures. Thus the rate of transmission 
 would be less when the room temperature was higher, but the 
 table will give results nearly enough correct for all practical 
 purposes. 
 
CHAPTER III. 
 
 Water Fronts, Coils and Heaters. 
 
 The usual provision made in kitchen range construction 
 for water heating purposes is that of a water front or water 
 back. This is simply a hollow cast iron box which is designed to 
 take up the space afforded by one or more sides of the firebox 
 and which receives its designation of water front or water back 
 according to the position in which it is intended to be fitted. 
 In the smaller sizes of ranges intended for use in cottages or 
 small apartments in connection with a boiler of 30 or 40 gall, 
 capacity the water front is invariably of the pattern occupying 
 the space at the front or back of the fire box. In the larger 
 ranges with ovens at each side of the fire box two sides or 
 three may be occupied by it, affording a much larger heating 
 surface which is capable of supplying hot water in sufficient 
 quantity, in combination with a boiler of 60 to 100 gall, capacity, 
 for a large household. 
 
 The style of the range determines the position of the flow 
 and return tappings in the water front. Those shown in the 
 accompanying illustrations, Figs. 6 to 10, show all the positions 
 in common use. From these it will be seen that the outlets may 
 be at the side of the range or the back according to what the 
 design requires, but the relative position of flow and return con- 
 nections are as a rule the same — the flow as near the top as 
 possible and the return as close to the under side of the casting 
 as can be arranged. This prevents the accumulation of steam 
 in the water front with attendant noise and even danger, and 
 also admits of sediment being well scoured out when the sedi- 
 ment cock at boiler is opened. 
 
 Frequently there is a partition in the water front extending 
 nearly the full length. This assures a good circulation through 
 it and a better heating effect as the water has to pass through 
 a longer circuit in contact with the heating surface than it might 
 take without this provision. The dotted lines in the illustrations 
 show how air or steam may accumulate in the water front 
 
 5^K 
 
26 
 
 HOT WATER SUPPLY. 
 
 when the upper connection is made at too low a point and how 
 sediment may accumulate below the level of the lower pipe. The 
 danger from the accumulation of air arises from the fact that the 
 metal may become overheated in contact with a fierce fire and 
 the interior pressure will then bulge it outward, weakening the 
 walls to the extent that a rupture may occur. The sudden liber- 
 ation of water at a high temperature and pressure may result in 
 its flashing into steam, which will do great damage when the 
 right conditions exist. The same results may follow the accumu- 
 
 kV^kkkkkkkkkW.V^kVkk^kkV^V^^k^kkkk^kk^^^^ 
 
 a 
 
 o 
 
 aw^.^^^^^^^vv^^^^^^v^^^^^v^^^^^^^^^^^ 
 
 Fig. 6 
 
 Fig. 8. 
 
 kV^^^^^VVV^V^^^VvVv^^^^^^^^ 
 
 "O" 
 
 p^^^<\^vv'w.v^vk's^v,^^^^'.-.^^vv^????yr} 
 
 O 
 
 t^VV^VVVVV^VsVV^^VvV^V.^^^^^^^^ 
 
 Fig. 7. Fig. 9. 
 
 Section Through Water Backs. 
 Dotted Lines Show How Air May Collect Above Connections. 
 
 lation of an undue amount of sediment on the inner surface of 
 the water front. In this case the walls become overheated by 
 reason of the extra thickness, the deposit of foreign matter pre- 
 vents the conduction of heat by the water and allows the 
 metal to become red hot and in its weakened state to give way 
 under the pressure. Indication of the presence of sediment in 
 dangerous amount is given as a rule by a swelling or bulge on the 
 wall in contact with the fire which grows larger on repeated 
 heating to high temperatures. 
 
 Some water fronts have the partition in a vertical position. 
 This is convenient with some designs of ranges as it enables the 
 flow and return connections to be made at the same level, the 
 partition deflecting the water inside so as to afford a circulation. 
 Theoretically the position at the back of the fire box should be 
 the most effective in which to place the water heater as the hot 
 gases passing to the flues will then pass over a portion of it but 
 
WATER FRONTS, COILS AND HEATERS. 27 
 
 in practice the difference between front and back or sides is not 
 noticeable. What is of more importance is the depth and width 
 of the fire box. When the size of the fire box is reduced too much 
 in either direction it will be found that the heat transmission 
 from the fuel to the water front is so great as to affect the baking 
 qualities of the range seriously unless the flue to which the stove 
 lis connected possesses an unusually good draft. Occasionally 
 also this condition works in the opposite direction and the fuel 
 in contact with the water front will be noticeably dull and the 
 water supply unsatisfactory. It will also be found hard to main- 
 
 Fig. 10. Section 
 Through 2-Side 
 
 IF 
 
 Water Back. Fig. 11. Coil Fitted to Increase Heating Power. 
 
 tain a fire when the dampers are checked down. The reason is 
 the obvious one that the range is overtaxed and therefore the 
 size of the fire box should be a factor in deciding as to the practi- 
 cability of heating a sufficient supply of water for domestic pur- 
 poses when it is proposed to use a water front in a range in which 
 none has been previously used. 
 
 Heating Large Quantities of Water. 
 
 In large establishments using powerful cooking stoves and 
 requiring large amounts of hot water it is quite possible and in 
 fact common to install a boiler of 60 to 80 gall, capacity which 
 is heated by a water back in the range. If the double oven type 
 of range is used which has the fire box in the center a water 
 back which extends around three sides of the fire box may be 
 provided. This will afford a large heating surface which with 
 the strong fire usually run where a large amount of cooking is 
 done will be sufficient to heat the water satisfactorily. It is quite 
 possible to expose 200 sq. in. of heating surface with a water 
 back of this description and on the basis of 2i/^ sq. in. to the 
 gallon of water that is sufficient to heat 80 gallons with ease. 
 
 It must not be overlooked however that such a large water 
 back is a severe tax upon a fire and when overdone will lead to 
 
28 HOT WATER SUPPLY. 
 
 unsatisfactory baking in the ovens. Therefore a water front snch 
 as that shown in Fig. 10 which is carried round two sides of 
 the fire box only and which even then is capable of heating a 
 more than ordinarily large boiler may be the safer to use in the 
 majority of cases. When placing water fronts in position it is 
 always well to bed them with fireclay and to point the joints 
 with that or with stove putty. This will add considerably to the 
 heating value of the fire by preventing an accumulation of ash 
 in the crevices and by preventing a current of air from passing 
 behind the water front and bricks. 
 
 Another point to look out for is that the stove is standing 
 level. It is not uncommon in old houses to find floors so much 
 out of the level by sinking of walls that the water front is high 
 
 , 
 
 Fig. 12. A Combination of Coil and Water Front. 
 
 at one end and this may considerably affect the circulation as 
 well as act injuriously on the water front should air or steam 
 collect therein. It also throws the tappings of the water front 
 out of the correct line so that the pipes connecting to it will be 
 pitching either up or down more than is desirable. This latter 
 condition has sometimes to be overcome by cutting a crooked 
 thread on the connections as it may be also due to a tapping not 
 being correctly made. 
 
 When an additional supply of hot water is required through 
 the extension of the plumbing system in a house or for any 
 other reason it is often accomplished by tapping the water 
 front as shown in Fig. 11 and carrying a brass pipe around 
 the fire box in contact with the hot coals or exposed to the hot 
 gases passing over the top of the oven to the flues. If the addi- 
 tional requirements are not great a pipe passing round two 
 
WATER FRONTS, COILS AND HEATERS. 
 
 29 
 
 sides and so throug'h the stove plates may be entirely satisfac- 
 tory, or it can be carried along the top of the oven and returned 
 to the fire box end again before passing out to be connected 
 to the boiler. It is important to see that a pitch upward is 
 maintained, otherwise the circulation will be impeded and ac- 
 companied by rumbling sounds caused by the accumulation of 
 air or steam in the coil. 
 
 Another method of extending the heating surface of a 
 water front is shown in Fig. 12. This is really a combination 
 of coil and water front, the coil being carried along the back 
 of the fire box and connected into the flow and return pipes 
 to boiler as shown. Such a coil is easily constructed of brass 
 pipe mth one return bend, unions being inserted between the 
 
 Fig. 13. Another Method of Extending the 
 Heating Surface. 
 
 water front and the tee on coil so as to enable the coil to be 
 pushed into place. The legs are brought through holes drilled 
 in the stove plates and the tees turned on in position. Yet 
 another variation is seen in Fig. 13, but this calls for drill- 
 ing the water front in another place. This ensures that all air 
 is removed from the water front and when the stove is of such 
 construction that the connection can be made in this manner the 
 additional ^heating power that such a coil affords will be con- 
 siderable. The arrows in the illustration denote the path of 
 the water in circulating throught the water front. The tapping 
 for the coil connection is made just above the level of the parti- 
 tion in the water front and that from the top is taken off at 
 one end in a line with the return connection. The flow connec- 
 tion used before the extension was made is plugged. In piping 
 
30 
 
 HOT WATER SUPPLY. 
 
 up a water front in this manner it is imperative that there should 
 be no burrs in the pipe or fittings and a smoother working 
 job will be obtained if there is room in the fire box to make the 
 piece of pipe and the tee of 1-in. pipe as shown, as then there 
 will be no retarding of the flow by friction with consequent over- 
 heating and noisy operation. 
 
 Instead of a cast iron water back it is common to use a coil 
 made of iron or preferably of brass pipe. This is generally 
 built by the plumber to fit the stove installed and consists of the 
 
 14. Coil Fitted Over a 
 Range Fire Box. 
 
 ordinary elbows and return bends in common use. It can be 
 made to fit one, two, three or four sides as desired and is 
 generally built in a simple two pipe style, although with a fire 
 box of large capacity and depth it may be built three pipes 
 deep. The size of pipe generally used for these coils is % in., 
 as then the fittings do not take np an undue amount of room 
 and the coil can be made to fit snugly to the walls of the fire 
 box. Unless special provision has been made for the use of such 
 a water heater by the maker of the stove the interstices of the 
 coil and the space left at top and bottom should be filled with 
 a good stove cement. This does not affect the heating qualities 
 of the coil and prevents overheating of the plates of the range 
 or leakage of smoke and gases to the room. As with the exten- 
 sion coil already spoken of the pitch to the outlet must be care- 
 fully watched. A dip at one of the bends caused by the action 
 of screwing in a pipe or tightening a union is easily made and 
 is often sufficient to retard the circulation to a serious extent. 
 
WATER FRONTS, COILS AND HEATERS. 
 
 31 
 
 A variation on the usual method of fitting the coil is shown in 
 Fig. 14. Here the coil is shown suspended over the fire and in 
 such a position as not to interfere with access to the fire box 
 through the two stove lids. This is not likely to give as much 
 satisfaction as the previous method, as the coil is subjected to 
 radiant heat only and this is of much less value than direct 
 contact with the glowing fuel. A coil of two pipes fitted to 
 three sides of the fire box is shown in Fig. 15. 
 
 Proportioning Coils and Water Fronts. 
 
 The proportions of water fronts and coils are not subject 
 to much variation to suit the needs of different households, 
 
 Fig. 15. A Coil on Three Sides of the Fire Box. 
 
 owing to the limitations which the construction of the stoves 
 in which they are placed entail. It is, however, occasionally 
 desirable to estimate the capacity of a water front or a coil be- 
 fore proceeding to install fixtures which would require a supply 
 of hot water therefrom and which might entail an additional tax 
 on the heating capacity which it was unable to carry. If the 
 boiler be a forty gallon one and two hours be required in which 
 to heat it to the desired temperature of say 110 deg. Fahr., it 
 will be easy to compute the time required to heat any extra 
 amount. As 1 B.t.u. is the equivalent of the heat required to 
 raise the temperature of 1 lb. of water 1 deg. Fahr. when the 
 water is at its point of maximum density — 39 deg., it will be 
 
32 HOT WATER SUPPLY. 
 
 seen that to raise 40 gall., or 333 lbs. 70 deg. will require 23,310 
 B.t.u. If this is divided by 2 it is seen that the rate of heat 
 transmission is H,655 B.t.u. for the surface exposed. As the 
 average size of the water front is about 5 in. by 15 in., that would 
 mean a rate of transmission of 22,377 B.t.u. per sq. ft. per 
 liour. This rate of transmission is high and will seldom be 
 reached in a kitchen range water front unless the draft is good 
 and a large fire is maintained. It is perfectly safe to estimate 
 the proportions of a coil on a basis of 15,000 B.t.u. transmitted 
 per sq. ft. per hour, as it is in more intimate contact with the 
 hot fuel than a water front. It is only necessary to find the 
 area of the pipe exposed to the fuel and calculate how many 
 B.t.u. the coil will transmit from the fuel to the water, using 
 a ratio of 15,000 B.t.u. per sq. ft. as a basis. When the num- 
 ber of heat units is found this should be divided by the number 
 of degrees it is desired to raise the temperature of the water 
 which will give the pounds that may be heated to that point and 
 this again being divided by 8.3 the sum is found in gallons. To 
 find the size of a coil or water front necessary to heat any 
 Mated quantity of water in a given time the process is reversed. 
 The consumption of fuel per sq. ft. of grate surface varies 
 greatly according to the local conditions. In estimating the 
 amount of fuel required to heat water in a kitchen range a 
 <»onsumption rate of 8 lb. per sq. ft. per hour should not be 
 exceeded while in a water heater of special design the rate of 
 -combustion may not exceed 3 lbs. per sq. ft. per hour. A heat 
 transmission of 8,000 B.t.u per pound of anthracite is generally 
 estimated. 
 
 It is not advisable to estimate sizes on the maximum require- 
 ments, the average household only uses hot water at its maxi- 
 mum rate for very short periods and it is economical to cover 
 these by an auxiliary heater as a rule. It must also be remem- 
 bered that the whole contents of a boiler will not be at a uniform 
 heat. The hottest water will be stored at the top of the boiler, 
 while that at the bottom will be cold until the fire has been run 
 for a considerable time. Therefore if water to a certain quan- 
 tity is to be heated in a stipulated time the average temperature 
 must be taken, as the hottest water will be drawn first. 
 
WATER FRONTS, COILS AND HEATERS. 33 
 
 The proportions of boilers for ordinary residences are not 
 determined by any theoretical consideration but by what ex- 
 perience has shown to be correct. The ordinary residence with 
 one bathroom and kitchen equipment is generally well served 
 when a boiler of 40 gallons capacity is installed, and a 50-gallon 
 boiler will serve a house with two or even three bathrooms very 
 well. 
 
 In apartment and tenement houses served from a common 
 storage tank it is common to provide 20 to 25 gallons per fam- 
 ily up to 15 families; in a house accommodating 20 families, 
 20 to 22 gallons per family ; for 25 families, 18 to 20 gallons per 
 family, and over that 15 to 18 gallons is usually sufficient. If 
 laundries are provided in the building the allowance should be 
 increased about 30 per cent, to balance the increased demand 
 for hot water on certain days. 
 
CHAPTER IV. 
 
 Range Boiler Connections for Various Conditions. 
 
 While it is not possible to show an example of every pos- 
 sible method of connecting ranges it is imperative to show all 
 of the boiler connections and methods of circulation that are 
 
 Fig. 16. Common Method of 
 
 Connecting Range with 
 
 All0"wance for Expansion. 
 
 Fig. 17. A Method of Con- 
 necting a Range to Secure 
 Quick Circulation. 
 
 likely to be met with in the work of installing hot water supply 
 in large or small houses, hotels, and public buildings. There 
 are many cases in which it is impossible to follow the stereotyped 
 plan, the strict letter of the law as laid down in theoretical works 
 on the subject. Where such departures are made in any of the 
 examples here proposed the reason for it will be given, and 
 where possible examples of installations which have been long 
 enough under observation to afford definite proof of the claims 
 set up for or against them will be illustrated. 
 
 For the first example is taken the simplest installation of 
 all, the ordinary 30 or 40-gal. range boiler with regulation con- 
 nection to water front, as shown in Fig. 16. Every plumber 
 knows how to connect a range like this. He knows that carry- 
 
 34 
 
RANGE BOILER CONNECTIONS. 
 
 35 
 
 ing his pipes along in the manner illustrated will, as a rule, 
 cause a circulation to take place. He knows that he is to allow 
 for ''swing'' to prevent leaks at the joints through expansion, 
 and that he is to provide a sediment cock or a tee with stop- 
 cock and connection to the waste water system at the lowest 
 point of the boiler connections. 
 
 But every plumber does not know what to do when the 
 circulation refuses to materialize; or when the boiler is hot at 
 
 Hot to - 
 Fixtures -> 1 
 
 M 
 
 t-t^-^ 
 
 
 Fig. 18. A Quick Heating 
 ConnectioH. 
 
 Door or 
 Window 
 
 Reh/rn bebw Floor 
 
 Fig. 19. 
 
 Connection to Clear a Door or 
 Window. 
 
 times and cold under apparently the same condition's. Also 
 what to do when heating of the boiler is accompanied by pound- 
 ing and rattling noises and vibration of the boiler. 
 
 Pounding. 
 
 The man who is up in the theory of his business will 
 promptly begin to analyze the symptoms. He will go carefully 
 over them and eliminate *' possibles" one by one until he finds 
 the cause of the trouble. No waste of time in experimenting 
 at haphazard; just a methodical application of the knowledge 
 he has gained from his books and papers and from his own 
 deductions and observations in his daily work. 
 
 Pounding is caused in several different ways. By over- 
 heating, owing to the water front or coil being of larger size 
 than is necessary for the size of boiler used. There is no cure 
 
36 HOT WATER SUPPLY. 
 
 for this except increasing storage capacity or reducing heating 
 surface by inserting a brick or other heat-resisting medium 
 between a portion of the water front or coil and the fire. A 
 radiator is sometimes fitted where such can be used with advan- 
 tage. This provides a ready means of collecting and dissipat- 
 ing satisfactorily the excess heat. 
 
 Pounding may also be caused by defective circulation 
 through sediment collecting in the water front, in circulating 
 pipes or in the boiler. This prevents a proper and continuous 
 supply of cold water to the water front, and the result is that the 
 water is overheated, steam bubbles form, and on encountering 
 the cooler water in the boiler in their circulating path, suddenly 
 condense, and partial vacuums are formed with the attendant 
 rumbling and snapping noises that are produced by the water 
 rushing in to fill them. 
 
 Insufficient pitch, or pitch in the wrong direction, will also 
 produce the same trouble through collection of air. 
 
 Connection to Facilitate Heating. 
 
 Failure to properly heat the boiler is occasionally difficult 
 to account for. In the first place it may be poor firing, which 
 will never be admitted by the complainant ; it may be poor coal^ 
 poor draft in the chimney, or insufficient heating surface. 
 
 "When trouble along these lines is encountered it is often 
 advisable to connect up the boiler after the manner shown in 
 Fig. 17. This, although a ** stiff" connection, is quite allowable. 
 In fact, in some respects it has the advantage of the other 
 method, as there is a minimum of frictional resistance to the 
 circulation and the natural flow or rise of the heated particles 
 of water is assisted by the sharper pitch of the pipes. 
 
 The author has had occasion to enlarge the size also, and 
 a 1-in. pipe instead of the customary % in. will make quite a 
 considerable difference in the efficiency of the system. 
 
 Then the size of the smoke pipe must be considered and the 
 draft tested to decide if the chimney is faulty. 
 
 The author has also found a partial stoppage in a water 
 
RANGE BOILER CONNECTIONS. 
 
 37 
 
 front, caused by parts of the core used in casting being left 
 in it, that was impeding circulation greatly, but yet not enough 
 to cause pounding or snapping through overheating. 
 
 It is always wise to examine thoroughly a new water front 
 before installing and to pass a bent wire through to prove the 
 passage at the end is elear. Also, in connecting to an old boiler, 
 
 Cold 
 
 £^Q!d_ 
 
 I 
 
 Hot to 
 r/Kfures 
 
 Gos 
 Heater' 
 
 ^^ 
 
 (aas 
 Heater 
 
 V^ 
 
 
 Fig. 20. Connection for a Gas 
 Water Heater. 
 
 Fig. 21. Connection of Heater to 
 Avoid Sediment in Boiler. 
 
 see that there is no deposit of ooze or rust on the bottom, as 
 this will often be dense enough to prevent the return circulation 
 to the water front. As much as 18 in. has been found in an 
 old boiler in investigating the cause of non-heating. Also make 
 sure that the supply tube is in good condition and clear. 
 
 Quick Heating Connections. 
 
 Variations on the regular methods of connecting an ordi- 
 nary range boiler may be made to suit special conditions. In 
 fact, some conditions demand a departure from the ordinary 
 methods. Such a condition may arise where the water front 
 or whatever the heating medium may be is so high that a proper 
 pitch cannot be given to the flow pipe and allow of its being 
 connected to the side opening in the boiler. In this case the side 
 connection is plugged and the flow pipe carried to a point im- 
 
38 
 
 HOT WATER SUPPLY. 
 
 mediately above the boiler, where it is connected to a tee on 
 
 the house supply as it leaves the boiler. 
 
 A feature of this style of connection is that the hot water 
 
 being delivered to the upper part of the boiler is more quickly 
 
 available. As it does not 
 have to pass through the 
 colder water in the boiler, 
 transmitting heat by convec- 
 tion to the contents, it follows 
 that a larger quantity of 
 really hot water is also avail- 
 able in shorter time than with 
 the other connection although 
 no gain would be shown in 
 heating the whole contents of 
 the boiler to a given tempera- 
 ture. 
 
 ^W^MMMMM^M^^^^MM^ This style of connection is 
 
 Fig. 22. Connection to Afford Free Flow generally known as a * ' quick- 
 
 Under Low Pressure. i .• 4.' ^ ff . j 
 
 heating connection, and 
 where small quantities of very hot water are required at frequent 
 intervals is a very satisfactory one to adopt. A combination of 
 the good features of both may be obtained by connecting with 
 the side opening also, as shown by the dotted line in Fig. 18. 
 This, while allowing of the hottest water being stored at the 
 top of the boiler for instant use, permits a proportion of the flow 
 from the water front to pass into the main body and, by mixing 
 with the colder water to bring the temperature of the whole to a 
 more or less equal state in a shorter time when no water is being 
 drawn. 
 
 Connection for Boiler With Door Intervening. 
 
 In many instances where the boiler has to be placed in a 
 closet or other apartment, a long run of pipe is necessary, and 
 often there is some obstruction which will not permit of a con- 
 nection to the side opening, even if pitch could be got for the 
 long run. In this case also the connection would be made to 
 the top of the boiler, plugging the side outlet. Where a door or 
 window has to be crossed the same method is advocated. 
 
 When a pipe is carried up to clear an obstacle of this 
 
RANGE BOILER CONNECTIONS. 
 
 39 
 
 nature it should enter the house supply over the boiler at a 
 slightly higher level than the ell at which it makes the change 
 from the perpendicular. If it pitches downward from the ell 
 air will lodge at the high point, and if pressure is low will 
 probably cause an air lock. The return pipe may be dropped 
 below the boiler level if necessary to clear a door or other ob- 
 struction, the sediment cock, of course, being placed at the lowest 
 
 Safety-^. 
 Vacuum sr-5? 
 Valve f" ^ 
 
 HottoF/xfures 
 
 w , Supply 
 
 B q > — i C i n c^ 
 
 V/,/',// // f '///'/ ^ y //'//// y /// f /////'//''///,"/'/ /M/l %y////////V//////////////////////////////////\ 
 f ///////// y /// y / r ///// y / y / y / y y y y''y'yyyyyyyyyy,/A 'iyyyyyy/yyyy/'/y/yyyyyyyyyy/yy///f/tf/y/y, y y, y/A 
 
 Fig. 23 and Fig. 24. 
 Two Methods of Connecting Vertical Boilers in a Horizontal Position. 
 
 point. This arrangement, shown in Fig. 19, should not be made 
 unless absolutely necessary, as the long circulation means loss 
 of heat and consequently slower heating of the boiler. 
 
 Connection for Gas Heaters. 
 
 A more or less common means of heating kitchen boilers 
 is that by a small gas heater, consisting of a coil of pipe, or a 
 series of hollow metal disks through which water is passed, 
 and a bunsen burner, the whole being enclosed in a sheet metal 
 or cast iron cylinder. This appliance is fitted directly to the 
 side of the boiler, as shown in Figs. 20 and 21, and has variations 
 in the way of automatic gas control and other features peculiar 
 to the several makers' designs. 
 
 The most commonly used connection is that shown in Fig. 
 20. This admits of the whole contents of the boiler being 
 heated, but is open to objection on the score that sediment from 
 the boiler may be carried along and deposited in the coils or 
 
40 HOT WATER SUPPLY. 
 
 disks of the heater, leading to a stoppage of circulation and 
 overheating of water with attendant pounding, and possibly to 
 a bursting of the disks or coil. This objection may be over- 
 come to a great extent by fitting a sediment chamber at the tee 
 marked A. If this is given proper attention and the deposit 
 periodically removed no trouble will be experienced. 
 
 A plan which is often recommended is to take the return 
 circulation from the side opening of the boiler, as shown in Fig. 
 21. This effectually prevents sediment entering the heater, but 
 reduces the storage capacity of the boiler by about one-half, as 
 there is no circulation and storage of hot water below the side 
 opening to which the return pipe is connected. 
 
 Connection for Low Pressures. 
 
 Occasionally the problem of providing a rapid flow of hot 
 water at the fixtures with a low head of water is encountered 
 and there are various ways and means of solving it more or 
 less successfully. The author has found the method shown in 
 Fig. 22 entirely satisfactory as it does not call for anything 
 outside of the standard type of boiler or fittings. 
 
 It shows a regular tank heater connected to a standard 
 tapped vertical range boiler in a manner calculated to allow 
 of the maximum flow through it. The supply tube is eliminated 
 and the two top tappings used for a twin connection to a 1^-in. 
 line of supply pipe. The cold supply is connected to the return 
 connection to the boiler and is also 1^4 i^i- diameter until it 
 is reduced at the bottom tee to 1 in. to suit the standard tapping. 
 The minimum frictional resistance to the flow is thus en- 
 countered as the combined area of the outlets more than equals 
 the area of the supply line and the same is true of the cold 
 supply and the inlets to the boiler. 
 
 A combined safety and vacuum valve fitted as shown en- 
 tirely prevents siphonage should the supply be intermittent 
 and is also a useful adjunct through its being calculated to open 
 under an excessive pressure or under a sudden shock from a 
 quick closing valve. Much has been written concerning the 
 undesirability of connecting the cold supply to the boiler in 
 this fashion, the statement being made that the cold water en- 
 tering is liable to flow clear to the top of the boiler and cool 
 
RANGE BOILER CONNECTIONS. 
 
 41 
 
 off the water leaving it. This may be true under a heavy pres- 
 sure, but there would be no advantage in using this connection 
 in that case, and under light or moderate pressures the author 
 has found this method satisfactory in every way. 
 
 Hot to Fixtures 
 
 Hot to Fixtures 
 
 Cold Supply 
 
 f 
 
 Cold 
 Supply 
 
 I 
 
 Rett 
 
 ^ 
 
 L=f pi§j^ta& 
 
 ^ 
 
 ^ 
 
 ' Vacuum 
 ValvQ 
 
 Flow 
 
 Return 
 
 ^ 
 
 mm. 
 
 f////y///^// 
 
 
 t3» 
 
 D 
 
 Flov 
 
 ^ 
 
 Fig. 25. Common Method of Con- 
 necting Horizontal Boilers. 
 
 'y/////////////////////////////////.'//''/.'.'////,'///f^ 
 
 Fig. 26. A Method that Requires 
 Only Three Tappings 
 
 Overhead Horizontal Boilers. 
 
 Lack of room or some similar consideration often favors 
 the placing of a range boiler in a horizontal position overhead. 
 If the standard vertical type of boiler is placed in an overhead 
 horizontal position the result will not be entirely satisfactory. 
 
 The best method that can be adopted in this case is open 
 to objection and the only course is to choose the least of the 
 evils. That which has the least against it is shown in Fig. 23 
 and a glance at the sketch will show at once that it is not free 
 from fault. The circulating pipes from the water front enter the 
 boiler through the top tappings, the return having a dip pipe 
 to ensure the whole contents of the boiler being circulated. The 
 supply should enter the bottom tapping and also, of course, have 
 a dip pipe, with the usual vent hole drilled in it. 
 
 A decided improvement over the vent hole is a combina- 
 tion vacuum and safety valve fitted as shown by dotted lines 
 in Fig. 23, as half the contents of the boiler could be siphoned 
 out before the vent hole would break the vacuum. It will be 
 noticed that the boiler cannot be properly washed out either. 
 
42 
 
 HOT WATER SUPPLY. 
 
 While the dip pipe on the return connection will siphon out the 
 bulk of the contents it does not remove sludge and other deposit 
 and this cannot well be scoured out in the ordinary manner. 
 
 The other method of connecting, however, shown in Fig. 
 24, while it does not possess this objection, has the graver one 
 that a steam pocket can be formed above the outlet, and thus 
 cause hammering and other serious troubles, and this fault is 
 sufficiently serious to warrant the recommendation of adopting 
 the alternative connection before described. A better plan still 
 is to discard this type of boiler and procure one tapped in a 
 manner that will insure a satisfactory job when connected up. 
 
 Connecting Regular Horizontal Boilers. 
 
 The usual method of connecting a horizontal boiler with 
 the range water back, or heater, is that shown in Fig. 25. It 
 will be seen that the boiler differs from those used in a vertical 
 position in having the tappings for cold supply and return in 
 the sides instead of the ends. This permits of all the contents 
 being drained when it is necessary to wash out the boiler, and 
 also insures circulation of the entire body of water. 
 
 The cold supply, entering through the top, is fitted with 
 a supply tube in the regular manner, and a hole drilled in it 
 a few inches from the boiler union 
 will effectually prevent siphonage 
 should the supply fail in the city 
 mains or be cut off by a stopcock 
 with waste outlet at a lower level 
 than the boiler. 
 
 An alternative method of con- Re^ 
 necting the boiler, using only three 
 tappings, is shown in Fig. 26. This 
 is a good system to adopt where the 
 pressure is low, but where a very 
 heavy pressure is carried in the 
 cold supply the water entering the 
 boiler through the return connec- 
 tion may be forced to the upper WW^!0^^WWW^y^W^ 
 
 part of the boiler and cool off the Fig. 27. Method Designed to 
 
 hot water stored there. A vacuum ^"^"' 'iTxture^s?''^'^ '"^ 
 
 Cold 
 
 Hot 
 
 'lH 
 
 =^ 
 
 PStrr— — ^ 
 
RANGE BOILER CONNECTIONS. 43 
 
 valve is used in connecting in this manner the cold supply from 
 the street main. This will open immediately the pressure falls 
 below that obtaining in the boiler and thus effectually prevent 
 siphonage back into the mains. This valve must, of course, be 
 fitted on a level above the top of boiler. Should the supply come 
 from an overhead tank the valve is unnecessary unless a faucet 
 or stopcock with waste outlet is fitted on the same line at a lower 
 
 level than the boiler. 
 
 A little variation on the method of connecting a horizontal 
 boiler is shown in Fig. 27. It will be noted that one tube is 
 connected with the cold water supply to the boiler and runs 
 down inside of the boiler to a point near the bottom. The 
 other opening at the top of the boiler is for the hot-water ser- 
 vice connection. The tube at one end of the boiler is designed 
 to bring the hot water from the water back near the top of the 
 boiler, so that it will find its way immediately to the hot-water 
 service piping. The opening in the other end is frequently 
 used for a return or circulating pipe, so as to keep the hot 
 water moving, so that as soon as the hot-water faucet is opened 
 at any fixture hot water will flow without any waste of the 
 water, as is the case when the cold water in the pipes has to be 
 drawn off to allow the hot water to reach the faucet, as is neces- 
 sary where there is no circulating pipe. The bottom opening in 
 the boiler naturally connects with the bottom or return opening 
 in the water back in the range. 
 
 Example of a Steam Heated Boiler Which Was 
 Not Satisfactory. 
 
 "While on the subject of horizontal boilers we may touch 
 on those of this type heated by steam coils. In very many 
 cases these are placed in the basement close to the steam boiler, 
 and on a level very slightly above the water line in the boiler. 
 If this happens to be of the low pressure domestic heating type, 
 care must be taken to connect up the coil so that condensation 
 will not be held up in it and so lower its efficiency. 
 
 In Fig. 28 is shown the style of connection referred to and 
 which illustrates a case the author has in mind. This coil had 
 never given satisfaction. The heater is in the basement of the 
 gymnasium of a large preparatory school and steam is not main- 
 tained in the boiler continuously. A battery of twenty-five 
 
44 
 
 HOT WATER SUPPLY. 
 
 showers is supplied from the hot-water boiler, and when these 
 are in use an extra large quantity of hot water is called for. 
 The pressure of steam necessary to heat the building is only 
 about 1 to 2 lb. and the complaint was that at that pressure 
 the coil was ineffective, the return being cold to the touch and 
 the heating effect on the boiler inappreciable. 
 
 There was a check valve on a horizontal part of the steam 
 eonnection just above water level of boiler, and the author con- 
 cluded this had stuck. Finding it in good condition, he con- 
 
 Flow 
 
 ColcP^ . 
 Supply ,••'« 
 
 Return 
 
 £ 
 
 
 ^ 
 
 ^///// /'// • 
 
 ^sz 
 
 AirKKlvo 
 
 'W)9ck Valve 
 
 
 Fig. 28. A Boiler Fitted Very Close to Water 
 Line of Steam Boiler. 
 
 eluded that the rapid condensation in the coil lowered the pres- 
 sure at the return end so much (at low boiler pressures) that 
 the water of condensation did not have head enough to over- 
 'Come the check before the coil stood partly full. The author 
 prepared to fit a small equalizing pipe to counteract this, and 
 in doing so lowered the check below the water line of the heater. 
 On plugging the tees and trying out he found that the coil 
 worked perfectly without it, the extra drop evidently being 
 sufficient to open the valve. He would have removed the check 
 entirely had the boiler been in continuous use or its level higher 
 above the water line of the steam heater. A Breckenridge air 
 valve, which was found in good condition, was carefully set so 
 as to insure quick egress of air when steam was raised and 
 the results are now satisfactory. 
 
 This example, while not very common, may be met with 
 from time to time, and the liability to failure through placing 
 
RANGE BOILER CONNECTIONS. 45 
 
 the boiler at too low a level must not be overlooked. "Where 
 the space available prevents a safe difference of levels being 
 obtained special care must be given to proportioning the steam 
 supply and returns so that the pressure at the supply end of 
 the coil will be as nearly equal to that at the return end as 
 possible. The equalizing pipe mentioned is a pipe of small 
 diameter connected to the flow and return connections before 
 the supply enters the coil in the tank for the purpose of se- 
 curing that the pressure will be equal in each, no matter what 
 the gauge pressure may be. This effectually prevents water 
 backing up into the coils from the steam boiler when the water 
 in the storage tank is cold and the steam is being condensed as 
 rapidly as it is supplied. 
 
CHAPTEE V. 
 
 Variations in Connections to Suit Special Requirements. 
 
 The problem of making hot water flow downward from a 
 range to a boiler on the floor below it may well be called the 
 plumber's fifth proposition — ^the **Pons Asinorum,'* for it has 
 puzzled more young mechanics, perhaps old mechanics also, than 
 almost any other that we have to solve. It has been explained 
 so often that it would seem as if every member of the trade 
 would be familiar with it and yet an inquiry turns up with 
 unfailing regularity in the trade papers every few weeks. Fig. 
 29 shows the usual method of connecting a boiler in this position 
 when the supply is direct from a city pressure main. The flow 
 pipe from water front is carried up to a point at or above the 
 ceiling of the kitchen and then turned down to connect into 
 the top tapping of the boiler, an air cock being fitted at the 
 highest point to draw off any air that may accumulate in the 
 loop or a fixture above this level supplied from a branch taken 
 from the top. The branch to supply fixtures is usually taken 
 from a point a little above the boiler connection as shown in the 
 illustration in Fig. 29. 
 
 Circulation is established and maintained between the 
 boiler and range water front by the cooling effect that the loop 
 in the piping affords. Here are two columns of water of equal 
 height. That in the descending leg, starting from the top of the 
 loop, is obviously the cooler and therefore the more dense and 
 by the law of gravitation must fall to balance the other and less 
 dense column of which the water front forms a part. Thus the 
 hot water is pushed up and around the loop and, becoming 
 slightly cooler as it progresses, descends into the boiler. 
 
 The results obtained in this system are not generally so 
 satisfactory as with the boiler on the same or a higher level 
 than the heater, owing to the slower circulation. A safe rule 
 for the height the loop should be made reads, "Twice the height 
 above the water front that the boiler is below it.'* Any extra ^ 
 
 46 
 
VARIATIONS IN CONNECTIONS. 
 
 47 
 
 height over this will tend to increase the efficiency and hasten 
 the circulation. 
 
 A point that is sometimes lost sight of in installing a boiler 
 in this way is the danger of emptying the water front by siph- 
 
 -Air Cock 
 
 Vacuum Vafves-'' 
 
 Cold 
 
 =€ 
 
 
 Fig. 29. Common Method of Con- 
 necting Boiler Below Stove. 
 
 Fig. 30. Connection to Prevent 
 
 Drawing Water Below Level 
 
 of Stove. 
 
 on age should the pressure in the city mains fail. Just as soon as 
 the pressure goes down the water must fall back into the boiler 
 through the return connection leaving the water front empty, 
 and if a very hot fire is maintained trouble will assuredly follow. 
 Also, if there is a branch from the hot-water pipe to a fixture 
 in the basement it is possible to draw the water back in the same 
 manner should the main house valve be closed at any time. To 
 get over this the connection can be made as shown in Fig. 30. 
 Here both the hot and cold-supply lines are shown dropping 
 from a point above the level of the water front, the branch to 
 
48 
 
 HOT WATER SUPPLY. 
 
 the basement fixtures being also taken from this level. Vacuum 
 valves fitted on both lines at the highest vertical point will ef- 
 fectually prevent siphonage of the boiler back through the cold 
 supply from the city main pipes or through the basement hot- 
 
 
 Fig. 31. Boiler on Floor Below Stove Supplied From 
 Attic Tank. 
 
 water faucet. This is an important point and should always 
 have consideration, as although the system shown in Fig. 29 
 will work perfectly in providing hot water the danger from the 
 above-mentioned causes is always present. 
 
 Fig. 31 shows the usual method of connecting a boiler below 
 the level of a heater when a tank supply is used. There is noth- 
 
VARIATIONS IN CONNECTIONS. 
 
 49 
 
 ing differing greatly from the method used in connecting when 
 the supply is from the city mains. Instead of using an air cock 
 or connecting a branch to some fixture to the highest point of 
 the loop to relieve it of air, an expansion pipe is connected here 
 
 =^ 
 
 ^==€ 
 
 ^aSt 
 
 MW 
 
 V.:., '////.■/////////,',,'////.. ',/////. ////^///'y/ A W//////////'.'///////////y'/////.'.','////////////A 
 
 Fig. 32. Conuection for Boiler on 
 Floor Above Stove. 
 
 Fig. 33. A Method of Connecting 
 to Favor Quick Heating. 
 
 and carried up and turned over the top of the tank. This al- 
 lows air to escape as it is formed and also serves as a ready 
 means of escape for the water when expanded by heat should 
 the supply valve happen to be closed. If the tank supply should 
 fail the same danger of emptying the water front w^ould exist 
 if a branch be taken to a basement fixture from the boiler and 
 therefore the connection should be made at a point above the 
 level of the w^ater front, or carried up to a point above it and 
 provision made to guard against siphonage before dropping to 
 the fixture in the basement. 
 
50 
 
 HOT WATER SUPPLY. 
 
 Connecting Boilers on Floor Above Heater. 
 
 The problem shown in Figs. 32 and 33 scarcely deserves to be 
 classed as a problem as there is barely room for any error in 
 making such connections. Occasionally a request for the proper 
 method of connecting a boiler on the floor above the heater is 
 
 made and as the exam- 
 ples shown are designed 
 to cover all combina- 
 tions in the practice of 
 the average mechanic 
 it cannot well be over- 
 looked. 
 
 As will be seen in 
 Fig. 32, the flow and 
 return connections are 
 made in the same man- 
 ner as if the range 
 were on the same floor 
 [ as the boiler, but the 
 pipes are continued 
 down through the floor 
 to the water front or 
 coil. The sediment cock 
 is placed at the lowest 
 point of the return 
 piping, that is, where 
 the turn is made to 
 connect to the water 
 front or heater. The 
 supplies to the various 
 
 _ fixtures must be taken 
 
 ^^m:^^:^<'/^//>^^:<v/:v/:v'.:'^:'^:^^>Z^^^ from the top of boiler 
 
 JScttt 
 
 z 
 
 ^ 
 
 Fig. 34. 
 
 Connections for Furnace Coil and 
 Gas Heater. 
 
 in the usual manner. 
 
 Supplying a fixture on 
 the floor below the boiler direct from the circulating pipes must 
 never be permitted as there would be a liability to empty the 
 boiler without the knowledge of the user should the cold supply 
 for any reason be cut off. This would entail danger of bursting 
 the water front when the cold water is turned in again should 
 
VARIATIONS IN CONNECTIONS. 
 
 51 
 
 a strong fire have overheated and evaporated the water left 
 below the level of the branch to the fixture. 
 
 Fig. 33 shows a quick heating connection made under the 
 flame conditions. This is a highly efficient method to adopt if a 
 good supply of very hot water is required as the height of the 
 circulating system in- _ 
 duces a rapid move- c====a^ ] 
 ment and the flow to 
 the top of boiler stores 
 the hottest water there. 
 The side connection 
 tapping may be plug- 
 ged or used to make the 
 combination connection 
 as shown. It is advis- 
 able to use it to secure 
 the best results. 
 
 Connections for Coil 
 and Gas Heater. 
 
 The most common ap- 
 plication of placing the 
 boiler on the floor 
 above the heater is 
 where an independent 
 hot-water heater, a coil 
 in a heating furnace or 
 a cook stove in a sum- 
 mer kitchen in the base- 
 ment is the heating ap- 
 pliance provided. ■ 
 
 When such is the case ^Z^vZ-Z^Zv^vZ^Z'/^Zv/}^^^^ 
 
 a gas heater is generally Fig. 35. connections Giving continuous Flow 
 ° . -,-,.. rr.1 . Through Gas Heater. 
 
 used in addition. This 
 
 provides a ready means of heating the boiler when the heating 
 furnace is not required or when it is not desirable to maintain 
 fire in the cook stovfe at all times of the day. 
 
 These gas heaters are usually connected as shown in Fig. 34, 
 the side connection to the boiler being used for the flow from 
 the coil or water front in the basement, while that from the gas 
 
 3=lQ 
 
 £ 
 
 ^ 
 
52 
 
 HOT WATER SUPPLY. 
 
 Jt=^ 
 
 heater enters the pipe leaving the boiler to supply hot water to 
 the various fixtures. An alternative method of connecting is 
 shown in Fig. 35. This greatly simplifies the piping and is gen- 
 erally efficient. The coils or discs of the gas heater act as a 
 
 radiator which cools off 
 
 ai^ 1 to some extent the wa- 
 
 ter flowing from the 
 furnace coil. The loss 
 is partly compensated 
 by the slightly in- 
 creased rate of circula- 
 tion obtained by the in- 
 creased height of the 
 flow pipe due to its en- 
 tering the top tapping 
 of the boiler and may 
 in most instances be 
 disregarded as the cas- 
 ing of the gas heater 
 prevents the radiating 
 surfaces of the coils or 
 discs from transmitting 
 as much heat to the air 
 as they would do if 
 fully exposed to it. 
 There is in reality little 
 to differentiate one 
 method from the other 
 and convenience alone 
 
 ===^=^ ^^^^^ dictate which is the 
 
 l'>;y>,r/>.^w%m^^r',:^^^^ best to adopt for any 
 
 particular set of condi- 
 tions. 
 
 Still another method is shown in Fig. 36. The gas heater 
 in this instance has its return connection made to the side tap- 
 ping of boiler. This obviates any chance of sediment finding its 
 way into the gas heater and also reduces the amount of water 
 stored by the heater so that the contents are at a higher tem- 
 perature in the upper part of the boiler where it is ready to be 
 drawn as soon as a faucet is opened. 
 
 ^caot 
 
 ^ 
 
 Fig. 36. Connection for Gas Heater to Reduce 
 Storage and Raise Temperature of Water. 
 
VARIATIONS IN CONNECTIONS. 
 
 53 
 
 Adding Storage Capacity. 
 
 To add to the capacity of a hot water system it is often con- 
 venient to install an extra boiler. This provides additional 
 storage capacity and if the water front is of sufficient size this 
 will often be found a satisfactory arrangement. The manner 
 in which a horizontal boiler may be connected to one already 
 
 Hot 
 
 ^ 
 
 i i 
 
 Cold 
 
 Supply 
 
 To Bath 
 
 Fig. 37. Method of Connecting Additional Boiler. 
 
 in position is shown in Fig. 37. The new piping is indicated 
 by the dotted lines. The present hot water service pipe should 
 be disconnected from the lower boiler and connected at the top 
 of the upper boiler. A pipe should be carried from the top 
 opening in the lower boiler to the bottom opening in the upper 
 boiler, and this pipe should be of the full size of the openings 
 in the boilers to ensure free circulation. 
 
 The pipe bringing the hot water from the water back should 
 be disconnected from the lower boiler and the opening stopped 
 with a plug. This hot water pipe should then be connected 
 with the middle opening of the upper boiler. This method 
 of piping will allow the cold water in the upper boiler to pass 
 to the lower boiler as the hot water enters it from the water 
 back, and the cold water will pass on to the water back and a 
 circulation be kept up. There should be no trouble from the 
 use of two boilers piped in this way, providing the water back 
 
54 
 
 HOT WATER SUPPLY. 
 
 ^ 
 
 ^ 
 
 ^ 
 
 & 
 
 =o 
 
 has the heating capacity to heat the extra amount of water 
 contained in the upper boiler. 
 
 A vertical boiler may be connected as shown in Pig. 38, 
 when the circumstances are similar, that is, when the water 
 back is sufficiently large to take care of the additional tax on 
 it. So that the flow from each will be equalized the connections 
 are made from the top of the boiler into a tee about half way 
 
 between the boilers. The cold 
 water supply is led into the two 
 boilers in the same manner. This 
 ensures that the friction in the 
 supply lines to and from each 
 boiler will be the same and 
 therefore the draft on each is 
 likely to be equal. If it is de- 
 sired to favor one more than 
 the other such as for instance 
 when one boiler is much larger 
 than the other and the water 
 drawn from the smaller would 
 be cold before the other was 
 
 ^ , emptied of all the hot water it 
 
 W///y////////y//y/////^^^^^^^^^ contained, the connections could 
 
 be such, by suitable sizing of 
 the pipes, that this could be 
 done automatically. Valves may also be inserted and set to 
 pass only the quantity desired from each. 
 
 When an increase in storage capacity of hot water is de- 
 sired it is generally more satisfactory in the end to install a 
 larger boiler rather than an auxiliary to the existing one, as 
 there is then no difficulty in securing positive circulation from 
 the water front. But there are many cases when to do so is not 
 feasible, owing to local features of construction or higher cost. 
 When an auxiliary boiler to the existing one is decided upon 
 local conditions again will dictate the best method of making 
 the connections. An important consideration to bear in mind 
 when arranging the piping for a connection like this is the de- 
 sirability of equalizing the flow to each boiler. Means should 
 be taken, by the use of the proper fittings and proportioning 
 of pipes, to insure as nearly as possible the same conditions 
 
 a£!tta& 
 
 Fig. 38. Connections Made to Equal 
 ize Flow from Additional Boiler. 
 
VARIATIONS IN CONNECTIONS. 
 
 55 
 
 in each water front, for if the resistance to the flow by friction, 
 etc., is about the same in each branch of the flow pipe there will 
 be a better chance of equal heating of the boilers. 
 
 Two Boilers Connected to One Water Back. 
 
 Figs. 39 and 40 illustrate the two most common methods of 
 connecting up two boilers to one water back on the same floor 
 level. "When the boilers are close together there is nothing very 
 hard to overcome in 
 securing a satisfactory 
 circulation to each, 
 and in this case the 
 connection best suited 
 is that shown in Fig. 
 39. A distributing T 
 or a Y can be fitted 
 at the branch to the 
 first boiler to promote 
 equal distribution, but 
 the reduction from 1 
 
 in. to % in. at this 
 
 •nmn t f pti d «! \c\ qppii rp Xv///////^////////////////////////////////'y/^^^^^^ 
 
 this satisfactorily. Fig. 39. connection for Two Boilers to One 
 
 Good pitch should be ^'^*''' ^^^^• 
 
 given to these pipes, crooked threads being cut to keep the verti- 
 cal parts plumb, and the connection to the side tappings of the 
 boiler, if the tapping is 1 in., should be made by a reducing ell 
 rather than by a bushing. This is done to eliminate friction as 
 far as possible. 
 
 Should the boilers be set far apart it may be impossible to 
 secure sufficient pitch to connect to the side tappings of both 
 boilers. In this case, one of them, or both of them if desired, 
 can be connected as in the case of "a quick -heating connection." 
 Fig. 40 shows two boilers with one of them connected in this 
 manner. A distributing tee can be used at the connection to 
 this boiler if it is thought necessary, but as a rule the extra 
 height of the circulation compensates for any tendency to 
 restricted circulation by reason of the velocity of the flow past 
 the tee retarding the flow to this boiler. Either of the boilers 
 
56 
 
 HOT WATER SUPPLY. 
 
 =rft: 
 
 1 
 
 in 
 
 may, of course, have the side connection, but generally that 
 nearest the range will have the side connection and that farthest 
 away the quick-heating connection. The judgment of the fitter 
 must be used to determine which it will be, but always the equal- 
 izing of the flow ought to be kept in mind. 
 
 Fig. 41 shows two boilers on different floors connected to 
 one heater. This is not very commonly 
 done, but where a powerful heater is 
 used it is quite successful and often the 
 construction of the building is such as 
 to prohibit any other method. 
 
 Boiler Heated by Two Water Backs. 
 
 Figs. 42 and 43 show exactly the re- 
 verse conditions, these 
 being examples of the 
 methods of connecting 
 two heaters to one boil- 
 er. The most common- 
 ly met with combina- 
 tion is where a laundry 
 
 
 Fig. 40. Connection to Equalize Flow to Boilers 
 
 stove and kitchen range are connected to one boiler, both heaters 
 being set close to the boiler. Again, where much cooking has 
 to be done two ranges are commonly used with the water backs 
 connected up as shown in Figs. 42 and 43. 
 
 It goes without saying that it is not good practice to con- 
 nect more than one heater, if they are to be in more or less 
 constant use, to the ordinary standard sized kitchen boiler, as 
 overheating will be sure to occur. If the boiler is of 60-gal. 
 capacity, or over, such trouble need not be apprehended. Fig. 
 42 shows one stove connected in the usual way to side connection 
 of boiler and the other through the top tapping. It is always 
 best, if circumstances will permit, to connect the range farthest 
 away from the boiler through the top connection, as the quicker 
 flow in the pipe counterbalances in some degree the longer path 
 it has to take and so better equalizes the work each water front 
 has to do. 
 
 When the method shown in Fig. 43 is used great care should 
 be taken to get sufficient pitch to the pipes. There is a tendency 
 
VARIATIONS IN CONNECTIONS. 
 
 57 
 
 toward retarding the flow at the point marked A, and this will 
 often cause rumbling and snapping sounds in one or other of 
 the water fronts, through the water becoming overheated. 
 
 By increasing the size of the pipe at the tee this may be 
 largely avoided and the use of 
 a Y as shown still further 
 improves the connection. It 
 is never, for obvious reasons, 
 advisable to fit valves on the 
 lines between the water fronts 
 and the boiler. If one of the 
 stoves is in a room which will 
 be closed at certain seasons of 
 the year, as is common in 
 some localities, it is better to 
 fit a second boiler which will 
 be heated from the stove in 
 that room than to connect it 
 with the boiler in the all-the- 
 year-round kitchen. This will 
 permit the water to be drawn 
 off the water front and its 
 connections and the closing 
 up of the summer kitchen en- 
 tirely if desired. The only 
 valves that will be required 
 will be on the cold and hot 
 supplies to the boiler in the 
 summer kitchen and the fit- 
 ting of these need add no ^^^- ^l- Connections for Two Boilers on 
 . T , , 1 , . I, .-, DiflEerent Levels. 
 
 risks to the operation of the 
 
 stoves as would be the case if valves were fitted on the connec- 
 tions and both stoves connected with one boiler. 
 
 Triple Connection to One Boiler. 
 
 A triple connection consisting of two ranges on the first 
 floor with a tank heater in the basement is shown in Fig. 44. The 
 utmost care is required in connecting the upper ranges so that 
 the long flow and return pipes will pitch correctly. As shown, 
 the connections of the tank heater provide for a continuous flow 
 
 F7777 
 
 ,..,..,,,,,■■,. .,,,,., 777777f77/777777f/777i 
 
58 
 
 HOT WATER SUPPLY. 
 
 through the water front to the boiler while the second range on 
 the first floor connects to the top of the boiler. An alternative 
 method is shown in the smaller sketch. Here the three flow 
 pipes are brought together and enter the side inlet of the boiler. 
 The size of the pipes should be proportioned so that the flow 
 
 Fig. 42. Boiler Heated from Two Water Backs. 
 
 i 
 
 ^ 
 
 QF \ 
 
 \ 
 
 It 
 
 a 
 
 OF ^1 
 
 
 Fig. 43. Another Method of Making the Connection. 
 
 from one heater will not retard that from the other. This would 
 lead to overheating and snapping sounds would be evident. 
 
 As in the ease of the connections of two stoves on the same 
 level to one boiler it is better to use two boilers than to attempt 
 to cut out one of the three water fronts at such times as it 
 might be desired to discontinue its use. The provision of valves 
 on the connections may lead to accident through neglect and 
 always obstructs the circulation to some extent. If the extra 
 boilers are set in a summer kitchen the supply pipes may be 
 run in a position to facilitate draining or protection from frost, 
 
 -f;: 
 
VARIATIONS IN CONNECTIONS. 
 
 59 
 
 and valves may be placed on the supply lines with less^ chance 
 of being overlooked. A special fitting may be used at the con- 
 nection to the top of the kitchen boiler should the circulation 
 
 I 
 
 r 
 
 Iff /y/y ////// ///V / ////^//y//y ,.,..,,,... ,,,,. .. ,, 
 
 Yy//y/A//y./y///yyyyyy.yyyyyyy ■ ■ '■'■■■'''■''■ ■ - '' ■ - -- .'. ^ ...',..'. .'^. ^ .'. y. 
 
 Fig. 44. Connecting Boiler from Three Water Backs. 
 
 i 
 
 be brought to there from the farthest away water front. This 
 is designed in such a manner as to admit the hot water to the 
 upper part of the boiler while preventing it from being drawn 
 away without entering the boiler when a faucet is opened on 
 the supply line. There is some chance of short circuiting the 
 boiler and of drawing cold water directly through the water 
 front and circulating pipe in some cases and this connection is 
 designed to avoid such being possible. 
 
CHAPTER VI. 
 
 Multiple Connections with Tank and Pressure Supply. 
 
 In any system of hot-water supply using one boiler and 
 two heaters a more positive and reliable circulation will be ob- 
 tained if one of the heaters is on the floor below the boiler, as 
 it is easier to install the piping so that the circulation from each 
 water front is assisted rather than retarded by the other. Fig. 
 45 shows such a system. The circulation through the two water 
 fronts is continuous and either of the stoves or both may be 
 used at one time without in any way changing the circulating 
 path of the hot water. The piping is neat and is easily installed, 
 and this is probably the most suitable method of making the 
 connections for ordinary requirements. A technical objection 
 may be offered to passing water through a front that may be 
 cold but the cooling effect may be ignored as it is hardly appre- 
 ciable. 
 
 Where a different style of connection is desired that shown 
 in Fig. 46 will be found satisfactory. The circulation from each 
 heater is separate and distinct and will not interfere with each 
 other. It will be noticed that the upper stove is connected 
 through the top tapping of the boiler, so that the circulation 
 in each case will have about the same speed. Many fitters prefer 
 this even though it entails more work and material than the style 
 shown in Fig. 45. 
 
 Still another method may be adopted. The return pipes are 
 fitted in the same manner as in Fig. 46, but the flow pipes are 
 connected and enter the boiler through the side tapping, as shown 
 in the small sketch in Fig. 44. When this is done the pipe 
 should be enlarged at the junction and connected with the boiler 
 at the largest size the tapping will take. If this is done the 
 retardation of the circulation from either one of the stoves by 
 the other will not be so likely to take place. There are many 
 cases where it is absolutely necessary to use the side tapping 
 in this manner and this care to enlarge the pipe will make all 
 the difference between a satisfactory job and a failure. 
 
 60 
 
MULTIPLE CONNECTIONS. 61 
 
 When the boiler is on the lowest floor, one of the heaters 
 being on the same level and one of them on the floor above, the 
 circumstances are somewhat different. We have already shown 
 the correct method of connecting up a boiler from a water front 
 above it and all that is necessary to add another heater is to 
 use the side tapping for the connection from the lower one. 
 Fig. 47 shows how this is usually done. Entire satisfaction will 
 result, at least the job could not be bettered, when the supply 
 to the fixtures is taken direct from the flow pipe at the top of 
 the boiler. But when the supplies to the fixtures are taken from 
 a secondary circulating system, and the flow to this secondary 
 loop is taken from this point, there is a liability to failure. At 
 this point marked A in Fig. 47, there is a conflict of currents. 
 The flow of water from the upper water front is passing down- 
 wards to the boiler with more or less velocity, while the heated 
 water in the boiler is being forced upwards to balance the cold 
 water in the return leg of the secondary circulation loop. Thus 
 one of the circulations is retarded and it is generally that from 
 the upper water front. The water becomes overheated and 
 steam is formed with the consequent pounding and hammering 
 noises in the boiler and water heaters. 
 
 If the supply is from an overhead tank and an expansion 
 pipe is carried from the top of the loop above the upper stove, 
 the noises will not be in evidence, but the water front will not 
 be doing satisfactory work. By using the method shown in Fig. 
 48 these troubles may be avoided, as there is very little resist- 
 ance to the circulation from either primary or secondary sources. 
 That from the upper heater has free and unrestricted access to 
 the boiler, that from the lower heater equal facility, and the 
 secondary flow leaves the boiler at the point where the hottest 
 water is stored. Should the supply to the boiler be from the 
 city mains proper provision must be made to guard against 
 siphonage by using a vacuum valve. 
 
 The correct position for these has already been shown, and 
 we need only repeat the caution to carry the cold supply to a 
 point above the upper water front level before taking off the cold 
 supply to the boiler branch. Thus the chance of emptying the 
 water front unknowingly is guarded against and danger of ex- 
 plosion or burning of the water front practically eliminated. 
 
62 
 
 HOT WATER SUPPLY. 
 
 Connecting Horizontal Boiler with Heaters on 
 Different Floors. 
 
 Where it is desired to set the boiler in a basement and heat 
 it from the kitchen range on the floor above as well as from 
 a tank heater in the basement the connections may be made as 
 
 
 Fig. 45. Continuous Flow Connec- 
 tion from Two Heaters. 
 
 Fig. 46. Separate Connections from 
 Each Heater. 
 
 shown in Fig. 49. These allow each heater to be used inde- 
 pendently of the other or both at the same time without con- 
 flicting currents to retard the circulation. 
 
 The supply to the fixtures is taken from the tank by a special 
 tapping, this being done so that the pipe may be carried to a 
 
 r 
 
MULTIPLE CONNECTIONS. 
 
 63 
 
 height sufficient to prevent any chance of the water in the upper 
 water front being drawn down below the level of the fire box 
 should the water supply fail and there be any fixtures at a lower 
 level than the water front. If the supply to basement fixtures 
 were taken from the boiler without rising above the next floor 
 level this might lead to serious trouble should the water be 
 
 Expansion fa 
 Affio Tank 
 
 I'//////////,'/////// '//'/'/'/'/'////'///'''////'//// 'o "/"///' V///' '/'''"/" ' "'"/',"//' '// '//////''/■''',"j 
 
 Fig. 47. Method Which Interferes with 
 Circulation to Fixtures. 
 
 Fig. 48. Method Which Allows Free 
 Circulation to Fixtures. 
 
 turned into the system again while the water front was red hot. 
 If desired, the flow connection from the tank heater may enter 
 the return connection of the water front on the floor above 
 instead of making a separate circulation to the boiler. This 
 simplifies the connections to some extent and gives the circula- 
 
64 
 
 HOT WATER SUPPLY. 
 
 aSc 
 
 J? 
 
 ^ 
 
 ^ nrm 
 
 < Qt 
 
 1^ 
 
 t-Hoffo 
 Fixtures 
 
 
 tion a continuous path 
 but it also increases 
 the travel of the wa- 
 ter to the boiler with 
 attendant loss of heat 
 so that very little is 
 gained. If a direct 
 pressure supply con- 
 nection to the boiler is 
 made a connection to 
 a fixture on one of the 
 upper floors should be 
 made to the highest 
 point of the loop to 
 remove any air col- 
 lecting there. In that 
 case also if thorough 
 protection against si- 
 phonage of the boile^ 
 and lowering of the 
 water line too far is 
 desired the supply 
 should be carried up 
 to a hisfh point as de- 
 scribed in Fig. 30, 
 
 Connecting Two Boil- 
 ers with Two Heaters. 
 
 There is always 
 more or less trouble in 
 store for the plumber 
 who installs a series 
 of range boilers with 
 individual heaters 
 when they feed into a 
 common supply line. 
 If any one of the heat- 
 \////////////////////////////////////////^^^^^^ ers IS tor tne time 
 
 being out of use there 
 
 Fig. 49. Horizontal Boiler Connected witli . , « 
 
 Heaters on Two Floors. IS every chance of 
 
 10 
 
 M 
 
 aOc^ 
 
MULTIPLE CONNECTIONS. 
 
 65 
 
 cold water being drawn from the boiler connected with it, 
 along with the hot water from the others, and instead of hot 
 water probably only a tepid supply is available. The equaliza- 
 tion of pressure throughout the system immediately a faucet is 
 opened causes this flow, 
 and the only way to posi- 
 tively prevent it is to 
 place valves on the lines 
 to cut out the cold boiler. 
 Needless to say, this is 
 not to be recommended, 
 as there is always a lia- 
 bility of their use being 
 forgotten or misunder- 
 stood. 
 
 When the boilers are 
 on different floors, as in 
 Fig. 50, and the upper 
 boiler the one generally 
 heated, the mixing of the 
 cold and hot water is not 
 so noticeable, especially 
 if a Y connection is made 
 at A, as there is then less 
 friction to overcome in 
 the short connection 
 from the vertical pipe in 
 drawing water from this 
 boiler than from the low- 
 er one. When the condi- 
 tions are reversed and ,____ 
 
 the lower boiler alone is m^^y^^:^^;^^^^^:'^^ 
 
 heated, the chance of Fig. so. connections for Two Boilers and 
 
 mixing is much increased ^^^ Heaters, 
 
 and it will be next to impossible to draw water at the faucets 
 at a temperature anywhere near that of the water in the boiler. 
 To make a more satisfactory job the method shown in Fig. 51 
 is recommended. This is absolutely reliable when both boilers 
 are in use, as the circulation between them brings the tempera- 
 ture of both to a practically uniform point throughout. 
 
66 
 
 HOT WATER SUPPLY. 
 
 When the upper water front is cold more work is put upon 
 the lower boiler, and unless the connection shown by dotted lines 
 is also made the upper half of the upper boiler must also be 
 heated before hot water can be drawn, and the circulation be- 
 tween the boilers 
 is at the same time 
 keeping the entire 
 contents of the two 
 at nearly uni- 
 form temperature. 
 When the upper 
 water front alone 
 is hea/ted this cir- 
 culation is not so 
 rapid, as the total 
 contents of the 
 upper boiler must 
 be hot before any 
 effect is shown on 
 the lower one. 
 
 The cold supply 
 may be omitted 
 from the upper 
 boiler or the valve 
 kept closed if de- 
 sired to insure the 
 whole contents 
 being available at 
 the faucets. This 
 style of range con- 
 ^ , nection is more 
 
 '//// /////y// //////////////// ^ '/ /^/ /////'/ ^ /'//'//////''// // '////' /I -.■. T 
 
 '// yyyyyy yyy ,'y y y y yy^^* yy y yyyy y y y f // f y / / / y J y y y/y y y y y y y y y Jy yyy* t/^ *yy^ ^ i^iiv^i ct-xi.^ \a. yj -^ \^ 
 
 Fig. 51. 
 
 Continuous Flow Through Two Boilers and 
 Two Heaters. 
 
 than that shown in 
 «the next illustra- 
 tion, Fig. 52, and certainly has much to recommend it on the score 
 of simplicity as well as efficiency. About the only weak point in 
 the system is the passing of the flow from the lower boiler 
 through the upper water front, as it is thus cooled off to some 
 extent. When the connection is made as in Fig. 52 this is over- 
 come, as the flow from the lower boiler enters the upper 
 
MULTIPLE CONNECTIONS. 
 
 67 
 
 combination with the flow from 
 It can be continued to the top 
 connection if preferred, or the 
 can enter the boiler in this way, 
 
 boiler through the side inlet in 
 the water front in the stove, 
 tapping as in a quick heating 
 flow from the upper water front 
 thus making the 
 two circulations 
 distinct. When 
 they both enter 
 through the side 
 opening the piping 
 must be enlarged 
 at the junction to 
 the largest size 
 possible with the 
 tapping provided. 
 This lessens the 
 chances of retard- 
 ing the flow from 
 either of the heat- 
 ers by that from 
 the other, a condi- 
 tion which makes 
 for overheating, 
 rattling and 
 pounding. 
 
 As in the previ- 
 ous example, the 
 use of a cold sup- 
 ply pipe in the 
 upper boiler is op- 
 tional, as when the ^^ . , ,, _^ 
 
 supply comes from ^'//'y''^y/y////////////////////'V/////^^^^^^^ 
 
 ri£ 
 
 Connection to Allow Use of One 
 Only if Desired. 
 
 stove 
 
 the lower one 
 alone every drop 
 of hot water can be displaced before cold is drawn. Objection 
 to this method of supply is sometimes made on the score that 
 the cold water shoots clear to the top of the boiler and cools it 
 off, but this is only the case under heavy pressures and ought 
 only to be considered when such obtain. Even then the effect 
 of the flow may be over-estimated. 
 
t)« 
 
 HOT WATER SUPPLY. 
 
 Joint Hot Water Supply for Two Flats. 
 
 The two methods of connecting boilers on different floors 
 with ranges on the same floor as the boilers, but which admit 
 of heating the entire system with either as may be convenient, 
 are shown in Figs. 53 and 54. 
 
 J^ 
 
 ■//////// 
 
 /'//////"///// f///"/////// ///'/'M "///'/// /''///'!l 
 '/^'f//'// 'f// '/''/''^^ """ ""'"^' "'""'' "/'"''A 
 
 Fig. 53. Joint Hot Water Supply for Two Flats. 
 
 In Fig. 53 is shown a 30-gal. boiler, connected up so that 
 all the hot water from the lower boiler will pass through it 
 before it is drawn at the fixtures. This has certain advantages 
 and also disadvantages. If the upper range is being run alone, 
 hot water will be readily drawn at any fixture without cooling 
 
MULTIPLE CONNECTIONS. 
 
 69 
 
 by mixing with the cold water from the lower boiler. If both 
 boilers are being run, all the hot water in both can be drawn if 
 desired, and the circulation is free and continuous through the 
 whole system. No valves are necessary on the hot supply pipes. 
 The valve on the cold supply to upper boiler may be kept open 
 
 
 Fig. 54. Two Boilers and Heaters Connected to a 
 Common Supply Line. 
 
 or closed, as desired, as the pressure from the tank is low and a 
 supply entering the upper boiler through the return would not 
 have velocity enough to cool the water in the upper part of 
 boiler. 
 
 "When the upper range is out of use, one disadvantage is 
 apparent : The lower range has to heat the water in the lower 
 
70 
 
 HOT WATER SUPPLY. 
 
 boiler and also that in the upper portion of the other before hot 
 water can be drawn at the fixtures. To get over this, fit a quick- 
 heating connection to the upper boiler, as shown by dotted lines. 
 This stores the water in the upper portion first, and hot water 
 
 is thus more quickly 
 M =* available at the fixtures. 
 
 The tank must be 
 high enough to take 
 care of the expansion, or 
 a continuous stream of 
 hot water will pass into 
 it from the expansion 
 pipe; and, also, there 
 will be a liability of 
 drawing air through 
 this pipe when a faucet 
 is opened, with attend- 
 ant gurgling and un- 
 steady flow. 
 
 Fig. 54 shows a 
 common method of con- 
 necting two boilers to a 
 common supply pipe. 
 The principal objection 
 to this system is the 
 liability of mixing cold 
 water from a boiler 
 which may not be m 
 use with the hot from 
 the other when drawing 
 from any of the faucets. 
 Valves may be fitted on 
 
 Fig. 55. An Unusual Method of Connecting the Supply pipes, but 
 Two Boilers and Heaters. ^^^ practice is objec- 
 
 tionable and the system shown in Fig. 53, although a little 
 more elaborate, is much to be preferred. 
 
 Unusual Double Boiler Connection. 
 Local conditions often call for the use of special methods of 
 making connections from two boilers and heaters to the hot- 
 
 f '/////y// //////////// /////////V/Z/y///////////// /////////, 'A 
 
MULTIPLE CONNECTIONS. 
 
 71 
 
 water supply lines. The two styles previously described can be 
 used successfully in most cases, but occasionally conditions are 
 such that a simpler method may be adopted and a considerable 
 saving in time and material effected without in any way impair- 
 
 Fig. 56. 
 
 TTTTrrr 
 
 Hot 
 
 1Z£ 
 
 Cold 
 
 J"! 
 
 
 
 ' 1 
 
 r^i° % 
 
 
 Common Method of Connecting Two Boilers on Same Level to Common 
 Supply Line. 
 
 ing the efficiency. Such a method is shown in Fig. 55. The only 
 example of this connection that the writer recollects was put in 
 by a hotel man to avoid changing the existing piping to suit one of 
 the more regular methods of installing the auxiliary boiler and 
 heater in the basement. In his case the upper fire is continu- 
 ously used and therefore the function performed by the lower 
 heater is simply preheating, and that of the lower boiler storage 
 of the pre-heated water until the opening of a faucet allows it 
 to pass into the upper boiler. 
 
 In some eases overheating of this upper boiler would certain- 
 ly take place and each time the opening of a faucet relieved the 
 pressure considerable noise would be made by the steam, but 
 where so much water is required and the drawings are so fre- 
 quent, as in this instance, this trouble does not arise. No doubt 
 this job would be a poor one where the upper fire is not in con- 
 tinuous use, as then absolutely no hot water could be drawn. 
 The connection should, therefore, never be made without careful 
 consideration and assurance that the right conditions prevail. 
 
 Suggestions on Double Boiler Connections. 
 In Fig. 56 is shown another example of the common style of 
 connecting two boilers to a common line of supply piping, but 
 
72 
 
 HOT WATER SUPPLY. 
 
 both boilers are on the same floor in this case. Here also one 
 may expect trouble ; in fact, the drawing shows an actual instal- 
 lation that was found unsatisfactory and remodeled. The 
 
 IZL 
 
 =0= 
 
 nt= 
 
 'W. 
 
 T|> A 
 
 a 
 
 Ql 
 
 3 
 
 r 
 
 M 
 
 1 ° 
 
 1 ' 
 
 a 
 
 
 t^l" a 
 
 'y///,y/yW/yy/y<'//yW////y^/y//,?y///////^^^^^ 
 
 Fig. 57. Method of Balancing Flow from Two Boilers. 
 
 trouble here lies in the liability to draw almost exclusively from 
 the nearer boiler, whether it be hot or cold. The only way in 
 which the hot water in the other boiler can be drawn is to close 
 the control valves on the cold one and this is an undesirable and 
 troublesome condition to impose on the user. A little better 
 service is gained by taking the outlets from the boilers to a point 
 
 =1^ 
 
 a^ 
 
 Tzr 
 
 ^ 
 
 :Gfi 
 
 M 
 
 -fTri 5> 
 
 Fig. 58. Connections for Circulation Between Two Boilers on Same Level. 
 
 midway between them, as shown in Fig. 57, and then connecting 
 into the main hot water line. This equalizes the friction so that 
 an equal amount of water is taken from each boiler. So long as 
 
MULTIPLE CONNECTIONS. 73 
 
 the water in each is near the same temperature the flow at the 
 faucets will be satisfactory and near the same point as obtains 
 in the boilers, but should one of them happen to be much cooler 
 than the other a considerable reduction must be expected. These 
 €onsiderations must have the attention of users, and if a steady 
 supply of hot water is demanded attention must be given to 
 flring the heaters equally. 
 
 Fig. 58 shows the same connection with a circulating pipe 
 which maintains a comparatively equal temperature of water in 
 the two boilers whether one or both heaters are in operation. 
 
CHAPTER VII. 
 
 Supply Connections and Distribution. 
 
 The most common system of distribution to the different 
 fixtures in small residences, flats and tenements is to carry one 
 main supply pipe from the boiler and from that take branches 
 at convenient locations for the different fixtures. This system 
 has objectionable features when the work is such that long runs 
 of pipe are required or such that branch connections are difficult 
 to make in a location that will allow of a stop cock for each 
 branch being fitted. In the first case a considerable quantity of 
 cold water has to be drawn each time a faucet is opened before 
 hot water is available. This is wasteful both of water and heat 
 as all the water that is drawn from the boiler and which stands 
 in the pipe from the faucet to the boiler is cooled each time the 
 faucet is closed again and must perforce be wasted by the next 
 user. In the second case it may be inconvenient to turn the 
 water off the whole system because of some fault on one line, 
 yet no provision can be made to avoid this owing to the manner 
 in which the pipes have been carried. 
 
 Again, if the pipes are turned down into the basement as 
 shown in Fig. 59, and which is a very common method of pipe 
 fitting, there is opportunity of air collecting in the loop and 
 retarding if not altogether stopping the supply to the fixtures. 
 This is more likely to occur when a low head of water is carried 
 in the system, as a high pressure will force any air collected in 
 the loop to the faucets each time they are opened. To avoid 
 this annoyance the pipe may be run as shown in Fig. 60, drop- 
 ping the branches to cellar fixtures and to those on the same 
 floor as the boiler while the others are taken from the top side 
 of the main pipe, thus providing opportunity for air to escape 
 freely. Stop cocks should be fitted on each branch and if these 
 are of the stop and waste pattern, allowing the water left in the 
 pipe to drain back when the stopcock is closed drip pipes may 
 be fitted as shown in Fig. 61, thus avoiding any leakage of water 
 on the floors or walls while the pipe is being emptied. 
 
 74 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 75 
 
 Supply from Water Tables. 
 
 Another plan often followed is one which requires consid- 
 erably more pipe and more labor but the results justify the 
 extra expense as a rule. This is the system where the hot and 
 cold supply mains are taken to a water table and the branches 
 taken from a distributing header. This makes an extremely 
 neat job which also has the recommendation of bringing all the 
 control valves to one point where they can be conveniently la- 
 
 Fig. 59. Common Method of Running Hot Water Pipes Which Tends to 
 Give Intermittent Supply Through Air Locking. 
 
 belled and the drips from the waste outlets collected into a pipe 
 carried to some convenient sink or to a floor drain. 
 
 The method of constructing the header is simple. It of 
 course may be built in two separate parts as shown in Fig. 62, 
 but better appearance is secured and also more compactness if 
 it is built as shown in Fig. 63. All the difference is that instead 
 of plugging the end tee the two end tees of each header are 
 connected by a solid nipple. This nipple is easily made if the 
 supply house cannot furnish them. Take a brass nipple of the 
 same length as those fitted between the rest of the tees and file 
 down inside it as far as can be reached until a perfectly clean 
 surface is secured. Then tin it, using cut acid and heating the 
 
76 
 
 HOT WATER SUPPLY. 
 
 nipple over the fire pot so that the solder will run well. If the 
 nipple is heated well it will only be necessary to rub the solder 
 on it, with an application several times of the acid brush. When 
 the inside is thoroughly tinned pack some paper in it, leaving 
 about % in. at each end. Then fill this space with solder, heat- 
 ing the nipple with a torch or over the fire pot to make the solder 
 iflow freely. The stopcocks should be fitted at the same height 
 on the vertical branch to preserve a symmetrical appearance 
 and each nipple should be of the same length. The main pipes 
 
 Fig. 60. Method of Running Hot Water Pipes to Fixtures to 
 Avoid Air Locking. 
 
 entering at the end should have a plug or petcock fitted in a tee 
 to admit of draining the line. All horizontal pipes run in a cel- 
 lar should be run on as equal a grade as possible to secure good 
 appearance and should either drain toward the header or to 
 some plug in the end of a tee. Adjustable hangers make the 
 fitting of these pipes much easier, as the pitch can be adjusted 
 to suit any condition. 
 
 Circulation o£ Hot Water to Fixtures. 
 
 When the plumbing fixtures to which hot water is supplied 
 are at any considerable distance from the range boiler, the ne- 
 cessity of drawing a large quantity of cold water before any 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 77 
 
 hot water is available becomes somewhat objectionable. This 
 consequence is avoidable and the waste of water is unnecessary, 
 as in nearly every case the hot water may be made available 
 almost immediately at each faucet by a proper system of circu- 
 lation between the boiler and the fixtures. This is generally 
 described as a ** secondary" circulation, distinguishing it from 
 that established between the boiler and heater, and is arranged 
 in a manner that will not affect the primary circulation. 
 
 There should be little in any ordinary building to prevent 
 
 Safety Vacuum l/afve. 
 
 Fig. 61. Drip Connections to Waste Outlets of Stopcocks. 
 
 a system such as this being installed in a manner likely to give 
 satisfaction. Structural conditions may, however, be such that 
 it is hard to follow any definite plan, and the fitter who has a 
 thorough grasp of the principles underlying his profession will 
 be the one who will be successful in such a case, as he will be 
 able to adapt his design to the building by taking advantage of 
 more than one method of securing circulation. For instance, it 
 is often very difficult to secure sufficient pitch between the floor 
 and ceiling to make a circulating loop work well, or objection 
 may be made to placing long runs of piping in such positions. 
 In such a case a combination of loops with a falling circulation 
 may be satisfactorily installed. There are many other combina- 
 
78 
 
 HOT WATER SUPPLY. 
 
 tions, some of whicli will be illustrated, and all of whieli ought to 
 be within the knowledge of the plumber who undertakes hot- 
 water supply on any other than the simplest scale. 
 
 An important consideration in this work is the provision of 
 Bufficient pitch to the pipes at all points and avoidance of air 
 pockets. Provision must always be made, by having a fixture 
 connection or other means of relief at the highest point in the 
 
 Pig. 62. A Hot and Cold Water Supply Header. 
 
 Fig. 63. A Header with Solid Connection Between Hot and Cold Ends. 
 
 circulating system, to allow air to escape. Fig. 64 shows a cir- 
 culating system in its simplest form. Here the supply pipe 
 simply forms a continuous loop which travels around the fix- 
 tures, branches being taken off at the points nearest to the 
 fixture. The pipe pitches upward from the boiler to the last 
 tee before it drops back to act as a return pipe. Thus any air 
 collecting in the pipe will be relieved each time this faucet is 
 opeiied. Should a very long run be necessary to reach the last 
 tee, the high point may be made at any of the other tees, the 
 point to be remembered being that the pitch to this point must 
 be continuously up and then continuously down, so as to avoid 
 pockets that would impede circulation. 
 
 In Fig. 65 we have a somewhat different arrangement of 
 piping supplying the same fixtures; each bath room having an 
 independent branch circulation. At the point marked A in this 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 7^ 
 
 illustration the better method of making the return connection 
 is shown. This is better than that shown at B, where the space 
 available is limited, as there is then no risk of having the circu- 
 lation stopped by sagging pipes forming air pockets. The loop 
 system may not oifer any 
 particular advantage over 
 the one first described, but 
 it may be that conditions 
 are such that it is the only 
 one that can be satisfac- 
 torily adopted, and in a job 
 of considerable size is gen- 
 erally to be preferred for 
 the reason that the circu- 
 lating path will probably 
 be shorter and the supply 
 consequently hotter. 
 
 In the system shown 
 in Fig. 65 there is some- 
 times a danger of drawing 
 cold water through the re- 
 turn at the last fixture on 
 the loop, as the friction on 
 the long length of pipe that 
 the water has to traverse is flliHliSSlilliSSRl^S?^^ 
 considerable, and the last Fig. 64. A Simple Circulating System for 
 fixture beingnearer ^° ^^^' 
 
 to the boiler on the return line than on the flow, the cold water 
 is somewhat liable to back up when the faucet is opened. To 
 remedy this a check valve is often fitted, but this acts somewhat 
 as an impediment to free circulation, and it is a better plan to 
 take the branch to this fixture from the flow pipe after it leaves 
 the boiler, making a separate loop for this alone, according to 
 the method shown in Fig. 66. 
 
 Swing check valves are the better pattern to use when it is 
 necessary to have them, but no matter how light they are they 
 are liable to become set either closed or open and so defeat the 
 purpose for which they were fitted. By setting a swing check 
 in an inclined position there is no interference with circulation 
 however sluggish, yet the check will close under a reverse flow. 
 
80 
 
 HOT WATER SUPPLY. 
 
 A Novel Hot and Cold Water Supply in Combination. 
 
 The arrangement of piping shown in Fig. 67 is rather more 
 of a novelty than an example of standard practice, but it em- 
 bodies some ideas which are easily applied and the connections 
 are simple and easily adapted to various conditions. 
 
 The equipment as shown in Fig. 67 consists of a 20 gal. 
 
 extra heavy galvan- 
 ized boiler, hung from 
 the cellar ceiling, con- 
 nected to a 6-in. water 
 heater in a steam- 
 heating boiler. The 
 hot-water pipe, % in., 
 runs to the basin sink, 
 with a stop under 
 the basin and a %-in. 
 circulating pipe is 
 taken out below the 
 stop and runs back to 
 the lower connection 
 between the boiler 
 and heater. The water 
 pipe runs to the ice 
 chest in i/2-in. lead 
 pipe, which is coiled 
 closely, covering the 
 entire bottom and then 
 rising and running to 
 the basin and sink, 
 with a stop near the 
 point of connection to the hot-water pipe. Over the pipe coil 
 in the bottom of the box there is a bottom of wooden slats, on 
 which the ice rests. The waste pipe from the ice box extends 
 through the bottom of the box with a little extension piece, so 
 that the pipe coil rests in and is surrounded by the melted ice 
 water. The drip empties into a closet tank on the lower floor. 
 An entire cake of ice is placed in this box and covered with 
 blankets. This usually lasts about a week or eight days, except- 
 ing in extremely hot weather. The water at the faucet is al- 
 
 
 Fig. 65. A Circulating System with Branclies 
 Planned to Avoid Air Locking or Sagging 
 Under Floors. 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 81 
 
 ways cold and refreshing. In the summer the hot-water stop 
 is closed and the ice-water stop opened, while during the sea- 
 son when the steam boiler is running the ice-water stop is closed 
 and the hot-water stop opened, thus providing a supply of ice 
 water in summer and hot water in winter with one system of 
 piping. The ice chest is 3x2x2 ft. 
 
 Features of Circula- 
 tion in a Cottage. 
 
 The example 
 shown in Fig. 68 con- 
 tains the problem of 
 heating a boiler with 
 a door intervening 
 between it and the 
 range and that of 
 making a circulation 
 to the heater in the 
 cellar while providing 
 a supply of hot water 
 at the fixtures imme- 
 diately on the open- 
 ing of a faucet. 
 
 To supply hot wa- 
 ter to fixtures below 
 the level of the boiler 
 or on the same floor as X^A^^^i:^^;^^'/:^;^^^ 
 
 Fig. 66. 
 
 Method of Supplying a Fixture Near 
 the Boiler, 
 
 the boiler so that the 
 hot water can be 
 drawn as soon as the faucet is opened it is necessary to form a 
 loop by running the pipe up from the boiler as far as possible 
 before descending to supply the fixtures. In this case the hot 
 water supply pipe to the fixtures should be run as shown in the 
 accompanying drawing. If it is not convenient to take the sup- 
 ply pipe across the ceiling it can be run as shown by dotted 
 lines. If this method is used the pipe should be carried even 
 higher before descending. The necessity of having an air valve 
 at the top of the loop is dependent upon the amount of pressure 
 carried in the pressure tank. If the system is run under low 
 pressure the air valve should be used so that it can be opened 
 
82 
 
 HOT WATER SUPPLY. 
 
 to let air escape when tlie pipe becomes air bound sufficiently to 
 stop the flow or circulation. 
 
 Tn Fig. 69 is shown a system for utilizing separate range 
 boilers in an apartment building. In addition to five floors of 
 
 Fig, 67. A Novel Piping System for Hot Water and Ice Water. 
 
 the building above ground, the range boiler in the janitor's 
 apartments in the basement where the heater is located, is also 
 supplied with hot water. A small round boiler having a 15-inch 
 grate, and rated to carry 200 square feet of direct radiation and 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 83 
 
 having a capacity for heating 100 gallons of water per hour 
 from 40 to 212 degrees, is connected with the six boilers, as 
 shown, each one of which has a capacity of 30 gallons. A 2- 
 inch flow main is carried up from the little heater and 1-inch 
 branches are taken to the side connections on all the boilers on 
 the upper floors. A tee is used at the side connection to receive 
 
 Pig. 68. A System Which Shows a Combination of Hard Conditions. 
 
 the branch from the basement heater and the pipe from the water 
 back in the range. As this main continues upward it is reduced 
 in size so as to insure each of the boilers receiving its necessary 
 supply of water. The return connections from the different 
 boilers run to a return main, which increases in size as it receives 
 the different connections and is carried to the boiler. The 
 boiler in the basement is heated by means of a 1-inch branch, 
 which is connected to the top of the boiler at the hot water ser- 
 vice outlet, and the return from this boiler is carried to a sepa- 
 rate opening in the base of the water heater. 
 
64 
 
 HOT WATER SUPPLY. 
 
 Fig. 69. System of Hot Water 
 
 Supply to an Apartment 
 
 Building Using Separate 
 
 Boilers. 
 
 This method of connecting 
 allows each tenant to use a coal fire 
 when an extra supply of hot water 
 is required for laundry or other 
 purposes. Each boiler is treated as 
 a radiator and piped accordingly. 
 It will be noted that the six boilers 
 have a capacity for holding 180 
 gallons of hot water, while the 
 heater is only rated to furnish 
 about one-half of this quantity. 
 This seeming lack of power is offset 
 by the storage capacity of the dif- 
 ferent boilers, and the allowance is 
 made for the fact that all of the hot 
 water in a boiler is seldom drawn 
 from it at one time. 
 
 Piping Systems in Large 
 Residences. 
 
 The system of hot-water sup- 
 ply circulation that is most suitable 
 for tall buildings of the office type, 
 or apartment buildings supplied 
 from a common heater, is that 
 known as the overhead or falling 
 circulation. This system is also 
 eminently suitable for buildings of 
 less pretensions, especially if there 
 is an attic in which the various 
 branch lines radiating from the 
 main risers can be carried to a point 
 directly over the fixtures they are 
 to supply. "When this is so it is 
 possible to install the piping in a 
 manner which calls for a minimum 
 risk of damage from leakages, as it 
 is necessary to put only a very little 
 of it under the floors of bath rooms 
 or toilet rooms. Where these are situ- 
 
SUPPLY CONNECTIONS AND DISTRIBUTION, 
 
 85 
 
 Expansion Rpe —• >^=^ 
 
 #==^ 
 
 ^ 
 
 Tank 
 
 ]i 
 
 Flow to 
 Fixtures 
 
 To Lavatory 
 
 To Bath 
 
 Kf 
 
 To Bath 
 
 Flow to 
 Fixtures 
 
 ToBath 
 
 
 To Si nk 1 
 
 ^ .. I I c 
 
 TbSrnk2 
 
 Return from 
 Fixtures 
 
 ^ 
 
 Strt 
 
 ,g-^ 
 
 Qw»: 
 
 tfV — »- 
 
 ^ 
 
 eturn from 
 Fixtures 
 
 
 T77T7T77T7r77V777rr777r7r77y77r777 
 
 /i /////>/// ///////tO'/''''/''''''''/''''''/''*''''''- 
 
 V///PPP7^v/7/7\ 
 
 J 
 
 Fig. 70. Drop Feed Circulating System for a Large Residence. 
 
S6 HOT WATER SUPPLY. 
 
 ated oyer rooms where a leakage might cause havoc with fur- 
 nishings this point is of importance, and also where the floors 
 of such bath rooms are of tile it is desirable to keep the piping 
 away for easy access. Fig. 70 shows an installation of this type 
 in a large residence, the boiler supply being from a copper lined 
 tank in the attic. As will readily be seen the difference between 
 this installation and one in a large apartment building is prin- 
 cipally that of proportion, as the principle is the same in each. 
 
 The supply to sink No. 1 is shown taken off the main riser. 
 This was done for convenience, the more general custom being 
 to carry this pipe to its highest point before any branch is taken 
 from it. There is nothing essentially wrong in making such a 
 connection, and it is certainly preferable to making one so near 
 the return connection of the boiler that there is a possibility of 
 reversing the flow when the faucet is opened and drawing cold 
 water back through the return pipe. Occasionally it is found 
 necessary to insert checks on the return connection to prevent 
 this happening, but this should never be done if the system will 
 work without them as they are always liable to become clogged 
 and remain permanently open or closed. If a fair velocity of 
 flow can be induced in the circulation system the chances of 
 drawing the reverse way are lessened, and again, where such a 
 liability is thought to exist, the connection can be made to the 
 drop line at a point above the level of fixture. The connection 
 for sink No. 2, for instance, might have been made through the 
 tee supplying the bath room immediately above it. 
 
 The horizontal piping in a system like this must be very 
 carefully pitched and the expansion pipe connected to the high- 
 est point so that air will not collect. It may be interesting to 
 the student of hot-water supply work to compare this installation 
 with one in a similar house in England. It will be seen that in 
 the English installation, Fig. 71, the range is of the built in type, 
 the circulation pipes being carried down behind rear plates to 
 the water back. The pipes pass through the wall immediately 
 above the mantel shelf to the boiler which is of a shorter and 
 wider build than those generally used in the United States. It 
 is placed on brackets of wrought iron and in a corner of the 
 kitchen above head level. As it is not large enough to serve the 
 house alone an auxiliary is placed in the attic and a circulation 
 is maintained between the two. A falling circulation is provided 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 87 
 
 Ejfpansion- 
 
 rnMimiirfiirmrffr; 
 
 ^ 
 
 i 
 
 a=t 
 
 
 *^ 
 
 ;•« 
 
 *-TankSuppff- 
 Cold Supply 
 
 BathRm 
 
 Lavatory 
 
 tkjth Room 
 
 ;at=a5=ft 
 
 Towel Rail 
 
 
 1 
 
 f 
 
 o 
 O 
 
 rzTri rrt utm / rz7J£x:tii7ti 
 
 &= 
 
 '^ 
 
 at 
 
 ^tA 
 
 — i n> -Q 1^ 
 
 Check Valve 
 
 7b Laundry 
 
 
 Water back 
 
 ^//^/y /^// / //'^^ / /f ////////// f //// ^ / y //'/////// ^ /////////// / //// //\v //'//////////' ^ // /y / f Y ^ ' ^' '^^^ ' ^^^^^/ Y^'A 
 
 Sediment 
 
 Fig. 71. Typical Hot Water Circulating System in an English Residence. 
 
88 HOT WATER SUPPLY. 
 
 to each bath room, short branches from the drop lines being all 
 that it is necessary to draw through before hot water is avail- 
 able at the fixtures. This of course commences above the upper 
 boiler, and is connected to the top of that. 
 
 A feature of the system is the towel rail, which is built from 
 1^4 131. brass pipe, nickel plated, and which is connected to the 
 circulating pipe through a valve. A safety valve is fitted just 
 above the range. This valve is generally of the dead weight pat- 
 tern with ground seats and in most cities its use is compulsory. 
 Hard copper is the material used for the supply and circulating 
 pipes, the water back also being of copper. For all high class 
 work this metal is recommended. The tank is a large wooden 
 one lined with sheet lead, walls of 6 lb. and bottom of 8 lb. The 
 overflow comes through the bottom. A ground spigot and socket 
 connection is wiped in the bottom so as to provide a convenient 
 means for flushing out the sediment collecting in the tank. 
 
 Circulating Loop on Same Floor as Boiler. 
 
 A circulating system which is constructed in a somewhat 
 different manner is shown in Fig. 72. In this case the main 
 circulating loop is carried along on the same floor as that on 
 which the boilers stand. This is often necessary by reason of 
 difficulties in the building construction which will not admit of 
 any other style being used. By taking a connection from the 
 highest part of the loop any air that may collect is removed 
 each time that fixture is used and there is less chance of draw- 
 ing cold water back through the return pipe with this form of 
 construction than if the return pipe were to be carried down 
 into the floor below the boilers and connected by returning to 
 them below the water line. It will be noticed that the boilers 
 in this system are heated by a water front in the kitchen range 
 and by a laundry heater and that valves are placed on the con- 
 nections to the latter. This is done so that the supply may come 
 entirely from the kitchen range except on such days as the 
 laundry is in operation when the additional call for water is such 
 that the extra power is necessary. If the valves were not closed 
 there would be little chance of drawing hot water at the laundry 
 fixtures or even at the bathroom nearest the boiler in the 
 laundry, as the flow will always proceed from the boiler offering 
 the least resistance and that on^ is nearer than the one in the 
 
SUPPLY CONNECTIONS AND DISTRIBUTION. 
 
 89 
 
 kitchen. Therefore the valves are closed and any mixing of hot 
 and cold water from the two boilers is eliminated. 
 
 To safeguard the boiler in the event of a fire being lighted 
 when the valves are closed a safety valve is fitted, a tee being 
 inserted in the outlet connection between the valve and the boiler. 
 The use of valves can occasionally be dispensed with if it is 
 possible to take the connections for the fixtures from a point in the 
 circulating loop that will be equi-distant from each boiler. Thus 
 
 To Bathroom 
 
 To Bathroom 
 
 3^ 
 
 ^ 
 
 To Bathroom 
 
 Hdt to F/xtures 
 
 =^ 
 
 ^ .■ i p t 
 
 '^ 
 
 ^ 
 
 QEZ3 
 
 Kitchen 
 
 "tink 
 
 ^ 
 
 *-Cold 
 
 Cold 10...A 
 Fixtures 
 
 
 ' y ////'//y/////V',V///'//// 'A /////yy///'/V/// '/////////////' 
 
 Fig. 72. A Loop Circulating System with, Two Boilers and Heaters. 
 
 the friction is equalized and the flow will come as easily from 
 one as the other. When this is done it will be found that the 
 flow will come from the heated boiler and that there will be al- 
 most none from the other. This is probably due to the difference 
 in density of the hot and cold water and the balance being in 
 favor of the heated boiler, the flow will proceed from there. 
 
 Circulating Water to Fixtures on Level Below Boiler. 
 
 When it is desired to supply fixtures on a lower level than 
 the boiler from a circulating system it will sometimes be neces- 
 sary to use a light swinging check valve on the return so as to 
 prevent the drawing of cold water back through the return pipe. 
 If the supply to the fixtures is large and a valve is placed in 
 the return pipe so that it can be set to pass only enough 
 water to maintain a circulation the chances of drawing cold water 
 at the fixtures by reversing the circulation will be somewhat 
 reduced. It is also possible by designing the piping properly 
 
90 
 
 HOT WATER SUPPLY. 
 
 to reduce the friction on the pipe between the branch and the 
 fixture so that it will be easier for the water to flow in the de- 
 sired direction than from the return connection to the boiler, and 
 this is a more desirable arrangement than the use of valves or 
 checks. Wherever possible the elimination of elbows and sharp 
 turns between the branch and the fixture will be an aid to en- 
 suring satisfactory flow. It must also be remembered that the sup- 
 ply must come from a great enough elevation to ensure motive 
 force enough in the descending column to overcome the differ- 
 ence in density at the return connection to the boiler. The 
 same principle that applies to the connection of water fronts on 
 the floor above boilers must be applied here. 
 
CHAPTEE VIII. 
 
 Hot Water Circulation in Large Buildings. 
 
 The hot water supply to apartment houses and other build- 
 ings requiring hot water in large quantities is somewhat of an 
 engineering proposition when the building may be twelve or 
 more stories in height. Up to this height, however, the depart- 
 ure from that followed in buildings of less proportions is not 
 great. When the house tank is placed on the roof and there are 
 fixtures on each floor and in the basement the flow at the differ- 
 ent levels is unequal owing to the great difference in pressure at 
 the different floors. This is corrected in some measure by the 
 provision of valves on the supply pipes to each fixture and the 
 excessive flow at the lower fixtures is thus checked and the 
 annoyance caused by spattering avoided. Where there is a pent 
 house and a sub-basement and the boiler and pumps are placed 
 at the lowest level the pressure carried there is somewhat high, 
 and in a building of twelve stories, not including the basements 
 and pent house, the pressure will approximate 90 lbs. at the 
 boiler. This pressure is not greater than is carried in many 
 city mains and is not a disadvantage otherwise than that it 
 causes a somewhat heavier pressure on the steam coil in the boiler 
 than the cast brass elbows used in the construction of coils will 
 stand unless these are made extra heavy. In some instances the 
 act of forcing the threaded brass pipes up to the end of the 
 thread with the idea that the joint is being made more secure 
 has caused the fittings to spread and the pressure of water being 
 heavier than that of the steam, water has entered the steam pipes 
 and led to trouble. To avoid this many engineers are using 
 wrought iron galvanized fittings with brass pipe, preferring to 
 take the chance of these corroding but making provision in their 
 construction for the easy replacement of coil headers, elbows, or 
 return bends. The system of circulation most commonly used 
 in such an installation as a twelve story apartment or office build- 
 ing is generally of the drop feed type. In this system the flow 
 pipe is carried clear to the top of the building and a vent pipe^ 
 
 91 
 
92 HOT WATER SUPPLY. 
 
 shown in Fig. 73, carried to a point over the house tank, is taken 
 from the highest point. From there the main return pipes are 
 taken and the different lines which are to supply the fixtures are 
 taken off at such points on these return pipes as may be con- 
 venient. The drop lines are carried down through the building, 
 sending off such branches as may be required and on reaching 
 the basement are connected into a main return line. At the foot 
 of the vertical line a control valve is usually fitted and in addi- 
 tion a check valve is placed behind this so that when faucets are 
 opened there will be no chance of reversing the circulation by 
 drawing water back through the return pipe. As there is con- 
 siderable expansion on the risers of a building of this height it 
 is usual to provide against damage resulting from it by putting 
 in the line a swing joint constructed of ells and short pieces of 
 pipe as shown in the illustration. When the pipe lengthens with 
 an insertion such as this all that happens is that the short piece 
 of pipe turns slightly in its fitting, allowing the lateral pieces to 
 rise and thus take up the movement without strain on the pipe 
 or fittings. The branch pipes to the fixtures may or may not 
 have control valves on them but it is good practice, and one usu- 
 ally followed to have valves on the exposed supply pipes to each 
 fixture. If the branch pipes have to run any distance laterally 
 it is well to make a return connection to the supply so that a 
 large quantity of cold water will not have to be drawn off each 
 time a faucet is opened. The method of doing this is indicated 
 in the illustration also. A valve may be placed on each leg of 
 the branch or a check valve only on the return connection, the 
 object being to prevent water flowing through it should it be 
 necessary to close the branch valve for any purpose. 
 
 Distribution From Rising Mains. 
 
 When a rising supply system is installed the piping is prac- 
 tically the same as that illustrated for the drop feed system. In 
 this case, however, the proportions are reversed and the sizes of 
 the pipes would be reduced as the higher elevations were reached 
 and the number of faucets to be supplied reduced. The con- 
 nections at the tank are made in the opposite manner also, as 
 may be seen by reference to Fig. 74. The branches are taken off 
 the main flow branch and after passing all of the connections 
 to the various apartments are collected into a common return 
 
CIRCtTLxYTION IN LARGE BUILDINGS. 
 
 93 
 
 ^l^^^^rai 
 
 Tank 
 
 Expansion az 
 Loop — oSc 
 
 =^ 
 
 ^Check Valve 
 
 Expansion i 
 Loop ^ 
 
 ^ 
 
 Check Valve 
 
 '4' 
 
 ^ 
 
 Check 
 Valve 
 
 LM 
 
 rSafefyValve 
 
 z=i^- 
 
 t~^ 
 
 
 ^ 
 
 ^Check Valve 
 
 afinc 
 
 -CheckValve 
 
 Cold Wafer 
 
 
 , , , ^ ,"','''',','/,',',","'"','/,' ^'/"^^"//'"'W'//"'','^' 
 
 Fig. 73. Drop Feed Circulating System in an Office Building or 
 
 Apartment House. 
 
94 HOT WATER SUPPLY. 
 
 and this enters the tank through a check valve as in the case of 
 the drop feed system and for the same reason. Expansion swing 
 joints must be made on each of the rising lines in the same man- 
 ner and it is well to provide for this also on the falling pipe. A 
 lateral connection to some distance from the vertical line should 
 have a circulation pipe also and if more convenient this may be 
 returned to the basement as an independent return as shown in 
 the illustration. The proportioning of the pipes in either system 
 should be done with care not only to equalize the flow of water, 
 but to equalize the circulation and so provide water of about the 
 same temperature at all points of the building. 
 
 Sectional System of Hot Water Distribution. 
 
 Another system of supply which can be used for buildings 
 of exceptional height or in places where it is desired to limit the 
 pressure carried in the lines is shown in Fig. 75. This may be 
 termed the sectional supply system, as the buildings are divided 
 into sections of as many stories as may be desired and each sys- 
 tem is in reality a separate one. To avoid the excessive pressure 
 entailed in supplying water from a height of twenty or thirty 
 stories, tanks are placed at different levels and the supply 
 can be pumped either periodically to these or it can 
 be automatically controlled. The illustration shows such cold 
 water supply tanks placed side by side with the hot water heat- 
 ing and storage tanks. In this case the tank for the cold supply 
 is supplying the hot water tank and cold water for all the floors 
 in its section on the stories below. The hot water tank is sup- 
 plying water to the floors above it up to the level of the next 
 section. The illustration shows two methods of circulation in 
 operation, one of them being the drop feed system already illus- 
 trated and the other being a rising supply system. In this the 
 branches for the fixtures are taken off the main in its upward 
 path, and the vent pipe is taken from the highest point and 
 returned over the top of the cold water supply tank. The return 
 pipe then returns directly to the hot water storage tank, enter- 
 ing through a check valve to prevent water being drawn back 
 by the flow at the fixtures. The pumps on the cold water supply 
 lines in such an installation may be automatically controlled so 
 that as soon as the water reaches the desired level in the tanks 
 the current is switched off. If cylindrical storage tanks are 
 
CIRCULATION IN LARGE BUILDINGS. 
 
 95 
 
 JL 
 
 
 
 
 
 Sixth Floor 
 
 L_ 
 
 
 
 
 JL 
 
 
 ' 
 
 
 
 " ' 
 
 
 *• ^ 
 
 «=< 
 
 t 
 
 i .'if 
 
 ^ 
 
 
 ' 
 
 -• „ 
 
 \ 
 
 
 Fifth Floor 
 
 3 
 
 ' 
 
 -• ^i 
 
 1 
 
 . *- 
 
 
 c ; 
 
 
 
 ))• 
 
 (C 
 
 
 ^1 
 
 \ 
 
 ^'' :: — ^ 
 
 „ 
 
 -< 
 
 
 
 
 =5^5?=- 
 
 
 ^ 1 
 
 
 
 
 4i 
 
 
 
 
 
 
 
 
 
 
 
 
 ' '//'/''''/'/^' ' '^ ' ^'//'''y/' ' 'Y//'//'/''/y/'////yp/77/P//////, ' y//^^^^^ 
 
 Fig. 74. A Circulating System for a Large Building Showing Branch Connections 
 from Rising Pipe and Return Connections from Fixtures. 
 
96 HOT WziTER SUPPLY. 
 
 used a vent pipe may be carried to a point above a fixture con- 
 nected with the waste pipe system or an overflow pipe may act 
 as a vent as well to ensure that no excessive pressure will be 
 carried on the system by the failure of the pump control. 
 
 Hot Water Supply to Shower Baths. 
 
 The proportioning of hot water heaters and supply pipes for 
 shower baths in gymnasiums, public baths and similar institu- 
 tions is a problem requiring more than ordinary care and atten- 
 tion to details. When the number and position of the showers 
 is known it is necessary to estimate the probable quantity of hot 
 water required to maintain a supply at the showers which will, 
 when mixed with the proper amount of cold water, give the 
 leather an ample supply at the desired temperature. The quan- 
 tity will vary according to the design of the shower used. Thus 
 with a 5 in. shower of the ordinary overhead type the amount 
 of water required to give a shower of sufficient strength is about 
 4 gal. per minute and as the diameter of the shower is increased 
 the quantity passed rises until it reaches 8 gal. per minute. 
 
 A heavier shower than this is not desirable, and this may 
 be taken as the maximum that will be used by the bather. With 
 the later type of needle, spray and shower baths, this quantity 
 is very much increased. On the other hand there is not much 
 need of estimating on a supply of water capable of maintaining 
 a flow at each of the various shower and spray attachments sim- 
 ultaneously, as they will seldom or never be used in this fashion. 
 
 To estimate the quantity of water required to mix with 
 the cold water to secure the ultimate temperature desired take 
 the temperature at which the water in the boiler will be main'- 
 tained and that at which the water is supplied from the main 
 pipes. Then multiply the number of pounds of cold water to be 
 raised in temperature by the difference between its temperature 
 and the desired final temperature of the mixture and th^n divide 
 that product by the difference between the final temperature of 
 the mixture and the temperature of the hot water. The quotient 
 will be the number of pounds of hot water that will be required 
 to mix with the cold water to produce the desired temperature. 
 
 As an example, suppose that we have 1 lb. of water at 60 
 deg. F. and we desire to bring it up to 85 deg. F. by adding a 
 •certain quantity of water at 160 deg. F. How much will be 
 
CIRCULATION IN LARGE BUILDINGS. 
 
 97 
 
 # 
 
 Expansion 
 
 Hot 
 
 ^ 
 
 -^t=M 
 
 *f 
 
 j9 
 
 ^ 
 
 Cold 
 
 ^ 
 
 # 
 
 1^ 
 
 OropFeed 
 Supply 
 
 " ^ ift ■ ■ . on nft- 
 
 f 
 
 # 
 
 ♦^1 rv, 
 
 v?:. ^, 
 
 Steam 
 
 aF 
 
 Expans/'o/^ 
 
 ct 
 
 ^ 
 
 CaW 
 
 ^ 
 
 J 
 
 <^ 
 
 Branches 
 
 on Flow 
 
 RiserSuppfy 
 
 % 
 
 Steam 
 
 -i 
 
 1^ 
 
 "2^f. -iiii zrrf r3)i ! 
 
 J 
 
 ^DropFeed ^ 
 
 o 
 
 O 
 
 Check ValvQ-' \ 
 
 Cold 
 
 % 
 
 I'ig. 75. Conventional Illustration of Sectional System of Hot Water Supply 
 
 to a Very High Building. 
 
98 
 
 HOT WATER SUPPLY. 
 
 required? Applying the rule, we have 85 — 60 = 25 and 
 25 X 1 = 25. We also have 160 — 85 = 75, and 25 -^ 75 = 1/3 
 lb. hot water required to heat the mixture to 85 deg. F. Or it 
 
 -.,.,■,. ^ . 1 (85—60) 
 
 may be stated like this: Quantity required = — ——r — — ^ — 
 
 160 — 85 
 25 
 This when further reduced becomes , which equals 1/3 of the 
 
 total quantity that is to be used. ''^ 
 
 
 ris bath 
 
 
 
 
 Fig. 76. An Installation of Showers in a Children's Home. 
 
 Now, to check up the accuracy of the foregoing, we will re- 
 verse the problem and work for the resultant temperature like 
 this : One pound of water at 60 deg. F. contains approximately 
 60 B.t.u. One-third of one pound of water at 160 deg. F. con- 
 tains approximately 53 1/3 B.t.u. and 60 -\- 53 1/3 = 113 1/3 
 B.t.u., and 1 lb. + 1/3 lb. — 1 1/3 lb. total weight of water. 
 
 113.333+^ 
 Therefore,— -zr^r^^ — = 85 deg. F., or the required temperature. 
 
 When the amount of hot and cold water that is necessary 
 has been found it is a comparatively simple matter to proportion 
 the pipes according to the head of water carried so that the sup- 
 ply will be equalized and a sufficient quantity be available at 
 each shower. The size of the heating boiler and coil or tank 
 heater should be ample and should be proportioned on the 
 
CIRCULATION IN LARGE BUILDINGS. 
 
 99 
 
 maximum requirements of the installation. The method of es- 
 timating the size of coils and heating surfaces in boilers is 
 explained elsewhere and all that will be necessary apart from 
 that will be the exercise of judgment in the proportioning of the 
 size of the storage tank. This will depend entirely upon how 
 long the baths are to be in operation, how long each user is al- 
 lowed to remain under the 
 shower and how many bath- 
 ers are to be provided for. 
 The conditions in each case 
 should be carefully consid- 
 ered and allowance made ac- 
 cording to the demands that 
 are to be made on the appa- 
 ratus. 
 
 Anti-Scalding Valves and 
 Water Mixers. 
 
 Specially designed mix- 
 ing valves are available for 
 attachment to the supply 
 pipes of shower baths, which 
 will prevent any danger of 
 scalding, as their construc- 
 tion and only possible means ^\L 
 of operation makes it nec- 
 essary to allow cold water 
 to flow before any hot 
 water is available. Thus the temperature can be adjusted to 
 a nicety by the bather or attendant, but in some installa- 
 tions it is desirable to have the mixing chamber under the 
 control of an attendant only, and in this case it may be in- 
 stalled as shown in Fig. 76. This shows a tank to which the hot 
 and cold water is brought and into the body of which the water 
 is introduced by bent pipes so that the two streams will mix and 
 provide an equable temperature, under the control of the at- 
 tendant, to all of the water flowing to the showers on the section 
 supplied from the mixer. A thermometer fitted in the side of 
 the mixing chamber enables the attendant to regulate the valves 
 to supply the showers at whatever temperature he decides is re^ 
 
 Fig. 
 
 77. Method of Connecting 
 
 and Cold Supply Pipes to 
 
 Shower Baths. 
 
 Hot 
 
100 
 
 HOT WATER SUPPLY. 
 
 quired. For shower baths in factory washrooms and other 
 places where an elaborate equipment is neither necessary or de- 
 sirable, mixing chambers that will give satisfactory service may 
 be constructed of pipe fittings as shown in Figs. 77 and 78. The 
 
 ^ 
 
 30 0)3 
 
 u5 
 o 
 
 fCnn — -t 
 
 SN 
 
 I 
 
 ''''''^'^^'^^'^<^^^^zz^;^w^m^^y^ 
 
 Fig. 78. A Simple Shower Mixing Pipe 
 for a Washroom. 
 
 elaborate douche, shower and spray baths that are the features 
 of spas, cures and some sanitariums are appliances that require 
 special experience and knowledge of the purpose for which they 
 are designed to successfully install and information that will be 
 required to proportion systems in which such appliances will be 
 used is best secured from the makers of the appliances. 
 
CHAPTER IX. 
 
 Double Boilers, Connections and Distributing Pipes. 
 
 Where the water supply will not rise to fixtures on an upper 
 floor, a tank is generally used to supply them, and in order to 
 supply these upper fixtures with hot water a double boiler may be 
 used and supplied from the same tank. The double boiler is 
 made in different forms, both vertical and horizontal. Sometimes 
 one boiler inside of another, and again two short boilers butting 
 together, each connected with a separate water supply and some- 
 times with a special water heating device or receiver. The one 
 in more general use is a boiler of smaller diameter inside of one 
 of larger diameter. The outer boiler is supplied from the regu- 
 lar water supply and connected direct with the water back. The 
 inner boiler is heated by the hot water in the outer boiler sur- 
 rounding it and is supplied from the tank above the fixtures. 
 
 The same principles govern the operation and circulation 
 of such boilers as govern in the ordinary single boiler. The receiver 
 mentioned is made with two separate chambers so arranged as 
 to secure an indirect passage of considerable length through 
 which the water flows. One chamber is connected with both the 
 water back and one of the boilers, and the passage of the heated 
 water through it to the boiler heats the water in the other cham- 
 ber, which is connected with the other boiler only. A more re- 
 cent practice is to cast the water back with a division, making 
 two separate parts and four openings, connecting a separate 
 boiler supplied from the tank with one part in the usual way and 
 another boiler supplied from the street service with the other 
 part. This avoids cooling the water in the tank boiler when a 
 large quantity of water is drawn from and enters the street 
 boiler, which is experienced with the use of double boilers. The 
 piping between the two boilers is so connected that both are sure 
 to be supplied in case either source of supply fails. 
 
 Although double boiler work is a system of years* standing, 
 the plumbers in general seem not much to blame for their lack of 
 knowledge concerning it, as the conditions favorable to the use 
 
 101 
 
102 HOT WATER SUPPLY. 
 
 of the same can be found in comparatively few places. The 
 plumbers who look no further than their present employment 
 do not care enough to investigate, since they can make no imme- 
 diate use of the knowledge. However, the truly ambitious 
 plumbers are not satisfied until they are familiar with every- 
 thing pertaining to their business, because they cannot tell how 
 soon circumstances will place them where they will sadly need 
 the information which at present is not required. 
 
 When the plumber is called upon to do a first-class job, it 
 is often optional with him whether he puts in one or another 
 kind of pipe. If, according to his knowledge, he thinks brass 
 pipe will answer best, then brass pipe is used ; but it is quite dif- 
 ferent in regard to the system to be employed. It is not so much 
 a matter of choice as to whether, the single or double system will 
 be used or not. The prober conditions must exist before the 
 double system can sensibly be preferred. A double system could 
 be placed under almost any conditions, but such work in the 
 wrong place would entail more work than would be necessary 
 to place a double system in the right place, in addition to the 
 difference in the original cost of the two systems. 
 
 Fig. 79 shows a double boiler system. Let us suppose that 
 the street pressure will force the water into the tank in attic 
 through A, instead of only to the second floor ceiling, for then 
 the pump in the basement would be unnecessary. The inside 
 boiler al and its system of pipe would also be useless. The pipe 
 M could be continued to the fourth floor for cold water and 
 branches made into J for hot water. If the street main furnished 
 regular pressure and clear water, the tank could in some cases 
 be omitted ; but where the tank is omitted the auxiliary to con- 
 stant pressure is lost — i.e., where tanks are used settled or fil- 
 tered water and regular pressure are assured, even though the 
 street supply be shut off for repairs for hours, which is not un- 
 likely. Were the pipe A delivering water to the tank from the 
 street pressure, it would have to be furnished with a ball cock 
 or something equivalent, instead of the bend at the tank, as 
 shown. Any one can see the folly of using such a system as 
 illustrated if the street pressure would reach the attic. 
 
 Where the conditions call for double system work, the 
 plumber is called upon to select and adapt the style most suit- 
 able for the place. It will be understood that there are different 
 
DOUBLE BOILERS AND CONNECTIONS. 
 
 103 
 
 Fig. 79. Piping for a Double Boiler System of Hot Water Supply. 
 
104 HOT WATER SUPPLY. 
 
 ways of arranging double boilers and the pipes leading to and 
 from them, and yet give results that are practically the same. 
 
 The first method used where there is available space is to 
 place the two boilers independent of each other, either vertical 
 or horizontal, as is most convenient. Having two independent 
 boilers necessitates having two water backs — that is, one fire box 
 with two water backs and connections from each back, making 
 the circulation to each boiler independent of the other. 
 
 The circulating pipes must always be from one back to one 
 boiler, unless a range with two fire boxes and two water backs 
 each is used, in which case the tank pressure boiler may be con- 
 nected with one water back in each fire box and the street pres- 
 sure boiler connected to the two remaining fire boxes in the same 
 manner. When such a range and connections are used, hot 
 water can be supplied to both systems from either fire box. For 
 some reason the boilers placed independent of each other seem 
 to give the greatest satisfaction. 
 
 The second method is the placing of one boiler within the 
 other. The difference between the capacity of the inner and 
 outer boiler should be equal or a little in excess of the capacity 
 of the inner boiler. The strength of the material for both shells 
 can be about the same, and should be sufficient to withstand the 
 effect of a vacuum without injury when formed into a shell the 
 size of the outer cylinder. Should the inner cylinder of such a 
 boiler be emptied or syphoned while the pressure is on the outer 
 shell no damage would be likely to ensue, because the inner shell 
 would only be required to support the weight of the water from 
 the street, increasing in pounds per square inch according to 
 the vertical head of water, in addition to the atmospheric pres- 
 sure. The inner shell being naturally stronger from its smaller 
 diameter, and having no side couplings to vary the strain or re- 
 sistance, it would withstand any probable test without injury. 
 It will be understood that the high, or tank, pressure is always 
 connected to the inner boiler. A different result might be ex- 
 pected were the high pressure connected to the outer boiler dur- 
 ing such a test as was mentioned above. In combination boiler 
 work the water back connections are always applied to the outer 
 shell, as one or the other must be heated by conduction. 
 
 Although there are few, if any, cases where a combination 
 boiler has been heated by circulation through the inner shell or 
 
DOUBLE BOILERS AND CONNECTIONS. 105 
 
 through both simultaneously from two water backs, there is no 
 reason why the latter could not be done successfully. The inner 
 cylinder should be made of copper, because it absorbs heat 
 quickly. The outer shell, if also made of copper, will secure 
 uniform expansion and make a much more durable job. 
 
 One way of arranging the pipes leading to and from a com- 
 bination boiler is to supply a tank situated in the attic or upper 
 floor from the street pressure by means of a pump upon the first 
 floor or in the basement. The supply to the inner cylinder is 
 taken from the tank, and is also connected to the street pressure, 
 by which, should the tank supply fail, the street supply will fill 
 the inside cylinder through a check valve. The tank and inside 
 cylinder supply hot and cold water to all the floors above those 
 for which the street supply can be relied upon. 
 
 Another method is substantially the same as the first, except 
 the additional convenience of being able to send hot or cold 
 water from the tank system to any fixture supplied by the street 
 pressure by means of certain connections and stops properly 
 placed in the kitchen. 
 
 A third way of using the double boiler system is as the first, 
 with the addition of what is known as reverse cocks to the 
 branches supplying the fixtures on the lower floors from the 
 street pressure. The reverse attachment referred to has six 
 openings and four stop cocks. They are set as follows: Upon 
 the upper street pressure floor hot and cold branches from both 
 street and tank supplies are brought to some convenient place 
 and carried up through a safe pan, in order that any leakage 
 from the cocks may be taken care of. Both of the hot supplies 
 are connected to one leg of the attachment and cold supplies to 
 the other leg. A lever handle is connected to the attachment 
 cocks is such a manner that it is only necessary to pull up the 
 handle to change from street to tank pressure, or vice versa. 
 
 A fourth arrangement of the pipes is a combination of the 
 stop cocks in the kitchen, mentioned in the second method, with 
 the reverse attachment, the reverse cock being placed upon the 
 third floor when there is only an intermittent supply from the 
 street to the third floor. Intermittent supply in some localities 
 is caused by excessive drawing at certain times during the day, 
 which in some cases causes the second floor to be uncertain if the 
 street pressure alone is depended upon. Automatic attachments 
 
106 HOT WATER SUPPLY. 
 
 can be bought from any stock house for uses mentioned above. 
 The object of double plumbing and everything pertaining to it 
 is to avoid the cost of unnecessary pumping, storage capacity, 
 etc., to as great an extent as possible. The true perception of the 
 conditions existing in any case is the greatest aid to rightly de- 
 termining which of the methods is best for the place, as well as 
 whether combination or independent boilers are most suitable. 
 
 Double system plumbing is principally used in three, four- 
 story and attic and five-story buildings, and the neatest exam- 
 ples of it can be found in residences. In high city buildings 
 where high pressure steam is used both for heating and lifting 
 water, other means of overcoming the irregular supply difficulty 
 are found. It should be remembered that double boiler work and 
 duplicate plumbing are not the same, the latter being merely a 
 separate supply to each fixture and in some cases both separate 
 and duplicate supplies. 
 
 The illustration is an example of double plumbing, which 
 differs from the first method described only by having the stop 
 cock No. 4 connecting the cold supply of both boilers above the 
 sink. Should the street supply fail in this case, it is only neces- 
 sary to turn stop cock No. 4 to supply the hot and cold street 
 pressure system from the tank. A reverse attachment can be 
 placed upon the second floor by simply making connections to 
 N L from e e through the reverse cock. The range used in this 
 job is of the ordinary type — i. e., one fire box and one water back. 
 Circulation takes place between the outer boiler a and the water 
 back Z through the pipes U V. The emptying pipe shown by W 
 is from the inside boiler al. Its stop cock No. 6 is connected 
 on the pressure side of cock No. 5, which prevents any possibility 
 of the inner cylinder being emptied while the tank pressure is 
 upon the outer cylinder. T is the sediment pipe through which 
 both boilers must be emptied, and is controlled by stop cock No. 
 5. S is a general drain, which discharges over the basement sink. 
 The pipes C and P have a small drain and stop to S from 
 above the check valves, but are not shown in the drawing. Hot 
 supplies are furnished with drains and cocks to S by continua- 
 tions of and E. The sink in this job is of porcelain, supported 
 by legs and furnished with two drainers and with splash back. 
 The drainers are supported by brackets, and the splash back 
 can be removed by unscrewing the sink faucets Y Y and remov- 
 
 
DOUBLE BOILERS AND CONNECTIONS. 
 
 107 
 
 ing two wood screws at each end. The sink waste is indicated 
 by h and the crown vent of its trap by i. The telltale pipe B dis- 
 charges above the basement sink, that the person pumping may 
 know when the tank is full. A is the supply to the tank in the 
 attic, from a force pump in the basement. The pump suc- 
 tion pipe is connected to the street supply C. Tank drain c is 
 
 Fig. 80. A Horizontal Double Boiler and Connections, 
 
 furnished with a cock near the tank. The tank overflow h is con- 
 nected to tank drain c. The tank cold main supply is first 
 brought into the kitchen through K, thence through branch N 
 to third and fourth floors, and up over the tank as shown, which 
 insures the main line draining out should the water be shut off. 
 
108 HOT WATER SUPPLY. 
 
 The inner cylinder is supplied with cold water through the 
 branch F from K. Pipe d is branched into K below the stop 
 cock as shown, which introduces the atmospheric pressure to the 
 upper end of K, allowing K to be drained without draining the 
 tank, should it be necessary to do so. The street pressure main 
 cold is introduced through C and to the outer cylinder through 
 branch I. Second floor cold is supplied from the street through 
 branch pipe M. The kitchen sink, pantry sink and laundry hot 
 water is supplied through pipes 0, E, and their branches. Cold 
 water to kitchen sink, etc., is supplied by branches from street 
 pressure pipe C. Should the tank pressure fail, the street pres- 
 sure will supply the inner boiler through branch D and a check 
 valve; thence via P and F. The check is used to prevent mix- 
 ing the tank and street water. Were a check omitted, high 
 pressure would always be upon the outer boiler and all the water 
 used would have to be pumped, by reason of the excessive pres- 
 sure holding the check on pipe C shut. The check is placed 
 upon street main cold C to prevent wasting the tank water into 
 the street main when both systems are doing duty under high 
 pressure; that is, when cock No. 4 is turned on. The check is 
 also necessary to prevent drawing water from the outer boiler 
 when the pump is in use. H is the main hot supply from the 
 outer boiler, J being the distributing hot to second floor. G 
 is the main hot from the inner boiler, L being the distributing 
 hot to the third and fourth floors. Both L and J continue up to 
 and bend over the tank in order to relieve any steam, vapor or 
 expansion that may occur. X X indicate the air chambers from 
 the sink faucets. It will be noticed that all pipes connecting to 
 the top of the boilers are brought down to a convenient point 
 above the sink to avoid using a stepladder when it is necessary 
 to turn the stop cocks. The bends made in the hot pipe for the 
 above reason prevent the successful use of a return circulating 
 pipe. Both inner and outer boilers may have return circulation 
 when the hot mains continue to rise above the boilers. The stops 
 in this job above the sink are all plain stops. All jobs of the 
 order here described should have the stop cocks and valves 
 marked, and a chart giving full information as to the use of each 
 one, both for regular service and in cases of emergency. 
 
DOUBLE BOILERS AND CONNECTIONS. 
 
 109 
 
 Horizontal Double Boilers and Connections. 
 
 A good example of piping work in the connections of a 
 horizontal double boiler is shown in Fig. 80. The water back 
 is not shown, but the pipes leading from it appear at the left, 
 connecting with the receiver. The boiler is suspended over a 
 kitchen sink that is connected with a grease trap. The apparatus 
 consists of two separate boilers, butting together, one supplied 
 from the street main and the other from a tank. The receiver 
 has two chambers, one heated by being surrounded by the hot 
 water in the other, which connects directly with the water back. 
 AA is the cold water supply from the street main. BB is a by 
 pass running cold water 
 
 <HotOuHef 
 
 HotOutlef-. 
 
 
 
 
 'Oold Inlet; 
 
 Coldlnlet- 
 
 Fig. 81. 
 
 Section Through a Double 
 Water Back. 
 
 through the outer chamber of 
 a grease trap to cool and 
 harden the grease that col- 
 lects on top of the water dis- 
 charged from the sink. C is a 
 branch to supply street boiler. 
 D is a branch connecting tank 
 and street supply to fill either 
 boiler. E is a check valve to 
 prevent tank supply from 
 
 leaking into street when the latter supply fails. F is street sup- 
 ply to sink. G is tank supply to sink and by branch H to tank 
 boiler and by branch D to street boiler. I is hot service from 
 street boiler. J is branch from I to sink. K is hot service from 
 tank boiler. L is branch from K to sink. M is cold water from 
 street boiler to receiver. N is hot water from receiver to street 
 boiler. is hot water from receiver to tank boiler. P is cold 
 water from tank boiler to receiver. Q is return circulating pipe 
 from tank hot service. R is return circulating pipe from street 
 hot service. S, sediment pipe from street boiler. T, sediment 
 pipe from tank boiler. U, cold water from receiver to water 
 back. V, hot water from water back to receiver. W, waste pipe 
 to sink from cocks to empty upper pipes and fixtures when sup- 
 ply is shut off. The stop cocks are numbered. 1, stop to street 
 supply ; 2 and 3, stops to by-pass and grease trap ; 4, 4, 4, stops 
 to sink and street and tank boiler ; 5, 5, stops to upper floor fix- 
 tures ; 6, 6, waste cocks to drain pipes when upper floor fixtures 
 
110 
 
 HOT WATER SUPPLY. 
 
 3 
 
 
 Fig. 82.~ Method of Piping a Residence 
 
 fronn a Double Section Water 
 
 Heater. 
 
 are shut off ; 7, stop to street 
 supply when tank supply is 
 used ; 8, stop to tank supply 
 when street supply is used; 
 9, stop to tank hot service to 
 sink when street hot service 
 is used ; 10, stop to street hot 
 service when tank hot serv- 
 ice is used ; 11 and 12, sedi- 
 ment stops to clean boilers 
 and receiver. When tank is 
 empty, tank boiler and kit- 
 chen fixtures can be supplied 
 from street by opening stop 
 cocks 4 on pipe D, 7, 8, 9 
 and 10. When street supply 
 fails, street boiler and kit- 
 chen fixtures can be supplied 
 from tank by opening stop 
 cocks 7, 8, 9 and 10 and 
 closing stop cocks 4, 4, 4. 
 
 The Use of Double Water 
 
 Backs and Sectional 
 
 Heaters. 
 
 A more or less common 
 custom in cases where the 
 pressure of water in the 
 street mains is insufficient to 
 raise the water to the upper 
 floors of a building, but 
 where it is desired to supply 
 at least a portion of it di- 
 rectly from the mains and 
 so avoid considerable pump- 
 ing is to use two boilers. 
 These are connected to a 
 sectional water heater of 
 which Fig. 81 shows the 
 Interior construction. This 
 
DOUBLE BOILERS AND CONNECTIONS. Ill 
 
 really amounts to two separate water heating systems 
 heated by one fire, as one side connects to a boiler 
 which is supplied directly from the city main pipe, while the 
 supply to the other comes from the house tank on the roof. All 
 the fixtures on the lower floors are supplied from the one that is 
 connected with the street supply pipe, while the upper floors are 
 connected with the house tank supplied boiler. A by-pass between 
 the two may be made so that in the event of the water supply 
 being short or being for any reason temporarily shut off, the 
 lower floors may also be supplied from the house tank. In case 
 a by-pass is fitted it is well to have a check valve on the street 
 connection as there is less chance of the water being emptied 
 back into the street main through the valve being inadvertently 
 left open when this is fitted. It must be remembered, however, 
 that it is necessary when a check valve is fitted to provide a 
 safety valve on the boiler to take care of the expansion of the 
 water in the system when heated. The method of making the 
 connections to the different floors is shown in Fig. 82, which also 
 shows a heater of two separate sections in use as an alternative 
 to the double water back type illustrated in Fig. 81. 
 
CHAPTER X. 
 
 Heating Water by Gas. 
 
 The value of illuminating gas as a means for heating water 
 for domestic purposes is too well known to require any elucida- 
 tion, but the manner in which the efficiency of any gas water 
 heater may be ascertained is worth some attention. It is com- 
 mon to calculate the heating value of ordinary illuminating gas 
 as being equal to 650 B.t.u. per cubic ft. In this case each cubic 
 foot of gas consumed will heat 650 lbs. of water 1 deg. Fahr., 
 as 1 heat unit is equal to raising 1 lb. of water 1 deg. Therefore 
 the amount of gas that must be consumed to raise a given quan- 
 tity of water to a desired temperature is easily calculated, and 
 when the actual results are ascertained by noting the gas con- 
 sumption, the percentage of efficiency of the heater is easily 
 found. If, for instance, it is desired to raise the contents of a 
 250 gal. storage tank to 155 deg. and the temperature at which 
 the water enters the tank is 40 deg., it will be seen that the dif- 
 ference is 115 deg, and that to raise each 1 lb. of water to that 
 temperature 115 B.t.u. will be required. Multiplying 250 by 8.3 
 gives the weight of the contents in pounds, each gallon of water 
 weighing approximately 8.3 lbs. Multiplying this sum by the 
 difference in temperature gives the total B.t.u. required to heat 
 the water. Then to find the number of cubic ft. of gas required 
 divide by 650. In this case there would be 238,625 B.t.u. re- 
 quired, and this divided by 650 would show a requirement of 
 about 367 cu. ft. Making allowance for loss of heat in flues and 
 by radiation, probably about 500 cu. ft. would be consumed, 
 showing a percentage of efficiency of about 70. 
 
 Efficiency of Gas Water Heaters. 
 
 Kelative to the efficiency of the various types of water heat- 
 ers, there are two kinds of efficiency: First, what is termed 
 the initial test, made when heater is new and burners and heat- 
 ing surfaces are clean and conditions entirely favorable; and 
 second, service efficiency, or the results obtained in practical use 
 under average conditions, with the heater receiving only the 
 
 113 
 
HEATING WATER BY GAS. 
 
 113 
 
 normal amount of attention as to cleaning of burners and heat- 
 ing surfaces and flue pipes. 
 
 One of the most important things that lead to high efficiency 
 in a gas heater is the vent pipe. If this has a good draft the 
 burners will remain clean much longer because of the better 
 
 combustion of -, _ . . — _ — — _^ 
 
 the gas and 
 there will be 
 a corresponding 
 increase in the 
 amount of heat 
 transferred from 
 the fuel to the 
 water. The effi- 
 ciency of a gas 
 heater will be 
 affected as much 
 as 20 per cent. 
 by the good or 
 bad draft in 
 the vent pipe. 
 
 The auto- 
 matic - instan- 
 taneous heater 
 of the better 
 makes shows an 
 initial efficiency 
 of from 80 to 
 85 per cent., 
 
 which is very ^^^- ^^' '^^^^^^^ ^^^ ^^^^ Heater. 
 
 high, especially when compared with heating and steam-gen- 
 erating apparatus in general. In the automatic-instantaneous 
 heaters the service efficiency is also very high, usually showing 
 from 75 to 80 per cent., even after the heater has had several 
 years of service with only the average maintenance attention. 
 
 In the circulating tank heaters, the better grade of double 
 copper coil heaters shows from 65 to 70 per cent, efficiency on 
 initial tests ; and, in service efficiency after years of use with only 
 normal attention, this type of heater usually shows within 4 to 
 5 per cent, of its initial efficiency test. The cast iron tank water 
 
114 
 
 HOT WATER SUPPLY. 
 
 heaters of the better types show practically the same initial 
 efficiency as the copper coil heaters, but service efficiency 
 is not nearly as good and the maintenance cost is usually much 
 higher than with the copper coil type. 
 
 Lower Efficiency of Automatic 
 Storage System. 
 
 in the automatic storage system 
 the initial efficiency and service effi- 
 ciency are less than with the automatic- 
 instantaneous heater. It requires about 
 1}^ cu. ft. of 650 B.t.u. gas to raise 
 one gallon of water 63 deg. F. on in- 
 itial test, as against 1 cu. ft. for the 
 automatic-instantaneous heater. On 
 the service efficiency the automatic 
 storage system does not hold up as 
 well as the automatic-instantaneous, 
 due principally to the fact that the 
 continuous hard service on the burn- 
 ers causes them to become corroded 
 or fouled very much sooner, and even 
 with occasional cleaning and with tank 
 
 T'ig. 84. Gas Heater of the heavily insulated it will usually re- 
 Kitchen Boiler Type. - ' r. . -» r / ^i. si 
 
 quire about 1^ cu. it. oi gas to raise 
 one gallon of water 63 deg. F. with gas of 650 B.t.u. quality. 
 
 Constructive Features of Gas Water Heaters. 
 
 It is now pretty generally conceded that the copper-coil 
 type of gas water heaters is preferable to all others. The very 
 liigh heat conductivity of copper, combined with its high me- 
 chanical strength, makes it an ideal material for a water-heating 
 receptacle. Being practically free from all tendency to corro- 
 sion, the water is never contaminated, the heating surfaces are 
 easily cleaned, and viewed from all standpoints heaters of this 
 construction far excel in durability and efficiency. 
 
 Eemovable and accessible burners of high heating power are 
 desirable. They must be of simple construction and easy to 
 >clean and repair. Interchangeable mixer nozzles are demanded. 
 In automatic heaters having thermostatic control, burners having 
 
HEATING WATER BY GAS. 
 
 IK 
 
 Heater 
 
 copper gauze plates are preferred; whereas in the burners for 
 circulating tank heaters the flame check screens are not favored, 
 but the straight-drilled burner is preferred. 
 
 On the tank heaters the solid type of jacket is giving way 
 to the open-front hinge-door type, with the pilot light eliminated, 
 thus necessitating the opening of door in 
 order to light the gas at the main burner. 
 
 In the automatic heaters the form of 
 mechanism combining thermostatic or tem- 
 perature regulation with water pressure con- 
 trol is the type generally favored by manu- 
 facturers of this class of water heater for 
 general use. 
 
 A difference of opinion exists as to 
 whether the internal or external type of ther- 
 mostat is preferred, the internal thermostats 
 being preferred by some on account of their 
 being located nearer the seat of activity, 
 while the external thermostats are often 
 favored because of their circulating features 
 and greater accessibility for adjustment and 
 repair. 
 
 The type of jacket for automatic heaters having the double 
 cast iron wall with large air space between, and with doors of 
 liberal size exposing the coil and burner compartments, has been 
 adopted by all manufacturers, thus permitting easy cleaning of 
 coils and burners or inspection while in use. 
 
 The automatic supplementary system of connecting heaters, 
 whereby all water is first taken through the ordinary tank, 
 heated by a coil in the coal furnace, is favored by practically 
 all water heater manufacturers and used by practically 
 all gas companies in making installations, especially in the cooler 
 climates where buildings are commonly heated in this way. 
 
 Instantaneous Bath Heaters. 
 
 These appliances are of two general types which may be 
 classed as contact and non-contact heaters. In the first, the 
 water is in actual contact at one point of the heater with the 
 heated products of combustion from the Bunsen burners. The 
 
 
 Fig. 85. Method of 
 
 Installing Kitchea 
 
 Boiler Heater. 
 
116 
 
 HOT WATER SUPPLY. 
 
 second heats the water indirectly by spreading it over a large 
 surface exposed to the gas flame. 
 
 This type of heater is generally of such attractive appear- 
 ance that it is an ornament to the bath room or apartment in 
 which it is placed. 
 
 The heater illustrated in Fig. 83 is 
 constructed of sheet copper, nickel 
 plated, with valves and supply pipes of 
 brass, nickel plated and polished. The 
 heater consists primarily of a number of 
 Bunsen burners placed under a shell, 
 over which water is caused to pass in a 
 thin sheet by being sprayed over a per- 
 forated cone, through which it passes 
 exposed to the intense heat from the 
 Bunsen burners and so down over the 
 lower part of the shell which is in the 
 form of a frustum of a cone 
 to the outlet tube. 
 
 When more than one fix- 
 ture is to be served a goose- 
 neck or offset is provided so 
 that an open end can be main- 
 tained to safeguard the 
 heater. A valve can be fitted 
 to the other outlet so that 
 water can be drawn freely, 
 without the necessity of run- 
 ning any through the open 
 end to the other fixtures. A 
 by-pass or pilot light is ar- 
 ranged so that it must be 
 turned on and lighted before the main gas valve is opened, thus 
 insuring that gas will not collect in the casing before the light 
 is applied. The water supply valve is also arranged so that 
 the lever must be automatically turned up by the action of 
 opening the gas valve. 
 
 The whole heater is placed on a white enameled iron shelf 
 supported by a bracket. The Bunsen burners are readily re- 
 moved for cleaning when necessary. A pipe must be connected 
 
 Fig. 86. An Automatic Water Heater 
 Attached to a Vertical Boiler. 
 
HEATING WATER BY GAS. 
 
 117 
 
 from the top of the heater to some convenient flue or carried to 
 the open air to remove the products of combustion. When taken 
 to the open air a hood should be fitted so that down draughts will 
 be prevented, but the vent should enter a heated flue whenever 
 possible. 
 
 The second type, the simple kitchen 
 boiler heater, is of a different construc- 
 tion to the type just described. Here 
 the water is circulated as it is heated to a 
 storage tank, from which it is drawn as 
 required. The heater generally consists 
 of a coil of copper pipe, as shown in Fig. 
 84, or a series of hollow discs connected 
 by short pieces of pipe which presents 
 a comparatively large heating surface to 
 the effect of a hot Bunsen 
 flame produced by a burner 
 placed at the base. The heated 
 products of combustion pass 
 through the coils of pipe or over 
 and around the hollow discs in 
 their passage to the outlet at 
 the top. This outlet must in 
 all cases be connected with a 
 heated flue or carried outside 
 and finished with a hood for 
 the same reason as that for 
 which the bath heater was 
 connected. 
 
 The range boiler heater is 
 generally connected as shown ^^- ^^• 
 in Fig. 85, that is the flow con- 
 nection is made to the upper tapping of boiler just where the 
 house supply is taken off, while the lower pipe is connected at 
 the bottom tapping of the boiler. Should the water be of such 
 a nature that there is danger of sediment choking the boiler or 
 coils the lower connection may be made to the side opening of 
 the boiler. This, however, decreases the hot-water storage capac- 
 ity by one-half, and a better plan is that where a sediment trap 
 or other means of collecting the sediment before it passes into 
 
 Pressure Controlled Gas 
 Water Heater. 
 
118 
 
 HOT WATER SUPPLY. 
 
 the heater is provided. Reducing the storage capacity, however, 
 •allows the water contained in the boiler to become hotter. The 
 position of the coil in relation to the Bunsen burner in this type 
 of heater is clearly shown in Fig. 84. 
 
 REGULATING COCK "C 
 F.QR FL_Oyy^OF_WATER 
 
 VENT TO FLUE 
 
 COILJ?ACKS 
 'HEAT ZONE 
 PILOT VALVE "B" 
 
 GAS COCK^A 
 
 AUTOMATIC 
 WATER VALVE 
 
 UPPER GAS VALVE 
 
 THERMOSTAT 
 GAS VALVE 
 
 HOT WATER 
 
 OUTLET (IN REAR 
 
 ^COLD WATER I 
 INLET (IN REAR) 
 
 CAS TO PILOT 
 
 GAS TO MAIM 
 BURNERS' 
 
 J'lLOT^BURNER 
 
 BURNER 
 POSITIONING Rl 
 
 PATENTED 
 CAS BURNERS 
 
 REMOVABLE CAST 
 IRON TOP 
 
 EXTERIOR CAST 
 IRON SHELL 
 
 DEAD AIR SPACE, 
 
 (INSULATION) 
 
 CAST IRON 
 
 COPPER HEATING COIL 
 
 (DETACHABLE AND ORAINABLE) 
 
 SPRING DOORS - 
 
 (SELF CLOSING) 
 
 FRONT JACKEiy 
 
 <wnH SPRING DOOR) 
 
 Pig. 88. Details of a Pressure and Thermostatically Controlled Heater. 
 
 When the hollow disc type of heating surface is used these 
 take the place of the coil and occupy the same relative position, 
 so that the heated gases pass over the surface in their path to 
 i;he outlet at the top of the casing. The water connection itself 
 
HEATING WATER BY GAS. 
 
 119 
 
 is generally relied upon to support the heater, but brackets can 
 he placed to support it when necessary. 
 
 The third type of gas heater in the list, that shown in Fig. 
 S6, is simply a refinement of the type just described. This type 
 is becoming increasingly popular for the reason that it is eco- 
 nomical in fuel. The refinement 
 consists in the provision of a gas 
 valve thermostatically controlled. 
 The thermostat consists generally 
 of a rod of some material (porce- 
 lain is commonly used), which 
 will expand to a considerable ex- 
 tent with the rise in temperature. 
 The arrangement is such that the 
 expansion will by a combination 
 of compound levers operate the 
 valve controlling the gas supply. 
 Thus if it is desired to maintain 
 the water in the storage tank at a 
 temperature of 160 deg. the gas 
 will be automatically turned on 
 and ignited by a pilot light as 
 soon as a fall in the temperature 
 in the boiler great enough to cause 
 the rod to contract and open the 
 gas valve occurs. The valve will 
 remain open just so long as the 
 temperature remains below the 
 predetermined point. When it 
 has been reached the expansion 
 
 of the porcelain rod is sufficient Fig. 89. Automatic Heater with 
 
 to close the valve and to hold it 
 closed until the water cools again. 
 
 The fourth type is built along different lines, but also has 
 the economical feature highly developed. This type of heater, 
 which is shown in Fig. 87, is not intended for use with a storage 
 tank but is intended to supply hot water instantaneously on the 
 opening of the faucet. This is accomplished by means of a pres- 
 sure valve which may be seen at the side of the heater immedi- 
 ately over the gas supply valve. The normal pressure in the 
 
 Thermostat Placed on the 
 Outside. 
 
120 HOT WATER SUPPLY. 
 
 water supply system, be it 10, 20 or 100 lb. per square inch, is 
 caused to act on this in such a manner that when all the faucets 
 on the system are closed it will maintain the plunger in such a 
 position in its cylinder that the rod which connects it with the 
 valve in the gas supply line is closed. As soon as the pressure 
 on the coil side of the water valve is relieved by the opening of a 
 faucet on any part of the line, this plunger moves and allows 
 the gas valve to open, thus allowing gas to pass to the burner. 
 The pilot light, which is contained in the burner chamber, im- 
 mediately ignites the gas and the water is heated instantaneously 
 as it passes through the coils to the faucet. Thus no gas is con- 
 sumed except at such time as the faucet is open. 
 
 To get the maximum economy the heater should be as near 
 the fixtures as is convenient and the pipes should be no larger 
 than absolutely necessary to provide a steady flow of water with 
 the pressure available. These valves are really very simple and 
 are not likely to cause trouble. The connections are extremely 
 simple. A cold supply to one side of the valve, a connection 
 from the coil to the hot-water lines and a connection to the gas 
 valve are all that are required. 
 
 This type of heater is being largely adopted for suburban 
 residence use and as it does away with the necessity of storage 
 tanks it is well suited for apartments where space is limited, 
 more especially as it can be readily placed in a corner of the 
 kitchen or in a closet if a flue for the discharge of the products 
 of combustion is available. This heater has a capacity of 2 to 3 
 gal. of water raised 60 deg. above the temperature of the cold 
 water per minute and its makers recommend that a pressure of 
 water of at least 8 lbs. per square inch be available for operating 
 the valves. The heater is illustrated in Fig. 87. 
 
 The next type includes the provision of both pressure valves 
 and thermostatic valves, an arrangement which on the larger 
 sizes is likely to effect a considerable saving of gas in this way. 
 When the faucet is opened the gas is immediately ignited and 
 heats the water to a certain temperature. If a thermostat is 
 provided a definite temperature may be decided upon and imme- 
 diately this is reached the thermostat will close the gas valve. 
 The water still keeps passing through the coil and just as soon as 
 
HEATING WATER BY GAS. 
 
 121 
 
 the temperature falls below the point decided upon it will auto- 
 matically open the gas valve again and keep it open until the 
 temperature again rises above the required amount. 
 
 This balances the varying pressures of gas at different 
 periods, as the first time the gas pressure is high more gas than 
 would be necessary might be passing and the water would be un- 
 necessarily hot. On the other hand for bathing purposes less 
 
 l/ept 
 
 Cos-*- 
 60s 
 Regulator 
 
 Thermostatic 
 Moment Volve 
 
 Thermostatic 
 .■Expansion Tube 
 
 ^^^.^ Mat Water 
 Qo^ to Fix tures 
 
 Return frorn 
 ^fyjsfures-ifony 
 
 Check ValvQ 
 
 ^Co/d^Vator 
 ^ inlQt 
 
 Fig. 90. A Heater of the Storage Type with Gas and Water Connections. 
 
 would be required, but when the fixtures are used by many mem- 
 bers of the family this point is often lost sight of and much hot 
 water is allowed to go to waste. The thermostat takes care of 
 this and provides the same amount of water at the same tem- 
 perature to all without special care or attention. 
 
 A heater of this type is illustrated in Fig. 88. The amount 
 of pipe in the coils will be noticeable. The illustration clearly 
 shows the position of the thermostatic and pressure valves and 
 the pilot valve and tube. A heater of a similar type but having 
 the thermostatic valve placed on the outside of the heater in a 
 tube connected with the coil is illustrated in Fig 89. 
 
122 
 
 HOT WATER SUPPLY. 
 
 For the larger size of heating installation, 'that is for in- 
 stitutions where large amounts of hot water are required, the last 
 type, the automatic heater with thermostatic control but no 
 pressure valve is the best adapted. This type is shown in Fig. 
 90. As will be seen it is practically the same as that shown in 
 Fig. 88, but is of a much larger size. The thermostat may be 
 placed either in the tank or the lower part of the heater. 
 
 !1 
 
 'CV'-^'-'-'-'-'i^^'-'-^'''-'-'^'-'->,V'-'-'-^^'-^^i\S"*^^'-'^"^^y-'"^*'^'^ 
 
 >< 
 
 
 X 
 
 
 
 
 
 
 
 
 
 
 
 
 L. . 
 
 r -— r 
 
 .\\nm;\vs>i^;^Tn' 
 
 1^ — 
 
 . .Icr3l. . 
 
 Fig. 91. Method of Installing Automatic Heater in a Flat 
 
 In the first case it is shaped so that a casing is inserted 
 through a tapping in the tank and in this casing the expansion 
 rod is carried. The valves operating the gas supply are in a 
 casing at the outlet end of the rod as shown in Fig. 90. 
 
 In the other case the rod is contained in a casing which is 
 placed in the burner chamber of heater and connected so that 
 the heated water acts directly upon the expansion rod. As it 
 lengthens with the rise in temperature in the coil, it acts on 
 toggles again and closes the gas valve at whatever point may 
 have been decided upon. This thermostat is shown in Fig. 88, 
 which also shows the Bunsen burners and the coils inside the 
 casing. 
 
 The doors on most of these heaters are mounted with springs 
 so that should gas be collected for any reason before being 
 ignited by the pilot light, any excess pressure will be relieved by 
 the yielding of the door. This obviates all risk of damage by 
 the explosion. 
 
HEATING WATER BY GAS. 
 
 123 
 
 Tlie best metliods of using and maintaining in good condition 
 all of the various types of heaters are amply described in the 
 various makers' catalogues and instruction sheets. These sheets 
 are invariably sent out along with the heaters and should be 
 carefully studied by those not familiar with the installation of 
 
 OoldWaterSui 
 
 
 Fig. 92. A Heater Connected as an Auxiliary. 
 
 such machines and should also be brought to the attention of the 
 customers so that mutual satisfaction will be obtained. For the 
 guidance of those who have not previously installed gas water 
 heaters a few rules may be of use. 
 
 1. Be certain that the pressure of water is sucH that the 
 supply will always be available at the highest fixture on the line. 
 
 2. Do not use a heater of the automatic pressure valve type 
 unless the water pressure is equal to the amount designated by 
 the maker of the heater. 
 
 3. Be sure the gas supply is ample. 
 
124 
 
 HOT WATER SUPPLY. 
 
 4. The vent pipe should never be reduced below the size 
 of the outlet collar on the heater and should not have a damper. 
 
 5. Always flush out the supply pipes before connecting 
 to the gas heater. This is important, as chips or lead used in 
 making the joints may lodge in the valves and cause trouble. 
 
 e--i*/nsufatia% 
 
 Fig. 93. Automatic Gas Heater and Coil in Furnace Connected to Large 
 
 Storage Tank. 
 
 6, Check the supply to the automatic heater down to what 
 the capacity of the heater calls for. This will obviate complaint 
 of lack of heating power through the customer drawing water 
 faster than it can be heated. 
 
 Various Methods of Connecting Heaters. 
 
 It has already been stated that ordinary boiler heaters can 
 be connected up in such a way that sediment will not collect in 
 the coils. Should a coil become choked it will manifest its con- 
 dition by snapping sounds due to the formation of steam and 
 the supply of hot water will be unsatisfactory. The coil should 
 be removed and thoroughly cleaned and the connection made 
 either with the return pipe connected to the side outlet of the 
 
HEATING WATER BY GAS. 
 
 125 
 
 boiler or connected through a sediment chamber which will col- 
 lect it at the lowest point. Fig. 91 shows an automatic heater 
 placed in an apartment and supplying kitchen and bath room 
 fixtures, while Fig. 92 shows how they may be connected as aux- 
 iliaries so that the coal stove can be used at any time and hot 
 water drawn from the boiler through a by-pass. If desired the 
 storage type of heater may also 
 be connected as an auxiliary to 
 a coal stove and the thermostatic 
 control may be used to maintain 
 the water at any desired tem- 
 perature at such times as it may 
 be desirable to have a low fire 
 in the coal stove. 
 
 These heaters may be con- 
 nected in many different ways, 
 but do not differ greatly from 
 other heaters, and the plumber 
 who understands the principles 
 which cause water to circulate 
 will have no difficulty in install- 
 ing any or all of the heaters. 
 
 The method of connecting a 
 coil in a house heating furnace to 
 a boiler also heated by an auto- 
 matic gas heater is shown in Fig. 93. The illustration also 
 shows how the insulation of the tank is put on to effect economy 
 in gas consumption. 
 
 Kitchen Range and Gas Heater Continuous Connection. 
 
 A continuous flow connection with a gas water heater of 
 the common kitchen boiler type and the water front in the range 
 is shown at Fig. 94. This is a neat method of connecting the 
 two fixtures which saves space and also prevents to some extent 
 short circuiting of cold water through one or other of the heaters 
 when one is not being used. The coils of the gas heater will 
 radiate a little heat when the hot water from the water front 
 is passing through them, but not enough to offset the advantage 
 possessed by the method in other respects. A double boiler con- 
 nection may be used to connect the flow pipe with that of con- 
 
 Fig. 94. Continuous Connection 
 
 for Gas Heater and Water 
 
 Back in Range. 
 
126 
 
 HOT WATER SUPPLY. 
 
 nection of the boiler so that the supply to the fixtures will be 
 drawn from the boiler and there will be no chance of short cir- 
 cuiting it and drawing through the water front instead of from 
 the boiler. 
 
 A Space Saving Method of Installing 
 a Gas Heater. 
 
 A departure from the usual method of 
 fitting kitchen boiler water heaters is shown 
 in Fig. 95. In this arrangement space is 
 saved and a neat appearing job is secured 
 as well while the method admits of con- 
 necting the flow pipe to the side connection 
 of the boiler if desired. The usual practice 
 of placing the same size boiler as is used 
 with a coal range and water back is open to 
 the objection that the expense of heating up 
 the entire contents of the boiler is heavy 
 and as the heater is, as a rule, capable 
 of heating the water almost as fast as it is 
 drawn, the amount of storage called for 
 with the use of a water back is unnecessary. 
 If then a 20 gal. boiler is placed in the 
 manner shown and the connection is made 
 to the upper tapping, the contents of the 
 boiler can be heated to whatever tempera- 
 ture is desired, and if this is not a large 
 enough quantity for the purpose intended, 
 
 x;^ Supply > 
 
 //- / • //// ///// "Av ////// 
 
 Fig. 95. A Space Sav 
 ing Method of In- 
 stalling a Gas 
 Water Heater. 
 
 the gas can be lit and the water heated 
 while it is being drawn, thus using the hot 
 water already stored with the additional 
 supply being heated. If the boiler has a 
 thermostatic control valve attached this will bring the burner 
 into action as soon as the watei" is drawQ and so avoid the 
 necessity of attention on the part of the user. The smaller 
 boiler will also show some economy in gas, as there is less loss 
 of heat by radiation and of course less water to maintain at the 
 desired temperature. 
 
 The method of installing the heater under the boiler is espe- 
 cially well adapted for positions where the ordinary method 
 
HEATING WATER BY GAS. 127 
 
 would cause some awkward pipe fitting. Such a position, for 
 instance, is often seen in the closets behind kitchen ranges in 
 houses of the two or three apartment style where space is lim- 
 ited and where it is common to install the boiler in this closet. 
 
 It may be well to state that when a gas heater is placed in a 
 closet or other position where it is in close contact with wood- 
 work the walls should be covered with tin to a sufficient distance 
 away from the heater to prevent its ignition through overheat- 
 ing. The tin should be nailed to cleats on the wall for the pur- 
 pose of affording an air space behind it, and asbestos board 
 should be put on below the tin. It is also important to see that a 
 proper flue connection is made to carry off the burned gases and 
 also any that may leak through the burner accidentally. 
 
CHAPTEE XI. 
 
 Heating Water by Steam Coils and by Injecting Steam 
 and by Coils in Heating Furnaces. 
 
 The designing and proportioning of heating systems for 
 either domestic or industrial hot water supply on a large scale 
 generally contemplates the use of steam as the heating medium. 
 This may be either the sole means of heating or only an auxil- 
 iary, but in either case a considerable amount of care must be 
 given to the proportioning as well as to the actual construction 
 to secure satisfactory results. The first thing that is necessary 
 is to find the amount of heat that will be required to maintain 
 the quantity of water required at the desired temperature. Then 
 the amount of steam that is required to convey that heat to the 
 water and the pipe sizes that will convey the necessary amount 
 of steam must be ascertained. There are quite a few factors that 
 must be taken into consideration in arriving at the required 
 data. The transmission of heat through the steam coil to the 
 water varies according to the nature of the metal used, and if a 
 close approximation to the actual steam consumption and pipe 
 sizes is to be arrived at this point must receive careful study. 
 
 Data on Heating Water by Steam. 
 
 A French author is responsible for the statement that for 
 the same difference of temperature between steam and water the 
 coefficient of the flow of heat through the wall of a coil of pipe 
 filled with steam and placed in a tank of water varies from 1 to 
 10, according to the speed of the circulation of the water. It is 
 said that 1 square meter of copper tubing placed in a liquid in 
 motion can condense about 3 kilograms of steam per sq. meter 
 per hour per degree of difference in temperature between the 
 steam and the water, which figure is equivalent to 0.34 lb. of 
 steam per sq. ft. per deg. Fahr. per hour, or about 329 B.t.u. 
 This figure corresponds to steam at atmospheric pressure and 
 water entering at say 140 deg. and passing away at 194 deg. 
 
 With an iron pipe coil having 1 sq. meter of surface placed 
 
 128 
 
HEATING WATER BY STEAM. 
 
 129 
 
 in a tank holding about 265 gal. it was found that without cir- 
 culation in the tank, that is, with the water left intact in the 
 tank, the water was heated from an initial temperature of about 
 53.6 degrees Fahr. to the temperatures noted in the accompany- 
 ing table. Opposite each temperature is given the number of 
 minutes required to warm this volume of water from the initial 
 
 ■ 6 — J" 
 
 s 
 
 Fig. 96. Arrangement of. Steam Coil in Hot Water Tank 
 to Allow for Expansion. 
 
 temperature to that stated, both for low pressure and for high 
 pressure steam : 
 
 ^r<>™ 53.6 steam at Steam at 
 
 degrees to I1/2 to 3 lb. about 60 lb. 
 
 122 deg in 35 min. in 33 min. 
 
 140 44 42 
 
 158 60 51 
 
 1^^ 95 60 
 
 194 120 68 
 
 212 77 
 
 A test was also made of the heating of water passed con- 
 tinuously through the tank. Apparently the same steam pipe 
 coil was used, presenting 1 sq. meter or 10.75 sq. ft. of surface. 
 It was found that starting with the water at about 53.5 degrees, 
 11/2 or 1.6 gal. were heated per minute to 176 degrees Fahr. ; 21/2 
 gal. to 167 degrees ; 2.9 gal. to 158 degrees ; 3.3 gal. to 149 de- 
 grees; 3.8 gal. to 140 degrees, and 4.75 gal. to 122 degrees. These 
 figures were obtained with the steam at about 1/2 to 3 lb. pres- 
 sure. "With the same arrangement, but with the steam pressure 
 at about 28 or 29 lb., about 9^4 gal. were heated to 140 degrees, 
 as compared with 3.8 gal. with steam at low pressure. 
 
 The author quotes from data of Thomas and Laurens, who 
 
130 HOT WATER SUPPLY. 
 
 give the transmission of heat through a copper tube through 
 which the water is passed with the tube placed in a chamber of 
 steam. The tube was 10 millimeters (0.39 in.) in diameter, with 
 the copper 0.04 in. in thickness. The total length was about 10.3 
 ft., so that its surface amounted to 1.06 sq. ft. The steam was 
 maintained at atmospheric pressure. The coefficients of trans- 
 mission were given for a velocity of the water at 0.1 meter per 
 second and for speeds two, three and four times as great, and 
 so on. These figures indicate the following rates of transmission 
 of heat in B. t. u. : 
 
 0.4 ft. per second, 335 B.t.u. per sq. ft. per degree per hour. 
 
 0.5 ft. per second, 390 B.t.u. per sq. ft. per degree per hour. 
 
 0.7 ft. per second, 455 B.t.u. per sq. ft. per degree per hour. 
 
 1 ft. per second, 510 B.t.u. per sq. ft. per degree per hour. 
 1.5 ft. per second, 560 B.t.u. per sq. ft. per degree per hour. 
 
 2 ft. per second, 610 B.t.u. per sq. ft. per degree per hour. 
 2.5 ft. per second, 655 B.t.u. per sq. ft. per degree per hour. 
 
 3 ft. per second, 700 B.t.u. per sq. ft. per degree per hour. 
 3.5 ft. per second, 750 B.t.u. per sq. ft. per degree per hour. 
 
 These figures are applicable to the ordinary type of water 
 heater with a coil supplied by steam and the type commonly 
 known and used as feed water heaters in which the water passes 
 through the coil exposed to the heat of the steam in a jacket. 
 This latter style is occasionally used for hot water supply in 
 factory wash rooms and laundries where exhaust steam is avail- 
 able with satisfactory results, and the rate of transmission is 
 higher with this type, as the foregoing table shows. In the ordi- 
 nary type of horizontal tank with brass or copper coils it is 
 common to allow about 1 linear ft. of 1 in. pipe to each 5 gal. 
 capacity. This works out at about 1 sq. ft. of heating surface 
 to each 15 gallons of water, and with steam at about 225 deg. 
 temperature the contents of the boiler should be heated in about 
 one hour to a temperature of about 170 deg. The proportions 
 given in the French tests fall a little short of this, but the 
 amount of heating surface necessary is best determined by as- 
 certaining the probable requirements of the building and making 
 allowance according to the pressure of the steam supply avail- 
 able. The coils usually fitted in horizontal boilers of the style 
 used for hot water supply are built of brass or galvanized iron 
 pipe with return bends or headers. In either case there should 
 be provision made for expansion by making swing joints on the 
 connections as shown in Fig. 96. This also shows the con- 
 
HEATING WATER BY STEAM. 
 
 131 
 
 nections made through the the boiler shell in such a way that 
 the coil can be removed from the boiler when necessary to re- 
 place a leaky pipe or fitting. Many engineers believe that better 
 service is secured by the use of galvanized iron headers or return 
 bends and ells rather than cast brass, owing to the liability to 
 spreading of the fitting when making the connections. The 
 forcing of the pipe into the last thread in the endeavor to se- 
 cure a thoroughly tight joint will occasionally cause this to occur 
 
 ^ 
 
 D/a^ro^. 
 
 Wafer Supph- 
 to Diaphragm 
 
 ^% "-ngr^' 
 
 t* 
 
 •*--x 
 
 oThermosfcrfic ^ 
 ^Expansion Tube 
 
 X^.VSS-VS-ZIZZZZZ- 1 
 
 "IZZi 
 
 )C:i_:-_.: _._-"-___: 
 
 
 <-.-"----::-_--_"- 
 
 "J 
 
 ^"::::."--:-_-_--_ 
 
 
 C:i:"-v--":::: 
 
 
 jC"~-"_":i""_~"_""":-"" 
 
 
 J 
 
 WaferSuppfy 
 Inlet '^^---*t 
 
 Fig. 97. Thermostatic Control of Steam Supply to Coil. 
 
 and where a high pressure is carried in the water supply the 
 water will find its way into the steam heating system and cause 
 trouble through raising the water level above its normal height. 
 A pressure relief valve is usually fitted on the boiler and a ther- 
 mostatic valve to control the steam supply. This acts through 
 the lengthening of a rod by expansion to close the steam valve 
 or by the expansion of a liquid contained in a closed chamber 
 which is caused to open and close the steam valve through a 
 diaphragm movement. Fig. 97 illustrates a thermostatic valve 
 operated by expansion. This opens a small valve on a pipe con- 
 nected with the cold water supply and the pressure is then 
 caused to operate on a diaphragm connected with a steam valve. 
 Thus when the water in the boiler reaches the desired tempera- 
 ture the expansion of the rod opens the small valve and the 
 pressure then closes the steam valve. As the temperature falls 
 the thermostatic element in the tank contracts, allowing the 
 
132 
 
 HOT WATER SUPPLY. 
 
 valve on the steam line to open again and to remain open until 
 the temperature rises again to the desired height. 
 
 Heating Kitchen Boilers by Steam. 
 
 Heating ordinary vertical kitchen boilers by steam is not so 
 often practiced, although it is done occasionally. The coils in 
 this case are generally spiral and made of copper or brass pipe. 
 The steam enters at the top of the coil and the return pipe 
 carries off the water of condensation. The usual allowance of 
 
 
 Fig. 98. Kitchen Boiler Heated by Steam. 
 
 1 linear ft. of 1 in. pipe to 5 gal. capacity would therefore call 
 for a coil of 8 ft. of pipe in a 40 gallon boiler and this is easily 
 provided. A simple steam heater which is fitted in the same 
 manner as the ordinary kitchen boiler gas heater has also been 
 used. This consists of a length of galvanized iron or brass pipe 
 through which passes the cold water supply from the bottom 
 of the boiler. Steam is introduced to the la'rge pipe as 
 shown in Fig. 98, and transmits its heat to the circulating pipe 
 passing through it. The water as it is heated rises and passes 
 into the boiler, being replaced with the cooler water from the 
 boiler, and thus a circulation is maintained. The length of the 
 pipe is determined by the size of the boiler and the time allowed 
 
HEATING WATER BY STEAM. 
 
 13? 
 
 to heat the contents. It is somewhat difficult to allow as much, 
 heating surface as is done when the steam is passed through a 
 coil, unless it is possible to continue the large pipe through the 
 floor into the basement or room below the boiler but the rate of 
 transmission of heat from the steam to the water inside the cir- 
 culating pipe is a little higher than when the process is the re- 
 verse as with a coil in a boiler. 
 
 Heating Water by Injecting Steam. 
 
 In large institutions and in business places such as laun- 
 dries and cleaning es- 
 tablishments it is 
 sometimes found de- 
 sirable to heat the wa- 
 ter required for wash- 
 ing and other pur- 
 poses by injecting live 
 steam into tanks at 
 a high pressure, the 
 tanks being of course 
 open, or at least not 
 under any water pres- 
 
 Fig. 99. A Steam Injecting Nozzle. 
 
 sure. This may be accomplished in several ways, two of which are 
 here described. When estimating the proportions necessary for the 
 quantity of water to be heated, the heat that will be given up 
 by 1 lb. of steam may be calculated and the quantity of water that 
 will be raised to the desired temperature ascertained therefrom. 
 The following table is not absolutely accurate, but may be used 
 for the purpose of reaching approximately the sizes of boiler 
 and pipes required, although the best plan to follow when cost 
 of operation or other details requiring accuracy are demanded 
 is to secure these from the basis of B.t.u. produced by the steam 
 and absorbed by the water. 
 
 In the table the figures are based on a steam supply at 85 
 lb. pressure, and the quantities of water heated by 1 lb. of steam 
 at that pressure are given in pounds: 
 
 Temp, of water to be 
 
 heated F°..70 80 90 100 
 
 To boiling... 7 71/2 8 8i^ 
 
 To 180° F... 8V2 9V2 101/2 12 
 
 110 120 130 
 
 91/2 101,^ 12 
 
 14 16 19 
 
 140 150 160 170 180 
 IBV2 16 19 23 Va 31 
 24 32 48 96 
 
134 
 
 HOT WATER SUPPLY. 
 
 To use this table the initial temperature of the water to be 
 
 heated must be found and subtracted from 212 deg. or 180 deg. 
 
 Fahr. according as the temperature desired is one or the other. 
 
 The difference in the temperatures is shown in approximate 
 
 figures in the top line. 
 
 Under the steam pressure named, Vs-in. pipe will inject 
 
 into open bodies of water about 1 
 lb. of steam per minute. 
 
 With steam from low-pressure 
 mains (containing only about two- 
 thirds as much heat in the liquids, a 
 difference but partially offset by the 
 greater latent heat) the difference 
 in total heat and decreased velocity 
 due to lower pressure will require 
 much more time to perform an 
 equal amount of work, say, in the 
 neighborhood of 10 min. and less 
 for pressures ranging from atmos- 
 phere, up, per pound of steam con- 
 densed at ordinary submergence. 
 The delivery should be, of course, 
 through a nozzle proportioned to 
 the speed and volume or work in 
 hand. 
 
 To ascertain correctly the 
 
 Steam 
 Injector 
 
 
 amount of steam required to heat 
 a given quantity of water per min- 
 
 Fig. 100. A Special Steam and 
 Water Mixing Attachment. 
 
 ute it need only be remembered 
 that the heat unit is that amount 
 
 of heat that will raise the temperature of water at 39 deg. Fahr. 
 
 at the rate of 1 lb. 1 degree. 
 
 Finding Quantity of Steam Necessary to Heat Water. 
 
 The pressure of steam available should be ascertained and 
 the total B.t.u. available from 1 lb. of steam will then be easily 
 applied and the quantity of water it will heat found. For in- 
 stance, steam at atmospheric pressure contains 1,140 B.t.u. per 
 lb. Then if it was desired to heat the water from 40 deg. to 140 
 
HEATING WATER BY STEAM. 135 
 
 deg. Fahr. 100 B.t.u. would have to be transferred to each pound 
 of water heated. Therefore one pound of steam would heat 11.4 
 lb. of water. 
 
 To find the quantity at higher temperatures and pressures 
 of steam the following table of number of B.t.u. in one pound 
 of steam at different temperatures may be used : 
 
 At 
 
 atmospheric 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1146 
 
 B.t.u. 
 
 Af 
 
 5 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1151 
 
 B.t.u. 
 
 At 
 
 10 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1155 
 
 B.t.u. 
 
 At 
 
 15 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1158 
 
 B.t.u. 
 
 At 
 
 20 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1161 
 
 B.t.u. 
 
 At 
 
 25 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1163 
 
 B.t.u. 
 
 At 
 
 30 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1165 
 
 B.t.u. 
 
 At 
 
 35 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1167 
 
 B.t.u. 
 
 At 
 
 40 lbs. 
 
 pressure 
 
 
 lb. 
 
 of 
 
 steam 
 
 contains 
 
 approx. 
 
 1169 
 
 B.t.u. 
 
 When capacities of different apparatus are quoted in calor- 
 ies the corresponding capacity in B.t.u. may be determined aa 
 follows: — A calorie is roughly four times as large as a British 
 thermal unit. For ordinary calculations this is the figure used ; 
 where more accuracy is desired the figure is 3.96. A British 
 thermal unit represents the amount of heat involved in heating 
 or cooling 1 lb. of water through 1 degree F. A calorie, or, as it 
 is sometimes called, a greater calorie, represents the amount of 
 heat involved in warming or cooling 1 kg. of water through 1 
 degree C. As 1 kg. weighs 2.2 lb. and 1 degree C. is 9/5 as large 
 as 1 degree F., the calorie is 2.2 X 9/5 = 3.96 times as large as 
 the British thermal unit. 
 
 When steam is introduced into a body of water in either a 
 closed or open tank the condensation is accompanied by con- 
 siderable noise due to the collapse of steam bubbles, the creation 
 of vacuum at the point of collapse and the rushing in of water 
 to that point to overcome the vacuum. To lessen this annoying 
 accompaniment to the heating process the steam jet may be 
 broken up and appliances are on the market which have been 
 designed with the especial object of injecting steam so that the 
 collapse of steam bubbles will be effected in such a manner, by 
 reason of splitting up the jet into many minute jets, that much 
 of the noise will be obviated. The manner in which this is often 
 done in laundries, woolen factories and other institutions where 
 open tanks are used for the purpose of boiling soap and for other 
 purposes, and which are generally heated in this fashion, is to 
 
136 HOT WATER SUPPLY. 
 
 drill a large number of holes in the submerged copper or brass 
 pipe, the end having been closed by plugging it. These lessen 
 the noise greatly and it can be still further lessened by making a 
 cage of perforated copper with fairly small perforations and 
 fitting this around the part of the pipe which has been drilled 
 for the steam emission. This cage simply acts to break up the 
 force of the steam jets and to co-mingle them with the water 
 more readily. 
 
 In a closed tank or boiler such as is used for domestic pur- 
 poses, a type of steam jet is procurable which is designed to 
 heat water noiselessly. This jet is in the form of an inverted 
 cone which is attached to the end of the steam inlet pipe inside 
 the tank and submerged in the water, as shown in Fig. 99. The 
 steam is made to discharge outwards and upwards, thus causing 
 a circulating motion in the contents of the tank and to avoid 
 the noise resulting from the collapse of steam bubbles, a small 
 air pipe carries air to the point where the steam escapes into 
 the water. This air mixes with the steam and prevents the sud- 
 den collapse of the bubbles with the attendant noise. The steam 
 and air supply are regulated to the proper proportions by valves. 
 This heater may be used in a tank either under pressure or 
 open, but when used as a closed system a pressure of air and 
 steam in proportion to the pressure of water must be carried 
 and check valves fitted on the inlet pipes to prevent water find- 
 ing its way back into the steam boiler. Another apparatus, 
 which is illustrated in Fig. 100, is fitted to the hot water boiler in 
 exactly the same manner in which a gas heater would be fitted. 
 From the illustration it will be seen that this takes the form 
 of a closed vessel through which the water from the boiler may 
 circulate and in which a steam jet with an outlet of special de- 
 sign is placed. As the water is heated it rises in the vessel and 
 passes into the boiler, being replaced by cold water which enters 
 through the lower connection. This process is assisted by the 
 design of the jet, which breaks up the steam into minute par- 
 ticles and passes it into the vessel or co-mingler as it is termed 
 in an upward direction, thus tending to hasten the speed of the 
 circulation to the boiler. In this type of heater the tank may 
 be under pressure if the pressure does not exceed that carried 
 in the steam boiler and if check valves are placed on the steam 
 
HEATING WATER BY STEAM. 
 
 137 
 
 supply line to prevent water from the tank finding its way into 
 the steam boiler should the pressure fall. 
 
 Steam as an Auxiliary Heater. 
 
 A tank may be connected with both steam coils and a water 
 heater of the usual type as shown in Fig. 101. This is commonly 
 done where steam is available from the heating system in the 
 winter time while the water may be heated from the tank heater 
 
 Sfeom Supply fo CoH—,. 
 Controlling Valve 
 io Steam Coil 
 
 Main Supply fo Building.;-'-^, 
 Mo in Cold Water 
 ^-■Supply 
 
 Heater Supply^ 
 
 f'-O-"-' "6-i ■•.V.'O: . .■■l<i. / 
 
 Heater Pit 
 Concreie Steps 
 Sides and Bottom 
 
 
 .■?•■ 
 
 Fig. 101. Method of Connecting Steam Coil and Heater to Hot Water Tank. 
 
 at such times as the heating system is not in use. In the illus- 
 tration the heater is placed in a pit but this need only be done 
 when constructional obstacles prevent the raising of the boiler 
 en a stand to such height as will allow of a return to the heater 
 by gravity of the return water. Valves are also shown on the 
 supply to both heater and tank, these being intended to enable 
 the cold supply to the heater to be closed at such times as the 
 water is being heated by steam, and so when the by-pass valve 
 is opened and that on the return connection lower down is 
 closed, cause the circulation to the building to take a shorter 
 path on its return to the storage tank. When the water is being 
 heated by the tank heater the reverse is the case, as then the 
 valve on the by-pass is closed and that on the return connection 
 opened while the cold supply valve at the tank is closed and the 
 feed water caused to enter the tank heater by the connection 
 
138 
 
 HOT WATER SUPPLY. 
 
 to the return pipe as it enters the boiler. A boiler stand built of 
 pipe is shown in the illustration as well. 
 
 Auxiliary Hot Water Heaters. 
 
 The economy attendant on the use of auxiliary hot water 
 heaters in the form of coils or specially designed vessels which 
 
 may be placed in 
 the fire box of a 
 steam, hot water, 
 or warm air fur- 
 nac without inter- 
 ference with its 
 efficiency for its 
 main purpose is ap- 
 parent. Where 
 such provision is 
 made for heating 
 the water for do- 
 m e s t i c purposes 
 during the season 
 that the heater is 
 in daily use, and an 
 automatic gas wa- 
 ter heater is used 
 during the remain- 
 der of the year, a 
 very high degree 
 of efficiency in the 
 service is obtained. 
 Most heaters are 
 now provided with 
 a passage way for the circulating pipes that connect such water 
 heaters. These generally are placed at the side of the fire box 
 door and are covered with a plate which is easily removed 
 should the connection be desired. Fig. 102 shows such a heater 
 installed in a Kelsey warm air furnace. In this case the flow 
 pipe is carried down through the monitor top of the warm air 
 chamber, then through the dome of the fire box and is connected 
 into the top of a cast iron water heater of special design, which 
 exposes considerable surface to the radiant heat of the fire. The 
 
 Fig. 102. 
 
 Auxiliary Heater Fitted in Warm 
 Air Furnace. 
 
HEATING WATER BY STEAM. 
 
 139 
 
 return connection is made by drilling a hole in the flange which 
 covers the junction of the vertical warm air passages and passing 
 the pipe through this. A gas tight joint is made by careful 
 fitting and the provision of a locknut on the outside surface of 
 the air passages where it passes through the flues. The connec- 
 tion may also be made by taking the return back through the 
 dome top, but in 
 such a case there is no 
 means of draining the 
 heater when it is out 
 of use for any reason. 
 Instead of the 
 cast iron heater a coil 
 of brass or iron pipe 
 is frequently used, 
 this being made to fit 
 closely around the 
 walls of the fire box 
 and as a rule being 
 placed at such a 
 height that at least 
 one pipe is in contact 
 with the fire. Such a 
 coil is shown in Fig. 
 108 fitted to the fire 
 box of a round sec- 
 tional boiler, the pipes 
 passing through the 
 plates at the side of 
 the fire door by means 
 of openings specially 
 provided. Such coils are easily built from brass pipe. In con- 
 structing them annealed or semi-annealed pipe should be 
 selected, as it may be bent more easily and a neater job will 
 result. The length of the coil should be ascertained by bending 
 a wire to the desired shape, taking care that the return bend 
 will be as close to the fire door as possible so that the maximum 
 benefit will be secured. The pipes should then be cut and 
 threaded and screwed into the return bend, when the two 
 can be bent together by passing them between two firmly 
 
 Fig. 103. Brass Water Heating Coil Fitted 
 in House Heater. 
 
140 
 
 HOT WATER SUPPLY. 
 
 Fig. 104. A Heater Adaptable for 
 Nearly all Furnaces. 
 
 fastened planks and bending a little at a time until the 
 desired shape is secured. Care must be taken to secure a pitch 
 from the lower connection clear around the coil until it passes 
 through the walls of the heater again, else there will probably 
 be complaints as to noise in operation through steam collecting 
 in the coil. If the fire box is a large one some provision may be 
 necessary to support the end of the coil at the return bend and 
 
 Fi the ingenuity of the fitter must 
 
 be exercised to secure this. An- 
 other type of heater is shown in 
 Fig. 104. This may be fitted 
 with ease instead of the coil de- 
 scribed and may be placed in the 
 fire box of any type of heater 
 where it is possible to secure the passage of the pipes. The 
 method of making the connection to the boiler under various 
 circumstances is described elsewhere. Such coils and heating 
 apparatus are also frequently used for the supply of hot water 
 to a radiator in some apartment too far from the heater to warm 
 satisfactorily with hot air. In such cases the rating given them 
 is about as follows : 
 
 Cast iron sections suspended from fire box crown 1 sq. ft. to 15 sq. ft. radiation 
 
 Cast iron sections in contact with fire 1 sq. ft. to 50 sq. ft. radiation 
 
 Pipe coil above fire 1 sq. ft. to 20 sq. ft. radiation 
 
 Pipe coil partly in contact with fire 1 sq. ft. to 35 sq. ft. radiation 
 
 As these ratings are based on a flow of water to the radia- 
 tors at 170 deg. Fahr. and as that is about the highest tempera- 
 ture maintained in hot water supply tanks, it may be calculated 
 that for domestic use: 
 
 1 sq. ft. of cast iron surface suspended over fire will heat 10 ga\. per hour 
 1 sq. ft. of cast iron surface in contact with the fire will heat 25 gal. per hour 
 1 sq. ft. iron coil surface suspended above fire will heat 15 gal. per hour 
 1 sq. ft. iron coil surface partly in contact with fire will heat 25 gal. per hour 
 1 sq. ft. coil surface, brass pipe coil, partly in contact with fire will heat 30 gal. 
 per hour 
 
 These figures are approximate only, having been compiled 
 from observation of results obtained under ordinary working 
 conditions rather than from the amount of heat absorbed and 
 transferred by the heating surface, from contact with the fuel 
 or by radiation therefrom. 
 
 If it is desired to calculate the lieat that should be trans- 
 ferred to the water and the amount of water that should be 
 
HEATING WATER BY STEAM. 
 
 141 
 
 heated to the desired temperature by a given amount of surface, 
 it is safe to allow a heating value of 15,000 heat units per sq. ft. 
 of coil, and for water heaters suspended above the fire a much 
 lower rating, possibly 8,000 heat units is an ample allowance for 
 the ordinary conditions found in heating boilers and furnaces. 
 Table of equivalent heating surface in pipe coils: 
 
 1 ft. of % in. pipe = 0.275 sq. ft. surface 45 in. of % in. pipe=:l sq. ft. surface 
 
 1 ft. of 1 in. pipe = 0.346 sq. ft. surface 35 in. of 1 in. pipe = 1 sq. ft surface 
 
 1 ft. of 1% in. pipe = 0.434 sq. ft. surface 28 in. of 1% in. pipe = l sq. ft. surface 
 
 1 ft. of iy2 in. pipe = 0.494 sq. ft. surface 24 in. of ly^ in. pipe = l sq. ft. surface 
 
 1 ft. of 2 in. pipe = 0.622 sq. ft. surface 20 in. of 2 in, pipe = l sq. ft. surface 
 
 Besides the coils of copper or brass pipe and the cast iron 
 heaters which are intended to be hung over the fire in warm 
 
 Fig. 105. Auxiliary Heater Made From a Radiator. 
 
 air and other furnaces there are many other designs of auxiliary 
 heaters. Those which are made in the form of a ring or the part 
 of a ring are common and as they may be fitted so that they are 
 in contact with the fire they generally give efficient and satisfac- 
 tory service. An ingenious arrangement is shown in Pig. 105, 
 where a heater of considerable power and heating value is con- 
 structed from the sections of an ordinary hot water radiator. The 
 heater is intended to be placed in the dome of a warm air furnace 
 and is made of radiator sections to the number and of such height 
 as the size of the furnace and the nature of the work performed 
 demand. If a heater is built up of 3 columns 18 in. high, there 
 will be a heating surface of about 7 sq. ft. available. As this 
 is not in direct contact with the fire the full transmission rate of 
 
142 
 
 HOT WATER SUPPLY. 
 
 cast iron heating surface cannot be applied to it, but if a rate of 
 10,000 beat units per sq. ft. is allowed this will mean a trans- 
 mission to the water of 70,000 heat units per hour when a strong 
 fire is maintained. This is equal to raising 700 lb. or 84 gal. 
 of water from 50 deg. to 150 deg. per hour. If the fire in the 
 furnace be run at a low rate and only maintained at a dull 
 red heat the transmission would possibly not be over 5,000 
 B.t.u. per sq. ft. when of course the water heated would be 42 
 gal. The allowance of 10 gal. per sq. ft. may be taken as a 
 good average for this also. The laundry stove, which combines 
 
 Fig. 106. Laundry Heater Fitted With 
 
 Water Section. 
 
 the purpose of heating sad irons with that of heating water, is 
 shown at Fig. 106. This is a common example of auxiliary 
 heater. 
 
 In arranging to heat water by an auxiliary heater in a 
 furnace it must not be expected that the heat that is being ob- 
 tained is heat that would otherwise go altogether to waste. Each 
 pound of fuel consumed has only so many heat units to give 
 up, and if it is transferred to the water for domestic or heating 
 purposes it stands to reason that it must rob some other part of 
 the heat that would have gone there. If, however, the heater is 
 of ample size for the work it has to do, there is economy in the 
 use of such a system of water supply as the heat losses in the 
 flues remains the same. 
 
CHAPTER XII. 
 
 Utilizing Excess Heat in Heating Rooms and Domestic 
 
 Appliances. 
 
 In many cases the kitchen range or laundry heater which 
 also supplies heat for the hot-water supply system is in use for 
 long periods when no hot water is required or it may by reason 
 
 fz/'Z/ftr////''////////'//////////////'///'//'''' ////// y/// '^///// ////'///' f //////////////////% 
 
 Fig. 107. Coil on Same Floor as Boiler Heated From Water Back. 
 
 of the large demand on its capacity be of larger size than the sup- 
 ply of water required would call for. In this case there is a 
 strong possibility of the water becoming overheated and caus- 
 ing annoying rumbling sounds each time the faucets are opened, 
 owing to the water at high temperature flashing into steam 
 when the pressure is temporarily lowered. One method of util- 
 izing this excess heat is to connect the system with a radiator in 
 some one of the rooms and it can thus be taken advantage of 
 in the winter season while it is not likely that the range will be 
 used to such extent in summer as to make the water excessively 
 hot for long continued periods. The size of radiator that may 
 be added without seriously affecting the supply of hot water may 
 
 143 
 
144 
 
 HOT WATER SUPPLY. 
 
 Both Room 
 
 be estimated by allowing 2 sq. ft. of surface for each gallon of 
 water that the water front will heat. 
 
 The methods of connecting the radiator or coil are similar 
 to that which would be followed on an ordinary hot-water heat- 
 ing system. Where it is desired to heat a room on the same level 
 
 as the range the connection is some- 
 what different. The manner in 
 which a wall coil set on the same 
 level as the boiler may bs heated 
 is shown in Fig. 107. 
 
 It will be seen that the connec- 
 tion is made by means of a Y on 
 the pipe between the water front 
 and the boiler. This is done so 
 that it may be switched off entirely 
 in warm weather and also so that 
 the water at its highest tempera- 
 ture will flow to the coil. It how- 
 ever can be connected with equally 
 satisfactory results at the top con- 
 nection of the boiler, as shown by 
 the dotted line. At the highest 
 point an air cock is fitted to relieve 
 the loop of air collecting there. If 
 the system is supplied from an 
 overhead tank this air cock can 
 be replaced by a pipe whicli 
 is taken to a point higher than the tank and then returned to a 
 point over it so that any water expanded back through it will be 
 delivered into the tank. No air cock is required on the coil as 
 the cock or air pipe on the high point relieves the coil of air 
 also. The return pipe is connected to the return connection of 
 the water front as shown and a stop cock on this pipe also ef- 
 fectively prevents water backing up into the coil at such times 
 as its use is not desirable. 
 
 Fig. 108. Coil on Floor Above 
 
 Boiler Heated from Water 
 
 Back. 
 
 Connecting Coils on Floor Above Range. 
 
 The circulation of water to a coil or radiator on the floor 
 above the boiler is a simple matter. Two methods of connecting 
 them are here shown. In Fig. 108 the circulation between the 
 
UTILIZING EXCESS HEAT. 
 
 145 
 
 back and boiler is fully maintained and is direct, while the cir- 
 culation between the boiler and heating coil or radiator is also 
 secured, the descending or cooler column — that is, the return 
 water from the heating coil — being arranged to flow in the same 
 direction as the same column from the boiler to the back. In 
 Fig. 109 the flow 
 pipe, or ascend- 
 ing column, is 
 taken directly 
 from the water 
 back to the heat- 
 ing coil, on the 
 horizontal part 
 of which pipe 
 is a circulating 
 pipe, to the 
 boiler. When 
 starting the fire, 
 the circulation 
 through the pipe 
 to the heating 
 coil will be more 
 rapid . than 
 
 Uil u Ugll llldl lO XV///////////////////////Av////////^^^^^^^ 
 
 the boiler. The pig. 109. Connections Direct From Water Back to Coil. 
 
 water in the 
 
 boiler will become heated by the return water from the heating 
 coil, as well as the partial circulation through the pipe. As the 
 temperature of the water in the boiler increases, the circulation 
 through the heating coil will decrease, and if the temperature 
 of the water in the boiler should become equal to the tempera- 
 ture of the water in the coil, which is not improbable, the circula- 
 tion in the heating coil will cease. If a valve was placed on the 
 circulating pipe and closed when the coil was used, the circula- 
 tion would be continuous and the water in the boiler would be 
 slowly heated by the return water from the coil. When hot 
 water is dra^Ti off for domestic purposes, if the pipes are ar- 
 ranged as shown in Fig. 109, the temperature of the heating 
 coil will be immediately reduced, as the hot water in the coil is 
 as liable to be taken off as that in the boiler, whereas in Fig. 108 
 
146 
 
 HOT WATER SUPPLY. 
 
 c 
 
 SSgal- 
 
 ^_4 
 
 Kyi 
 
 ^ 
 
 =^ 
 
 =*& 
 
 "^^^ 
 
 ^ 
 
 y 
 
 CT'U^^ 
 
 &=&> 
 
 ///7/////////y////////////// /////////////////////////> /////f/////////////''/' 
 
 Fig. 110. Hot Water Boiler Placed in Attic as Storage and Radiator. 
 
UTILIZING EXCESS HEAT. 
 
 147 
 
 the liability to withdraw the hot water from the coil does not 
 exist, and the incoming cold water only retards the supply of 
 heat to the coil. The difference between the two plans may be 
 thus summarized: In Fig. 108 the heating of the domestic 
 water supply in the boiler is not interfered with, and the circu- 
 lation through the 
 heating coil is not 
 liable to be reduced 
 or to cease; whereas 
 in Fig. 109 the heat- 
 ing of the water in 
 the boiler is liable to 
 stop the circulation 
 in the heating coil, 
 and the withdrawal 
 of hot water for do- 
 mestic purposes and 
 the incoming cold wa- 
 ter will tend to cause 
 irregular circulation 
 between back and 
 coil, and back and 
 boiler. For the radi- 
 ating surface a return 
 bend coil may be 
 used of 114-inch pipe. 
 The length of coil 
 may be about 3 feet 
 6 inches, eight to ten 
 pipes in height, but 
 the size of the room 
 and the capacity of 
 the water back must determine this. The flow and return pipe 
 may be of %-inch pipe, if the coil is not unusually far from the 
 boiler. The use of plain or galvanized iron pipe is a matter which 
 may be determined from experience when considering the require- 
 ments of the case. So far as heating the air is concerned, plain 
 pipe is more desirable than galvanized pipe, but the latter pipe is 
 presumed to be less liable to produce rust in the water for domes- 
 tic purposes. There is no objection to the use of a radiator if pre- 
 
 Fig. 111. Radiator Connected to Supply System 
 and Extended Heating Surface at Water Back. 
 
148 
 
 HOT WATER SUPPLY. 
 
 ferred. When these are used on the same floor as the boiler, the 
 wall pattern should be selected so that the return connection may 
 be kept above the level of the water front. Better service will 
 result when this is done. 
 
 Co/dfo Boiler-^ Hot-^ 
 
 Hifchon 
 
 Dining Room 
 
 Fig. 112. A Room Heated by Warm Air and Hot Water from the Kitchen Range. 
 
 The equivalent in pipe coils of 1 sq. ft. of radiation may be 
 found from the following table : 
 
 LENGTH OF IRON PIPE REQUIRED TO EQUAL 1 SQ. FT. OF RADIATING 
 
 SURFACE. 
 
 % In About 3 ft. 8 in. 
 
 1 About 2 ft. 11 in. 
 
 1 14 , '. About 2 ft. 4 in. 
 
 11/2 About 2 ft. in. 
 
 2 About 1 ft. 8 in. 
 
 Warming a Room by Installing an Extra Boiler. 
 
 Another plan often used is to install an extra boiler instead 
 of a radiator or coil and to place this in some room that requires 
 
UTILIZING EXCESS HEAT. 
 
 149 
 
 Relief 
 
 heat so that the radiation from its surface will effect this pur- 
 pose while the amount of water held in store for immediate use 
 is much increased. An example of this method is shown in Fig. 
 110, where an attic bedroom has been warmed by the circula- 
 tion of water to an extra boiler placed therein. In this case the 
 water is heated by a coil 
 in the warm air furnace 
 as well as by the water 
 front in the kitchen 
 range and the circula- 
 tion of both coil and wa- 
 ter back is primarily to 
 the first boiler. The flow 
 to the upper boiler is 
 taken from the top of 
 the lower one and the re- 
 turn enters the heater 
 section or coil in the 
 hot air furnace so as to 
 maintain a circulation 
 throughout. It could, 
 however, have been connected to the return pipe below the upper 
 boiler with satisfactory results. 
 
 Connecting a Radiator to Domestic Supply Lines. 
 
 A little variation in the method of connecting a radiator 
 on the floor above the boiler is shown in Fig. 111. The flow pipe 
 here is taken from the supply pipe to the fixtures and returns 
 through a separate pipe to the lower connection of the range 
 boiler. An air valve is necessary on the radiator to relieve it 
 of the air collecting there. The manner of extending the surface 
 of a water front to provide extra heating surface for a large 
 radiator is also shown. This has been described elsewhere in 
 this book. The valve may be fitted on the return connection if 
 preferred, but there will probably be some local circulation in 
 the radiator if this is done. 
 
 Kitchen Stove Warming Room by Hot Air and Hot Water. 
 
 An ingenious arrangement for the utilization of excess heat 
 from a kitchen range is shown in Fig. 112. This range has a 
 
 Fig. 113. Cold Water Storage Tank Provided 
 
 With Warming Coil Heated by 
 
 Water Back. 
 
150 
 
 HOT WATER SUPPLY. 
 
 special construction which permits part of the heat of combus- 
 tion, after doing duty in warming the ovens and water front to be 
 utilized in heating air which is delivered to a near by room in 
 the same manner that warm air is delivered from a regular heat- 
 ing furnace. In this case, however, advantage was taken of the 
 warm air duct to run the hot water pipes to a coil in the room to 
 
 Fig. 114. Two Coils on Different Floors Heated by 
 Water Back. 
 
 which the warm air was conducted. The illustration shows how 
 the pipes were connected to a horizontal boiler placed above the 
 range and how the pipes passed up through the floor register to 
 the coil. As a means of relieving the system of air a pipe con- 
 necting with the bathroom fixtures was taken from the highest 
 point. 
 
 There is still another useful purpose to which the warm 
 water not required for domestic purposes can be put. In many 
 instances the cold water storage tank is placed in an unheated 
 
UTILIZING EXCESS HEAT. 151 
 
 attic and in winter there is considerable danger of the pipes and 
 tank freezing. It is an easy matter to construct a coil around 
 the tank in the manner shown in Fig. 113, and to connect this so 
 that there will be a circulation of water to it at all times which 
 will guard against freezing even when the temperature is at an 
 extremely low point. If the expansion tank is placed as shown, 
 there will be sufficient water always therein to give a little head 
 of water above the coil, as the water when hot will stand up in the 
 tank a little higher than the level of the water in the cold water 
 storage tank owing to the difference in density. If connected as 
 shown the supply to the coil maj^ be cut out in mild weather 
 without affecting the circulation in the rest of the system. 
 
 Warming Several Rooms From the Kitchen Stove. 
 
 In such cases as those in which the water for domestic pur- 
 poses is entirely heated by steam or by a special heater the 
 excess heat of a kitchen range not required for cooking is often 
 utilized for heating rooms. This does not require the use of a 
 boiler, as the water front then simply takes the place of the 
 ordinary house heating boiler, although of course few water 
 fronts have capacity enough to heat other than a small room. 
 Fig. 114 shows the water front in a kitchen range heating two 
 coils, one of which is on the second floor. The circulation is such 
 that either or both coils can be in operation without affecting 
 it and the expansion tank at the highest point of the loop takes 
 eare of the expansion in the system and also stores water enough 
 to allow of a certain amount of evaporation without constant 
 attention in refilling. 
 
 Fig. 115 shows two radiators on the second floor connected 
 in such a manner that they may be heated either by the kitchen 
 range or by the coil in a warm air furnace or by both. The con- 
 nections to the radiator are made in each case so that the supply 
 comes from overhead, obviating the use of an air valve and allow- 
 ing the water to be circulated through either or both radiators 
 as desired, or merely around the circulating loop without warm- 
 ing the radiators. The same method can be used in supplying 
 radiators on a system from which the domestic supply is taken, 
 but in that case an expansion tank would not be required as the 
 relief pipe would be turned over the top of the storage tank in 
 the attic and a boiler would be required to maintain a constant 
 
152 
 
 HOT WATER SUPPLY. 
 
 Fig. 115. Two Radiators on Second Floor Heated by Water Front and 
 
 Coil in Furnace. 
 
UTILIZING EXCESS HEAT. 153 
 
 supply of hot water for use at the fixtures. The connections 
 would then be made as shown in Fig. IIG, and the cold supply- 
 would of course be constant instead of being merely filled as the 
 evaporation lowered the level in the system. 
 
 A Plate Warming Closet Heated by Hot Water. 
 
 One of the greatest conveniences in a residence is a warming 
 closet or table in the butler's pantry or kitchen. This enables 
 food to be kept warm or plates and other dishes kept warm for 
 serving the food, and such a closet may easily be warmed by the 
 water from the kitchen range boiler. 
 
 Fig. 117 shows how the water may be circulated to various 
 fixtures so that hot water is available instantly at the opening 
 of a faucet, while the warming closet is heated by the return 
 pipe. This can be by-passed as shown by the dotted lines if de- 
 sired, so that the closet may be left unwarmed at will. The fix- 
 tures on the upper floors should be connected to the supply pipe 
 so that the act of opening a faucet would remove the air col- 
 lecting at the highest point, or if a tank supply is used the pipe 
 should be vented from the highest point. If all the connections 
 are made in the manner shown there will be little chance of 
 water being drawn through the return and so reversing the flow 
 for the time being. If, however, a connection must be made 
 lower than the coil and there is a possibility of the water being 
 drawn back from the return connection instead of the flow, a 
 light check valve may be inserted. This can be inserted in such 
 a fashion, by pitching a section of the return pipe, that the 
 swinging check will hang almost vertical and will therefore offer 
 very little obstruction to circulation, while it will close immedi- 
 ately the flow is reversed. The manner of hanging the check 
 valve is shown in Fig. 118. 
 
 Heated Towel Rails. 
 
 A fixture of considerable utility in the bath room, and one, 
 moreover, that can be made to have an exceedingly attractive 
 appearance, is the heated towel rail ; yet it is one that has been 
 almost entirely overlooked by plumbers. The ordinary bent 
 tube as a convenience for hanging towels upon is good enough 
 but the comfort and convenience of having always warm and dry 
 towels in the bath room are so obvious that when these fixtures 
 
154 
 
 HOT WATER SUPPLY. 
 
 ff^ 
 
 Hof fo Fixtures 
 
 V 
 
 Cold, to Boiler 
 
 P 
 
 I 
 
 I 
 
 :\ 
 
 VSf% 
 
 ^^^^Ml^il^^^^S^li^^^^^^li^5^ii!5 
 
 Fig. 116. Radiators Fitted in Connection with Regular Domestic Supply System. 
 
UTILIZING EXCESS HEAT. 
 
 155 
 
 are shown to a prospective customer a sale will result almost 
 every time. 
 
 Towel rails heated by a circulation of hot water from the 
 ordinary domestic supply are commonly used in England. In 
 fact, no first-class bath room or toilet room would be considered 
 complete without one, and there will probably be some consid- 
 able use made of this fixture in America now that American 
 manufacturers are including them in their catalogues. The pat- 
 
 Lavafory 
 
 Bcttk 
 
 Lavatory 
 
 Lovofory 
 
 Fig. 117. Connection to Warming Closet or Table from Water Back. 
 
 tern commonly in use in English bath rooms is illustrated in 
 Fig. 119. This rail is built of brass tube, li^ in. or 1^ in. in 
 diameter, and is, of course, nickel plated. The tees ar^ of an 
 ornamental design and wall and floor flange connections are 
 provided for flow and return pipes. Where all four flanges are 
 fixed to the wall the controlling valve is generally placed between 
 the wall flange and the rail and, of course, the flow may enter 
 the top rail instead of the bottom if preferred. This is some- 
 times desirable and, of course, necessary if the supply comes 
 from overhead. 
 
 A larger rail, designed to stand clear out in the room, is 
 also used. This is called a double rail and the name is descrip- 
 tive of the fixture, as it is simply two rails cross-connected. The 
 connections to these are, of course, always in the floor. The 
 method of connecting a towel rail is identical with that of con- 
 
156 HOT WATER SUPPLY. 
 
 necting a radiator, and there is no trouble in heating them at 
 all if the position is such that a circulation is possible. 
 
 The size of these towel rails varies according to the designs 
 of the different makers, but 30 in. wide is found generally suit- 
 able for a three-tube rail. A towel rail to give satisfactory re- 
 sults, even if it has not so good an appearance, can be con- 
 structed from the ordinary stock pipe fittings. One-inch brass 
 
 pipe, tees, right and left 
 ells, petcock and a few 
 nipples are all that are 
 required, and if care- 
 fully built quite a good- 
 looking fixture can be 
 
 Fig. 118. Method of Fitting Check Valve to produced. Solid nippleS 
 Allow It to Swins Freely. ^^^ ^^^ -^ ^^^ g^^^^^ 
 
 that are not to be used for flow or return connections, and a pet- 
 cock or air valve fitted at the top of the rail will allow for occa- 
 sional relief of air. This rail is illustrated in Fig. 120. 
 
 Utilization of Waste Heat in Heating Water for 
 Domestic and Other Purposes. 
 
 Many schemes have been brought forward in the way of 
 securing economy in fuel by utilization of heat otherwise going 
 to waste for the purpose of heating water. Among those may 
 be mentioned that of using the waste heat of a gas or oil engine 
 by circulating the water from the cooling jacket through a coil 
 whicK is placed in the water storage tank. This is applicable in 
 any factory or other place such as a creamery, where a gas 
 engine is run for any length of time. Even if the heat gener- 
 ated by the engine is not sufficient to warm all of the water re- 
 quired to the desired temperature, it will at least be enough to 
 sensibly raise the temperature and thus save fuel by causing the 
 initial temperature from which the heater has to raise the water 
 to be considerably higher. The condensation from steam traps, 
 hot closets and other manufacturing appliances where the water 
 of condensation is not returned to the boilers may be used ad- 
 vantageously in a similar manner. These are not applications 
 of heating practice that lend themselves readily to illustration, 
 as each case must be treated according to local conditions, but 
 
UTILIZING EXCESS HEAT. 
 
 157 
 
 one application of the idea is seen in Fig. 121. This installation 
 is in a steam laundry and there are so many institutions where 
 large quantities of hot water are running to waste that it would 
 seem that whenever large quantities of hot water are used and 
 discharged into the sewers this scheme might be profitably 
 adopted. A very 
 considerable sav- 
 ing in fuel is 
 effected and the 
 necessary coil and 
 tanks are simple 
 and comparatively 
 inexpensive to in- 
 stall. It also has 
 the advantage of 
 reducing the tem- 
 perature of the 
 wastes entering 
 the sewers, and 
 this is eminently 
 desirable. 
 
 In Fig. 121 
 
 is shown the supply to a hot-water tank in a steam 
 laundry passing through a coil made of about 800 ft. of 2- 
 in. galvanized iron pipe. This coil is made in two sections, one 
 being placed in each compartment of the concrete tank as shown 
 in plan in Fig. 122. The object of making the tank double is 
 to insure the waste water passing through its entire length, con- 
 nection between the two being made only at the ends furthest 
 from inlet and outlet pipes by means of 4-in. thimbles in the par- 
 tition wall. Into this tank is discharged all the hot waste water 
 from the washing machines, and as the temperature of this will 
 average around 180 deg. and the heating surface of the coil is 
 approximately 500 ft., it will be understood that the temperature 
 of the supply is raised to a very considerable extent in passing 
 through it. 
 
 The pipe from coil to boiler is covered, as is also the boiler, 
 with asbestos covering, and the steam supply to coil heater in 
 the boiler is thermostatically controlled. Thus heat is conserved 
 at both ends and the amount of steam required to maintain a 
 
 Fig. 119. Towel Rail with Floor Connections. 
 
158 
 
 HOT WATER SUPPLY. 
 
 supply of hot water to the laundry has been reduced to an ex- 
 tent that has made the installation of the coil and tanks worth 
 while. 
 
 Water Heating by Garbage Burning. 
 
 Another development in the economical use of fuel and the 
 conservation of heat otherwise going to waste is seen in the com- 
 bination garbage incin- 
 erator and water heater. 
 These heaters are pro- 
 ductive of considerable 
 economy in many cases 
 as the garbage and 
 wastes of the building 
 are often of sufficient 
 quantity to provide a 
 large proportion of the 
 heat necessary for the 
 hot water supply. The 
 construction of one type 
 of these garbage burning 
 water heaters is shown 
 in Fig. 123. It will be 
 seen that the garbage does not come in actual contact with the 
 fuel on the grate of the fire box, but is contained in a receptacle 
 immediately above it. This has a grate formed of pipe con- 
 nected to the double shell of the heater. Thus besides the heating 
 surface afforded by the walls and dome, the pipe which forms 
 the receptacle holding the garbage also acts as heating surface. 
 The garbage dries over the fire and is gradually consumed, giv- 
 ing up its heat to the water in the process and where a good draft 
 is available the process of combustion is carried out very com- 
 pletely. Such a heater is proving of value as a ready means of 
 disposing of the waste paper, straw and other litter of shipping 
 rooms in business houses, and the garbage and household wastes 
 of apartment buildings and hotels. The connections to the tank 
 are made in the same manner as with an ordinary tank heater, 
 and the drafts may be controlled by a thermostat or by hand as 
 desired. 
 
 Pig. 120. Towel Rail Made of Pipe Fittings. 
 
UTILIZING EXCESS HEAT. 
 
 159 
 
 Advantage is generally taken in bakeries of the heat of the 
 sand which covers the ovens to retain their heat in warming the 
 water used in the work of the employees. In Fig. 124 is shown 
 a common method of heating water. In this case the boiler is 
 simply buried in the sand and the supply connection made to 
 the side outlet. The cold water supply enters the boiler through 
 
 JCkftd^umh fo Boiler 
 
 7y7777>/7//7/7?/7/P7: 
 
 Hat Supply fo Machines 
 
 Outfef 
 foSe\^r 
 
 Quick Action 
 urainoQG VaivQ 
 
 Steam Supply fo Coil--,, 
 
 Boiler Supply-' 
 
 / e Wafer 
 ^mrum Machines 
 
 BoiterSupply — '■ 
 
 pj^^""^ " ^^^^^^^^^^^^^^^^^ 
 
 % '*"-To Sewer ^'^ Wastewater 
 from Machines, 
 
 Quick Acting Drainage ^Ive 
 
 Figs. 121 and 122. Elevation and Plan of Method of Utilizing Waste Heat 
 
 From Laundry. 
 
 one of the end tappings and the pipe is deflected toward the 
 bottom so that hot water will always be drawn as long as the 
 boiler is heated. The remaining tappings are plugged, there 
 not being any opportunity of fitting a sediment cock unless a 
 boiler with a special tapping on the side is secured, or a dip 
 pipe fitted as shown, when a pipe may be brought out through 
 the brickwork and a sediment cock fitted to the end of it. 
 
 Heat is transmitted to the boiler from the sand and an 
 ample supply of hot water is generally available. This system, 
 however, has the disadvantage of being difficult to get at for 
 minor repairs and in localities where much sediment is deposited 
 or where the water tends to corrode the boiler rapidly the al- 
 ternative system sSown in Fig. 125 is preferable. This has a 
 
160 
 
 HOT WATEli SUPPLY. 
 
 copper or brass coil running along one side of the oven, the 
 pipes being brought through and connected to the boiler in the 
 usual manner. The boiler may be placed higher than usual to 
 admit of the connection being made to the side tapping, as 
 shown, or it may be placed at the usual height and a connection 
 made to one of the top tappings. In either way it is an eco- 
 
 Fig. 123. A Garbage Burning Water Heater. 
 
 nomieal way of providing hot water and utilizing heat otherwise 
 not fully utilized. Still another method may be employed in 
 heating water by the heat of the sand on the top of the oven. 
 This is accomplished by making a flat coil, which is buried in 
 the sand and connected to the boiler in the usual manner. In 
 most cases it will be necessary to use a horizontal boiler and to 
 place this at a height which will admit of making the connections 
 to it so that a pitch will be secured from the coil to the side or 
 end connection of the boiler. 
 
 It is well to make the coil rather long or to use pipe of 
 
UTILIZING EXCESS HEAT. 
 
 161 
 
 large diameter, 1^4 iJ^- ^^^ preference. This is necessary owing 
 to the lower heat of the sand than that available when the coil 
 is placed inside the oven, and to the fact that the absorption of 
 heat from the sand tends =^ 
 
 to keep the layers next 
 to the pipe at a some- 
 what lower temperature 
 than the rest. The draw 
 off cock in this case is 
 fitted to the coil and 
 brought to a point out- 
 side of the brickwork. 
 
 Care should be 
 taken to lay the coil so 
 that there will be no op- 
 portunity for air to col- 
 lect and so that it pitches 
 upward continuously to 
 the boiler connection and 
 down from the return 
 connection to the draw 
 off cock. Brass pipe is best suited for such a coil and it may be 
 made either with iron headers or return bends to avoid spread- 
 ing the fittings in making the joints. Where it is desired to 
 supply one large boiler 
 with hot water from 
 coils in several ovens it 
 may be well to connect 
 them into a header and 
 from there make the 
 connection to the boiler. 
 The returns in such a 
 case would also be con- 
 nected through a header 
 to the lower tapping of 
 the boiler. Care must 
 be taken in doing so to 
 make the connections so 
 that the flow from each 
 
 . Fig. 125. A Bakery Boiler Heated by Coil in 
 
 coil would be equalized. Oven 
 
 Fig. 124. Method of Heating Boiler by Plac- 
 ing it in Sand Over Oven. 
 
CHAPTER XIII. 
 
 Air-Locking in Hot Water Supply Systems — Expansion 
 of Water, Relief Pipes and Valves. 
 
 Much of the unsatisfactory service of hot water supply 
 systems is undoubtedly due to partial air-locking in the pipes 
 causing stoppage, or at least retarding of the circulation. This 
 is especially evident in those systems supplied at low pressure 
 from an overhead tank as then the conditions are more favorable 
 to the holding back of water by a pocket of air formed by a slight 
 depression in the line or by improper connections. When the 
 tank is at some considerable elevation or the supply is taken 
 directly from the city supply mains the trouble is not so ap- 
 parent as then there is sufficient pressure behind it to overcome 
 the resistance of the air in any trapped portion. Where lead 
 is the material used in the construction the sagging that results 
 through the expansion of the pipe and improper supporting of 
 lateral runs is often responsible for an air pocket. Lead has 
 a peculiar property that distinguishes it from the other metals 
 used for water supply piping in that it ''cannot come back." 
 That is when it is expanded beyond its normal area or pro- 
 portions it remains in the formation that the expansion has 
 caused it to take. This is why lead pipe laid across joists with- 
 out a supporting strip soon sags and forms pockets between 
 each joist. The sagging is hastened and carried to a greater 
 extent when the pipe is used for hot water and if the system 
 is a circulating one the operation is very soon faulty. The 
 same result may be experienced with the use of galvanized iron 
 or brass pipe if it is not carefully laid so as to obtain a proper 
 pitch. Where branch pipes to bathrooms and other apartments 
 are carried up and a circulating pipe is returned either direct 
 to the heater or to a return pipe serving other rooms as well, 
 this fault may easily occur at the point where the return con- 
 nection is made. The illustration in Fig. 126 shows what is 
 meant and how the circulation is affected by the drooping of 
 the branch pipe to the supply end either by insufficient support 
 
 162 
 
AIR-LOCKING AND EXPANSION. 
 
 163 
 
 or by careless fitting. Another constructional cause of poor 
 supply is sliown in Fig. 127. In this case the complaint wilKbe 
 that no water can be drawn at the t\ ash trays or that the supply 
 is intermittent and poor. The cause is the trapping of air in 
 the loop made by the supply pipe and indicated by the dotted 
 lines in the illustration. It has already been explained that 
 water at normal temperature contains a considerable proportion 
 of air and that as the temperature of the water rises its capacity 
 
 P 
 
 7 
 
 5 
 
 ±^5 
 
 Fig. 126. Circulating Connections Inoperative Through Lack 
 
 of Pitch. 
 
 to absorb air falls and therefore a considerable quantity is 
 liberated when the water in the range boiler is brought to the 
 high temperature that its heating in the water front gives it. 
 This air has no means of escape and lodges in the highest point 
 of the water supply system, forcing back the water as it does 
 so. If then there is not sufficient head of water to overcome 
 the resistance of this air pocket when the faucets at the wash 
 trays are opened there will be no flow of water as the dip that 
 is formed by the branch as it passes down to the basement forms 
 a complete trap which prevents the escape of the air. Two methods 
 of overcoming the trouble are shown in Figs. 128 and 129. 
 
 The first of these shows a circulating system with the re- 
 turn pipe taken off close to the tank and with the flow pipe 
 continuing up to and turning over the top of the tank to allow 
 of the escape of air as it is liberated. Another pipe in a similar 
 position performs a like service for the cold water supply pipe 
 and enables it to be emptied should the valve at the tank be 
 closed. These pipes also prevent the accumulation of undue 
 pressure in the system and obviate the expansion back into the 
 tank of hot water from the boiler as would take place in the first 
 arrangement. The second system shows an arrangement which 
 
164 
 
 HOT WATER SUPPLY. 
 
 has some advantage over the first in that it requires less pipe, 
 the air in the branch pipe will be readily drawn off at the fix- 
 tures each time they are opened and there will be less chance 
 of reversing the circulation by the act of drawing water. 
 Another reason is that when the water in the tank is low there 
 is a possibility of drawing a certain amount of air in through 
 the expansion pipe owing to the slight resistance that the water 
 above the return branch and the strong suction that the act of 
 
 Bafh 
 
 Lav. 
 
 % 
 
 3B» 
 
 Trays 
 
 — . — — — . — * 
 
 Sink 
 
 Wafer Pocket 
 pre\fenfinq_ escape 
 
 AirPocket 
 
 JPt 
 
 Cold fo tank 
 
 t=^ 
 
 % 
 
 ^ 
 
 Fig. 127. Branch Pipes Connected so that Supply will be Unsatisfactory. 
 
 drawing it at a fixture on the lower floors has. This will 
 cause a sputtering and intermittent flow at the fixtures. This 
 disadvantage is avoided by using the construction shown in 
 Fig. 129. This trouble is as likely to occur in large systems 
 on the drop feed principle. When the supply to apartment 
 houses and office buildings is laid out so that a circulation is to 
 be maintained in each line and these are supplied from over- 
 head as shown in Fig. 74 the utmost care must be taken in lay- 
 ing the lateral pipes at the top of the loop so that the large 
 quantity of air which is being liberated in the system will have 
 immediate vent. As a rule the house tank is at a sufficient 
 height above the loop to offset any chance of drawing air back 
 through the expansion pipe, but not at such a height that an 
 
AIR-LOCKING AND EXPANSION. 
 
 165 
 
 air lock would be forced by the pressure of water tbat was avail- 
 able from it. 
 
 A Unique Remedy for Air-bound Hot-water Service. 
 
 In arranging for tbe hot-water service to a number of 
 plumbing fixtures, as shown in the illustration, Fig. 130, the 
 
 % 
 
 =^ 
 
 To Bath 
 
 To Trays 
 
 i ? 
 
 To Lavatory 
 
 ^ 
 
 Cold Wafer 
 " Supply to Boiler 
 
 * T:>S,nk 
 
 ■^ 
 
 aEZ3 
 
 ir//////////'/f '/ '///'// /y//'f /////// '///// f /''//'//// y/'/^^^/y^ ', '/ '/// '///^ f ////,///'/// '/A 
 
 Fig. 128. A System Which will Provide a Good Supply to all the 
 
 Fixtures. 
 
 piping instead of being pitched down from A to B was 
 pitched up from A to B, with the result that three of the 
 depressed risers nearest B became air bound and it was impos- 
 sible to get hot water from fixtures on these lines. 
 
 An elevation of the piping system is presented in Fig. 130 
 
166 
 
 HOT WATER SUPPLY. 
 
 with the tank heater and the hot-water storage tank at the left, 
 showing a riser running directly up to the point A. The work- 
 men were instructed to have the pipe to pitch down from A 
 to the point B, but, unfortunately, this was not done. The 
 piping was erected with a pitch in the other direction, so that 
 the air which was carried into the system with the water from 
 the street main was liberated at the top and gradually accumu- 
 
 
 Fig. 129. Method of Connecting Branch Pipes to Ensure Proper 
 Circulation and Supply. 
 
 lated to stop the circulation in the three supply risers at 
 the right. 
 
 Naturally, complaints were made and it was necessary to 
 make some change which would afford relief. It had been the 
 expectation with the pitch in the other direction that whatever 
 air was carried up and liberated at the top of the piping would 
 be carried along in supplying the various fixtures and that no 
 trouble would be experienced. An automatic air valve might 
 liave served to afford relief, but the question as to its continuing 
 
AIR-LOCKING AND EXPANSION. 
 
 167 
 
 in good condition and operating continuously was too uncertain 
 to permit its use. 
 
 As a result, an old boiler-feed regulator was connected at 
 the point B and arranged as shown in Fig. 131. The ball cock 
 was connected to the inlet in the ordinary manner. All of the 
 other openings were plugged, except that at the bottom, which 
 connected with the hot-water piping system. This allowed the 
 
 4> <• — • 
 
 
 
 
 
 
 
 AirR}cf<efabove^^ 
 
 ] 
 
 A 
 
 
 
 
 
 
 B 
 
 — 1 
 
 
 
 
 
 
 <- 'A,rb 
 
 vnd" — > 
 
 — 4 
 
 
 
 
 
 
 
 
 -^ 
 
 1 
 
 X \ * 
 
 < 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 UJ 
 
 <H-r-i 
 
 
 
 
 
 
 
 .1^ 
 
 
 1 
 
 1^ 
 
 ov. 
 
 
 
 
 
 
 &.• 
 
 L 
 
 /~. 
 
 i 
 
 
 Fig. 130. Diagram Showing Air Vent Placed to Relieve 
 System at High Point. 
 
 air to pass up the pipe into the tank and as it accumulated it 
 forced the water down, so that the float opened the cock and 
 allowed the air to escape. Thus it will be seen that when there 
 was little water in the tank, the air was allowed to escape, 
 but the float would rise with the water and close the cock to pre- 
 vent the escape of water. A check valve was placed at the tank 
 heater as shown 
 
 Expansion of Water Through Relief Pipes. 
 
 When a hot water installation is made with a supply com- 
 ing from an overhead tank it is occasionally difficult to secure 
 
168 
 
 HOT WATER SUPPLY. 
 
 as much elevation for this as is desirable. This condition fre- 
 quently obtains in houses of the bungalow type owing to the 
 style of roof that this type calls for. When such difficulties 
 arise and the tank is placed at a height very little above that 
 of the highest fixture to be supplied or of the boiler as is shown 
 in Fig. 132 there is likely to be trouble from too much hot 
 water being forced back through the expansion pipe. This is 
 of course taken to the tank and turned over the top with this 
 purpose in view, but an excessive amount added to the water 
 may increase the temperature of the water stored there so much 
 that it will be unfit for drinking purposes and unpleasant to 
 use for others. 
 
 The condition may arise in more than one way. It may 
 be due solely to the increase in volume due to the heating of 
 the water and its consequent relief through the expansion pipe. 
 It may be due to collection of the steam and air bubbles 
 liberated from the water in the water front by the process of 
 heating, for it must be remembered that water at high tempera- 
 tures will not hold as much air in solution as will water at nor- 
 mal temperature and therefore it is freed as the water becomes 
 heated. 
 
 It may be due to circulation if the tank is low. This would 
 be set up by reason of the expansion pipe virtually forming a 
 flow pipe, the cold water supply pipe acting as a return pipe 
 and thus causing the cold water tank to act as a storage reser- 
 voir for hot water. 
 
 To appreciate this the following table of increase of volume 
 in the water at different temperature should be studied. 
 
 Increase in volume of water from 40 deg. to 250 deg. Fahr. : 
 
 Temperature. Volume. 
 
 40 degrees .1.0000 
 
 50 degrees 1.0004 
 
 60 degrees 1.0012 
 
 70 degrees 1.0023 
 
 80 degrees 1.0038 
 
 90 degrees 1.0055 
 
 100 degrees 1.0074 
 
 120 degrees 1.0121 
 
 140 degrees 1.0175 
 
 160 degrees 1.0238 
 
 180 degrees ?.030'^ 
 
 200 degrees 1.0384 
 
 212 degrees 1.0433 
 
 230 degrees 1.0512 6 lb. pressure or over. 
 
 250 degrees 1.0604 15 lb. pressure or over. 
 
 Pressure 
 Atmospheric. 
 
AIR-LOCKING AND EXPANSION. 
 
 169 
 
 y^\T escape 
 
 This table will show that if the water is heated to only 
 180 deg. Fahr. the water will be increased in volume to some 
 l/30th of its bulk. That is if there is 60 gal. in the boiler and 
 another 15 gal. in the pipes and water front there will be 
 added to the tank in the attic by expansion from the water 
 heated 2% gallons of water. 
 
 This is when the tank is at such a height that the flow is 
 not continuous through circulation as indicated or at which the 
 water is forced back by air or steam 
 pressure. To avoid these condi- 
 tions the expansion pipe must be 
 taken off the boiler in such a man- 
 ner as to provide a free passage- 
 way for the air as it is liberated 
 from the water and which will not 
 tend to promote a circulation which 
 will be maintained by the inflow of 
 cold water to replace that sent up 
 into the storage tank through the 
 expansion pipe. The manner in 
 which this can be done is shown 
 in Fig. 132, If it is desired 
 to keep all the water which 
 
 is sent up the expansion pipe from mixing with the cold water 
 in the tank it is a simple matter to fit an expansion tank pro- 
 portioned to the size of the boiler and which will contain the 
 hot water without allowing it to flow over into the storage tank. 
 This is shown in Fig. 133. At the same time it must not be 
 overlooked that a certain proportion of the increased volume 
 will be relieved through the cold water supply pipe and that 
 this will back up into the tank through the pipe. To guard 
 against this a check valve may be fitted, but as the water will 
 be cold anyhow this is not a great objection. An old fashioned 
 method was to form a trap on the pipe supplying the cold water 
 but this was generally done when the open type of hot water 
 storage tank placed on the same level as the cold water cistern 
 was used, the supply being taken from one tank into the bot- 
 tom of the other. The trap prevented any circulation being 
 set up between the two tanks, but did not prevent a certain 
 
 Fig. 131. An Automatic 
 Relief Tank. 
 
 Air 
 
170 HOT WATER SUPPLY. 
 
 amount of the cooler water at the bottom of the hot water tank 
 from backing into the other. 
 
 ^ 
 
 Safety and Vacuum Valves. 
 
 The provision of pressure relief valves is a safeguard which 
 is usually adopted on all hot water tanks of any size and which 
 could with advantage be used on ordinary kitchen range boilers 
 in many cases. In towns where the use of water meters on the 
 house supply is imperative and where the supply to the hot 
 water boiler is taken directly from the main pipe there is no 
 means of relief for the pressure generated by expansion of the 
 water through heating should a check valve be placed between 
 the boiler and the meter. This check valve is usually called 
 for by the water company or municipal authorities to prevent 
 hot water being forced back through the meter and so damag- 
 ing it. The provision of a relief valve at the boiler obviates the 
 chance of a dangerous pressure being raised when a strong fire 
 is maintained in the range as it will open and allow a portion 
 of the water to escape as soon as the pressure in the system 
 rises to a point beyond that it is desired to carry. The valves 
 in common use are of the ground seat variety with a spring 
 which is adjusted to a tension equal to the pressure it is de- 
 sired to carry in the system. Another type has a lever and 
 weight which is adjustable to various pressures. These valves 
 are shown in Fig. 134. Vacuum valves work in the opposite 
 manner from safety valves, that is instead of opening when a 
 pressure is raised they open when a partial vacuum is created. 
 The object of using them is to prevent the contents of the 
 boiler from being siphoned out through the supply pipe should 
 the pressure in the cold water supply pipe fail for any reason. 
 A break in the main pipe or the drawing of more than the ordi- 
 nary amount of water from the main pipes such as might re- 
 sult from an excessive call on the main for fire purposes may 
 result in the supply failing and as the water falls back from 
 the boiler it creates a vacuum in the tank or pipes which might 
 lower the water to a dangerous extent. Should this occur 
 where a vacuum valve is fitted the vacuum would be destroyed 
 by the admission of air through the valve which would open 
 automatically. Combination pressure and vacuum valves may 
 b3 had so that the danger of either excessive pressure or 
 
AIR-LOCKING AND EXPANSION. 
 
 171 
 
 siphonage may be easily averted with a minimum degree of 
 expense and fitting. When these valves are placed over a 
 kitchen boiler they should be fitted as close to it as possible and 
 if of the combination variety, should preferably be placed on 
 the cold supply inlet, a tee being inserted for that purpose. 
 If this is done practically no water will be siphoned out of the 
 boiler when the vacuum valve comes into action as air is admitted 
 
 ^xpans/on H: 
 
 ^ 
 
 ,'-Hof 
 
 ^■Co/d- 
 
 im: 
 
 ayinr;;. 
 
 ^ '-Q'~cu/afion'> 
 
 Fig. 132. Hot Water Supply System Liable to Give Trouble From Expansion 
 
 of Water Into Tank. 
 
 directly to the cold water pipe. If placed on the other con- 
 nection the water may be lowered to the level of the vent hole 
 on the dip pipe before the vacuum is broken. Fig. 135 shows 
 how the valve may be easily fitted and also how it should be 
 fitted when the supply is taken into the tank at the lower side. 
 
 Collapse of Copper Boilers. 
 
 The use of a copper boiler of very light gauge is not ad- 
 visable for two reasons. The first of course is the comparatively 
 short life of the boiler through the extra wear and tear on it 
 caused by repeated contraction and expansion which the thin 
 shell is unable to withstand without giving out at some of the 
 joints in time. The second is the liability to collapse due to 
 accidental formation of a vacuum in the boiler by siphonage 
 or condensation of steam formed therein by overheating. When 
 a vacuum is created the thin shell is unable to resist the at- 
 mospheric pressure of 14.7 lb. per sq. in. and the boiler col- 
 lapses. So long as the boiler is full of water this pressure has 
 
172 
 
 HOT WATER SUPPLY. 
 
 no effect on it of course or even a much heavier pressure will 
 be w^ithstood if the pressure is on the internal surface as is the 
 case when the supply comes from a city main. When a vacuum 
 has been created and the boiler has been crushed it is not un- 
 common for the returning water to expand it again so that it 
 regains its original shape, but this of course is exceptional and 
 the correct course is to make provision for the absolute pre- 
 vention of a vacuum. If the system is supplied from an over- 
 head tank this is very easily done by carrying a relief pipe 
 
 X 
 
 "^ 
 
 £xDansfon 
 Tank 
 
 P 
 
 Tank 
 
 Fig 133. Method of Connecting i ^-i • i- -i r. 
 
 Expansion Tank to Avoid ^^^^^^ ^^ emptied of 
 Flow of Hot Water Into 
 Storage Tank. 
 
 from the top of the boiler to a point 
 over the tank or by fitting a vacuum 
 valve at the boiler. 
 
 The use of relief pipes and 
 vacuum valves is not general, but 
 is adopted sometimes where the 
 supply pressure is low or from a 
 tank, to provide for the expansion 
 of the water or the escape of air or 
 steam. They also permit air to 
 enter the boiler to prevent the 
 formation of a vacuum when the 
 
 water by 
 siphonage or by the condensalion 
 of steam. The proper place to con- 
 nect the valve or relief pipe is at the top of the boiler, but if 
 the hot water pipe rises direct from the top of the boiler without 
 any dip the relief pipe may be connected at the highest point 
 and run up above the level of the water supply. 
 
 Where the supply to the boiler comes directly from the 
 street main the vacuum valve effectively prevents the boiler 
 from being siphoned empty should a break occur on the main 
 or other cause operate to allow the water supply to fall back 
 in the pipes. As soon as the pressure is removed and the water 
 falls back drawing air behind it the vacuum valve opens and 
 effectively prevents the water from being forced out through 
 the supply pipe by atmospheric pressure. The usual provision 
 of a vent hole in the boiler tube is not an absolute safeguard 
 as it is not operative unless a faucet is opened to admit air 
 and then only when the water falls below the small hole. As 
 this is generally kept down from the top of the boiler so that 
 
AIR-LOCKING AND EXPANSION. 
 
 173 
 
 cold water will not pass through it too quickly and mix with 
 the hot water leaving the boiler this means that at least six 
 inches of the water in the boiler will be siphoned before the 
 action ceases. If then the faucet should be closed and the water 
 in the system become overheated steam forms in the boiler and 
 on the return of the cold water its sudden condensation may 
 form the vacuum and the boiler collapse. 
 Copper boilers should be made of heavy 
 sheet and in addition should be rein- 
 forced with bands brazed on the inter- 
 nal surface. This will give them stabil- 
 ity to resist atmospheric pressure at 
 least. Fig. 136 shows an installation in 
 which the boiler collapsed and the condi- 
 tions which led to it. 
 
 It is certain that the collapse was 
 caused by steam in the boiler due to great 
 heating capacity of the pipe water front 
 
 Pig. 5 34. Two Types of Relief Valves. 
 
 and lack of pressure in the supply. From the top of the boiler 
 to the level of the water in the tank, as shown in the illustra- 
 tion, would hardly be over 6 feet. Using the thumb rule of 
 water pressure of % pound to each foot in height, a pressure 
 of only 3 pounds would be exerted at the top of the boiler by 
 the supply. The large water heating surface exposed by the 
 construction of the water front would enable steam to be 
 generated freely and passed to the boiler. The accumulation, 
 of steam at the top of the boiler would drive the light pressure 
 water supply back to the tank and would discolor the copper, 
 slightly. Drawing off hot water at any faucet would let 
 cooler water enter the boiler and pass to the water back, when 
 the generation of steam would be stopped and the steam from 
 the boiler would follow along the hot water service pipe, both 
 
174 
 
 HOT WATER SUPPLY. 
 
 actions tending to condense the steam and create a vacuum. If 
 tlie vacuum was of considerable extent it would not be filled 
 with water before the atmospheric pressure of about 14.7 pounds 
 to the square inch on the surface of the light copper boiler 
 would cave it in. 
 
 A repetition of the conditions causing the collapse was 
 rendered impossible by taking a relief pipe from the outlet 
 pipe at the boiler as shown by the dotted line and carrying this 
 up to the tank, turning it over the top to allow any water ex- 
 panded up through it to fall back into the storage tank. The 
 collapse of double boilers may be caused by making the con- 
 
 Fig. 135. Methods of Fitting Combined Vacuum and Safety Valve to 
 Horizontal and Vertical Boilers. 
 
 nections in the wrong way. If the pressure on the inner boiler 
 was very heavy and it was emptied either accidentally or in- 
 tentionally the same conditions would be present as with the 
 single copper boiler described. Therefore it is a good plan to 
 connect the sediment cocks in the manner shown in Fig. 137 
 so that the outer boiler must be emptied before the contents of 
 the inner one can be drawn off. This is the practice where 
 there is any possibility of collapse occurring and as it is no 
 more difficult to connect in this fashion than in any other the 
 safeguard is worth making in all cases. 
 
 Method of Avoiding Excessive Pressure in Hot Water 
 System Where Check Valves Are Used. 
 
 In most water supply systems where meters are required 
 by the water company or municipal authorities it is obligatory 
 to fit a check valve on the main pipe at a point behind the 
 meter. 
 
AIR-LOCKING AND EXPANSION. 
 
 175 
 
 This is intended to prevent the hot water as it expands 
 from backing into the meter and so damaging the parts with 
 which it would come in contact. While this effectually prevents 
 the damage to the meter it leads to a dangerous condition in 
 the hot water system as when the boiler supply is taken direct- 
 ly from the main pipe there is no means for relief of the water 
 
 «r"-<» 
 
 Fig. 136. A System in Whi:h the Boiler Collapsed and the Means Taken to 
 
 Avoid its Recurrence. 
 
 when its volume is increased by heating and a dangerous pres- 
 sure is liable to be raised. 
 
 This danger can be avoided by the provision of a safety 
 valve on the boiler, but there is another method which appeals 
 to many who do not care to have the safety valve. This con- 
 sists of making a by-pass around the meter and check valve 
 and in this by-pass to fit another check valve with the swing- 
 ing valve working in the opposite direction. This as will be 
 seen from the illustration in Fig. 138 allows any excess pres- 
 sure generated by the expansion of the water to be relieved 
 through this valve, as immediately the pressure exceeds that 
 carried in the water main the check valve will open and allow 
 water to flow back into the main pipe. 
 
 Either a globe or a swinging check valve may be used but 
 the latter is generally used in hot water work owing to its 
 
176 
 
 HOT WATER SUPPLY. 
 
 lighter action. Another method is simply to drill a small hole 
 in the check valve that is fitted behind the meter. This is 
 calculated to relieve the pressure as it is generated but not to 
 
 Fig. 137. Method of Connectinor a Double Boiler. 
 
 To Main 
 
 Q 
 
 Wafer Meter 
 
 P 
 
 Fig. 138. Use of Check Valves and By-pass to Prevent Undue Pressure 
 
 From Expansion. 
 
 pass any more than a tiny stream of hot water, which mixing 
 with the cold water in the pipe would not appreciably raise 
 its temperature. 
 
CHAPTER XIV. 
 
 Common Complaints and Their Remedy — Unsatisfactory 
 
 Heating of Water. 
 
 Occasionally a complaint will be received that no hot water 
 can be drawn at the fixtures and that even when a good fire is 
 maintained in the range the trouble continues. There are sev- 
 eral causes which may operate to cause these conditions, but the 
 most common probably is that the fire is not maintained in as 
 good condition as the people believe. On examination of the 
 fire box when such a complaint is made it is common to find the 
 fuel in contact with the water front burning very dull, and the 
 cause of this may be that the fuel is banked up too high in the 
 fire box under the mistaken notion that the heavy firing will add 
 to the heating power of the boiler. As a rule it simply obstructs 
 the passage of the hot gases to the flues and prevents proper 
 combustion. The failure to keep the fire clean will of course 
 have the same result as the supply of oxygen is then insufficient 
 to support proper combustion and there is neither satisfaction 
 or economy in maintaining a fire in this condition. Then the 
 size of the coal may be the seat of the trouble. If the grate and 
 the provision for the admission of air is not designed to suit coal 
 of the smaller sizes a bright and hot fire will be impossible when 
 it is used and conversely, if too large coal is used the pieces 
 do not lie close enough to the heating surface to have the full 
 effect that is necessary to heat the water properly. 
 
 In many modern ranges also the fire box is so narrow that 
 the heat transferred to the water front cools off the coals to 
 such an extent that the layer in contact with the heating sur- 
 face is not consumed at the same rate as the rest. "With a deep . 
 fire box the heat in the general body of the fire is sufficient to 
 overcome this cooling effect without affecting seriously the value 
 in heating the other parts of the stove. This skimping of size 
 is responsible for much of the trouble that is experienced when 
 water fronts are put into stoves that previously were used for 
 baking only, and where the difference in the baking qualities of 
 
 177 
 
178 HOT WATER SUPPLY. 
 
 the range after the installation of the water front has been very 
 noticeable. In such cases it is better to use a coil of brass pipe 
 than the water front as its cooling eifect is much less noticeable. 
 
 Stoppages in Water Front May Cause It. 
 
 Another cause of bad service is that occasionally parts of 
 the core, pieces of wire and sand are left in the water front and 
 these lodge in the passageway at the end, which connects the 
 upper and lower parts of the water front. This may be present 
 in quantities sufficient to seriously affect the circulation to the 
 'boiler and yet not in sufficient quantity to stop it altogether 
 ;and so make its presence known by snapping sounds due to 
 — - — -«^^.^^ formation of steam in the water 
 
 *-^s^5^PSi^^^^^ front. In such a case very care- 
 
 '^ ^^ ^^^^^ ^^^^^^ ful inspection is necessary to locate 
 
 the stoppage and to see that it is 
 entirely removed. The other things 
 to look to are the arrangement and 
 size of the connecting pipes to the 
 boiler, the amount of pitch given 
 ""Vepair S ^Z^. *° the pipes, the number of elbows on 
 
 the connections and the distance of 
 the boiler from the stove. If this latter is too much it is quite 
 possible that the water is cooled to such an extent before reach- 
 ing the boiler that the circulation is very sluggish. If the sizes 
 of the pipes and connections are too small, of course enough 
 water is not being circulated to keep the contents of the boiler 
 up to the temperature desired. The same thing applies to the 
 pitch of the pipes and the number of elbows on it. There may 
 be an unnecessary amount of friction to overcome. 
 
 The Boiler Supply Pipe May Be Rusted OS. 
 
 Still another reason for the poor supply may be that the 
 dip pipe on the cold supply to the tank may have rusted off or 
 the connections may have been crossed and the hot supply pipe 
 been connected to the cold by accident. Again the water front 
 may be encrusted with lime and so practically insulated. If the 
 supply system is a circulating one it may be that water is being 
 drawn through the return pipe to the fixtures instead of by the 
 regular flow pipe, and that a light check valve will have to be 
 
COMPLAINTS AND REMEDIES. 
 
 179 
 
 fitted to prevent this reversal when a faucet is opened. These 
 are the factors which generally operate to cause trouble and 
 which should be tracked down when investigating a complaint. 
 
 Corrosion of Kitchen Boilers and Temporary Repairs. 
 When a galvanized iron range boiler begins to show signs 
 of corrosion after years of service this generally appears in the 
 form of small pinholes, the 
 major portion of which will 
 probably be in the upper 
 part of the boiler. Repair 
 plugs are made which are 
 easily inserted in such 
 holes, these being made of 
 steel, tempered, and of such 
 a shape that the}^ form for 
 themselves a thread on the 
 shell of the boiler by the 
 action of screwing them 
 into place. A shoulder on 
 the plug is fitted with a 
 fiber washer, and this on 
 being made up against the 
 boiler shell secures a water 
 tight joint. Should the 
 corrosion have progressed 
 too far to use such a small plug it may be possible to repair 
 the leak by driving into the hole a tapered steel pin which 
 will turn the metal inward and so form a surface which may be 
 tapped for a standard pipe size plug. Fig. 139 shows how this 
 may be accomplished. Another way of stopping a leak of this 
 nature is to drill out the corroded part securing a hole about % 
 in. dia. Then a hexagonal headed machine bolt about % in. long 
 and about 3/16 in. thick is secured and a nut fitted to it. A 
 brass washer about % i^- diameter which will fit snugly over the 
 bolt is then slipped over it and a well fitting fiber washer placed 
 behind it. The method of fitting this plug is to take out one of 
 the boiler unions in the crown and then to lower the bolt into the 
 boiler by means of a thin string which is wound around it, and 
 which hangs down below the bolt. A piece of wire bent in the 
 
 Figs. 140 and 141. Method of Inserting 
 Bolt and Washer to Repair Leak. 
 
180 
 
 HOT WATER SUPPLY. 
 
 form of a hook inserted through the hole which has been drilled 
 to enlarge that caused by the corrosion is made to catch the 
 string, and so pull the bolt through the hole, as shown in Fig. 
 141. Then the nut is put on and the washer drawn tightly up 
 against the inside wall of the boiler. Before putting it into 
 place the shell should be scraped free of rust by a bent wire filed 
 so that it has an edge which will remove the unevenness of the 
 corroded surfaces. Fig. 140 shows the bolt with its washers and 
 nuts. 
 
 Hot Water Has a Milky Appearance. 
 
 A not uncommon complaint is that water as drawn from the 
 faucets has a milky appearance, which disappears in time, leav- 
 ing the water as clear as that drawn from the cold water faucet. 
 
 Fig. 142. A Wiped Joint Swelled and Broken by Water Hammer. 
 
 In cold water supply pipes this condition is sometimes noticeable 
 in systems where a pump is used to elevate the water. It is 
 also noticeable in the supply to houses on elevated situations on 
 a city supply, and is due to air becoming emulsed with the water 
 when more than the water will absorb at its normal pressure and 
 temperature is present. This air may have been collected in the 
 system when the pipe was partly emptied for repairs, and as the 
 water was turned on again it is driven before the water and col- 
 lects at the highest points, where it escapes with the water, giv- 
 ing it the appearance noted above. In the case of hot water the 
 milky appearance is due to the water being full of small globules 
 of steam. This condition is seldom found except with heavy 
 firing or with a large water back when but little water has been 
 used for a time. This enables all the water in the boiler to be at 
 very nearly an even temperature. The boiler being subject to a 
 
COMPLAINTS AND REMEDIES. 181 
 
 pressure from the city mains, sometimes as miicli as 80 pounds, 
 enables the water to be heated to several degrees above the boil- 
 ing point, and immediately on opening the faucet this pressure 
 is very materially reduced, enabling the water in the boiler and 
 piping to expand into steam. It runs in this condition with the 
 milky appearance mentioned, and as all of the steam cannot 
 escape instantly some will be carried to the vessel, and as it 
 gradually passes off the water will become clear. If the water is 
 what is known as hard and more or less impregnated with lime 
 in solution the excessive heating will liberate the lime, which, if 
 in sufficient quantity, will give the effect described but which 
 will disappear as the lime settles. 
 
 Water Hammer in Boiler Connection. 
 
 The subject of the illustration. Fig. 142, was furnished by a 
 Philadelphia plumber, and represents a piece of pipe which was 
 taken from a job where he was called to make some repairs. 
 The broken end shows the solder in a joint that was wiped on 
 the side connection to a kitchen boiler, and which was swelled and 
 broken, it was thought, by water hammer. The enlargement 
 is very uniform, there being no special swelling in one side, as is 
 usually the case, and it will be noticed that the solder has 
 stretched quite as much as the pipe. The pipe is very heavy, 
 %-inch pipe, which shows the power of the concussions which 
 finally broke the joint, after a leak which occurred in the swelled 
 part had been stopped by hammering metal into the opening. 
 To those who are not acquainted with water hammer it is ex- 
 plained as being due to steam that has formed in the water back 
 passing to a point where it condenses, creating a vacuum which 
 is filled by an inrush of water that strikes with a much greater 
 force than is generally appreciated. When a water back is large 
 and steam is generated freely this striking is frequent, and the 
 result is as shown. A larger opening or a water way of the full 
 size of the pipe through the side connection would carry the 
 steam into the boiler before it condensed. 
 
 Removing a Lukewarm Water Complaint. 
 
 Whether there is any justice in it or not the stove manu- 
 facturer is called upon to make good many things for which he 
 is in no way responsible, and a short time ago it was necessary 
 
182 
 
 HOT WATER SUPPLY. 
 
 Hof Wafer Ouf/ef 
 
 for a manufacturer to send a salesman some distance to look 
 into the cause for a faulty service in the hot-water supply from 
 one of his ranges. Fig. 143 shows the manner in which it was con- 
 nected. As can be seen, there is nothing wrong with the con- 
 nection between the range and the boiler. This range and the 
 water front are frequently used in connection with boilers of 
 larger capacity, and have ample capacity for the 30-gal. boiler 
 with which it was connected in this case. Nevertheless, the range 
 was blamed for the trouble, as is the usual experience of stove 
 
 manufacturers, until it 
 was demonstrated that 
 in place of the range and 
 water front being at 
 fault the trouble was 
 due to the gas water 
 heater connection, which 
 though it had a stopcock 
 to shut off the circula- 
 tion through the water 
 heater when it was not 
 in use, was not turned 
 off. In consequence, it 
 
 'afer 
 Heater 
 
 l^, >^//. ,///^^.^y.,?.,\ ' y, /,/,,///>/////// y//r//'/^///\ was a simple matter for 
 f/^^../../^//././//.^.,/./..,/^/,,//./.,^/^.///, //./;» ^^ gQ^^ water flowing 
 
 Fig. 143. A Water Heater Connection Which • . .^ . -n ^.^enever 
 Gave Poor Service. ^^^^^ ^^^^ uouei NMienevei 
 
 the hot water faucet 
 of any fixture was open to short-circuit through the bottom 
 of the boiler and up through the gas heater into the hot- 
 water service pipe to mingle with the hot water and give only a 
 lukewarm supply of water. Just as soon as this stop-cock on the 
 supply pipe to the gas water heater was shut off the trouble 
 immediately stopped. 
 
 Apparently this customer had had similar troubles in a num- 
 ber of cases, but had never before learned exactly how to get over 
 them, and said it was worth a great deal to him. It certainly 
 entailed an unnecessary expense upon the manufacturer, but for- 
 tunately they are the exceptions, and in most instances the men 
 to whom furnaces, ranges and stoves are sold know their busi- 
 ness so thoroughly well that they do not overlook just such 
 troubles as this and solve their problems alone. In consequence 
 
COMPLAINTS AND REMEDIES. 183 
 
 there are no hard feelings when occasionally a good customer 
 finds himself stumped and needs assistance. 
 
 Cold Water Drawn at Hot Water Faucet. 
 
 In a system of hot water supply where a boiler on the second 
 floor was heated by a coil in the basement and one in the kitchen 
 range, there was a complaint that it was impossible to draw as 
 much hot water as should be expected. The connections were 
 made as shown in Fig. 144, and it was found that when the fau- 
 cets were opened the cold water rushing into the boiler at the 
 same end as that at which the supply pipe was connected short 
 circuited, and instead of forcing the hot water out of the boiler 
 to the faucets, took the shortest path through it and only a small 
 quantity of hot water was sent into the pipes before the cold 
 water followed it. The trouble was remedied by making the 
 connections as shown in Fig. 145. In this it will be seen that the 
 cold water supply enters the boiler at the opposite end to that at 
 which the hot water leaves it, and this is sufficient to force all the 
 hot water it contains out as the cold water enters. The trouble 
 could have been remedied by using dip pipes inside the boiler 
 also, but this is the most certain way. 
 
 Rusty Water. 
 
 One of the chief causes of complaint, and one that is very 
 hard to eradicate, is that of rusty water. The rust may be pro- 
 ceeding from one of many causes, and it may be impossible to 
 prevent its accumulation in the boiler, as for instance when the 
 water that is supplied had a particularly active effect on the 
 pipes and water front. There is, however, a method of making 
 the connection that will alleviate the trouble greatly. If the 
 boiler supply tube be taken out and a brass tube substituted 
 which will have the end plugged and a number of holes drilled 
 around the pipe at its lower extremity it will be found that the 
 rush of water into the boiler instead of stirring up the rust on 
 the bottom will be directed against the sides, and will therefore 
 have no such effect. The conditions can be still further improved 
 by the use of a duplex boiler connection, as shown in Fig. 146, 
 for the hot water circulating connection, as in this case the water 
 entering the boiler will also be delivered into the body of water 
 already in the boiler, and so avoid any eddies while the hot 
 
184 
 
 HOT WATER SUPPLY. 
 
 water is drawn from the highest point in the boiler. The boiler 
 tube drilled and plugged as described is shown in Fig. 147. 
 
 Making an Extra Connection to a Boiler. 
 
 For the purpose of making an extra connection to a boiler 
 to suit the needs of a circulating system of supply to a distant 
 
 e 
 
 SOGollons 
 
 Return to Boiler--' 
 
 '■Hot to Fixtures 
 "Boiler Supp/y 
 
 ^ 
 
 . Collin 
 Kitchen Range (^ 
 
 Hot Wafer 
 to Fixtures 
 
 ^ 
 
 P 
 
 =aai 
 
 Cold Water 
 to Fixtures 
 
 P 
 
 ^ 
 
 xt 
 
 ^ ii .'^'i^iSis^^ - 
 
 Fig. 144. Connections to a Horizontal Boiler Which Caused Short Circuiting. 
 
 fixture or to take in the return from a radiator which it is de- 
 sired to heat from the kitchen range, it is sometimes necessary to 
 drill a hole and make a new connection to the boiler. Fig, 148 
 and the description shows how this may be easily and effectively 
 
COMPLAINTS AND REMEDIES. 
 
 185 
 
 done. After the water has been withdrawn from the boiler it is 
 a comparatively simple matter to arrange for another connection 
 with the boiler shell. First, it is necessary to make a hole in the 
 side at the desired point and of the right diameter, to allow the 
 piece of threaded pipe, preferably 1 in. in diameter, to be in- 
 
 Small VeqfHole 
 in 
 
 5) 
 ^Coifhfymace 
 
 //yy//y/////y//r///yyy/yyAy///fy/y ' y// ^ ^/y / y / ^ //• y^/^f/// y / / / y y y / f ^ ^ y / / ^ ////^ / // / / y / / f ^ y / / / / / ^ / / / ^ / / ^ ^ ^ /^'l 
 
 VyVyy/,Y//yy/yV/////y///////y/////y///yV/yV/,v,v/yV/////^^^^ 
 Fig. 145. Changes Made in Boiler Connections to Provide Satisfactory Supply. 
 
 serted. Next it is necessary to file at opposite points on the circle 
 notches just wide enough and deep enough to allow a lock 
 nut to be passed through. If a hole is drilled in the lock nut so 
 that a wire can be inserted for holding it until the pipe is screwed 
 
186 
 
 HOT WATER SUPPLY. 
 
 into it, it will facilitate the work of making the connection. The 
 pipe should have a long thread, so that a lock nut can be screwed 
 up against an iron washer covering a soft washer, all of the 
 threads on both washers and the surface of the boiler being coated 
 first with rather thick red lead. Then when the lock nut is 
 screwed up tight the opening in the boiler will be eif ectively cov- 
 
 Boiler 
 Union 
 
 ooooooc 
 ooooooo 
 ooooooo 
 
 OODOOOO 
 
 ooooooo 
 ooooooo 
 ooooooo 
 
 Fig. 146. A Duplex Boiler 
 
 Connection W hi c h Prevents 
 
 Short Circuiting. 
 
 Fig. 147. Boiler Tube Which 
 
 Will Not Stir Up the 
 
 Sediment. 
 
 ered, as shown in the illustration herewith. Owing to the boiler 
 shell being curved, it is well to have the soft washer pretty thick, 
 or to form the iron washer covering it to the shape of the boiler 
 shell, and when the lock nut is screwed up some strain should be 
 put on the wrench to make sure the joint is tight. The outer end 
 of the nipple is then ready for any pipe connection that may be 
 needed. 
 
 Hot Water Supply to Barber Shop. 
 
 A satisfactory outfit for the supply of hot water to a barber 
 shop may be made as described in Fig. 149. This consists of a 
 copper tank 13% in. diameter and 13 in. high made out of 16 oz. 
 copper, so that it will be stiif without the use of beads. The top 
 is made in the form of a flat cone in the center of which is left a 
 hand hole with a cover 5 in. diameter. This is made to lift off, so 
 
I 
 
 COMPLAINTS AND REMEDIES. 
 
 187 
 
 that the tank may be filled with water as required. Immersed 
 in the water is a coil of % in. brass pipe made by winding the 
 pipe around a wooden block until turns enough have been made. 
 The coil is 8 in. in diameter and contains 12 to 18 ft. of pipe as 
 may be required. Eighteen feet of pipe will heat enough water to 
 supply a shop with four chairs even when they are busy. The 
 coil is fastened into the tank by lock nuts, a gasket being put 
 between them and the copper. 
 
 The burner chamber is made of black sheet iron with 1 in. 
 holes punched around 
 the upper and lower 
 edges. The chamber 
 is 7 in. high and 
 a hole about 4 in. 
 by 6 in. is cut to 
 allow of the burner 
 being lighted. It is 
 better to leave this 
 without a door, 
 
 L-RedLead 
 "Gasket 
 
 Fig. 148. 
 
 '"Long Threaded 
 
 ^,, 'l—-Jron Washer 
 ^LockNufs 
 Method of Making Extra Connection, 
 to Boiler. 
 
 as there is more air then for proper combustion. An ordinary 
 Bunsen burner can be used or a small boiling ring such as is used 
 for cooking. The space between the base and the stand on which 
 it is placed may be filled with sand to guard against fire. The 
 apparatus, of course, is connected with the water supply system 
 and provides hot water instantaneously, so a valve is fitted to 
 control the supply and to pass only as much water as can be 
 heated to the desired temperature. The copper chamber requires 
 attention, and must be kept filled with water, but if the cover 
 is a good fit there is not much loss by evaporation. 
 
 Comparative Value of Lead and Brass for Range Connections. 
 
 Lead pipe as a material for the connection of range boilers 
 and water fronts possesses only one recommendation — its free- 
 dom from corrosion. In many towns the use of lead pipe is 
 almost compulsory owing to the rate of corrosion of iron pipe 
 with the water provided for public use, and in these towns there 
 is generally quite a large repair business done in connection with 
 the replacement of range boiler connecting pipes or the repair of 
 leaks at joints. This is due to the great amount of wear and tear 
 caused by the expansion and contraction of the pipes, and as lead 
 
188 
 
 HOT WATER SUPPLY. 
 
 W/P/ ' -^^ ' 
 
 does not withstand this movement very well it soon gives out at 
 the bends or joints where the motion is retarded. Sagging of the 
 pipes also occurs. This is due to the pipes becoming very easily 
 bent when heated and by the expansion lengthening them and 
 the inability of the lead to recover its original shape entirely 
 when cooled again. The connections to the boilers and water 
 fronts are made by means of brass unions wiped to the lead 
 pipe and screwed into the iron. The method of connecting a 
 ■5'Cover p^ boiler with lead pipe is shown 
 
 in Fig. 150. Brass pipe may be 
 used for boiler connections in 
 the same manner as iron ; that 
 is, elbows,, tees and other fit- 
 tings may be procured in the 
 same designs and in the same 
 sizes as in iron. It may also be 
 easily bent, and when this is 
 done neatly it offers a medium 
 for a permanent and smooth 
 working job, as there are no 
 sharp turns to obstruct the 
 circulation. When brass pipe 
 is threaded and screwed into 
 a fitting of the same material 
 care should be taken not to 
 force the thread in further 
 than is necessary to secure a 
 tight joint. If a thread with much taper is cut, and it is at- 
 tempted to screw the thread far enough home to hide all the 
 thread it may easily happen that the fitting will be spread and it 
 will be impossible to secure a tight joint. It is better to see that 
 a good sharp thread is cut, and that it is not so full that the whole 
 length cannot be made into the fitting without straining it se- 
 verely. It is advisable to examine all fittings for sandholes be- 
 fore inserting them also, as they are liable to contain small flaws 
 which are easily overlooked until the water is turned in. Brass 
 pipe does not corrode like iron, and there are no minerals met 
 with in potable waters that have any injurious effect on it, al- 
 though it is of course liable to become stopped with sediment 
 like other pipes. A method of connecting a range with brass pipe 
 
 Q (T&^ ^y O 
 
 LjQhfini 
 enin\ 
 
 ^ 
 
 ^ 
 
 I'Hofes 
 i"apatf 
 
 Q O^plf OO OO 
 IJ^^ 
 
 I 
 
 to 
 
 V. 
 
 I 
 
 Fig. 149. 
 
 A Water Heater 
 Barber Shop. 
 
 for 
 
COMPLAINTS AIn^D REMEDIES. 
 
 189 
 
 showing the unions used, and also supports for the gas heater, is 
 shown in Fig. 151. The nipple between the cross tee and the 
 floor flange is made solid, this feature being intended only to 
 secure rigidity. It is customary to use unions at the water-front 
 end and it is often more convenient to fit them at the boiler as 
 well. This applies especially where the pieces are long and 
 where it would be difficult to turn the piece into the boiler 
 tapping direct. In cutting threads on brass pipe some men will 
 
 W//. ///■'■/■.-'■■-'''■-'■■''■■'•/■''■'■■■'■■■'■'■'■■'■'■■'■■ ■■'■'^/■•* r/'-'/A/-///////////-'////////////////////'///-/-' ■■■■''■'■■'■■/■■ ■■'■* 
 
 Fig. 150. Range Boiler Connected Fig. 151. Range Boiler Connected With 
 With Lead Pipe. Brass Pipe. 
 
 not allow oil to be used, but the point is a minor one, and if a 
 good grade of lubricating oil is employed the die seems to work 
 better when treated as if iron pipe were being threaded. 
 
 Copper pipe is used to a great extent in English practice, 
 but has no advantage that brass does not possess. It is impera- 
 tive that it be tinned, inside at least, and it is commonly supplied 
 tinned outside as well. Two grades are procurable. Hard 
 copper pipe is best suited for work where fittings are em- 
 ployed, as it will stand up as well as brass or iron pipe. Where 
 it is desired to bend the pipes, soft or annealed copper is 
 preferable. This is easily worked, but requires hangers at fre- 
 quent intervals when fitted in long lengths. Brass pipe may 
 also be supplied in annealed or semi-annealed form and is easier 
 to bend for boiler connections than the hard brass quality. 
 
TYPICAL EXAMINATION QUESTIONS ON THE 
 
 THEOEY AND PEACTICE OF HOT WATER 
 
 SUPPLY INSTALLATION. 
 
 CHAPTER 1. 
 Pages 7 to 15. 
 
 1 — Define the meaning of the word "Circulation" as applied in the 
 practice of hot water supply fitting. 
 
 2 — What is the cause of circulation? 
 
 3 — Is the density of water the same at all temperatures between 
 freezing and boiling points ? 
 
 4 — What takes place in a body of water when heat is applied to the 
 low.er part of the vessel in which it is contained? 
 
 5 — What do you understand by the term "Motive Column"? 
 
 6 — Why should a dip in the pipes of a hot water supply system 
 prevent circulation? 
 
 7 — Define the meaning of Combustion. 
 
 8 — What is the relation of Heat to Combustion? 
 
 9 — Can you define an application of radiation, convection and con- 
 duction in the practice of heating water? 
 
 10 — ^Which means of transmitting heat is the most effective, radia- 
 tion, convection or conduction? 
 
 11 — Why does the production of smoke and its emission at the 
 chimney of a heating plant indicate a lack of economy? 
 
 12 — What is necessary in a firebox to secure the highest economy 
 and most perfect combustion? 
 
 14 — What is the average heating power of anthracite and the aver- 
 age amount of heat per pound of fuel transmitted to the water? 
 
 15 — What is the difference between a strain and a stress? 
 
 16 — What is the relation of elasticity to elastic limit? 
 
 CHAPTER 2. 
 Pages 16 to 24. 
 
 17 — Is a pipe conveying hot water more liable to corrosion than 
 one conveying cold water? 
 
 18 — What is the difference between corrosion and sedimentation? 
 
 19 — What are the principal causes of deposits in water fronts and 
 boilers? 
 
 20 — Why should corrosive influences appear to be most active at 
 temperatures between 140 and 180 Fahr.? 
 
 190 
 
TYPICAL EXAMINATION QUESTIONS. 191 
 
 21 — In view of the more severe corrosive influences in hot water 
 systems operating at high temperatures, what may be done to miti- 
 gate the trouble? 
 
 22 — How is the hardness of water measured and classified? 
 
 23 — Can a permanently hard water be used without danger of 
 precipitating sediment in the water front or pipes? 
 
 24 — How may the presence of lime in water be made evident in a 
 hot water supply system? 
 
 25 — What is a good method of removing lime and kindred deposits 
 from water fronts and pipes? 
 
 26 — Is there any method of piping a hot water boiler to avoid 
 precipitation of lime? 
 
 27 — What is the best type of fittings to use in pipes liable to stop- 
 page by such deposits? 
 
 28 — Is there any appliance that may be fitted to the connecting 
 pipes of a boiler and water front to facilitate removal of sediment? 
 
 29 — In what conditions is it important that there should be no heat 
 loss by radiation from hot water pipes or storage boilers? 
 
 30 — Can you describe any method of preventing heat losses? 
 
 31 — What effect on the rate of heat loss by radiation has the paint- 
 ing of a storage tank? 
 
 32 — Is the heat loss the same with the use of all kinds of paints if 
 the same number of coats are applied? 
 
 CHAPTER 3. 
 Pages 17 to 33. 
 
 33 — What are the correct positions of the tappings for connections 
 in water fronts or water backs? 
 
 34 — What is the object of having a partition in a water back? 
 
 35 — Is there any danger of damage being done to water fronts by 
 accumulation of sediment or steam? 
 
 36 — What indication Is given of accumulation of sediment in the 
 appearance of a water front? 
 
 37 — What is the most effective position in the firebox for a water 
 heater? 
 
 38 — How may the water heating and baking qualities of a range be 
 depreciated by the proportions of the water front and firebox? 
 
 39 — ^What is about the maximum exposure of heating surface pos- 
 sible in a kitchen range water back? 
 
 40 — Why should water fronts be bedded with cement or fireclay? 
 
 41 — Is it important that the stove should be set level? 
 
 42 — How may the heating surface of a water front be easily ex- 
 tended? 
 
 43 — How are coils for water heating made to fit kitchen range fire 
 boxes? 
 
192 HOT WATER SUPPLY. 
 
 44 — What should be particularly guarded against in fitting coils 
 of the usual type to a kitchen range? 
 
 45 — Is the type of coil fitted in a position over the fire box as 
 efficient as that which is in contact with the fuel? 
 
 46 — How is the capacity of a water front computed? 
 
 47 — What is the highest rate of heat transmission that should be 
 ■estimated in water fronts and coils in proportioning sizes of a water 
 supply? 
 
 48 — Should the maximum requirements of a household be made the 
 basis on which to estimate the proportions of heating power required? 
 
 CHAPTER 4. 
 Pages 34 to 45. 
 
 49 — ^What is meant by "allowing a swing" to the joints in a range 
 boiler connection? 
 
 50 — What is the cause of pounding in range boilers? 
 
 51 — What should be investigated first when a complaint of an in- 
 sufiicient supply of hot water is registered? 
 
 52 — How may such a complaint be due to partial stoppage of a 
 water front? 
 
 53 — ^When a new range and water front is connected up to an old 
 boiler and mich a complaint is made, what should be the course of 
 investigation that should be followed? 
 
 54 — How is a boiler connected when the side connection is lower 
 than the upper tapping of the water front? 
 
 55 — What is understood by the term "quick heating connection"? 
 
 56 — When a connection of this sort is made are the whole contents 
 of the boiler brought to an equal temperature quicker than with the 
 other style? 
 
 57 — How is a boiler connected with a water front when a door or 
 window intervenes? 
 
 58 — What is the usual practice in connecting a gas water heater 
 with the kitchen boiler? 
 
 59 — How can these connections be made to mitigate stoppages 
 through deposit of sediment in the coils? 
 
 60 — How may a vertical range boiler be connected with the supply 
 and cold water system to provide an ample flow when the pressure 
 of the cold water supply is low? 
 
 61 — Is any disadvantage generally attributed to the system of sup- 
 plying cold water to a boiler through the bottom tapping? 
 
 62 — How may the connections be made to a standard vertical boiler 
 when it is necessary to fit it in a horizontal position? 
 
 63 — Why is the provision of a vacuum valve on the boiler consid- 
 ered preferable to the common custom of drilling a hole in the feed 
 tube? 
 
TYPICAL EXAMINATION QUESTIONS. 193 
 
 64 — Why is it better to have all the tappings of a horizontal boiler 
 in the sides instead of the ends? 
 
 65 — What disadvantage is likely to result from setting a steam 
 heated horizontal boiler at a level very little above the water level 
 of the steam boiler? 
 
 66 — What is the object of fitting an equalizing pipe to the steam 
 supply and return pipes of the coil? 
 
 67 — How may careful proportioning of the steam supply and return 
 pipes offset any possible disadvantage of the low level of a steam 
 heated boiler? 
 
 CHAPTER 5. 
 Pages 46 to 59. 
 
 68 — What is the principal requirement in the piping connections of 
 a boiler set on the floor below the range with which it is connected 
 to ensure satisfactory heating? 
 
 69 — What is the cause of circulation in a system constructed in this 
 manner? 
 
 70 — What is the rule generally followed in arriving at the height 
 of the circulating loop? 
 
 71 — Is there any possibility of emptying the water front accidentally 
 when the boiler is fitted at a lower level than the range? 
 
 72 — How may the connections to fixtures be made to effectually 
 prevent emptying of the water front or the circulating loop below 
 the highest point? 
 
 73 — Is it necessary to provide an air cock on a circulating loop 
 when the supply is taken from an attic tank? 
 
 74 — Should a fixture on the lower floor be supplied from the pipe 
 connecting the boiler with the water front when the range is on the 
 floor below the boiler? 
 
 75 — Is it of any advantage to connect the boiler by both top and 
 side tappings when the water front is on the floor below it? 
 
 76 — What is the best way of connecting an additional horizontal 
 boiler to an existing one when extra storage capacity is required? 
 
 77 — How may two vertical boilers be connected to ensure that the 
 flow will proceed equally from each? 
 
 78 — How may two boilers be connected so that the supply from one 
 will be larger than that from the other? 
 
 79 — Wha^ should have chief consideration in connecting two boilers 
 to one water back? 
 
 80 — Should the same type of connection be used when the boilers 
 are far apart as when they are close together? 
 
 81 — How may equal distribution to the two boilers be promoted by 
 the use of special fittings? 
 
 82 — What is the best method of connecting two boilers on different 
 floors to one water front? 
 
194 HOT WATER SUPPLY. 
 
 83 — Why should the range farthest away from the boiler be con- 
 nected to the top tapping? 
 
 84 — Is there any possibility of retarding the flow from one heater 
 by the flow from the other? 
 
 85 — What would be the consequences of this retarding of the flow 
 in the water front? 
 
 86 — How would the connections to two water fronts on one floor and 
 one on a lower floor be made to one boiler on the upper floor? 
 
 CHAPTER 6. 
 Pages 60 to 73. 
 
 87 — Is there any objection to passing the flow from a water front 
 on one floor through the water front on a floor above and so into the 
 boiler? 
 
 88 — Is it good practice to connect more than one water front to the 
 side tapping of a boiler? 
 
 89 — How should a boiler in a basement be connected with a water 
 front on the floor above and a tank heater in the basement? 
 
 90 — When a circulating pipe is brought down from a water front 
 on the floor above the boiler and the supply to a circulating loop 
 leaves the boiler at the same tapping will satisfactory service be 
 given ? 
 
 91 — How may a fixture be connected with circulating loop so as to 
 prevent accumulation of air in the system? 
 
 92 — What is the principal fault experienced with the method of 
 water supply necessitating the connection of more than one boiler to 
 a common main hot water supply line? 
 
 93 — Is there likely to be as much trouble when the boilers are 
 on different floors as when they are on the same level? 
 
 94 — What advantage is secured by causing the water in the two 
 boilers to be circulated between each other? 
 
 95 — Can a system using more than one boiler be operated from a 
 cold water supply to one boiler only? 
 
 96 — How should a system that is to supply two flats be installed so 
 that the water will be available to each house when heated from 
 either boiler? 
 
 97 — What is likely to take place if an expansion tank or rather a 
 cold water supply tank over which an expansion pipe has been fitted 
 is placed at a level only slightly above the boiler? 
 
 98 — Is it possible to take the supply from a heated boiler in a base- 
 ment and introduce it through the cold water feed tube to a boiler on 
 the next floor with any degree of success? 
 
 99 — How may the flow from two boilers on the same floor be 
 equalized so that a slight superiority in temperature in one boiler 
 would cause a little stronger flow from that one and an equal flow 
 when the temperature is equal? 
 
 ^ ^ 
 
TYPICAL EXAMINATION QUESTIONS. 195 
 
 CHAPTER 7. 
 Pages 74 to 90. 
 
 100 — "What are the most objectionable features in the ordinary 
 system of hot water distribution? 
 
 101 — Are any of the objectionable features in a non-circulating 
 system of hot water distribution emphasised when a low pressure of 
 water obtains? 
 
 102 — What advantage is obtained by using the header or "water 
 table" method of distribution? 
 
 103 — What is the best method of constructing such a water table? 
 
 104 — What is the difference between a primary and a secondary 
 system of hot water circulation? 
 
 105 — Is it advisable to continue a circulating loop to a fixture under 
 the floor and close up to the fixture? 
 
 106 — What should be done to prevent the accumulation of air in 
 the circulating pipes? 
 
 107 — How is a system of circulation with independent loops to each 
 fixture or set of fixtures constructed? 
 
 108 — Does such a system possess any advantage over a simple con- 
 tinuous circulation system? 
 
 109 — How is water prevented from backing up the return pipes 
 when a faucet is opened on a circulating loop? 
 
 110 — Are swing checks better than globe checks on a circulating 
 system? 
 
 Ill — Is it possible to install one system of piping to supply hot 
 water or cold water at will? 
 
 112 — What must be done to obtain circulation to a fixture when a 
 door or window intervenes between the boiler and the fixtuj'e? 
 
 113 — How may a number of apartments be connected so that each 
 will have a separate boiler heated at will from a gas heater or from 
 a common heater placed in the basement? 
 
 114 — How should such a system be piped to secure a minimum 
 chance of leakage from the circulating pipes? 
 
 115 — What is the difference between a drop feed or falling circula- 
 tion system and a rising supply system? 
 
 116 — What are the principal points of difference between this sys- 
 tem and the English intermediate cylinder system? 
 
 117 — What is the purpose of a water heated towel rail and how 
 should it be connected to the hot water supply system? 
 
 118 — How would a circulation system be arranged if the boiler was 
 on the same floor as the fixtures? 
 
 119 — Where should a safety valve be fitted to be most effective? 
 
 120 — How may water be circulated to fixtures on a level lower 
 than the boiler? 
 
 121 — How can the insertion of a valve in the circulating system be 
 made to act as a preventative of reversing the circulation? 
 
196 HOT WATER SUPPLY. 
 
 CHAPTER 8. 
 Pages 91 to 100. 
 
 122 — How is the flow of water equalized on the different floors in 
 buildings of great height? 
 
 123 — What disadvantage is experienced through the carrying of 
 extra heavy pressures at steam coil heated boilers? 
 
 124 — What is being done in modern buildings to avoid this dis- 
 advantage? 
 
 125 — What is the most common type of circulating system used in 
 office and apartment buildings? 
 
 126 — Why are control valves fitted at the base of the loops in a 
 drop feed system as well as at the connection with the main distrib- 
 uting pipe on the top floor? 
 
 127 — How is the expansion on the long stretches of pipe taken up? 
 
 128 — How are the lateral connections connected back to cause a 
 circulation to be promoted in them when the distance from the drop 
 pipe to the fixture is great? 
 
 129 — What is understood by the sectional system of hot water 
 supply? 
 
 130 — How are the proportions of hot water boilers and heaters for 
 a battery of shower baths estimated? 
 
 131 — How many gallons of water a minute are passed by the average 
 shower head? 
 
 132 — Should the amount of water that is possible to be passed 
 through the showers simultaneously be taken as the proper amount 
 to base the proportions of the heater and boiler upon? 
 
 133 — What is the proper method of estimating the resultant tem- 
 perature from mixing hot and cold water? 
 
 134 — How may a simple mixing chamber be constructed so as to 
 provide a means of regulating the temperature at the showers inde- 
 pendent of the bather? 
 
 135 — Describe a simple mixing chamber suitable for showers in 
 factory washrooms or other places where strong construction is 
 necessary. 
 
 CHAPTER 9. 
 
 Pages 101 to 111. 
 
 136 — What is the purpose of a double boiler? 
 
 137 — Is the type of double boiler in which one cylinder is placed 
 within the other the only kind in use? 
 
 138 — Which of the cylinders is connected with the supply from the 
 attic tank? 
 
 139 — How may a water front be constructed to serve the same 
 purpose as a double boiler? 
 
 140 — When two separate boilers are used instead of a double boiler 
 how are the ranges connected? 
 
TYPICAL EXAMINATION QUESTIONS. 197 
 
 141 — Is there any danger of collapse of th.e boiler shell of a double 
 boiler when one or other of the boilers is emptied? 
 
 142 — How should the sediment cocks be placed to obviate the for- 
 mation of a vacuum and invite a condition that would cause collapse 
 of the boiler? 
 
 143 — How are the two systems connected so that the supply to the 
 fixtures may be switched from the street to the tank supply if de- 
 sired? 
 
 144 — ^Why is it recommended that a check valve be fitted on the cold 
 water supply pipe from street mains when a double boiler system 
 is used? 
 
 CHAPTER 10. 
 Pages 112 to 127. 
 
 145 — How may the efficiency of a gas water heater be calculated? 
 
 146 — What is the average heating value of illuminating gas? 
 
 147 — How is the amount of gas required to heat a certain volume 
 of water estimated? 
 
 148 — ^What is the average efficiency of the ordinary gas water 
 heater? 
 
 149 — Does a tank heater of the circulating type show as high effi- 
 ciency as an automatic instantaneous heater? 
 
 150 — Why are copper coil heaters considered preferable to those 
 using hollow discs as heating surface? 
 
 151 — What are the principal requirements of a good gas water 
 heater? 
 
 152 — What is the difference between the internal and external type 
 of thermostatic valve on gas heaters? 
 
 153 — What is a bath heater of the non-contact type? 
 
 154 — How should this type of heater be erected so as to supply 
 more than one fixture? 
 
 155 — Where should the vent pipe that carries the products of com- 
 bustion be connected to? 
 
 156 — How should the water connections of a kitchen boiler heater 
 be made when it is feared that sediment may choke the coils? 
 
 157 — Describe the general construction of a thermostatic gas valve 
 for a water heater? 
 
 158 — How are the valves on the type of water heater which comes 
 into service on the opening of a faucet operated? 
 
 159 — Why is it advisable to have the pipe sizes as small as is pos- 
 sible to give a satisfactory flow at the fixtures? 
 
 160 — What is the advantage of having a heater equipped with 
 thermostatic as well as pressure operated valves? 
 
 1.61 — What is the best type of control to use on gas heaters supply- 
 ing water to large institutions through a storage tank? 
 
198 HOT WATER SUPPLY. 
 
 162 — Why are the doors of the heaters mounted on spring hinges? 
 
 163 — What are the six principal rules to observe in the installa- 
 tion of gas water heaters? 
 
 164 — What evidence will be given by a heater of the choking of the 
 heating coils by sediment? 
 
 165 — How should a continuous flow connection with a water front 
 in a coal range and a gas heater be made? 
 
 166 — How may a kitchen boiler heater and a boiler be installed to 
 occupy the smallest possible space? 
 
 CHAPTER 11. 
 Pages 128 to 142. 
 
 167 — Is more heat transmitted from steam to water passing con- 
 tinuously through a tank than to water at rest within the tank? 
 
 168 — ^What is the usual allowance of heating surface in steam coils 
 per gallon capacity of storage tank? 
 
 169 — ^Why should safety valves be fitted to steam heated storage 
 tanks? 
 
 170 — How are steam coils in storage tanks controlled by thermo- 
 static valves? 
 
 171 — How are kitchen boilers heated by means of steam? 
 
 172 — Can a kitchen boiler be heated by steam without the use of 
 coils? 
 
 173 — How much quicker may water be heated by injecting steam 
 than by heating it by transmission from coils? 
 
 174 — How many pounds of water may be heated by injecting one 
 pound of steam at 85-lb. pressure if the water be heated from 70 
 degrees to boiling point? 
 
 175 — Does it require more time to heat water by steam at low 
 pressures than at high pressure? 
 
 176 — How is the quantity of steam necessary to heat a given 
 quantity of water to a determined temperature estimated? 
 
 177 — How many B.tu. are there in 1 lb. of steam at 5 lb. pressure? 
 
 178 — WTiat is the value of a Calorie in B.tu.? 
 
 179 — How may the noise of condensing steam when heating water 
 by injection be lessened? 
 
 180 — Describe the construction of a Co-mingler? 
 
 181 — What is necessary to prevent water finding its way back 
 into the steam boiler when water is heated in a closed tank by 
 injection? 
 
 182 — How should a steam boiler and coil be connected up to act as 
 an auxiliary to a tank heater using coal for fuel? 
 
 183 — What types of heaters are in general use in the fire boxes of 
 hot air and steam heating boilers to provide an auxiliary supply of 
 hot water? 
 
TYPICAL EXAMINATION QUESTIONS. 199 
 
 184 — Where should a coil be placed in a hot water heating boiler 
 to give the best results in heating water for domestic purposes? 
 
 185 — What is the best kind of pipe to use in making such a coil? 
 
 186 — What is the heating value of cast iron water heaters when 
 suspended above the fire in the fire box of a steam heating boiler? 
 
 187 — How much difference is there between cast iron and brass 
 as a heating medium? 
 
 188 — How many B.t.u. should be allowed per square foot of coil 
 surface when estimating the heating capacity of a brass coil? 
 
 CHAPTER 12. 
 Pages 143 to 161. 
 
 189 — What are the usual methods adopted to utilize excess heat 
 generated by a kitchen range or tank heater? 
 
 190 — How may the size of a radiator that can be heated by a 
 water front in a kitchen range be approximately estimated? 
 
 191 — What difference should be made in connecting a radiator on 
 the same floor as the water heater and in connecting one on the 
 floor above it? 
 
 192 — How is the air that is relieved in heating the water prevented 
 from collecting in the system when a radiator is connected to a 
 hot water supply system supplied from an overhead tank? 
 
 193 — Can a radiator be connected so that the hottest water will 
 be delivered there before b,eing stored in the boiler? 
 
 194 — Is it preferable to use galvanized iron pipe for coils used in 
 warming rooms when connected to a system supplying water for 
 domestic purposes also? 
 
 195 — If a radiator is used instead of a coil which pattern should be 
 used if it is to be placed on the same floor as the kitchen range? 
 
 196 — How much % in., 1 in., 1*4 in., 1*^ in. and 2 in. pipe is 
 required to equal 1 sq. ft. of heating surface? 
 
 197 — How can a room be warmed by installing an extra boiler? 
 
 198 — Can a room be warmed by means of hot air supplied by a 
 kitchen range? 
 
 199 — How would the piping system necessary to warm several rooms 
 be laid out if the coils or radiators were to be heated from a 
 kitchen range? 
 
 200 — How should the connections be made to a plate warming 
 closet heated from the' domestic hot water supply? 
 
 201 — How may a check valve be inserted in the return connection 
 of a circulating system so that it will not prevent free circulation 
 yet will close as soon as a faucet is opened and a tendency to draw 
 through the return pipe is shown? 
 
 202— What are the usual types of heated towel rails offered by 
 manufacturers and how are they connected? 
 
200 HOT WATER SUPPLY. 
 
 203 — Describe some schemes of utilizing waste heat in heating water 
 for domestic and manufacturing purposes. 
 
 204 — How may the heat of waste water from plumbing and other 
 fixtures be turned to account in heating water? 
 
 205 — Describe the construction of a reliable water heating garbage 
 burner. 
 
 206 — ^What are the usual methods of heating water in bakeries? 
 
 207 — Is it advisable to bury a boiler in the sand over a bakers oven? 
 
 CHAPTER 13. 
 Pages 162 to 176. 
 
 208 — ^What is the cause of air locking in a hot water distributing 
 system? 
 
 209 — What causes lead pipe to sag? 
 
 210 — Can the method of connecting branch pipes to circulating loops; 
 cause air locking under any conditions? 
 
 211 — How may the practice of carrying a pipe to the basement 
 before rising to the fixtures cause stoppage of supply? 
 
 212 — How may the cause of intermittent flow at fixtures be some- 
 times attributed to the position of a relief pipe on a hot water 
 system? 
 
 213 — Can any mechanical device be utilized to allow air to escape 
 from circulating systems under pressure without allowing water 
 to escape? 
 
 214^ — What is the cause of water continually flowing through a relief 
 pipe into the supply tank of a hot water supply system? 
 
 215 — Has the elevation of the supply tank any bearing on the 
 subject? 
 
 216 — How much does water increase in volume by heating? 
 
 217 — Can water be forced out of the boiler through the relief pipe 
 by pressure of steam formed in the water front by overheating? 
 
 218 — Is there any advantage in fitting an expansion tank to a 
 relief pipe? 
 
 219 — When may a trap be used on the supply pipe to prevent 
 circulation back from the hot water tank to the cold water tank? 
 
 220 — ^Where should a boiler safety valve be fitted? 
 
 221 — What is the difference between a safety valve and a vacuum 
 valve ? 
 
 222 — On which part of the system should a vacuum valve be placed? 
 
 223 — What is the cause of the collapse of copper boilers? 
 
 224 — ^What can be done to prevent the collapse of copper boilers 
 when the supply is from the street mains? 
 
 225 — Can collapse of boilers be laid in any case to lack of 
 pressure in the cold water supply? 
 
 226 — How can the raising of excessive pressure in hot water supply 
 systems where a check valve is fitted on the supply pipe be avoided? 
 
TYPICAL EXAMINATION QUESTIONS. 201 
 
 CHAPTER 14. 
 Pages 177 to 189. 
 
 227 — ^What is the first thing that should be investigated when a 
 complaint of insufficient hot water supply is made? 
 
 228 — Why has the size of the coal used a bearing on the satisfactory 
 service given by a hot water supply system? 
 
 229 — Is it possible for a water front to be choked partially so that 
 the circulation to the boiler will be retarded without overheating 
 the water in the water front? 
 
 230 — What effect on the heating of water is made when the boiler 
 feed tube has become corroded and has dropped off? 
 
 231 — How may small holes in a kitchen boiler caused by corrosion 
 be satisfactorily repaired? 
 
 232 — What is the cause of a milky appearance in hot water? 
 
 233 — Has water hammer any detrimental effect on the piping of a 
 hot water system? 
 
 234 — Can water be short circuited from a boiler through the con- 
 nections to a gas water heater and how may it be avoided? 
 
 235 — What is the usual cause of cold water being drawn at the 
 hot water faucet? 
 
 236 — What is the cause of rusty water being drawn at the fixtures? 
 
 237 — How may the drawing of rusty water be avoided by a simple 
 expedient? 
 
 238 — How would a boiler be tapped to insert an extra connection? 
 
 239 — Describe the apparatus used for heating water in a barber 
 shop? 
 
 240 — What is the comparative value of lead and brass as metals 
 for the connecting pipes of range boilers and water fronts? 
 
INDEX. 
 
 Adding capacity by installing extra boilers 54 
 
 Air bound service, Remedy for 165 
 
 Air locking, Method of supplying fixtures to avoid 75 
 
 Air locking in supply lines 162 
 
 Alkaline water, Heating by indirect method ....... 20 
 
 Aluminum bronze, Painting boilers and pipes with .... 22 
 
 Anthracite, Heat emitted by 14 
 
 Anti-scalding valves .99 
 
 Apartment house, Separate range boilers for 82 
 
 Appearance of hot water 180 
 
 Appliance for injecting steam 136 
 
 Automatic storage gas water heaters 114 
 
 Auxiliary boilers 54 
 
 Auxiliary heaters, special 139 
 
 Auxiliary heaters. Steam coils 137 
 
 Auxiliary heaters. Furnace coils 138 
 
 Auxiliary heaters. Coils in steam boilers 138 
 
 Available heat 14 
 
 Bakeries, Heating boilers in 159 
 
 Barber shop heating tank 187 
 
 Bituminous coal. Heat emitted by 14 
 
 Boilers, Bakery 158 
 
 Boiler, Connections for on floor above heater 50 
 
 Boilers, Copper, collapse of 171 
 
 Boilers, Corrosion of 179 
 
 Boilers, Bakery-heating by coils in sand 160 
 
 Boilers, Horizontal 41 
 
 Boilers, Kitchen, heating by steam 132 
 
 Boiler, Making extra connection to 187 
 
 Boilers, Proportioning 33 
 
 Boilers, Regular horizontal pattern 42 
 
 Boilers, Separate, in apartment house 82 
 
 Boiler, Steam heated which was unsatisfactory 43 
 
 Boilers, Supply pipe rusted off 178 
 
 Boilers, Upright, placed horizontally 41 
 
 Boilers, Water hammer in . 181 
 
 Brass coils. Building 138 
 
 Bronze, Effect of in insulating pipes 22 
 
 B.t.u. in pounds of steam at various pressures 135 
 
 By-passing checks to avoid excessive pressure 174 
 
 203 
 
204 INDEX. 
 
 Capacity, Increasing of water fronts 29 
 
 Capacity of cast iron auxiliary heaters 140 
 
 Cast iron heater ratings 140 
 
 Cause of pounding in range boilers 35 
 
 Chambers, Mixing for factories 100 
 
 Chamber, Sediment collecting 21 
 
 Check valves on supplies, By-passing 175 
 
 Circulation, Distribution to fixtures on floor below boiler ... 89 
 
 Circulation, Features of in a cottage 81 
 
 Circulation, Loop on same floor as boiler 88 
 
 Circulation of water to fixtures 76 
 
 Circulation of water through relief pipe 169 
 
 Circulation, Principles of . 8 
 
 Circulation, Reversal of 79 
 
 Circulation, Sectional system for high buildings 94 
 
 Circulation, System for large buildings 91 
 
 Coils, Adding to water fronts 29 
 
 Coils, Fitting over fire in stove 30 
 
 Coils, Proportioning 31 
 
 Coke, Heat emitted by 14 
 
 Cold water drawn at hot water faucet 183 
 
 Collapse of copper boilers 171 
 
 Collecting chamber. Sediment 21 
 
 Collection of air in connections 36 
 
 Combination hot and cold water supply 80 
 
 Combustion, Complete 14 
 
 Combustion, Imperfect 14 
 
 Combustion, Temperature of 10 
 
 Complaints and remedies 177 
 
 Condensation in steam coils. Effect of 44 
 
 Conduction of heat 13 
 
 Connections, Attic tank supply to boiler below level of stove . . 48 
 
 Connections to coils in bakers' ovens 158 
 
 Connections, Boilers heated in bakeries 158 
 
 Connections, Boiler in attic as radiation and storage 146 
 
 Connections, Boiler on floor above heater 50 
 
 Connections, Boiler placed below level of stove 46 
 
 Connections, Coil and gas heater to reduce storage 52 
 
 Connections, Coil heated direct from water back . . " . . . . 145 
 
 Connections, Comparative value of lead and brass 187 
 
 Connections, Continuous flow through coil and gas heater ... 51 
 
 Connections, Double boilers 101 
 
 Connections, Double water back 110 
 
 Connections, Expansion tank 172 
 
 Connections, Extra boiler capacity 53 
 
 Connections for coil and gas heater 51 
 
 Connections for gas water heaters 125 
 
 Connections, Heating coils on floor above range 144 
 
INDEX. 205 
 
 Connections, Horizontal boiler 41 
 
 Connections, Horizontal boiler with two heaters on different floors 62 
 
 Connections, Horizontal double boiler 109 
 
 Connections, Joint supply to two flats 68 
 
 Connection, Making extra to boiler 185 
 
 Connections, Multiple 60 
 
 Connections, Plate warming closet 153 
 
 Connections, Quick heating 37 
 
 Connections Radiator to domestic supply lines 149 
 
 Connections, Range boiler 34 
 
 Connection, Range boiler with door intervening 38 
 
 Connections, Range boiler and gas heater 39 
 
 Connection, Range boiler for low pressures 40 
 
 Connections, Space saving method for gas water heaters . . . 126 
 
 Connections, Special 46 
 
 Connections, Steam coil and tank heater 137 
 
 Connections, Stiff . 36 
 
 Connections, Suggestions on double boiler 105 
 
 Connections, Supply and Distribution 74 
 
 Connections, Swing joint 34 
 
 Connections, Three water backs to on^ boiler 57 
 
 Connections, Towel rails 153 
 
 Connections, Two boilers to one water back 55 
 
 Connections, Two boilers heated by one water tack 56 
 
 Connections, Two boilers with two heaters 64 
 
 Connections, Two boilers and heaters on same floor ..... 72 
 
 Connections, Unusual with two heaters and two boilers .... 70 
 
 Connections, Warming several rooms from kitchen stove . . . 151 
 
 Connections, Waste water heating coils 157 
 
 Connections, Water hammer in 181 
 
 Continuous connection for gas water heaters 125 
 
 Convection, Transmission of heat by 13 
 
 Copper boilers. Collapse of 171 
 
 Copper pipe annealed and hard 189 
 
 Corrosion, Effect of temperature on 16 
 
 Corrosion, Means of mitigating effects of 17 
 
 Corrosion of kitchen boilers 179 
 
 Corrosion of Water Fronts 16 
 
 Crooked threads. Need for at stove connections 28 
 
 Data on heating water by steam 128 
 
 Defective circulation cause of pounding . 36 
 
 Degrees of hardness in water 18 
 
 Density of water 8 
 
 Density, Effect of in circulation 8 
 
 Density, Temperature of maximum 8 
 
 Distribution by circulation . 75 
 
 Distribution, Circulation to fixtures below boiler level .... 89 
 
206 INDEX. 
 
 I 
 
 Distribution, English system of piping 86 
 
 Distribution, Equalizing flow from two boilers on loop .... 89 
 
 Distribution from drop feed mains 91 
 
 Distribution from rising mains 92 
 
 Distribution, Methods of by direct pressure 74 
 
 Distribution of supply 74 
 
 Distribution, Piping in large residences . 84 
 
 Distribution, Supply from water tables 75 
 
 Distribution, Supply to fixtures to avoid air pockets 164 
 
 Double boilers and connections 101 
 
 Double boilers. Arrangement of piping 102 
 
 Double boilers, Horizontal 109 
 
 Double boilers, Reverse cocks for 105 
 
 Double boilers. Separate 104 
 
 Drawing cold water through return . 79 
 
 Drip pipes on stopcocks 74 
 
 Drop feed mains 91 
 
 Economy in good design of firebox 14 
 
 Efficiency of gas water heaters 112 
 
 Elasticity, Definition of 15 
 
 Elastic Limit, Definition of 15 
 
 Emptying water front through supply pipes 47 
 
 Equalizing pipes for steam coils 45 
 
 Equalizing pressure in large buildings 91 
 
 Equivalent heating surface in coils 141 
 
 Equivalent surface of pipe coils in 1 ft. of radiation 148 
 
 Excessive pressure in boilers, Avoiding 174 
 
 Expansion loops on risers 94 
 
 Expansion of water, Table of 168 
 
 Expansion of water to tank 163 
 
 Expansion of water through relief pipes 167 
 
 Extension coils in firebox 29 
 
 Extending heating surface of water fronts 29 
 
 Failure to heat properly 35 
 
 Finding quantity of steam required Idi 
 
 Fitting coil on fioor above range 144 
 
 Furnace coils as auxiliary heaters 138 
 
 Galvanized pipe in coil heating 147 
 
 Garbage burners 158 
 
 Gas, Heating value of 112 
 
 Gas, Heating water by 112 
 
 Gas heater connections 39 
 
 Gas water heaters, Automatic instantaneous 113 
 
 Gas water heaters, Circulating tank 113 
 
INDEX. 
 
 207 
 
 Gas water heaters, Construction of 114 
 
 Oas water heaters. Contact type of bath 116 
 
 Gas water heaters. Control of gas supply in 121 
 
 Gas water heaters, Efficiency of 112 
 
 Gas water heaters, Features of 113 
 
 Gas water heaters. Hints on installation 123 
 
 Gas water heaters, Instantaneous bath type of 115 
 
 Gas water heaters, Kitchen boiler type of 117 
 
 Gas water heaters, Large type for storage 122 
 
 Gas water heaters, Non-contact type of 116 
 
 Gas water heaters, Position of for economy 120 
 
 Gas water heaters. Pressure controlled . . . . • 119 
 
 Gas water heaters, Protection of walls from 127 
 
 Gas water heaters. Space saving method of connecting .... 126 
 
 Gas water heaters. Storage type of 114 
 
 Gas water heaters, Storage type with thermostat 119 
 
 Gas water heaters. Thermostatically controlled 119 
 
 Gas water heaters, Various methods of connecting 124 
 
 Hard water 18 
 
 Hardness in water, Effect of 18 
 
 Hardness, Removal of in water 18 
 
 Heat 10 
 
 Heat, Development of 11 
 
 Heat, Emission of B.t.u. from various fuels 14 
 
 Heat Losses from pipes 22 
 
 Heat Losses, Effect of paint on 22 
 
 Heat, Losses from kitchen boilers 22 
 
 Heat Losses, Table of through painted surfaces 23 
 
 Heat, Luminous and Dark Rays 11 
 
 Heat, ]\Ieasurement of 10 
 
 Heat, Most effective application of 13 
 
 Heat of various fuels 14 
 
 Heat, Production of by combustion 12 
 
 Heat, Transmission of 12 
 
 Heat transmission from coils 32 
 
 Heated towel rails 153 
 
 Heating appliances for hard water . 20 
 
 Heating, Insufficient of water fronts 35 
 
 Heating kitchen boilers by steam 132 
 
 Heating surface in lineal feet of coil 141 
 
 Heating water by gas , 112 
 
 Heating water by injecting steam 133 
 
 Heating water by steam coils 128 
 
 Horizontal boiler connections 41 
 
 Horizontal double boilers 109 
 
 Hot water tank for barber shop 187 
 
 Hot water, Milky appearance of 180 
 
208 INDEX. 
 
 Imperfect combustion 14 
 
 Improper pitch of pipe, Effect of 163 
 
 Incrustation of water heating appliances by lime 20 
 
 Injecting steam in heating water 12& 
 
 Injecting steam to heat water. Table of quantities 133 
 
 Kitchen boiler gas water heaters, Types of 117 
 
 Kitchen stove warming room by warm air and water .... 14^ 
 
 Laundry, Waste heat in utilized 157 
 
 Laundry water heaters 142 
 
 Lead and brass connections. Comparative value of 187 
 
 Level, Stoves out of 27 
 
 Lime in water backs 18 
 
 Lime, Precipitation of ... 18 
 
 Loop circulation on same floor as boiler 88 
 
 Loop, Height of loop on connection to boiler on lower level . . 47 
 
 Lukewarm water complaint 181 
 
 Maximum density of water, Temperature of ' . . 8" 
 
 Milky appearance of hot water 180 
 
 Mixing steam and water 134 
 
 Mixing valves 99 
 
 Motive force of water 9 
 
 Multiple connections ' . 60 
 
 Narrow fireboxes, Effects of 177 
 
 Noise caused by injecting steam . 135 
 
 Noise in water fronts and boilers 26, 35 
 
 Overheating of boilers 35 
 
 Oxygen, Amount of in water at different temperatures .... 16 
 
 Oxygen, Solubility in water 16 
 
 Oxygen, Supply of to firebox . 14 
 
 Partitions in water fronts 25 
 
 Permanently hard water 1& 
 
 Phenomenon of heat 10 
 
 Pitch of circulating pipes 78 
 
 Plate warming closet connections 153 
 
 Pounding in range boilers 35 
 
 Pressure relief valves 170 
 
 Prevention of siphonage . ^ 170 
 
 Proportions of coils and water fronts 31 
 
 Proportioning steam coils 129 
 
 Proportioning supply to shower baths 96- 
 
INDEX. 209 
 
 Quick heating connection 37 
 
 Radiation 12 
 
 Radiation, Transmission of heat by 12 
 
 Radiators connected to range boilers '. . . 148 
 
 Range boiler connection 34 
 
 Ratings of cast iron heaters 140 
 
 Relief pipes 172 
 
 Relief pipes, Expansion of water through 167 
 
 Relief valves, Pressure 170 
 
 Remedy for air bound service 165 
 
 Removal of hardness in water 18 
 
 Removal of lime in water backs 18 
 
 Repair of boilers 179 
 
 Resultant temperature of mixing hot and cold water 98 
 
 Retarding of flow in water fronts . . . . 30 
 
 Reverse cocks for double boilers 105 
 
 Reversal of circulation 79 
 
 Risers and branches in large buildings 92 
 
 Rusty water 183 
 
 Safety and vacuum valves 40 
 
 Safety and vacuum valves 170 
 
 Sagging of pipe, Effect of 162 
 
 Sectional heaters Ill 
 
 Sectional system of distribution 94 
 
 Sediment collecting chambers 21 
 
 Sediment, Prevention of in gas heater connections 40 
 
 Separate range boilers in apartment house 82 
 
 Shower baths. Anti-scalding valves for 99 
 
 Shower baths. Factory mixing chambers 100 
 
 Shower baths. Mixing and tempering supply to 96 
 
 Shower baths. Supply to 96 
 
 Siphonage, Prevention of 170 
 
 Siphonage, Prevention of at range boilers 40 
 
 Size of boilers for water supply 33 
 
 Smoke, Cause of in combustion of fuels 14 
 
 Softening, Apparatus for water . 19 
 
 Solution for removal of lime from water backs 18 
 
 Steam as an auxiliary heater 137 
 
 Steam coils in water heating 128 
 
 Steam heated boiler which was unsatisfactory 43 
 
 Steam nozzles for hot water heating 136 
 
 Steam required to heat water 129 
 
 Steam supply, Thermostatic control of 131 
 
 Storage capacity of boilers, Adding to 53 
 
 Stoppage of water fronts 17 
 
 Stoppage in water front 178 
 
210 INDEX. 
 
 Strains and stresses 15 
 
 Supply and distribution 74 
 
 Supply pipe to boiler rusted off 178 
 
 Surface, Adding heating to water fronts 29 
 
 Suspended coils in firebox of stoves . .30 
 
 Swing joint in boiler connections 34 
 
 Swing joints, Expansion on risers in high buildings 94 
 
 System of distribution in large residences 84 
 
 Table of B.t.u. in steam at various pressures 135 
 
 Table of expansion of water 168 
 
 Table of capacity of steam coils 129 
 
 Table of transmission rate from steam with varying velocity of 
 
 water through tank 130 
 
 Table of quantity of water heated by injecting steam .... 133 
 
 Tank heaters, Laundry 143 
 
 Temperature, Resultant of mixing hot and cold water .... 98 
 
 Thermal efficiency of gas 112 
 
 Thermostatic control of steam supply 131 
 
 Threads, Cutting on brass 188 
 
 Towel rails. Making from pipe fittings 156 
 
 Towel rails warmed by water 153 
 
 Transmission of heat from coils 32 
 
 Transmission of heat from steam 130 
 
 Triple connections 57 
 
 Unsatisfactory heating 177 
 
 Using coil in laundry to warm water 157 
 
 Utilizing excess heat in warming rooms 143 
 
 Utilizing waste heat 156 
 
 Vacuum valves on boilers 40 
 
 Valves, Anti-scalding 99 
 
 Warming closet connections 153 
 
 Warming room by installing extra boiler 149 
 
 Waste heat. Utilization of 156 
 
 Water, Oxygen in solution in 16 
 
 Water, Motive force of 9 
 
 Water, Sediment in 16 
 
 Water, Quantity of hot required 33 
 
 Water backs, Double 110 
 
 Water fronts, Accumulation of air in 26 
 
 Water fronts, coils and heaters . 25 
 
 Water fronts. Heat transmission to 32 
 
 Water fronts. Increasing capacity of ......... 29 
 
 Water fronts, Insufficient heating cf » 35 
 
INDEX. 
 
 211 
 
 "Water fronts, Position of tappings in 25 
 
 Water fronts, Position of in firebox 26 
 
 Water fronts, Proportioning 31 
 
 Water fronts. Reason for partition in 25 
 
 Water fronts, Retarding flow in 30 
 
 Water fronts. Special shapes 27 
 
 Water front. Stoppage in 178 
 
 Water hammer in connections 181 
 
 Water heaters. Laundry 143 
 
 Water heating garbage burners 158 
 
 Water mixing valves 99 
 
 Water softening apparatus , 19 
 
 Water tables. Method of constructing 75 
 
 Wood, Heat emitted by ... 14 
 

 JUN 11 1913 
 
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