1 Steam Heating for Buildings; OR HINTS TO STEAM FITTERS. DESCRIPTION OP STEAM HEATING APPAEATUS FOR "W.UIMING AND VENTILATING PRIVATE HOUSES AND LARGE BUILDINGS, WITH REMARKS ON STEAM, WATER, AND AIR, IN THEIR RELATION TO HEATING ; TO WHICH ARE ADDED USEFUL MISCELLANEOUS TABLES. WILLIAM J. BALDWIN, steam Heating Engineer. WITH MANY ILLUSTRATIONS. NEW YOR] JOHN WILEY & SONSr^^lg^ 15 AsTOR Place. 1881. 7r Copyright, 1881, Bt JOHN WILEY & SONS. PRESS OF J. J. LITTLE & CO., 10 TO 80 ASTOR PLACE, NEW YORK. V PEEFACE. The dearth of practical information on steam heat- ing, and the want felt by the young steam-fitter, in almost all branches of his trade, has suggested to me the necessity of explaining, so far as lies in my power, some of the many questions which often arise. This volume has no scientific pretensions beyond what are actually necessary to explain a few laws, which affect the action of steam, water, and air, within pipes ; and is simply a Vade Mecum of practical results to the fitter which the trade has tacitly adopted — from re- peated failures at first it has come to practical success eventually. These results I call " Hints," since I make many assertions I do not explain, which are known to be facts, and which will be of more real value to a beginner, than a long-drawn exhortation of both sides of th^ question, defeating its own object by leaving the stu- dent undecided. Most of the tables, and all of the diagrams but one, were especially made for this volume. CONTENTS CHAPTER I. GRAVITY CIRCULATING APPARATUS. PAGE I 1 Gravity Systems of Piping 1 j 2 Nomenclature 3 3 Water-]me 5 ' 4 How a Building is Piped 6 5 Two Heaters from the same Connection 6 \ 6 Outlets of the Risers 7 ' 7 Risers 7 8 Radiator Connections 8 9 Steam-mains (see Chapter XY.) 9 I 10 Return of the Water under all Conditions of Pressure 10 11 The Size of Mains 10 12 How Steam-pipes should leave the Boiler 11 13 Relief Pipes 11 I 14 Pitch of the Main 12 | 15 Tees in a Main 12 I 16 Stop-valves in Risers 12 17 Stop- valves in Mains 13 18 Main Return-pipes 14 19 Dry Return-pipes 15 20 Check-valves in Returns 15 Y ^ vi CONTENTS, CHAPTER II. RADIATORS AND HEATING SURFACES. PAGE 21 Vertical Tube Radiators 17 22 Steam Entering a Radiator 18 23 Cast-iron Radiators 20 24 Sheet-iron Radiators 21 25 Coils 21 26 To Estimate Heating Surfaces for Direct Radiation 22 27 Isolated Buildings 24 CHAPTER III. CLASSES OF RADIATION. 28 How Direct Radiating Surfaces should be Placed 26 29 Indirect Radiators 27 30 Indirect Radiator Boxes 28 31 Aii'-flues 28 32 Change of Air in Rooms 30 33 Direct-indirect Radiation 30 34 Position for Indirect Heaters with the Action of Air in Rooms, etc., and the Cause of Cold Feet 32 35 Cold-Air Inlet-ducts 34 CHAPTER IV. HEATING SURFACES OF BOILERS. 36 Fire-box and Flues 36 37 Crowding the Fire-box with Hanging Surfaces 38 38 Corrugated Fire Surfaces 39 39 Boilers which have Given the Best Results 39 40 Proportioning Boilers 40 41 Can a Boiler be Robbed of its Heat by the Gases of Combus- tion ? 40 42 Revcrberatory or Drop Flue Boilers 41 43 Will the Quantity of Water within a Boiler Effect Evapora- tion ? 41 CONTENTS, ^ CHAPTER V. BOILERS FOR HEATING, ETC. PAGE 44 Simplicity of Parts 42 45 Requirements for House Boilers 43 46 Construction of Upright Boilers 45 47 Construction of Horizontal Boilers 46 48 Contracted Passages under Boilers 46 49 Technical Names of Parts of Boilers, and their Setting 47 CHAPTER VI. FORMS OF BOILERS USED IN HEATING. 50 A Source of Danger to the Fitter. 49 51 Upright Boiler without Tubes 49 52 Upright Multi-tubular Boiler 50 53 Upright with Steam-dome 51 54 Upright Drop-tube Boiler 53 55 Base-burning Boiler 56 56 Horizontal Tubular Boilers 57 56^ Horizontal Multi-tubular Boilers 60 CHAPTER VII. REMARKS ON BOILER SETTING. 57 Thickness of Walls 63 58 Marshy or Sandy Ground 63 59 Why Boiler Walls Crack 63 60 Fire-bricks in a Furnace 65 61 Front-connection Division 65 62 Dead Plates 67 63 Bridge-walls 67 64 Ash-pits 67 65 Lugs on Boilers 67 viii CONTENTS. CHAPTER VIII. PROPORTION OF THE HEATING SURFACES OF BOILERS TO THE HEATING SURFACES OF BUILDINGS. PAGE 66 Eelation of Boiler to Heaters 69 CHAPTER IX. RELATION OF GRATES AND CHIMNEYS TO BOILERS. 67 Grate of a House Boiler 74 68 Size of Grate to Boiler 75 69 Size of Chimneys 75 70 Examples of Grates and Chimneys 76 71 Ta' le of Grates and Chimneys. 78 72 Conclusions Drawn. 78 73 Why Grates Break ? 80 CHAPTER X. SAFETY VALVES. 74 Boilers Bursting when Working at Ordinary Pressures 83 75 The Office of the Safety-valve 83 76 Decrease of Pressure under the Valve 84 77 Table of Lift of a 4-inch Valve at various Pressures 84 78 Graphic Illustration of the Size of the Opening of a 4-inch Valve when Blowing off at various Pressures 85 79 Formulae for Calculating the Size of Safety-valves 86 80 Construction and Operation of Safety-valves 87 CHAPTER XI. DRAFT REGULATORS. 81 Diaphragms 91 82 Construction of Regulators 92 83 Connecting Regulators 94 CONTENTS. ix PAGK 84 Doors to be Regulated 94 85 Consti'uc'tion of Doors for Regulator 95 CHAPTER XII. AUTOMATIC WATER-FEEDERS. 86 Construction 96 87 When a Water-feeder should be used 98 88 Connections to Water-feeders 98 89 Draught in Pipes 99 CHAPTER XIII. AIR-VALVES ON RADIATORS. 90 Where they should be Placed 100 91 Drawing Air from Coils, etc 100 92 Air- valves. Construction and Design 103 93 Waste of Water from Air-valves at High Pressure 104 CHAPTER XIV. WROUOHT-IRON PIPE, 94 Description of Pipe 106 95 Nominal Size of Pipe .106 96 Table of Standard Dimensions of Pipes 107 97 How to Calculate the Relative Areas of Pipes 108 98 Table of Relative Areas of Pipes 110 99 Diagram of Relative Areas of Pipes 112 100 Expansion of Pipes and its Relation to Steam-mains 113 101 Expansion of Return-pipes 114 102 Effect of Lime and Moisture on Pipes 115 103 Expansion of Pipes Buried in the Ground 115 104 Expansion-joints and how to Compensate without them ...... 115 105 Connecting Boiler, Domes, etc , 116 X CONTENTS. PAGE 106 Expansion of Cast-iron 118 107 Expansion of Wrought-iron 118 108 A Table of Linear Expansion of Wrought and Cast Iron Pipes 119 CHAPTER XV. MAIN-PIPES. 109 Size of Mains 120 110 Loss of Heat from Imperfect Apparatus 120 111 Heat or Power Necessary to put Water into Boilers 122 112 Poor Economy to Use Small Piping 122 113 Necessity for Providing for a Direct Return 123 114 How to Determine the Size of the Main 123 115 The Uiiit of Size in Pipes 124 116 Relation between Heating Surface and Diameter of Pipe 124 117 Diagram of the Size of Main-pipes for Gravity Apparatus 125 CHAPTER XVI. STEAM. 118 Temperature of Steam 128 119 Technical Terms 128 120 Table of Elastic Force, Temperature, and Volume of Steam. . 130 121 Calculations on Steam, Water, etc 131 122 Diagram of Rankine's Formula 132 CHAPTER XVIL HEAT OF STEAM. 123 The Unit of Heat 134 124 Sensible and Latent Heat of Steam 134 125 A Diagram of Sensible and Lalent Heat of Steam and Water. 137 126 Equivalents of Heat 138 CONTENTS. xi CHAPTER XVIII. Am. PAGE 127 What Air Is 140 128 Air Necessary for an Adult 141 129 Specific Weight and Volume 141 130 Expansion of Air 142 131 Watery Vapor in the Atmosphere 144 132 Quantity of Moisture Air is Capable of Taking Up 144 133 Drying Power of Air 145 134 A Table of the Watery Vapor Air is Capable of Taking Up. . . 145 135 Saving in Time by High Temperatures in the Drying Room. . 146 136 What Does Ventilation Cost ? « 146 CHAPTER XIX. HIGH-PRESSURE STEAM USED EXPANSIVELY FOR HEATING. 137 Systems 150 138 The HoUy System 151 CHAPTER XX. EXHAUST STEAM AND ITS VALUE. 139 Thermal Value 159 140 How Hot can Feed-water be Made 160 What Percentage of the Coal Heap does the Heating of the Feed-water Represent 160 How much of the Exhaust Steam can be used in Warming the Feed -water 161 141 Warming Buildings with Exhaust Steam 162 142 Loss from Back Pressure 162 143 Exhaust and Live Steam in the same Coils 163 Xii CONTENTS. CHAPTER XXI. BOILING AND COOKING BY STEAM, AND HINTS AS TO HOW THE APPARATUS SHOULD BE PIPED. PAGE 144 steaming and Vegetable Steamers 165 145 Steam-kettles 170 140 Warming Water in Tanks 176 147 Warming Water at the Nozzle or Cock 177 148 Warming Water for Baths, etc., when there is no Steam- boiler 178 CHAPTER XXII. DRY BY STEAM. 149 Description * 180 150 Laundry-drying 182 151 Dry Kilns and Other Modes of Drying 186 CHAPTER XXIII. STEAM-TRAPS. CHAPTER XXIV. BOILER CONNECTIONS AND ATTACHMENTS. 157 Feed-pipes, Blow-off Cocks, Valves, Gauges, etc 200 CHAPTER XXV. MISCELLANEOUS ARTICLES. 158 Cutting Walls and Covering Risers 206 159 Turning Exhaust Steam into Chimneys 207 160 Soldering of Pipes and Brass Fittings 209 161 Painting Pipes 210 CONTENTS, xiii CHAPTER XXVI. PAGE MISCELLANEOUS NOTES AND TABLES OF SERVICE IN ESTIMATING 211 APPENDIX A. SPECIFICATION FOR A STEAM-HEATING APPARATUS, INCLUDING COOK- ING, WASHING, AND DRYING 223 INTRODUCTION. Within twenty years, the warming of buildings with steam carried through pipes became a science ; pre- viously, it was a chaotic mass of pipes, and principles. A low-pressure gravity apparatus is the most health- ful, economical, and perfect heating appliance known, and may be constructed to heat a single room, or the largest building, with a uniformity which cannot be at- tained by any other means. By a gravity apparatus is meant, one without an out- let, whose circulation is perfect, wasting no water, and requires no mechanical means to return the water to the boiler. It may be likened to the circulation of the blood — the boiler being the heart ; the steam-pipes, the veins ; and the return-pipes, the arteries : thus carrying heat and life into every part of a building. When reference is made to steam-pressure in this volume, it is understood to mean pressure above the atmosjjhere. Nearly all tables of reference on steam are given in absolute pressures — namely, pressures includ- ing the pressure of the atmosphere — which iinapparent pressure has to be overcome before it is appreciable on a steam-gauge ; and, as the steam-fitter has little, if anything, to do with pressures below atmosphere, the tables, etc., herein used will be modified, to commence XV xvi INTRODUGTION. at atmosplieric pressure (14 jV pounds of the absolute scale), thus conveying comparison in the ordinary terms to which the steam-fitter is accustomed ; and preventing the necessity of a mental calculation, which always in- volves fractions, and enjoins a task which should not be thrown on a beginner. Therefore, all pressures men- tioned will be apparent pressures — namely, pressures that would be indicated by a properly regulated steam- gauge. BALDWIN'S STEAM HEATING FOR BUILDINGS. CHAPTEK I. GRAVITY CIRCULATING APPARATUS. 1. The loiv-pressure gravity circulation is at present very mucli used in the steam heating of private houses, churches, and schools. Its principal merits, when well done, are : It is safe ; noiseless ; the temperature of the heating surface is low and uniform ; all the water of condensation is returned into the boiler, except a very small loss from the air-valves ; it is easy to keep the stuffing-boxes of the heater-valves tight ; and it is no more trouble to manage than a hot-water apparatus. There are four systems of low-pressure steam-piping, whose principal features are : 1st. Main distributing pipes and distributing risers, with corresponding return mains and risers (see Fig. 1, at A). 2d. Main distributing pipes and distributing risers, with a corresponding return main, and a separate return riser for every coil or healer ; the return risers not con- 1 SYSTP^MS OP PIPING. Fig. 1 2 STEAM HEATING FOR BUILDINGS. necting with each other until they are below the water- line (see Fig. 1, at B). 3d. Main disuributing pipes and distributing risers, Avith corresponding return mains and no return risers, the distributing riser carrying the water of condensa- tion back, through a relief, to the main return pipe on the floor of basement (see Fig. 1, at C). 4th. (The single-pipe job, always a small one.) A single pipe for every heater, run directly from the top of the boiler to the heater, rising all the time in the direction of the heater, and of size sufficiently large that the steam passing to the heater, to supply the loss from condensation, will not interfere with the condensed water returning along the bottom of the pipe. System No.. 1 can be run at any pressure, j)rovidcd the pipes are sufficiently large in diameter and properly put up, and is the system commonly used in large buildings ; not because it gives the very best results, but because it gives ordinarily good results and saves much pipe and labor. System No. 2 should alioays he used in private houses^ and in buildings where extremely low pressure is em- ployed, as with this system a job can be made per- fectly noiseless, when done with care, and there is never any difficulty in expelling the air. System.s 3 and 4 are only employed in low-pressure heating, and when very large horizontal mains are used they give good results ; but are not to be recom- mended for large or complex jobs. For those not acquainted with the technical names of the different parts of the systems, and to prevent mis- conception of terms used, the following explanation is given : ORAVITY-GIRGULATING APPARATUS. 3 NOMENCLATUEE. 2. The same names always apply to the same part of the circulation, no matter what the system. The word circulation means the whole distribution of j^ipe in any one job. The Main Steam or Distributing Pi]^. — The nearly horizontal live-steam main, generally near the cellar ceiling {a' a" a"'). The Main Return Pipe. — The nearly horizontal pipe on the floor, or thereabouts, of the cellar, for carrying the condensed water back to the boiler {h' b" b"). The Steam Riser. — The pipe that carries the steam from the main distributing pipe to the radiators (c' c" c"). The Return Riser. — The pipe that carries the con- densed water from the radiators to the main return {d d'). The Stexim-Riser Connection. — The pipe that joins the main distributing pipe and sfceam riser (e' e). The Return-Riser Connection. — The pipe that connects the return riser with the main return pipe on the floor, and which has one or more T's in it, below the water- line, — to receive the steam-riser relief (//). The Steam-Riser Relief. — The pipe that connects the bottom of the steam riser with a T, in the bottom of the return-riser connection, or main return pipe, below the water-line, to carry the water that runs down the steam riser into the return-riser connection or main return pipe (g g). ^ Main Relief Pijjes. — Connections between the main steam and return pipes, to throw the water carried from the boiler, and that condensed in the main steam-pipe, 4 STEAM HEATING FOR BUILDINGS. into tlie return main, also employed as an equalizer of pressure in the system (h). Badiator Connections.— "^hQ pipes wliicli run from tlie risers to tlie radiators, both steam and return, usually no longer than is necessary to get spring enough for the expansion of the risers (i i i). A Belay.— The jumping up of a main steam-pipe, with a main relief at the lower corner. This is to admit of keeping the main steam-pipe near the line of the risers and the ceiling, and above the water-line, when the main lines are long (j). Fitch— I^ the inclination given to any pipe, and in ^^^^^^^^^^ the steam mains of a low-pressure apparatus, it should be down and away from the boiler (except in System ORAVITY-CIRGVLATINO APPARATUS. 5 No. 4), and, if possible, toward the boiler in the main return. (When the water and steam run in the same direction through pipes, one source of noise is pre- vented.) 3. Water-Line. — The general level of the water in the boiler and throughout the apparatus. In some cases, •where the boilers are at a distance, or in a subcellar, and the fitter wishes to gain the advantages of having returns and reliefs coming together heloiv icateVj he makes an artificial ivafer-line by raising the main return pipes higher than his connectious before he drops to the boiler. It is also necessary to bring a relief from the main steam-pipe to this raised part of the return to prevent siphoning into the boiler. Fig. 2 shoAvs how this should be done. It frequently happens in buildings where the line of the floor is below the water-line, that there are good reasons for not running the return pipe on the floor, when a modification of what is shown in Fig. 2 may be used ; the return pipe being hung from the same hang- ers as the steam-main, and immediately below it, but raised about as shown before being dropped to the floor at the first favorable position. Still another modifica- tion is to trap each return riser with an inverted water siphon by running the return riser five or six inches below the main return pipe, then rising and connect- ing with it. When any of these means have to be re- sorted to, it would be well to have a pet-cock at their lowest points to draw the water from them in cold weather should they not be in constant use, as these water-traps might freeze. 6 STEAM HEATING FOR BUILDINGS. HOW A BUILDING IS PIPED. 4. The steam-fitter should commence his work in a new building at an early period of its construction ; and architects and parties paying for the work should see that the contract for steam heating be let when the mason and carpenter work is let. The risers are the first work done in a new building constructed in the ordinary way. If the builder and steam-fitter have an understanding at the commence- ment of the work, the former can leave the proper re- cesses in the walls exactly where the steam-fitter wants them. This will save much work to the fitter, and pre- vent the mutilation of the walls, and be no expense to the mason. "When the walls are up, the joists in their places, and the roof-boards or roof on, the steam-fitter should then put up his risers. If the building has not more than three floors to be heated, it will answer to rest the risers on a support at the bottom of the recess ; but in higher buildings the risers should be suspended by the middle, so that the expansion may be divided. By allowing the riser to go both up and down from the middle, the steam-fitter will be able to get along with shorter radiator connections, and will avoid the deep cutting of the floor joists. 5. The steam-fitter should avoid, as much as possible, taking ttvo heaters from the same steam connection on a floor, and if it be unavoidable, he should drop his re- turns down, and bring them into the return riser some distance apart ; or, better still, he should run them separately down below the water-line (System No. 2), as it will prevent one heater from taking the air from the others. GRAVrrY-CIBGULATINO APPARATUS. 7 6. If the risers are on the side of the room, so that their outlets come between the joists, it is best to keep the Ts about Jialf-icay bciicecn the laths and the flooring, as this admits of nippling np, and leaves room for cross- ing the pipes, if required, below the floor. But if the outlets come at the side of the joists, care must be taken that the T's come in the exact 2olace. In a building with ' the risers resting on the bottom, and all the expamion upivard, the top outlet must be the most distant below the top of the joist, but only low enough to come within f of an inch of the floor w^hen expanded to the ut- most; so also with the rest of the T's, according to their distance from the bottom of the riser. 7. With low-pressure steam, the steam risers should be large. The general practice with steam -heaters is to reduce one size of pipe for each floor. This rule is not arbitrary ; but as architects' specifications usually call for it, there are no objections, provided the pipe is large enough. In System No. 1 the return riser is generally one size smaller than the steam riser, but it should never be smaller than | of an inch pipe. In System No. 2, where many return risers are brought down in the same place, a 1-inch pipe for large heaters, and a f-inch pipe for small ones, are the usual sizes. "When the risers are in, the outlets should be plugged up with pieces of pipe a foot or so in length, instead of the ordinary plug, as the latter is often difficult to get out when the plastering is done. The risers should then be tested with cold water to from 100 to 200 pounds per square inch ; this will show if there are any cracked fittings or split pipe, and will 8 STEAM HEATING FOR BUILDINGS. save much time and annoyance wlien steam is gotten up. When automatic air-valves are to be used on the steam- heaters, a f-inch pipe should be run in the riser recess, with an outlet at each floor to receive the air-valve connection. The lower end of this air and vapor pipe should be taken to the nearest sewer, outside of the sewer traps. 8. At this stage of the work, and before the floors are laid, the radiator connections should be run, and firmly fastened in their places, making due allowance for the thickness of the furring on the walls, for the plastering, and for the baseboard. The radiator connections are usually run 1 inch or 1^-inch for the steam connection, with a corresponding J or 1 inch pipe for the return, according to the size of the heater; IJ-inch steam-pipe being enough for a direct radiator of 150 square feet of heating surface, at low pressure, with a main of sufficient size. When the radiator valves are threaded right-handed, the elbows on the ends of the connections may be left- handed, to admit of connecting, by a right-and-left-hand nipple below the valve, and between the valve and elbow, or vice vei^sa. When both valves are at the same end of the radiator, it is better to have the right and left nipples between the valves and the radiator. With this arrangement both valves of the radiator can be connected simultane- ously, and the movement of the radiator will be in the direction of the valves. It also admits of the discon- nection of a heater after simply closing the radiator valves. When the radiators are to be connected by any of the GRAVITY-CIRCULATING APPARATUS, 9 foregoing plans, the connections can be firmly fastened (but not confined at their ends), so they may come in their exact places through the floors. The free ends of the connections should be closed with pieces of pipe long enough to come above the floors when laid. The air-pipe should also be run at the same time, and brought through the floor in close proximity to the position the air-valve will occupy on the heater. At this stage of the work the steam-heater usually waits until the floors are laid, plastering done, partitions set, and the basement graded. 9. Steam Ilains. — Nearly all the success of the ap- paratus depends on its steam mains, their sizes, and how they are run, A job has never yet been spoiled by having its steam mains large; still, there should be a limit to their size, to prevent unnecessary expense, and to keep the con- densation and radiation of the distributing pipes at a minimum consistent with the actual requirements of the heating surfaces. The size of steam mains depends on the pressure of steam to be used, the distance it is to be carried, the temperature of the exposure of the heating surfaces, and their extent. But as it is not my intention here to speak of steam used expansively, I shall endeavor to give sizes only for dirext returny or gravity-circulation apparatus. Gravity-circulation apparatus are of two kinds, low and high pressure. The low-pressure apparatus de- pends for a circulation on the difference of level of water in the return risers and the boiler, irrespective of the steam pressure at any part of the distributing pipes ; but the maximum pressure of steam to be car- 10 STEAM HEATING FOR BUILDINGS. ried must never exceed the equivalent of a difference in level of water between the water-line of the boiler and the lowest part of the distributing main. There is another condition under which this system will work, and that is, an increase of pressure sufficient to nearly establish an initial pressure throughout the apparatus ; but the difference in pressure at any part of the apparatus must not exceed the equivalent of a head of water between the water-line in the boiler and the lower part of the steam main. It is then a high-press- ure gravity circulation. A well-arranged gravity circulation should be made to work at any pressure ; for with its heating surface properly proportioned it can be made to meet the exi- gencies of fall, winter, or spring weather, by simply carrying a pressure suitable to the occasion. 10. To have the water of condensation return directly into the boiler, under all conditions of pressure, the main pipes must he large enough to maintain the pressure of the boiler, ivithin 1 or 1^ pounds, in every part of the ap- paratus, and the water-line of the boiler should be not less than 4 feet from the bottom of the horizontal distributing mains at their lowest part ; and that dis- tance will only answer in short mains, such as those used in the generality of city business buildings and blocks. In large public buildings and others, having their boilers in out-houses, the difference between the boiler line and the mains should be all it is possible to get. 11. A main should not decrease in size according to the area of its branches, but very much slower, and should be rated by the heating surface and the distance it is to be carried. Neither should the main at the QRAVITY-CIRGULATING APPARATUS. H boiler be equal to the aggregate size of all its brandies — an expression very much in vogue in specifications for steam heating. Mains which have given the best results leave the boiler of sufficient size (calculated from practical re- sults), and are reduced very slowly, if at all, until very near the end. The area of the cross section of a 1-inch steam-pipe is taken as unity, for the sake of easy calculation, in the rating of steam-pipes, and the area of a l-incli pipe in tlie main, at the holler^ to each 100 square feet of heating sur- face, mains included, is deduced, from the size of the mains and heating surfaces of some of the best heated buildings in the United States, and has been the writer's rule for some years. 12. When the main steam-pipe leaves the boiler, it should, if possible, be carried high at once, and have the stop-valve at the highest part in the pipe, so that condensed water cannot lodge at either side of it when shut. This will prevent cracking at this part of the pipes when the valve is opened. If this arrangement cannot be carried out, and the valve has to be nippled on the dome of the boiler, or if there are several boilers, and they have to be made interchangeable with regard to their use, there should be a relief of large size in the main, just outside the valves. 13. It is well to mention here that a relief which leaves the steam-pipe must be brought into the return pipe in a position corresponding exactly to where it leaves the main ; that is, when it comes from the out- side of the main stop-valve, it should be taken to the outside of the main return valve. Otherwise, if an at- tempt is made to shut off, and both valves are closed, 12 STEAM HEATINa FOR BUILDINGS, the water will back up and fill the apparatus. So, also, ^ith all branches, risers or connections ; if there is a valve in the steam part, tliere must also be one in the re- turn, and reliefs must leave the steam-pipe and enter the return on corresponding sides of the respective valves. 14. From the highest point the main steam-pipe should drop slowly, as it recedes from the boiler (1 inch to 10 feet being a fair pitch), that the course of the steam and the water may be in the same direction. A main steam-pipe should not run very close to the wall up which the risers go. There should be room enough for a riser connection (2 or 3 feet), and when the mains are long, and the expansion great, the dis- tance should be increased. 15. The T's in the main, for the riser connections, are better turned iq^ than sidewise, as by nippling an elbow to them you can get any desired angle, and should the measurement for the main be a little incorrect, it will make no difference. This arangement also makes a good expansion joint, if the mains have much travel. Where the pipe reduces in size, it is well to put a re- lief in the lower side of the reducing fitting, as the water that is pocketed there, by the large pipe, pitching in the direction of the smaller one, may be the cause of crack- ing and noise in the pipe. Some steam-heaters use an eccentric fitting in reducing, which brings the bottom of the pipes on the same line and makes nice work. 16. When it is necessary to have stop-valves to the risers, the steam-fitter often places them in the riser connections, with a valve also in the riser relief. This arrangement requires three valves, and also stops the local circulation and equalization of pressure when they are closed. GBA VITY-CIRGULA TING APPARA TU8. 13 It is better to use only two valves, one to the steam and one to the return riser, and place them a few inches up the riser, above the riser connection, which brings them also above the steam-riser relief, saving a valve and lessening the chances for noise in the pipes. In System No. 2, where the returns are carried down separately, and collected together below the water-line, the return valve should be below all such connections, and the steam-riser relief should have a separate con- nection with the main return, and have no valve. Straightway valves are best for risers. The extreme end of a steam main should be con- nected by a relief with the main return, being, in fact, a continuation of the main down and into the return. 17. Stop-valves in main steam-pipes are either globe, angle, or straightway. When a globe valve is used, it should be turned with its stem nearly horizontal, as 14 STEAM HEATING FOR BUILDINGS. shown in Fig. 3. The reason for this is obvious, when we consider that the water of condensation in any pipe runs along the bottom of it. When a globe valve is turned up, as in Fig. 4, the water in the pipe has to half fill it, before it flows over the valve seat, to pass along in the pipe. But, when the valve is on its side, it is different, for then the side of the opening of the valve seat is as low as the bottom of the pipe. Neither should the stem of any valve be quite hori- zontal when it can be avoided. It should be raised enough (10 degrees) to prevent water from collecting in the threads of the nut and stem, and being forced out, by the pressure of the steam, through the stuffing-box, which makes a constant dropping of water, which it is almost impossible to hold with ordinary packing. But with dry steam it can be held. Globe or angle valves should be so turned in a heat- ing apparatus that by simply closing the valve to he packed^ and its correspondinj valve in the return, or vice versa, and waiting for the steam to cool down, the stuff- ing-box or gland can be removed without the escape of steam. To do this it is necessary to have the pressure side of every pair of valves turned toward the boiler. By the pressure side of a valve is meant the under side of the disk. 18. 3Iain Return Pipes. — In small apparatus (up to 3- inch steam-pipe) they are usually run one or two sizes smaller than the corresponding steam-pipe. In returns which are below the water-line, or are trapped to give them an artificial water-line, and conse- quently always full of water, there are no curreyits but the flow of the water toward the boiler. This style of return admits of the smallest piping, but good practice GRAVITT-GIRGULATING APPARATUS 15 has placed it at one quarter of the area of the steam- pipe, for all conditions, for apparatus with larger than a 3-inch steam-pipe. In apparatus with less than 3-inch pipe, the return is usually only one size smaller than the steam-pipe, that it may have a practical magnitude, and thus avoid the possibility of getting it stopped with the dirt or sedi- ment carried to an elbow with the current of the water. 19. In dry returns — /. c, which have no water-line — there are local currents, often going in contrary direc- tions, the water gravitating toward the boiler, the steam flowing to the heaters, and the air — the greatest source of annoTjance to the steam-heater — going to every place except out of the air-valve. This style of return is not much used, but in cases where there is no basement it can- not always be avoided. One-half the area of the steam-pipe has been found, in practice, to give good results in dry return pipes. 20. Check-valves are generally used in return pipes where they enter the boiler. Some steam-heaters leave them out on account of the back pressure they cause to the return water ; but the practice is very much to be condemned v/hen two or more boilers are connected, as an inequality in draught, or the cleaning of a fire, will make a small difference of pressure between boilers, causing the water to run from one boiler to another through the return pipes. Check-valves of large area in the opening, with a small bearing on the seat, can be made that will not give more than a quarter of a pound back pressure. If the valve is not ground, and cleaned frequently, when the job is new, there will be nothing but the actual weight of the disk to overcome. 16 STEAM HEATING FOB BUILDING 8. It is sometimes convenient to reduce a return pipe where it enters the boiler for a short distance. This may be done to a limited extent, bearing in mind the actual quantity of water to be admitted to the boiler in a given time. Extra strong pipe and fittings should be used in all returns and feed-pipes, from where they are tapped into the boiler, to outside the brickwork ; and when they are exposed to the action of the fire it is well to cover them with a " slip tube" made of a larger size, ordinary steam pipe. CHAPTEK 11. RADIATORS AND HEATING SURFACES. 21. All radiators — box coils, flat coils, plate or pipe surfaces, arranged to warm the air of buildings — are heating surfaces. The vertical tube radiator is now the accepted type of a first-class heater, and nearly all manufacturers have their own peculiar style, with varying results as to ef- ficiency. The steam-fitter or purchaser should use great caution in the selection of radiators. The common return-bend radiator, Plate I., Fig. 1, is the most widely manufactured ; it is not patented, and is second to no other vertical tube-heater. The construction is simple ; a base of cast-iron. A, be- ing simply a box, without diaphragms, with the upper side full of holes, about 2i inches from center to center, tapped right-handed; a pipe, B, for every hole, 2 feet 6 inches or 3 feet long, threaded right and left handed, and half as many return bends, C, as there are pipes tapped left-handed. The manner of putting these heaters togetlier is to catch the right-handed thread of two pipes one turn in the base, then apply the bend to the upper and left threads of the same two pipes, and screw them up simul- 2 17 18 STEAM HEATmG FOR BUILDINOS. taneously with a pair of tongs on each pipe, while a second person holds the bend with a wrench made for the purpose. Steam-fitters who buy bases, and make only a few radiators, to keep the boys at work when in the shop, should count each set. of threads in ; but they who make for the trade gauge their threads and pipes, so as to always enter the base first. If the pair of pipes in any one bend are not plumb, screw the pipe at the side from which they lean a little tighter, which will shorten that side and draw the bend over. 22. I will here explain the action of steam entering a radiator, as nearly all the patents on the so-called posi- tive circulating radiators are to facilitate the expulsion of the air and the admission of steam. The general impression among steam-fitters is, that when steam enters a radiator the air is backed up and confined in the top of the pipe ; and it will be, when the pipe is single and closed at the top, without any of the usual means to get it down, although steam is not quite one-half the weight of air, which may seem an anomaly to the scientific engineer. When two pipes are connected at the top with a bend, or when there is an inside circulating pipe, or diaphragm of sheet-iron slipped into it, the air immediately gives way and falls in the pipes nearest the inlet first ; but should there be no air-valve on the radiator, the air will be crowded at first to the further end of the radiator, and should the system be a gravity circulation, without an outlet to the atmosphere, it will remain in the radia- tor, impairing its efficiency and often deceiving the no- vice, as it in time heats by contact with the steam ; but when there is a thumb-cock or air-valve on the radia- RADIATORS AND HEATING SURFACES. 19 tor, usually on the furthermost pipe from the inlet, the result is quite different. In the common return-bend radiator and others of good construction the action is direct, and the pipes heat consecutively, excepting, per- haps, the pipe the air-valve is on, and a few near it, which sometimes heat ahead of their order, on account of the draught of the air- valve. Thus, when the steam enters a well-constructed radia- tor, the air falls to the base, and is driven out at the air- valve, the pipe of which may be run down inside the base (as is seen at D, Fig. 1), which will bring it into the lower stratum, drawing it off to the last. This is the most simple test for a good heater. Any kind of radiator that nearly always has a few cold pipes, sometimes in one part of the heater, and sometimes in another, should be avoided. Fig. 2 shows a device (patented) for making a return- bend radiator positive. The pockets A A, filling with condensed water, makes a seal which at times prevents the flow of steam along the base and forces it in a con- tinuous stream through the pipes (see arrows in cut). Figs. 3 and 4 show cross section of modifications of positive return-bend radiators. Fig. 3 can be used as a vertical radiator only, but Fig. 4 can be used in any position from perpendicular to horizontal, as seen at Figs. 5 and 6, and is peculiarly adapted to indirect heating. Single-tube radiators, welded or closed at the top with a cap, with an inside circulating device, are also much used ; some of them compare favorably with the return-bend radiator, but are slower in heating. Fig. 7 shows the first of this class put on the market. A is the cast-iron base, B the welded tube, and C the 20 STEAM HEATING FOB BUILDINGS. septum of wrought iron slipped inside tlie tube and projecting an inch into the base. This heater depends on the gravity of the air for a circulation. Fig. 8 shows another heater of this class which is positive in its action. A, cast-iron base ; B, diaphragm cast in base ; C, welded tube ; D, inside tube, open top and bottom, and screwed into the diaphragm. The action of the steam can be seen by the arrows. Fig. 9 shows a fire-bent tube radiator very positive in its action. 23. Cast-iron radiators are of two kinds, plane and ex- tended surfaces. Plane surfaces, as the trade understands them, may be either flat, round, or corrugated, provided the coring or inside surface of the iron corresponds and follows the indentations of the outside, as in Fig. 10, and in all wrought-iron heaters. Extended surface is understood when the outside surface of the heater is finned, corru- gated, or serrated, with the inside straight, as in Fig. 11. For direct radiation, where the heater is placed in the room, there is little or nothing gained by having the surface of the heater extended, and a steam-fitter, in calculating the extent of his heating surfaces, should not take into consideration the whole outside surface of such a heater ; he should simply treat it as if the projections were cut off, leaving a flat or plane surface. For indirect heating (the coil being under the floor or in a flue) the result is a little different as com^^ared with shallow plane surface coils, where the air cannot stay long enough in contact with them to get thoroughly warmed, but presses into the room without hindrance. In this case the extended surface gives a better result, not because a square foot of the surface can transmit as BADIAT0R3 AND HEATING SURFACES. 21 much heat in the same time, but because it hinders the direct passage of the air, hokling it longer in contact and preventing stratification. The cast-iron vertical tube radiator is a quick heater, the large size of the tubes causing chambers large in size and few in number, thus expediting the expulsion of the air. Fig. 12 shows a stack of cast-iron extended-surface radiators for indirect heating. 24. Sheet-iron radiators are used in very low-pressure heating, the commonest form of which is the flat Eussia- iron heater, seamed at the edges and studded or stayed in the middle, with a space of about | of an inch be- tween the sides. They are used in a one-pipe job. COILS. 25. Coils are always made of wrought-iron steam-pipe and fittings, and though not considered an ornament are first-class and cheap heaters. Fig. 13 shows a flat coil, w^hich is a continuous pipe, connected with return bends at the ends, and strapped with flat iron, and is a very positive heater. Fig. 14 shows a miter or wall coil. It is composed of headers or manifolds, A A ; steam-pipes, B ; elbows, C ; and hook plates, D. There are many modifications of this coil, but one in- dispensable point in the making of it is, it must turn a corner of the room, or miter up on the wall. The pieces- from the elbows to the upper header are called spring pieces ; they are screwed in right and left, and are the last of the coil to be put together. If a coil is put together, straight between two headers, 22 STEA3I HEATING FOB BUILD mG8. as seen at Fig. 15, it will be like Fig. 16 when heated, and cannot be kept tight for a single day ; the expansion of the first pipe to heat, being a powerful purchase to force the headers asunder, and when it cannot do so it will spring them sidewise. TO ESTIMATE THE AMOUNT OF HEATING SUEFACE NECESSAKY TO MAINTAIN THE HEAT OF THE AIR OF INCLOSED SPACE IN BUILDINGS TO THE DESIEED TEMPERATURE. 26. The ordinary rule-of-thumb way, of the average pipe fitter, is, to multiply the length by the breadth of a room, and the result by the height, then cut off two figures, from the right hand side, and call the remainder, square feet of heat- ing surface, with an addition of from 15 to 30 per cent, for exposed or corner rooms. In computing heating surfaces, there is much more to be considered, and it is evident, the amount of surface necessary for a good and well constructed building, will not be enough for a cheap and poorly put up one. The cubical contents of a room, occupy only an in- ferior place, when estimating for large rooms and halls, and no place at all, in figuring for small or ordi- nary office rooms or residences, which are heated from day to day throughout the winter. In a small room, on the second floor of a three story building, with only one outside wall, no windows, and the whole furred, lathed, and plastered, while all the other rooms of the building are heated, and maintained to 70^ Fahr. ; place a portable heater, and keep it there, until the room is heated to 70'' also, then remove it. How long will it take to cool 10^ ? Answer, perhaps two hours. Now make a window without blinds, and you find it cools 10° in less than half the time. Why ? BADIATOnS AYD REATINQ SURFACES, 23 Because the glass of tlie window, being a good trans- mitter of heat, it is able to cool more air than the whole outside wall. You may now say : What about the in- side walls and floors ? Why, they actually help to maintain the heat in the room by conduction, etc., from the other rooms. Thus, the windows are i\\Q first and most considerable item. Secondly, consider the outside walls and how they are plastered — whether on the hard walls, or on lath and furring. Thirdly, the prospect — whether ex- posed or sheltered. Fourthly, whether the whole house is to be heated, or only part of it ? and, lastly, what the building is to be used for. TABLE OF POWER OF TRANSMITTING HEAT OF VARIOUS BUILD' INa SUBSTANCES, COMPARED WITH EACH OTHER. Window glass 1,000 Oak and walnut 6G White pine 80 Pitch pine 100 Lath and plaster 75 to 100 Common brick (rough) 120 to 130 Common brick (whitewashed) 135 Granite or slate 150 Sheet iron 1,030 to 1,110 In figuring wall surface, etc., multiply the superficial area of the wall in square feet, by the number opposite the substance in the table, and divide by 1,000 (the value of glass), the product is the equivalent of so many square feet of glass in cooling power, and may be added to the window surface and treated in the same way. The following method has given good results, and is not wholly empirical. The writer has used it for many years in preference to any other: 24 STEAM HEATING FOR BUILDINGS. Divide the difference in temperature, between that at ivhick the room is to be kept, and the coldest outside atmosphere, by the difference, between the temperature of the steam pipes, and that at which you wish to keep the room, and the product will be the square feet, or fraction thereof, of plate or pipe sulfate to each square foot of glass, or its equivalent in wall surface. Thus : Temperature of room, 70° ; less temperature outside, 0"" ; difference 70°. Again : Temperature of steam pipe, 212° ; less temperature of room, 70° ; differ- ence, 142°. Thus : 142 --70 = 0.493, or about one half a square foot of heating surface, to each square foot of glass, or its equivalent. It must be distinctly understood that the extent of heating surface found in this way, offsets only the win- dows and other cooling surfaces it is figured against ; and does not provide for cold air admitted around loose windows, or between the boarding of poorly constructed wooden houses. These latter conditions, when they exist, must be provided for separately. 27. In isolated buildings, exposed to prevailing north or west winds, there should be a generous addition of the heating surfaces of the rooms on the exposed sides, and it would be well to have an auxiliary heater, to pre- vent over-heating in moderate weather. In windy weather it is well known to the observant, that the air presses in through every crack and crevice on the windward side of the house ; and should they take a candle, and go to the other side of tl\e house, they will find that the flame of the candle will press out through some of the openings. Thus the air in a house, blows in the same general direction as the wind outside, and forces the warmed air to the leeward side of the RADIATOBS AND HEATING SURFACES. 25 house ; this is why the sheltered side of a house is often warmer in windy weather than in ordinary cold weather. Simple conditions, which tend to the warmth of a house, in windy and cold weather, ivithout stopping the leakage of air, under doors or around windows are : 1st, blinds on the windows inside ; 2d, blinds on the win- dows outside ; 3d, window shades and curtains ; and, papered walls. The leakages are really blessings in disguise, in houses which are not systematically venti- lated. CHAPTEE ni. CLASSES OF RADIATION. Heating surfaces are divided into three classes : 1st, direct radiation ; 2d, indirect radiation ; and 3d, direct- indirect radiation. 28. Direct radiating surfaces embrace all lieaters placed within a room or building to warm the air, and are not directly connected tvith a system of ventilation. The best place in a room to put a radiator, is where the moist air is cooled — namely, before or under the ivindoios, or on the outside ivalls. When the heater is a vertical tube radiator, or a short coil, which can oc- cupy only the space of one window, and when, as often occurs in corner rooms, there are three windows, the riser should be so placed as to bring the line of radia- tors in front of, and under the windows where they will do the most good — as the middle window. It is better still, when a small extra cost is not considered, to use two heaters, and place one in front of each extreme win- dow. When the room is large, and has many windows, the heating surface should be divided into as many parts as there are windows ; or, if the occupants object to so many windows being partly obstructed, divide into half as many parts, and distribute accordingly. 26 CLASSES OF RADIATION. 27 In schools or buildings with many windows, where children or persons cannot change their positions, but have to remain seated for several hours at a time, care must be taken that the heating surface is very evenly dis- tributed. A coil run the whole length of the outside wall is best, but if any kind of short heaters are used, every window should have its quota. Should a single window be left unprovided for, it will be found by ex- periment that a cold current of air will fall down in front of such window, and flow along the floor, in the direction of the nearest heaters, and cause cold feet to any who are in the line of its passage. The natural currents in a room with the outside at- mosphere the coldest, are doum the windows and out- side walls, and tip at the center or rear walls. This downward and cold current, should be met by the heated and upward current from the radiator, and reversed and broken up, as much as possible. 29. Indirect radiation embraces all heating surfaces placed outside the rooms to be heated, and can only he used in connection ivith some system of ventitation. There are two distinct modifications of indirect radia- tion. One, where all the heating surface is placed in a chamber, and the warmed air distributed through air ducts, and impelled by a fan, in the inlet or cold air duct. Tlie other, where the heating surface is divided into many parts, and placed near the loiver ends of verti- cal flues, leading to the rooms to be heated. The first of this class — namely, chamher-heat — has not proved a great success, and architects and steam heat- ing engineers are likely to have very little to do with it, as it has been found, that in windy weather it is almost impossible to force air to the side of a building against 28 STEAM HEATING FOB BUILDINGS, which the wind blows. The second of this class does well, as it admits of taking advantage of the force of the wind, to aid in bringing the warmed air into the rooms. In estimating the heating surface for low pressure in* direct radiation, it is well to nearly double what would be used for direct radiation. 30. The indirect heater is usually boxed, either in wood lined with tin, or in sheet metal. The former is best when the cellar is to be kept cool, as there is a greater loss by radiation and conduction through metal cases ; otherwise metal is best, as it will not crack, and when put together with small bolts can be removed to make repairs, without damage. 31. The vertical air ducts are usually rectangular tin flues built into the wall when the building is going up ; sometimes they are only plastered ; but round, smooth metal linings with close joints give much the best re- sults. The cross section of an air duct should be com- paratively large, as a large volume of warmed air, with a slow velocity, gives the best result. There should be a separate vertical air duct for every outlet or register. In branched vertical air ducts, one is generally a failure. The heated air from one heater, may be taken to two or more vertical air ducts, when they start directly over it ; but one should not be taken from the top, and the other from the side ; or the latter will be a total failure, unless the room to which the flue runs is exhausted ; i. e., the cold or vitiated air of the room is drawn out by a heated flue or otherwise. Inlet or cold air ducts are best, when there is one for every coil or heater ; and its mouth, or outer end, should CLASSES OF RADIATION. 29 face the same way as the room to be heated. By this means, when the wind blows against that side of the house, the pressure is into the cokl air duct, and materially assists the rarefied column of air, in the ver- tical duct, to force its way into the room. Often the steam-heater uses only one large branched cold air duct ; but this system will give trouble unless all the rooms are exhausted. The steam-heater should not take a job of indirect heating unless the building has been arranged especially for it, with some efficient system of flues, sufficient to change the entire air in a given time, not to exceed one hour. Frequently, the architect makes no provision for draw- ing out the cold or depreciated air, other than an open fire-place, and often they make no outlet. Such a room as the latter cannot be warmed by indirect heating at all. But when there is a chimney, or an unwarmed outlet or foul air flue, the heated column of air in the vertical hot air flue, is generally sufficient to force its way through. Very large rooms, with high ceilings, are difficult to warm by indirect heating alone. A cheap and good way to draw, or exhaust, outlet or foul air flues, is to connect them all to one large annu- lar flue, around the boiler chimney flue. Warmed fresh air flues should be in, or near the out- side walls, and should discharge near the windows ; and foul air flues should be in the inner walls, and have an opening near the floor and ceiling, with register valves, to allow the occupant to use either, or both, as he thinks proper. 30 STEAM HEATING FOR BUILDINGS. 32. To find the time in minutes, it will take for a room of known cubical contents, to change its air through a flue of one square foot cross section : Multiply the velocity of the air through the flue in feet per second, by 60, and divide the cubical contents of the room in feet by the result. Thus : Velocity of air 5 feet x GO = 300 -^into cubical contents, say, 4,000=13.3 minutes. To find the time for other sized fines, multiply this re- sult by the cross section of flues, in square feet, or frac- tions thereof. The velocity of the air in heating flues with only a natural draught, rarely reaches 8 feet per second, no matter what the conditions ; and 2 feet, 45 feet, and 6.2 feet respectively, are fair averages of velocities for first, second, and third floors of a house. 33. Direct-indirect radiation embraces all heating surfaces placed within, or partly within, the room to be warmed, indirect connection ivith some system of ventilation. Heaters of this class are usually placed on the out- side walls or under windows, following the same general CLASSES OF RADIATIOI^. 31 rules as direct radiation, excepting tlie clusters are deeper, so as to prevent the cold air from -rusliiug through without being warmed. Fig. 5 is a favorite modification of this style of heat- ing. It is a section of a room, showing the action of the currents of air. A A, outside wall ; B, partition wall ; C, radiator ; D, inlet flue ; E, damper or valve ; F, ven- tilating flue or foul air outlet ; G, fresh air mixing with the air of the room ; H, air of the room passing along the floor to the heater ; I, a percentage of the air in the room passing off by the ventilator. Fig. 6 is another modification of direct-indirect radia- tion, where some of the local heat is employed to exhaust or draw out the vitiated air of the room. The arrows show the action of the air currents. ^ is a section of a radiator built with a sheet-iron flue, B, between the tubes, and passing through a hole, cored in the base, which connects with the register in the floor, and a foul air flue in the wall. Some of the radiant heat, etc., from the radiator, A, 32 STEAM HEATING FOR BUILDINGS. warms tlie slieet-iron flue, B^ wliich in turn warms tho air within it, causing an acceleration of the current in the foul air flue, and consequently drawing an equal amount of fresh air in at the opening, C. In estimating heating surfaces, for direct-indirect heating, it is well to use once and a half as much as would be used for direct radiation alone. There is this further distinction between the three systems of radiation : Direct radiation warms only the air of the room and maintains the heat. Indirect heat- ing warms only the air that passes in, and cannot warm the same air twice, and consequently has to raise the temperature of all the air that passes, from the outside temperature, to that necessary to maintain the tempera- ture of the room, and make up for the loss by ventila- tion. Direct-indirect radiation warms part of the air over again, and warms all the air admitted for ventila- tion, which latter can be varied to suit the occupants. POSITION FOR INDIEECT HEATERS. 34 "With indirect radiation, the heating apparatus being steam, a building cannot be other than sufficiently ventilated ; but it frequently happens in large rooms, with very high ceilings, or large auditoriums, as churches, schools, theaters, or assembly rooms of any kind, that they are not always satisfactorily heated ; for it is difficult to warm them by indirect radiation alone, unless there is a heater to each register, and many reg- isters placed before the windows, supplemented by di- rect radiators, placed near doors or passages, through which there will be strong local currents. Heated air from a few large registers in a very large CLASSES OF llADIATION. 33 room, goes directly to the ceiling, and fills tlie room from above, expelling tlie same amount of air through the ventilators ; if the building had no windows, this would answer; but as buildings have windows — which cool the air rapidly, there will be a falling of air, in front of the windows, which has not been pressed down, by the warm air above ; but has fallen of its own gravity, by losing its heat, from contact with the cooling surfaces of the building ; and these downward currents, having nothing to neutralize them, pass cold along the floor, in their passage to the ventilator, or to an ascending cur- rent of warm air — caused by the heat given off from the bodies and lungs of the audience. This is why people in churches and theaters suffer from cold legs and feet, and sometimes have a cold cur- rent on their heads, which makes the occupant certain — the window is open a little ; though a thermometer near by marks 70'', for the thermometer is not in the cold current. If a building must be heated entirely by indirect radiation (except where the occupants can change their position and draw down curtains, or close inside blinds), use as many heat registers as possible, and place them in front of the windows, or where a cold current is likely to come down. Usually in office rooms, and ordinary rooms in resi- dences, one register in the coldest part of the room can be made to answer ; but if the room is large, with many windows, more should be used. Figs. 7 and 8 are sketches of indirect radiators in position, showing a heater to each register. Fig. 7 be- ing for a lower floor, and Fig. 8 for upper floors ; where the air is carried through a flue in the wall. 3 34 STEAM HEATING FOR BUILDINGS. Rooms warmed this way wlien they have a fire-place, or a ventilating flue of proper size in the inside wall, with sufficiently large heaters and registers before the windows, or in the outside walls, should never fail. 35. It will be seen, that the dampers in the cold air inlets, are not automatically regulated. They are some- times so regulated, to prevent the freezing of the coils ; but when the steam and return pipes are sufficiently large, coils are seldom frozen ; for when steam is up. CLASSES OF RADIATION. 35 they cannot freeze, and when steam is not up, there is no water in the coils to freeze, for it has subsided to the water line. Only an apparatus with scant pipes and parts will freeze, unless the coil is too close to the water line, or partly below it. Indirect coils, if they have valves, should never be shut off in very cold weather. If the room is not to be heated, close the registers and inlet ducts. The closing, or partly closing of a valve, may freeze a coil, by inter- rupting the circulation. The closing of one valve, and the leaving open of the other, is sure to freeze a coil, if exposed to sufficient cold ; as in either case, it will fill with water. This applies to all radiators. CHAPTEE IV. HEATING SURFACES OF BOILERS. 36. The direct heating surface of a boiler (fire-box), has a yalue, several times greater than the indirect sur- face (flues and tubes) ; but the shape of the furnace, its size, and the angle of the heating surface, as well as the length, size, and position of the flues, give a greater or less value to the indirect surface ; but these values are only comparative. In constructing boilers for heating apparatus, an effort should be made to have the greatest amount of direct surface, with a minimum amount of indirect surface ; for it is desirable to have slow combustion, with thick fires, and thus reduce the attendance to a minimum. When furnaces are comparatively small, with a high rate of combustion, flue surfaces may be lengthened with beneficial results ; but in a private house, with a self-feeding boiler (base-burner), or one which has a deep furnace, constructed to put in six to eight hours' coal, and keep steam uninterruptedly for that time, a great part of the heating surface should be in the fire- box ; the heat from the gases being comparatively low tempered, and the amount passed in a given time small. It would be well to say, that most writers on boilers, 36 HEATING SURFACES OF BOILERS. 37 put too higli a value on what is termed direct heating surface, in contradistinction to indirect or flue surface. Not that the value of a square foot of surface in a fire-box of ordinary construction has not 2 J to 4 times the value, for the same size of average tube surface, but they con- vey the idea, that by increasing surface, near, or in the fire-box, and decreasing the tube surface, near, or in the direction of the chimney in a threefold proportion, to the increase in the fire-box — they can evaporate as much water with the decreased surfaces. Below certain sizes and proportions (which have already been attained in boilers of ordinary good construction), this may be so, but when a fire-box or furnace is large enough for proper combustion, the surface of it is then receiving all the radiant heat there is, and by increasing the sur- face directly exposed to the action of the fire (beyond the required chamber for combustion), it will be neces- sary to have the surface of the fire-box as a whole, more remote from the fire ; as radiant heat from any source has its effect decreased, directly as the surface ivhich ab- sorbs it. From a central point of heat, the rays diverge on all sides, and the intensity diminishes inversely as the square of the distance, which will be found to be directly as the surfax^es of different sized spheres, ivhich might surround it ; the value of the heating surface (for radiant heat), de- creasing for each unit of distance, in a geometrical pro- gression, whose ratio is 4 The above can be likened to the fire in an upright boiler ; assuming it has no down- ward radiation. In horizontal boilers, or boiler with long fire-boxes, or fired within horizontal cylindrical furnaces, the fire can be likened to a long column of heat, from which the 38 STEAM BEATING FOB BUILDINGS. rays go off parallel to each other in the line of its length, but diverge in a line of its cross section ; which will give an inverse geometrical progression whose ratio is 2, as the decreased value of the surface, for each unit of distance it is removed from the fire ; but in any case, the assertion, that the intensity of radiant heat decreases directly as the surface which absorbs it, will hold good for any shape of fire, or any shape of furnace ; and that hanging tubes, projections, or corrugations in a fire- box, receive nothing from the radiant heat that would not be received by the plain surface ; so, although a person may take 4 foot of tube surface away, and add one foot to the fire-box, without perceiving they lost anything, yet they cannot, in a boiler that is already \ furnace, and | flue, whose gases af combustion escape at a sufficiently low temperature, take away all the flues, or a large percentage of them, and by adding i of their surface to the fire-box, makes as much steam. 37. All that can be gained by croivding the fire-box with surfaces, hanging or otherwise (which must not in- terfere with combustion), is, to reduce the bulk of the boiler ; the surfaces will be the same still, for the same work. It is therefore poor economy to reduce the size, when nothing else is gained, and make surfaces which will fill up on the inside with sediment, choke up in the tubes, or between them with soot and ash, and wear out in one-third of the ordinary time. It is an incontrovertible fact, that boilers with very small parts, require more surface for the same work done, than with large and plain parts ; because of the impossibility to thoroughly clean them, and the rapidity with which they choke ; the nearness of the tubes allow- ing the dirt to bridge between them. HEATING SURFACES OF BOILERS. 39 A maximum of fire-box, with a minimum of flues, is proper, and should be the rule in house heating^ where there is generally plenty of room in the cellar. 38. If the surface of the fire-box be increased by pro- jections or corrugations, for the purpose of an increase of surface in contact with the highly heated gases of the furnace, the folds should be large and in vertical rows, * so nothing can find a lodgment on them. 39. The boilers which have given the best evapora- tive results, as well as the least trouble, and lasted the longest, have been the simplest, and the evaporative re- sults of a boiler depend more on the care with which they are kept clean> and the unimpeded circulation of the water within them, than on any peculiar disposition of the heating surface. Large boilers, compared to the work, are most eco- nomical ; but the limit is hard to fix, there are so many conditions to be taken into consideration, as well as styles of boilers ; and as it is really the size of the grate, and the velocity of the draft, compared to the work to be done (after the boiler is large enough), which regu- late the economy — hence a sufficiency of boiler, with the rigid grate surface, to burn the fuel, accomplish the most satisfactory results. A boiler that may do very well for the first year, may not give satisfaction the second year. Such will be the case with boilers barely sufficient for the work, which, while they are clean, and the person in charge of them has a pride in doing well, will pass muster ; but the second year, when the novelty has passed off, it Avill be * quite different then, complaints will be heard, and one investigating steam apparatus with a view to putting it in his house, will be apt to reject it. Then it is too late 40 STEAM HEATING FOR BUILDINOS. to assert : tlie trouble is known and can be easily remedied. 40. In proportioning the size of boilers, all calcula- tions must be based on the supposition that the boiler will be neglected to a certain extent, and that there are parts of the best boilers which cannot be properly cleaned, and that all boilers deteriorate in transmissive power (the gravity return least of all, as the return water is pure) more rapidly at first, until a point is reached, where external deposits fall off, after which the impairment is slow, and caused only by slight deposits on the inside, chiefly oxides, which have a high trans- missive power themselves. 41. Can a boiler, it may be asked, be robbed of its heat, by the gases of combustion, by retaining them too long in contact, in passing through long flues? Not if they are internal tubes or flues ; but there is a point be- yond which there is no gain, — namely, where the tem- perature of the gas and the steam becomes the same. Up to that point, the gases of combustion being the hotter, impart heat to the flue, but beyond it, neither the flue can impart heat to the gas, nor the gas to the flue, as they are of the same temperature. Boilers, when they are new, should have some such point, which simply moves nearer the chimney, as they become old and dirty. The rate of combustion will also give this point a variable position, for the time being. Some engineers think it preferable to let the gases of combustion escape at a higher temperature than the steam. In that case, the point can be assumed to rep- resent any constant difference of temperature of the gas, above the steam. BEATING SURFACES OF BOILERS. 41 42. Eeverberatory, or drop flues, in upright boilers, save mucli Leat. A cause of loss of heat, in upright boilers (and possibly in many other boilers), which have a great many tubes, many more than the aggregate area of the chimney, is, the heated gases, find the tubes directly over the fire, and pass out rapidly at a high heat, of their own gravity, leaving the gas in the outer rings of tubes, inert as may be seen in almost any up- right boiler, where the tubes of the outer circles are clogged with dirt ; the velocity of the draft, in the mid- dle tubes keeping them comparatively clean ; but when there is a row of drop tubes, as shown in Fig. 14, or a flue built around the outside of the shell of the boiler, with brickwork, with the chimney flue leading from the bottom, as shown in Fig. 13, the gases are then clraion outf or "exhausted " by the heat in the chimney ; and the gases around the upper part of the boiler, become uniform in temperature, and stratify, the lowest being drawn off first, and the others following according to their temperature. When combustion is good, and the gases as they leave the boiler and enter the chimney flue, have not too high a temperature, the water within such a boiler has ab- sorbed all the available heat ; hence, to increase the sur- face of such a boiler, will not do much good, unless the grate surface is also increased ; since all the heat evolved has been absorbed. 43. Will the quantity of water within a boiler effect evaporation ? Many steam heaters, and others, use boilers, com- posed of very small parts, so as to have the greatest surface with the least water, with a view to evaporate more water in a given time ; and cite the time, betiveen 42 STEAM HEATING FOR BUILDINaS. starting thejlre^ and tlie time steam is up, as a proof of it. This is a mistake ! The reason why steam is gotten up quicker, is because there is less water to heat to 212*^ before steam begins to make, but beyond that, the re- sult, with regard to steam making is the same, for the same surface, other things being equal. What is gained in first time, with sensitive boilers, is more than compensated for, in house heating, by having boilers which contain a large quantity of water, by keep- ing steam where a new fire is put in ; as boilers which contain small quantities of water are rapidly chilled, as well as rapidly heated, and must be fired often, and regularly. Fire engine boilers, require to be sensitive, and when much power, with small weight is a desideratum, they are all right. CHAPTEE V. BOILERS FOR HOUSE HEATING. 44. Boilers for heating apparatus should have very few parts, and be as simple as it is possible to make them ; every part of them being constructed with a view to permanency ; and parts that wear out more rapidly,- such as grates, should be so arranged that they can be renewed by the most inexperienced person. 45. Requirements for house heating boilers are : 1st. They should contain a quantity of water, suffi- ciently large to fill the pipes, and radiators, with steam, to any required pressure, witJiout lowering the ivater enough in the boiler to require an addition, when steam is up ; for should the steam go down suddenly, there will be too much water in the boiler. This occurs in boilers made with very small parts, or pipes, which have a small capacity, at the water line, and require great care ; for should the boiler have an automatic water feeder, set for the true water line, it will fill up, but cannot discharge again, when the steam goes down ; while, if it has no feeder, there is danger of spoiling the boiler, as the water is in the pipes in the form of steam. For the quantity of water necessary to fill the pipes, 43 4A 8TEAM HEATING FOR BUILDINGS. with steam at any pressure, at a maximum density, see Table 29. 2d. The fire-box should be of iron, with a water space around it, as in upright, or locomotive boilers ; to prevent clinkering on the sides, and the necessity of repairs to brickwork, which are imavoidable in brick furnaces. 3d. The fire-box should be deep, below the fire door ; to admit of a thick fire, to last all night, and thus keep up steam. 4th. The fire-box should be spacious, for the sake of good combustion. 5th. The flues and tubes should be large, and in a vertical position, so they will not foul easily, and that any deposit would fall to the bottom. 6th. The heating surface should be great in diameter, instead of in the direction of the chimney, and the last turn be a drop. 7th. They should, if possible, be constructed of such shape and design, that they will require no sweeping, or cleaning, other than removing the ashes ; but when it is unavoidable, every facility should be made for easy access to such parts ; because they are often operated by inexperienced persons (house servants), who will condemn anything which gives trouble to them. 8th. The fire-grate must be easy to clean (anti- clinker), and so designed, it will not crack or break when heated (see Grates, page 80). 9th. The grate and ash-door must be so constructed, that a new grate can be put in quickly by any one. 10th. There should be no tight dampers in the chim- ney flue, and when the flue goes out near the bottom BOILERS FOB BOUSE HEATING. 45 (drop flue), it may be dispensed with altogether ; but the fire and draft-doors should be made to close air- tight (planed), so as to be capable of entirely damping the fire. This will prevent the possibility of coal gas escaping into the house ; the damping of a fire, by shutting off its supply of air, is the proper way ; for the draft of the chimney being unimpaired, draws all the harder on any crack, or crevice, in the brickwork, causing an inward current, which entirely precludes the escape of gas. 11th. The perpendicular height of the boiler should not be too great for the cellar, so the water line will not be too near the level of the main pipes. 12th. It should be so inclosed in brickwork as not to perceptibly raise the temperature of the cellar, in w^hich it is, and have the whole outside of the boiler, heating surface, if required, by having either an up- ward or downward flue. When upright boilers are constructed with drop tubes, as shown at a, Fig. 14, or with drop flues, as shown in Fig. 13, it is generally necessary to use a direct smoke pipe, as well as a bottom pipe, as shown, in which case an upper damper is required, and possi- bly it is better to have a lower damper also ; the two dampers should be connected at right angles to each other by a rod, as shown at /, Fig. 14, which prevents the possibility of having both dampers closed together. 46. In upright boilers, for house heating, the propor- tion of fire-box to the flue surface admits of almost any modification, as the boiler can be made of large diam- eter, with high fire-box and short tubes, drawn in at the bottom, with dead plates, for the desired size of grate, or drawn in, as shown in Fig. 12. 46 STEAM HEATtNG FOR BUILDINGS. 47. Horizontal multi-tubular boilers admit of very little modification ; an increase of diameter, with short shell and large tubes being best, for slow combustion, with a great distance between the grate and boiler, and no bridge-wall, other than enough to keep the fire on the grate. A chamber behind the bridge-wall is not of any par- ticular service, when the bridge-wall is low ; but mak- ing contracted throats, at the bridge-wall, or behind it, to make the heat " hug " the boiler, is a mistake. What is wanted in the furnace, and under the whole length of the boiler, is space sufficient for complete combustion. Below a certain size of cross section combustion is interfered with, and the oxygen which passes through the fire will not combine with the unconsumed carbon, which has been decomposed by the heat at the grate ; but with ample space this ignition will be continuous, until complete, with a sufficiency of oxygen, where the temperature is not below (800°) eight hundred degrees Fahr. For a high rate of combustion the boiler may be longer, with tubes of small diameter and with great space under the boiler. 48. A contracted passage, or having only the area of the chimney at the bridge-wall, may impinge more heat on that particular part of the boiler, but it will not cause the evolution of more heat ; and the sum total remaining the same, it will do the same duty, whether absorbed by a small part of the boiler, to which it may do injury, or by the whole surface at a more general temperature. The extent of the sides of the furnace, when made of brick, may be used as an argument against a large BOILERS FOR HOUSE HEATING. 4:7 chamber ; but the loss through a brick wall is so little that it will not offset the benefit. Figs. 18, 19, and 20 show a horizontal multi-tubular boiler, as ordinarily set ; 18 being longitudinal section, 19 half front and half cross section, and 20 floor plan. 49. The different parts of boilers, and their settings, have technical names, applying to the correspond- ing parts of all boilers, as far as ' the construction will permit; the shape, sometimes, modifying the name, and increas- ing or lessening the parts. As an example, a return- flue boiler, and a drop - return- flue boiler are shown (Figs. 9 and 10). The return-flue boiler can be used as a stationary or marine boiler with or without water-bottom ; the drop-return being constructed for stationary boilers, as it has no steam chimney, and the smoke connection is a sheet iron breeching. 48 STEAM HEATING FOB BUILDINGS, A. Boiler-shell. B. Steam-dome. C. Boiler heads. C. Flue sheets. D. Tube. F. Flues. G. Back connection. H. Front " or smoke connection. I. Smoke J. Furnace, or fire-box. K. Ash-pit. L. Water-bottom. • M. Steam chimney (marine). N, Smoke chimney (marine). 0. Man-hole, to back connection. P, Bridge-wall. Q. Braces. B. Stay, or socket bolts. S. Grate bars. T. Coking, or dead-plates. U. Front-bearer. V. Back-bearer. W. Division, between front connection and fire-box. X Boiler-fronts, cast iron. Y. Side walls. Z. Lugs. The division between furnaces, and the sides ot tur- naces, are called "Legs" in fire-box boilers. The same letters apply to the corresponding parts of the horizontal boilers, Figs. 18 and 21. CHAPTEK VI. FOEMS OF BOILERS USED IN HEATING. The conditions required for heating boilers, which are of such proportions they may be fitted up to work automatically, are simplicity of construction, durability of parts, and ordinary economy in firing. 50. A source of danger to the success of the young steam-fitter and to many inexperienced in steam-fitting — is their endeavor to construct ideal boilers, which usually prove to be failures. It is far better to use boilers proved successful by others, and improve their weak points, after your own experience with them. Suc- cess lies in that which will give least trouble, and will not wear out rapidly— the burning of a few tons of coal more or less in a year, is not a proper test ; as the conditions of management, the size of the house, the amount of ventilation, the number of hours the ap- paratus is operated in the year, and last, though not least, the comfort and satisfaction— all must be taken into consideration to prove economy. 51. Fig. 11 shows the simplest form of upright boiler, used for heating, excepting, perhaps, one with a flat crown sheet. The grate is drawn in at the bottom, by a slanting annular dead plate, as shown ; the center ^ 49 50 STEAM HEATING FOR BUILDINGS. part of tlie grate only has openings. The brick-work is very simple, and is built around the boiler, leaving about a three -inch space for a flue, and the smoke pipe is taken out at the bot- tom. It does not rate very high in point of economy of fuel ; but it is very easily kept clean, and lasts a long time. 52. Fig. 12 shows an upright boiler (multi-tubular), which is drawn in at the fire- box, to the size for the grate. This dispenses with the annular dead plate, and makes a very permanent piece of work. This boiler is set to carry the heat, when it leaves the tubes down one side of the boiler, and up the other, passing under a septum of iron, or a division wall, which may be run very near the boiler, but so as not to press against it. When the tubes of this boiler are not smaller than two and a half inches, or longer than three feet, and nothing but hard coal is used, it will require cleaning but once a year, provided there is no leak in the fire-box, or about the ends of the tubes. "^ To clean them, — remove the cover a\ and use a steel wire tube brush. The cover a' is covered with sand, or fine ashes, on the toj), * Much moisture causes the fine white ash which comes from hard coal to bake on the heating surfaces, and should be prevented. FORMS OF BOILERS USED IN HEATING. 51 and in the space c, around the top, to prevent radia- tion, or danger from fire. It will be noticed, this boiler is set on a cast iron jDlate, to give it stability. This plate is most satisfactorily made in two parts, and bolted toojefcher, which will prevent the heat of the fire from cracking it, after it is set. The grate is here shown, a little higher than it is usually set; but it would be well to keep it as high as the rivets. 53. Fig. 13 shows the ordinary upright boiler, set for heating. It has a peculiar steam dome, as show^n (patented), which prevents an excessive heat on top, and it is claimed slightly superheats the steam. It also has an ash-sifting grate, which saves much dust, in the 52 STEAM HEATmG FOR BUILDmGS. manipulating of the ashes, and prevents the grate proper from burning out rapidly. 54. Figs. 14 and 15 show an upright multi-tuhular drop tube boiler. Fig. 14 is a vertical section, on a center line, and Fig. 15, a half cross section, to show the walls and tubes. In Fig. 14, jP P is the fire-pot, or dead plate ; F, the fire-box, or furnace ; G, the grate ; H, a bar set in the brickwork of the ash-pit, in such a way, it may be removed to put in a new grate, and into which the grate is pivoted, a certain distance below the edge of the fire-pot, to admit of shaking and cleaning from the bottom ; the amount of opening is FOnMS OF BOILEBS USED IN BEATINO. 53 regulated bj washers, on the j)ivot of the grate, to suit the size of coal used ; 0, the direct tubes ; a', the drop \flat coil, when the return pipe does not run be- low the water lines, but permits of live steam entering the coil from the lower end, and forcing the air toward the middle of the coil. Some steam-fitters put an air valve on a return-bend, at a point about \ the length of 100 AIR VALVES ON RADIATORS. 101 the coil from tlie lower end, but the result is often a disappointment. The best way in case of box coils and flat coils, is to carry their return pipes helow the ivater line and any work so piped will never prove troublesome in this respect ; for the current of the live steam is always from the steam to the return valve. The idea of the air always gravitating through the steam, and finding the lowest part of a heater composed of small pipes, is erroneous, unless the steam is let in one top. In what is called the atmospheric radiator, the steam enters on top, with a hole near the bottom to let the air out, and a drain to carry off the condensation in the bottom. Steam enters this radiator through a very small pipe, with a nicely graduated valve, which admits any desired quantity of steam, and which fills doivnioard, and permits a part, or the whole of the heating surface of the radiator to be used. It may be likened to a balloon partially filled with gas, the gas always remaining in the top.* With system "No. 2," low pressure steam piping, there is never any trouble to discharge the air, and for extremely low pressure (private house heating) it should be used. Air and steam mix within a heater, to a certain extent and at certain pressures ; this mixture being of doubtful gravity. Steam at the pressure of the atmosphere, and a tem- perature of 212° Fahr., has a gravity about one half that of air at the pressure of the atmosphere, and a temperature of 34° ; but when the air is increased in * These heaters cannot be used in a gravity return apparatus. 102 STEAM HEATING FOB BUILDINGS. temperature about 160^ the steam is tlien about two- thirds the gravity of the air. 92. Air valves are various in design, but may be separated into three kinds : the old-fashioned pet-cock, a compression thumb-screw valve, and the automatic air valve. The first needs no explanation, and may be used on rough work, but should not be used on fine work, for a plug cock will not stay tight on steam work, and will leak on the floors, and wet the ceilings. The second is much used, and is simply a small angle valve, with or without a stuffing-box, as shown in Fig. 35. The third (the automatic air valve), embraces nearly as many designs as there are manufacturers of heating apparatus ; but the principle used is the same in each instance, viz., the taking advantage of the difference of expansion of any two metals that will stand the action of steam, one of which has a greater coefficiency of ex- pansion than the other ; and in reality becomes a metal- lic thermostat, which operates a little valve. Fig. 36 shows a simple form of this arrangement ; A, being a strip of cast iron ; B, and b, strips of brass, set against shoulders on the cast iron, and (7, the valve and ATE VALVES ON RADIATORS. 103 STEAM HEATING FOR BUILDINGS. Tz^ 3S stem, passing through holes in the bar ?), and the cast iron ^, and screwing into the other brass {B). When heated above the temperature at which they are fitted, the brass ex- pands more than the iron and forms a bow shape, as shown, and draws the valve to its seat ; the dotted lines show its normal position. The stem, where it screws through the brass B, forms a regulator, which can be adjusted with a screw driver, applied to a slot in the valve. The outside D may be a piece of pipe, or a casting, with a boss on the side of it, to tap a small pipe into, so as to carry the vapor away, if required. Fig. 37 is another modification of the same principle, but has a point of excel- lence worth mentioning, to wit — a vapor cup, as seen at a. The center stem A has less expansion for the same increase of heat than the case B, and when it expands, closes the valve ; but, as stated, the point most worthy of note is the vapor cup. Any condensed steam which escapes through the valve runs down the small pipe h, and drops in the evaporating cup a, which forms an annular chamber around the case, which is always hot when steam is on the radiator. For private houses, and offices, this is an advantage, as the es- cape from the valve can be regulated so as to give any desired moisture to the air in a room. AIR VALVES ON RADIATORS. 105 Fig. 38 shows a form in which one metal only (brass) can be used, the rods h h not being expanded as much as the case Aj for the reason they are outside, and not in direct contact with the steam. When the case A ex- pands, it presses on the thumb-screw (7, forming a valve. 93. There is still another kind of air-vent used which is simply a small-chambered fitting, with a very small hole bored in it, which always remains open and is attached to a radiator in the ordinary way. Where the pressure does not exceed 1 lb. above atmosphere it may be used ; but for high pressure it will not answer, for the waste may be very great, since a hole -3^ of an inch in diameter is capable of passing about 1 lb. of steam in 33 minutes at 50 lbs. pressure ; which from 100 vents in 24 hours would be more than two tons of water.* * The above is a theoretical computation based on the flow of steam through a theoretical orifice, when no allowance is made for friction in so many little holes, which might reduce it one half, but even then it is so considerable that attention must be drawn to it. CHAPTEK XIV. PIPE. 94. There are two kinds of wrought iron, steam and gas pipe — namely, lap-welded and butt-welded. There is no lap-welded pipe smaller than 1| inch, though butt- welded pipe is made of all sizes, excepting extremely large sizes. Lap-welded pipe is considered the best, although for sizes smaller than two inches it makes little difference which is used, if the butt-welded pipes are properly made. The butt-welded pipe is the most uniform in size, and generally works easier, as it is softer. All the pipe and all fittings made in the United States and Canada are supposed to be of standard dimensions ; so the whole is interchangeable. Occasionally in old buildings pipe is found, which is known as " old gauge," which is somewhat larger than the pipe now in use. 95. The size of pipe is standard, but the standard is arbitrary ; the inside diameter being nearest the nomi- nal size of the pipe, which it always somewhat exceeds ; small sizes are most disproportioned (as can be seen by reference to the table of " Standard Dimensions of Wrought-iron Pipe," or to the diagram of sizes of pipe). The threads on the ends of pipes should taper yi^- of an inch for an inch in length of thread. 106 PIPE. 107 JO qoui j.kI 1> QO 00 ^ ^ ^^^'^00 OOGOOOOOOOOOOOOOOOCO (Mrii-ii-ir-iT-Hr-iT-i^ io;oojJod;qSio,\i 5 ^^l000T--CD0iOOt>i0O£-TPOt-^C0O«0 OOOOi-iTHCi050CJ'<* 00 (M GO ouo SuiuiBJuoo y d o 1-H cQ d o o d oi d 05 Tj^ -rH aj i> -"i^ CO oi ci th p:^ OOOlOt-l-COOSt-'^l^COTHi-lrH lO CO t- TJH Oi tH •B3JV iBcua:>xa: 03 CiC500-^eOt>-rt<10 0T-iT-IOrl^lCO-<-iCOO»OC';ccQ-rHO — T-HOJOOJOOOCOi-iGOTti'^OtOOOCl'^OTrt-l- a OOOOO T-l(MOiTf OOCQiOCSTj^Tt^iOOOOOO •89JV" ItJOJOJUI CI -rH O 00 CO l> „; t-^i-H^COCiOOOOCOOOl^OOOClt'OCOOO O OOCSOCOOOCOlOQOOOOOCOCOCiOOCOCOCOCO ^ OT-itHCOlOOO'^OCOt-COOOt-CiCSOOC-OCOOO C O OOOO Ot-I 05 CO "rfi i>0 C03l>CO-i-l ■r-IOO-rHl!OCi»OOJ>lO'^-rtUO « rtii>l0OC0OO-T-iT-ic^CilCMio^cocQoioiT-ir-(T-iddddddddd •93BJJIH apTSiii JO ■jooj ajBubs jadadij; joqiSuaT L'0C500T-(00t>»-'5I>O00I> tJ^OOIOt-I ■j:^ 100i>COCOl^OJ>^'^'^4>'rt"'*iOCO'^t'G^jaO g i-iOOT-lOOt-COOOlOCiOCiOOC-OlO'^'^CO '^^ -<*di>dTtiOl>OOlOCO'^«OCO^ ;s t> C5 OJ lo C5 CO T-( o o CO o i:s CO o i> -r-i to o CO c-" •3 o3coTHooiT-(c ^ THr-((MC:»COTtC500?'*10i>OCOi--OCO TH-rHTHi-HrHCQCiCJCOCO •90UDJ3J g' 00-^05»>OGQJ(0tHM*"^OO00C0O'^C0O£-L'0 Si Mi>05d •ssaoJiDiqj, 2' C000-r-lCSC0^O».'5T^'^l>«0J:-»>0SO-^C5-^O ^ 32002'^'^^'*"*»^0^(MC0^1.0 000C>^0 -^ OOOT-(rHT-(T-lT-lT-l(M05C5C^(MC5C07CC»0 •g TJ^OOQOOCOOOSCOOOIOOJOOJOOOOOI' B, doodT-iT-iT-iT-(cooc5d uopuiBiQ apisui 33 ■o tH tH tH « (M CO CO Tl< Tf 10 «0 l> 00 05 108 STEAM HEATmO FOR BUILDmOS. DIAGRAM OF CROSS-SECTION OF WROUGHT IRON PIPE. ACTUAL SIZE. RELATIVE AREAS OE PIPES. 97. The young steam-fitter lias not always a just conception of how the size of one pipe compares with PIPE. 109 that of another ; not knowing how rapidly the area of a pipe increases with an increase of diameter. When the diameter of a pipe is doubled, the area has increased fourfold, and if one having { the diameter of another, it has but ^V of its area. Thus, the area of the cross sections of circular pipes are to each other, as the squares of their diameters. As circles and squares always bear the same relative proportions to each other, and as either can be likened to the cross section of a pipe, the beginner can always find the number of times, the area one pipe will divide that of another, by making a square {a') and calling the side of it the diameter of the smallest pipe ; then around the smaller square construct a larger one, the side of it being the diameter of the larger pipe, with the corner b forming a common corner for both squares. Thus, if the square a' represents a 1-inch pipe, and you draw around it a square 3| inches on the side, and lay the larger square off into squares, the size of the smaller one, as shown, the J number of the whole squares and the sum of the parts of the squares within the larger square, is the number of times a 1-inch pipe will go into a 3j-inch pipe. It will be seen, there are nine whole squares, six half squares, and one quarter square, which equals 12J squares : the number of times a 1-inch pipe will go into a S^-inch pipe. To prove the above according to the rule — ''Pipes are to each other as the squares of their diameters,^* square the smaller pipe for a divisor, and the larger a-'. ' 1 1 i 1 i -__L__.LJ 110 STEAM HEATING FOR BUILDINGS. pipe for a dividend^ and the quotient will be the num- ber of iimes. Example : 1x1=1. 3.5 X 3.5 175 105 l.jl3.25(12.35— Ans. Ex. — To find how many times a |-inch pipe will go into a 2-inch pipe. .75 X .75 2 X 2. 375 525 .5625)4.0000(7.11— Ans. 3.9375 .5625 6250 5625 6250 5625 625 + 98. The following table, has been calculated for the use of the steam and gas-fitter. PIPE. Ill -(«■ *l« Cfcft : ..k e*T. HTl Xto H'N |H-r|e*w ?^-r -,'-|-,'•^.l-''*|^^1■Mx Oi -«# |0 Tj^ TjH Tt< T-t T-H l«0 lo to Tj* « Uh 1-1 TH to to TH '^ C ^'». HJ. -1* t^iN Una -U -^.b. --1 J> 00 O li> 05 ^ tH O? t> to ''t CO TH TH |tH ■^ 05 100 Tf CO CO ^ 1 Ico i 1 1 1 1 1 1 1 1 1"^'°! 1 -■'^1 I'-^^l l~'"l H'N -1=^ UlTfUl^ H-N ^ \^ lo g b ^,^ ^ s^ te h '^ ^ <^ h r r lO It- CO iO <^ r^ io? 1 1 1 1 1 1 1 1 III Ulo ^tol 1-Hc.l 1 U^-kI La>l^i5k^-| lO }g§^|^S;::h^^^^r O iO O r^ tH ^ 1 tH 1 1 ' 1 ' ' 1 U< o r-l Jl -la. |.J«| 1 I'TiicI |.cla| «»i -lav -1*) t-'a H-* ^ CO TtH 00 iO <=> t- -^ a T^\y^\^ C a N-H (M t> »o CO tH T-t tH 1 00 Oi 00 ^ (N tH Ic- 1—1 1 1 1 1 1 1 3-.1'-- l-l-K -'^. -iw eo o ^ -^ «D ko 05 to rt^ C« tH rH t' ?0 CO tH liO tH 1 1 1 ^ 1 -rl^i -|3> -I* Ha ^if c^ \<=> 8 '* to tH CO Tl* ^ ?crease the pipe one size, to give them a practical magnitude, to overcome loss by short turns, etc. Main pipes should not de- crease in size, according to the area of their branches, but should be proportioned by the same rule as for determining the size of the main the first time. The same is true of the large branches. Find what they have to supply steam for, and proportion them as you would a main, figuring their own surface as radiating surface unless they are to be covered. SIZE OF MAIN PIPES. 127 Occasionally steam lias to be carried long distances to a dozen or so large radiators, as in a railroad depot, or in one or two story buildings, which cover much ground. In a case of this kind, it Avould be w^ell to increase the diameter of the pipe, one or two sizes, to provide for loss by friction, etc., but in high buildings fully heated this will not be necessary, unless the pipes pass through cold hall-ways, or are unusually exposed. CHAPTEE XYI. STEAM. 118. Tempeeatures of steam according to tlie different formulae, all agree at the atmospheric pressure, but as the pressures become high, they vary slightly : Keg- nault and Kankine are nearly alike, while the experi- ments of the Franklin Institute are about five degrees higher for 75 lbs. apparent pressure. 119. The technical terms, used about steam by writers, and the expressions in vogue amongst steam-fitters, want some explanation to make them clear, as many of them are synonymous and the fitter does not always know what is meant. Pressure — Is the force of steam, usually expressed in pounds per square inch, and " elastic force " ; " expan- sive force " ; " tension," and " elasticity,'' are synonyms. Temperature. — The heat of steam, usually expressed in English and American books in degrees of FalirenJieif s scale.^ Density. — The weight of a cubic foot of steam, com- pared to a cubic foot of water. Syn. — Weight of water in steam. * The use of Centigrade and Reaumur scales and foreign weights and measures, are very much to be condemned in English reading books or papers for practical men, the reduction to familiar terms often requir- ing more mental effort than the problem to be solved. 128 STEAM. 129 Maximum density of steam, — The proper quantity of water in the steam, suitable to the pressure, i.e. when the steam is neither superheated nor laden with par- ticles of water mechanically. Syns. — Dry saturated steam ; dry steam. Superheated steam. — Expanded by heat, or an increase of pressure by heat, without the addition of water. Wet steam. — Water carried up into the steam by force of ebullition, and held in the steam by the rapidity of evolution, when the steam space of a boiler is not large enough. Syn. — Saturated steam. Foaming. — A condition differing from wet or saturat- ed steam, by having an excess of some foreign sub- stance in the water, causing it to seem lathery and which appears to give the water in the boiler a tem- perature above what would be due to the pressure, by retarding the separation of the steam, and raising the whole mass of water into a froth. Syns. — Priming ; drawing water. Priming in a boiler is effected by two causes — viz.: Taking away the steam in intermittent puffs, faster than it is made and foaming. Priming in boilers is generally an effect : foaming a cause. Volume. — The space occupied by a given quantity of water, should the water be converted into steam, the relative volume decreases as the pressure increases. Syns. — Kelative volume ; bulk for bulk. Specific gravity of steam. — The lueighf of its bulk, compared to the same hulk of water, air, or any other substance it is contrasted with. Syn. — Density. Specific heat of steam. — The heat of a given iceight, •compared to a given loeight of air, iron, or any other substance it is contrasted with. 130 STEAM HEATING FOB BUILDINGS. 120. The annexed table gives the appare^it pressure of steam from atmosphere to 100 lbs. in pounds per square inch ; absolute pressures in inches of mercury, and temperatures in degrees Fahrenheit (to within one half degree), according to Regnault, the volume being calculated. TABLE NO. 5. ELASTIC FORCE, TEMPERATURE AND VOLUME OF STEAM. ELASTIC FORCE. Temperature of Steam RELATIVE VOLUME Average Rise of Temperature Ajyparent Pressure of Steam in lbs. per Square Inch. Absolute Pressure in Indies of Mer- corresponding to its Press- ure. Bulk of Steam compared to Bulk of Water. for one lb. Pressure for each 10 lbs. cury. 30.0 212.0 1710.0 -^ 1 32.03 215.5 . 1612.0 2 34.07 219.0 1523.0 3 36.11 222.0 1442.0 4 38.15 225.0 1372.0 5 40.18 227.5 1312.0 -2.8 6 42.22 230.0 1248 7 44.27 232.5 1194.0 8 46.30 235.0 116S.0 9 48.33 237.5 1103.0 10 50.37 240.0 1061.0 11 . . . 242.0 ' 13 .... 244.0 13 .... 246 .... 14 .... 248.0 15 60.50 250.0 "895.0 1.75 16 .... 252.0 17 253.5 18 254.5 19 . . . 256.0 .... 20 70.75 257.5 718.0 21 259.0 22 260.5 23 .... 262.0 .... 24 .... 263.5 '700.0 -25 so! 91 265.0 684.0 -1.5 26 . . . 266.5 .... 27 .... 268.0 28 269.5 29 271.0 30 9i;i2 272.5 'eiio STEAM. TABLE No. ^—Continued. 131 ELASTIC FORCE. RELATIVE VOLUiME Temperature of Steam Average Rise of Temperature Apparent Pressure of Steam in lbs. per Square Absolute Pressure in Inches of Mer- corresponding to its Press- ure. Bulk of Steam comparf^d to Bulk of Water. for one lb. Pressure for each 10 lbs. Inch. cury. 31 274.0 -^ 32 275.5 33 277.0 .... 34 .... 278.5 35 loi^si 279.5 558. -1.3 36 280.0 .... 37 .... 283.0 38 .... 283.0 39 284.5 40 lii."5 285.5 'sio J 41 .... 286.5 .... ^1.15 42 .... 288.0 .... 43 .... 289.0 44 200.0 45 121^7 291.0 '476. 50 131.88 297.0 435. 55 302.0 [1.0 60 152.25 307.0 '396. 65 70 172! 43 311.0 015.0 '343. [-0.8 75 020.0 [0.8 80 193! 6 323.0 '305. 85 327.0 [0.7 90 213^38 331.0 *283. 95 100 233! 76 834.0 337.5 "260. [-0.65 121. When the pressure in inches of mercury is not given, multiply the apparent pressure in pounds per square inch by 2.0376, and the answer will be the inches of mercurij above atmosphere; or that which an old fashioned mercury column would show. Example.— lOlbs. x 2.0376 = 20.376 inches of mer- cury. If the absolute pressure is required, add 30 to the above. (20.37 + 30 == 50.37. See table.) 132 STEAM HEATING FOR BUILDINGS. When the volume of steam is not given, add 459 to the temperature of the steam ; multiply the product by 76.5, and divide by the absolute pressure in inches of mercury; the answer is the volume, or number of cubic feet, a cubic foot of water will occupy when made into steam at the pressure required. Example. — Eequired the volume for 10 pounds press- ure, temperature 240" Fahr. — 240 + 59 == 699 x 76.5 = 53473.50-50.37=1061.9 (see table). To find what a cubic foot of steam will weigh at dif- ferent pressures, divide 1000 by the volume, correspond- ing to the required pressure, and the answer will be the weight in ounces. Example. — What will a cubic foot of steam at maxi- mum density weigli, at 40 lbs. per square inch. — Vol- ume 510 --1000:^=1. 96 oz. To find the number of cubic feet of steam a pound of water will make at the different pressures. — Divide the weight of a cubic foot in ounces (as above) into 16, and the answer will be the volume in cubic feet to the pound. Example. — How many cubic feet of steam, at 20 lbs. pressure, will one pound of water make. — Volume 718 -- 1000 = 1.39 -- 16.0 = 11.5 cubic feet to the pound of water. (See Diagram of dry saturated steam.) To find the weight of steam necessary to raise a given quantity of water a certain number of degrees. — Sub- tract the lowest temperature of the water from that to which it is to be heated for a dividend, — subtract the highest temperature of the water, from 1147 for a di- visor, and the quotient from these will be the weight of the steam compared to the weight of water. STEAM. 133 Example.— Find the weight of steam necessary to raise water from 75^ to 190\— Thus 190^- 75°= 115, for a dividend 01147-190 = 957, divisor 0-957 ~ 115 = 12 or Jy2_. the weight of the water. To find the weight of water, a given weight of steam will heat. — Proceed as above, only transjpose the divisor and dividend. PressLire J:n Lis Per tS cj^z^-ccre Jnch ^love MiTzzospAe're Example. — 115 -^ 957= 8.32 times the weight of the steam. 122. The above diagram of Kankine's formula has been modified to commence at the atmospheric pressure — 15.7 of the absolute scale being one pound here, and shows at a glance the cubic feet of steam to the pound weight of water, at the different pressures, as well as the temperatures, corresponding to the pressure. CHAPTEK XYII. HEAT OF STEAM. 123. The unit of heat is the raising the temperature of one pound (16 oz.) of water one degree Fahrenheit, and is the standard measure of values used in all calcula- tions pertaining to heat. The equivalent in /orce of the unit of heat, is the rais- ing of 772 pounds avoirdupois, one foot high, and is called the mechanical equivalent of heat. The equivalent of the unit of heat in the warming of air, is 48 cubic feet of dry air, raised one degree in temperature.* 124 Sensible and latent heat. — Steam has a tempera- ture corresponding to its pressure, as given in the table, and that apparent temperature is known as the sensible heat of steam ; but it is found that steam contains more heat than a thermometer will show ; heat that can be made manifest in the warming of air, water, etc., warm- ing a very much larger quantity than would appear by a comparison of the temperature of the steam, with the * In calculations made on the air of drying rooms, etc., the weight of water vaporized must be Diovided for, as so much water converted into steam. 134 HEAT OF STEAM. 135 ordinary temperatures of water, and tliis extra lieat, which is not sensible to the thermometer, is called latent heat of steam. "When a solid becomes a liquid, or a liquid becomes a vapor, heat is absorbed, more than was necessary to raise it to the temperature of conversion, and this la'ent heat does work in the destruction of the force of cohe- sion and other occult changes which take place, and must be absorbed /Vo?7i some otJier substance. In the case of steam in a boiler, it comes from the fuel during com- bustion, and when a pool of water is vaporized in the street, it comes from the sun directly, and from the earth, air, etc., indirectly. When steam or vapor is con- densed, this same quantity of heat that was received — no matter where, is again given off to any substance within its influence, air, water, etc., colder than itself, and it is this property, to convey more heat within ordi- nary controlable temperatures, than any other substance which makes water and its vapor so valuable.* It takes as much heat to melt a pound of snow from a temperature of 32"", to water at 32^, as would warm a pound of water from 72^ to 212°. This heat is ab- sorbed by the water in changing from a solid to a liquid, and must be given off again before the water could be frozen. From the temperature of ice, to 212° under the press- ure of the atmosphere, there is no heat made latent in confinement, the water receiving only 180° of heat ; but in the conversion of one pound of water at 212°, to steam at 212°, it receives 966 more units of heat : enough to warm 5^ pounds of water from 32° to 212°, or to cool * Water has the greatest specific heat of any known substance. 136 8TEAM EEATING^ FOR BUILDINGS. 9 pounds of iron from redness to zero. And tliis heat is the latent heat, and the real thermal value of the steam. The sum of the sensible and latent heat of steam, is nearly the same for all pressures. At atmosphere, the sensible heat is 212% and the latent 966°.6- 1178^6 as the total heat ; at 100 pounds the sensible heat is 337.5, and the latent 8748, equalling 1212.3 as the total heat ; the difference being 33.7, but this difference is not mani- fest in the heating of water when the steam is allowed to expand to atmospheric pressure in cooling, for it expends itself in force, w^hich would be manifest in an engine, and account for the " startling discovery " of Mr. Holly, when he asserts " The power is taken out, and the heat left in the steam ; and that every unit of heat that left the boiler, remained in it (the steam) as long as it was steam at any pressure." (Pages 25 and 26, circular of 1880.) This is a mistake. Steam allowed to expand to its full volume against atmosphere, exerts nearly the same force as if expanded against the piston of an en- gine — plus the loss by radiation, etc. Actually, the heat is carried out of the boiler ; being another form of heat made Intent, the extra units remain- ing in the steam in the form of force, which a little cal- culation will show, though it falls short of the actual theoretical duty, being 26,000 foot pounds, when the difference is 33.7 units. Hence the assertion — the toted heat of steam is the same for all pressures, is correct in making calculations on warming, as it is presumed the steam is expanded to at- mosphere in using ; the total heat, however, according to the experiments of Eegnault, increases as the pressure advances. The annexed diagram has been constructed from the HE A T OF STEAM. 137 S§|^§^ FreAAure vnPi^nncU. tables of Kegnault, to sliow tlie increase of heat, above tlie coiiij- stant 1146.6, which is usually taken as the sum of the heat of steam — from 32° upwards. It also shows the number of units in latent and sensible heat of steam, compared with each other ; the ordinate s of the curve A B showing the sensible heat, from one pound pressure to 200, counting from the line marked zero, or counting from any other imaginary line, as 32^ (ice), or from the line E F, which may be taken as the temperature of return water. The difference between ordinates of the curve A B, and the curve C D, gives the latent heat of steam for the different pressures noted. The difference between the ordinates of the curve C D, and the con- stant line 1146.6, shows the in- crease of the sum of the heat, above the constant 1146.6. 125. A pound of water con- verted to vapor in the open air, or a pound of water vaporized from clothing in the drying room, requires very nearly the same heat as would be required to evaporate one pound of water to steam, in a boiler; and for 138 STEAM EEATINO FOR BTIILDINQ8, all practical calculations it can . be taken as the same. Thus, the weight of steam necessary to dry clothing, or to evaporate water, in any kind of cooking apparatus, etc., can never be less than the weight of the water driven off ; and of necessity, it will be greater to supply the loss by radiation, or in warming the fresh air of a drying room (which must be changed as often as it becomes saturated), and from other causes. 126. Equivalents of heat. The heat necessary to warm a pound of water at mean temperature (39° Fahr.) one degree {the heat unit), will warm three and three-quarter pounds of air, one degree ; 23^0 pounds of vapor of water, one degree ; 9 pounds of iron, one degree, and very nearly 2 pounds of ice, one degree.*^ The heat necessary to convert one pound of water from the temperature of feed water, or return water, at 178°, to steam at one pound pressure (or to any press- ure not noting the slight increase for high pressures), is 1,000 heat units, and will heat 48,000 cubic feet of dry air one degree ;■ or 4,800 cubic feet of air 10 degrees; or 480 cubic feet of air 100 degrees, making no allow- ance for the expansion of the air, which will increase the bulk -1^4 for a difference of 100 degrees ; in other words, the 480 cubic feet will be increased to 583 when heated 100 degrees, and the 4,800 will be increased to 4,920 or jV of its bulk for a rise of temperature of 10 degrees. The heat necessary to warm one cubic foot of water, from the temj)erature of the return water to steam, is * It must not be confounded with melting the ice, but refers to changing the temperature of ice below 33°. HEAT OF STEAM. 139 capable of warming 41,000 cubic feet of dry air from zero to 72 ^ but if the air absorbs 5 grains of vapor of water for eacli cubic foot — as from clothes in a drying room, it will be equivalent to the fall of the temperature of the air to 37.8, but if the moisture is already in the air, and has only to be warmed (superheated), it will not be equal to the cooling of it, one and a half degree. One grain of water vaporized is equivalent to cooling from 6.86 to 7.2 cubic feet of air one degree according to the initial temperature, and is a constant ; but 1,000 grains of vapor already in the air, warmed any number of degrees, cools 3^0 4 cubic feet of the air the same number of degrees. When water is evaporated at the expense of the heat of the air, it makes a large factor, which cannot be over- looked ; but vapor already in the air, when warmed along with the air, forms a small factor and is not of much practical consequence. CHAPTEE XVIII. AIH. 127. AiB is a mixture whose parts are not chemically combined : consisting of 77 per cent, of nitrogen, and 23 per cent, of oxygen, by weight, when considered pure, i. e. when it is in the conditon best suited to support animal life. It also contains about y-oou of its volume of car- bonic acid gas and some watery vapor, and is capable of absorbing any other gas, or vapor, to a certain extent, distributing them throughout the whole atmosphere, by what is called the law of gaseous diffusion — a property which gases have of mixing and diluting, which prevents gases of the most opposite specific gravities from strati- fying for any considerable time. Prof. Youmans says, — This effect will be produced even through a mem- brane of india-rubber; carbonic acid gas rising and mixing with hydrogen, though twenty times heavier. Thus exhaled air, and air contaminated in any other way, is perpetually made respirable by diffusion. This property is of the utmost importance to air, for if its elements were to become separated, or the addition of a noxious gas to remain separated from the mass, death would be the result in all unventilated houses in a very iew hours. It frequently happens in mines, and wells, where the entrance is small, and there are not sufficient disturbing influences, that poisonous 140 AIR. 141 gases become abundant, the diffusion being too slow for the generation of the deleterious gas. In confinement, air may have its oxygen increased or diminished ; an increase of 2 or 3 per cent, causing fever, and a diminution of 3 per cent, causing death, if the carbonic acid gas from the lungs is exhaled into such air and the air inhaled afterward. 128. The amount of fresh air necessary for respira- tion for an adult, is stated to be about 300 cubic feet in 24 hours, meaning fresh air which had no specific con- tamination ; but as air in rooms is likely to be breathed again, in a more or less degree, and as it is vitiated by moisture from the skin and lungs, and by other means well known to people of ordinary intelligence, 300 cubic feet per hour should be little enough to provide for in ordinary ventilating, not with the expectation of keeping the air absolutely pure ; but to keep it in a statr of dilution, which will not be injurious, if it receives no other contamination than that from the body in health. Hospitals should be supplied with ventilating appar- atus capable of supplying 3,000 cubic feet of air per hour to each patient ; with means to double or quadruple the quantity by forcing it (as with a fan) in times of contagious disease, or in very warm weather. An ordinary kerosene lamp destroys about 40 cubic feet of air in an hour, possibly as much as two persons would use. 129. Air, assumed as unity, is taken as the standard of weight of gases, when its temperature is 60^ Fahr and the barometer 30 inches. Air for the same weight, at a temperature of 34^, oc- cupies 8272 times the space water does ; a cubic foot weighing 527 troy grains. 142 STEAM HEATING FOB BUILDINGS. At the temperature of 32°, 13i cubic feet of air weighs (a few grains over) one pound avoirdupois, which increases to 14^, 14jV, and 15^, for 60, 70 and 100 degrees respectively. 130. The expansion of air is nearly uniform at all temperatures, expanding about -^\-^ of its bulk at 32°, and for each increase of one degree in temperature. Begnault putting it a little less, while Dr. Dalton puts it as high as 4J3, and other authorities have put it at 4^0 • ^^J of these formulae being near enough for small differences of temperature. The following table will show the increase or de- crease, of one thousand cubic feet of air at a tempera- ture of 32°, when the expansion is j^^. Temperature... 20'—, Volume 895, Temperature ... 32° + , Volume 1000, Temperature ... 70° + , Volume 1077.5, To compute the volume for other temperatures, its volume at 32° being unity, use the following — Rule. — Divide the difference between 32° and the re- quired temperature by 490 ; to the answer add one (whole number), if the required temperature is above 32°, but if it is below, subtract it from one and multiply the volume of air at 32, by it. Example. — Find the volume a thousand cubic feet of air at 32° will be at 212°.— Thus, 212^-32°-: 180°-- 490 =0.367 + 10=1.367x 1000 + 1367-0 cubic feet. TABLE NO. 6. 10°-, 914, Zero. 0, 10°+, 935, 953, 20° + , 975, 40° + , 1017, 50° + , 1036, 60° + , 1057, 80° + , 1098, 90° + , 1128, 100°+-, 1139. AJB. 143 To find what a volume of air at 70 will be at 40. — Multiply the volume by the number corresponding to 40, and divide by the number corresponding to 70. To find what a volume at 40 will be at 70. — Multiply by the number corresponding to 70, and divide by the number corresponding to 40. Example. — Kequired what a volume of 3417-0 cubic feet of air at 100" will be at 50°.— Thus, 3417 x 1036 = 3539988-0^1139 0=:31080 cubic feet. The following table is copied from a text-book, and given as Dr. Daltons'; though it does not agree with that which is given as his difference of expansion ; it agrees very nearly with other tables which are given as his. It shows the increase of bulk from 75° to 680° when the volume at 32° is 1,000. TABLE NO. 7. Fahr. Bulk. Fahr. Bulk. Temp . 75 ...1099 Temp 97 ....1146 ' 76 Summer heat . . ...1101 98 . . . . 1148 ( 77 ...1104 99 ....1150 ( 78 ...1108 100 ....1153 i 79 ...1108 110 ....1173 I 80 ....1110 120 ....1194 i 81 ...1113 130 ....1315 I 83 ...1114 140 ....1353 < 83 ...1116 150 . ...1355 ( 84 ...1118 160 ....1375 ( 85 ...1131 170 ....1395 < 80 ...1133 180 ....1315 i 87 ...1135 190 ....1334 ( 88 ...1138 300 ....1364 (( 89 ....1130 310 ....1373 (( 90 ...1133 313 Water boils... ....1375 ( 91 ...1134 303 ....1558 (( 93 ...1138 393 ...1739 (( 93 ...1138 483 ....1919 « 94 ...1140 573 ....2098 it 95 98 ...1143 ...1144 680 ....3313 144 STEA3I HEATING FOR BUILDINGS. WATEEY YAPOE IN THE ATMOSPHERE. 131. Air is capable of holding a certain quantity of vapor of water, or any other condensable vapor, in solu- tion, so to speak — the proportion depending on the temperature of the air. The warmer it is, the larger quantity it will hold, and as it becomes cool again, it deposits it, or forms clouds or fog, which condense on anything colder than the air ; leaving the air upon raising its temperature, capable of taking up more moisture, to be again deposited in dew or rain. It is this property of air which gives it its drying qualities. The atmosphere is seldom laden with moisture to its utmost, and is still capable of taking up more moisture ; this difference being its drying poiver, w^hich is going on, in a more or less degree, at all temperatures. 132. An absolutely dry atmosphere is an almost im- possibility. The coldest air contains some moisture, but it is not always possible to tell how much, as air is seldom saturated to its maximum ; so to find the quantity of w^ater, air at a certain temperature is capable of taking up, a quantity of the air must be cooled until the mois- ture becomes apparent — forming a deiv ijoiid — when a knowledge of the quantity of moisture already in the air can be had from tables (the result of experiments of Dr. Dalton and others, who have made a study of the hygrometric state of the atmosphere) which give the greatest quantity of vapor the air is capable of contain- ing, for the different temperatures. Thus, if air is cooled from 70 to 50, and shows condensation at the latter point, all the moisture the air is capable of taking up for 70 is the difference between the quantities of vapor at those temperatures in the table. AIM. 145 133. The drying power of air, which enters a drying- room, is therefore, the difference between the maximum saturation for the highest temperature of the air, and its deiU'jJoint before its enters. The object in introducing this subject, and giving the following table of the quantities of vapor, air is ca23able of taking up, is to show the great economy there is in time, and some saving in heat, by having the highest possible heat in a drying room, that will not injure the goods or materials to be dried. TABLE NO. 8. 134. — A TABLE OF THE QUANTITY OF VAPOR OF WATER WHICH AIR IS CAPABLE OF ABSORBING TO THE POINT OF MAXIMUM SATURATION, IN grains PER CUBIC FOOT FOR VARIOUS TEMPERATURES- Degrees Fahr. Grains in a cubic foot. Degrees Fahn Grains in a cubic foot. 10 11 85 12-43 15 1-31 90 14-38 20 1-56 95 lG-60 25 1-85 100* 19-12 30 219 105 22-0 33 2-35 110 25-5 35 2-59 115 30-0 40 300 130 42-5 45 3G1 141 58-0 50 4-24 157 85-0 55 4-97 170 112-5 60 5-82 179 138-0 65 C-81 188 166 70 7-94 195 194-0 75 9-24 212 265 80 10-73 * Up to 100 degrees the table has been copied from the Encyclopedia Britannica, where the full table to 100, advancing by degrees, can be found. Beyond 100 degrees the table has been calculated from the elastic force of vapors according to Regnault, and are approximately correct. 10 146 STEAM HEATmQ FOB BUILDINGS. 135. It will be seen by a study of the table, that the quantity of vapor, per cubic foot of air, increases very rapidly as the temperature advances — a common differ- ence of about 25 degrees in the rise in temperature of the a r, doubling the quantity of moisture it is able to take up. Hence, all other things being equal, an in- crease in temperature of 25 degrees in a dryiug-room will reduce the time for drying one half, and an increase of 50 degrees will reduce the time to one-fourth, and so on in that geometrical ratio. The saving in heat, is not so apparent, as it takes just so much heat to vaporize a certain quantity of water, and the quantity of heat is a constant. But there is a saving, in not having to heat the air, and the moisture it contains from its initial temperature, so many times as compared to the amount of moisture carried off ; in other words, the amount of heat necessary to evaporate the moisture will be the same for all temperatures, but the quantity of heat lost in the application is less, for the air can be moved more slowly and kept in contact with the materials longer, or until it is fully saturated, and its desiccating power is apparent to the last. This is especially true in drying woods, as the high heat tuill penetrate ivood and expel moisture^ even when the air is not capable of holding any more moisture in suspension. THE COST OF VENTILATION. 136. A house 40 x 40 ft. is warmed and ventilated in two stories. Each story is 11 feet in the clear, making 33,600 cubic feet, and it is desirable to change the air in the house once in each hour, which is ample to maintain a very pure atmosphere. In order to know its cost, a AIB. 147 business man would proceed to figure in the following way : The steam-heater has told him the apparatus put in, would convert between 10 to 12 pounds of the return water to steam, at an expenditure of one pound of coal (a pretty high average) ; consequently, the next thing to know is, ivhat is the equivalent of 1 Ih. of coal in the ivarming of air. Now it is admitted that a cubic foot of water, losing one degree of its heat, will warm 3,000 cubic feet of air one degree, and that one pound of it, will warm 48 cubic feet of air one degree ; but in con- verting the pound of water to steam, it absorbs heat, equivalent to warming it 1,000 degrees, which, of course, is equivalent to warming 48 cubic feet of air 1,000 de- grees, or 480 cubic feet 100 degrees, or 4,800 cubic feet 10 degrees.^ Thus the fact is established, that a pound of steam returned to water, will warm 4,800 cubic feet of air 10 degrees ; but it is not so well established that the coal evaporates 10 to 12 times its oivn ircight of icater from the temperature of the return. If the water was return- ed at 180^ Fahr. and the coal the best, 14 pounds of the water, converted to steam, would be the greatest possi- hle theoretical quantity ; but 11 to 12 has been attained in practice, though it is not common, 8 to 10 being ordin- ary for house boilers. So, for the sake of safety, and to * The quantity of air, water or steam, will warm, is figured according to the specific heat of each, for the same weight. Approximately, water requires 3| times as much heat to warm a given weight of it, any num- ber of degrees, than the same weight of air ; but as air occupies 827^- times the space water does, for the same weight, it will have to be mul- tiplied by this factor (relative volumes), and by the heat. — Thus, 1 X 827.5 = 827.5 x 3.75 — 3103. As air contains a little moisture, which must be warmed also, the odd 103 may. be dropped, and is usually fig- ured at 3000. 148 STEAM HEATING FOR BUILDINGS, get the price as high as the poorest practice would make it, he takes only one-half the theoretical quantity and figure it at 7 pounds of water to the pound of coal. Thus we have 4800 x 7 - 33600 cubic feet of air, which can be warmed 10 degrees by one pound of coal. But it ap- pears that 10 pounds of coal have been burned per hour, a quantity sufficient to warm 33,600 cubic feet of air I'OO degrees. Whence, then, is this apparent discrepancy? Assume air outside to be 20^ Falir., and as it passes the heat registers it has a temperature of 120 degrees, having been warmed, just 100 degrees, in passing through the in- direct radiator ; but an examination of the air, as it goes out at the ventilating register, shows its temperature to be 70, which would suggest 50 degrees of the heat had been utilized in the rooms, in maintaining the temperature, and the other 50 had escaped through the ventilator, and been lost as heat ; but it has produced veniilation, and the movement of the air. Now, the ventilating flues aggregate 2 square feet of cross section, and the air, as it escapes, has a velocity of 5 feet per second in the middle of the flues, and which, if it were not for the friction of the sides, would pass 36,000 cubic feet in an hour. Making some allowance for friction, we will say 33,600 cubic feet of air passes in an hour, exactly the cubic contents of the part of the house, ventilated ; tak- ing one half of all the heat with it, or what represents 5 lbs. of the coal burned in the hour. Thus the ventilation of a good home can be thorough- ly done for Ij cent per hour, when coal cost 5 dollars per ton, less than 3^ cents per 100. M. cubic feet of air moved under conditions, which all preponderate against the price ; the difference of temperature between the in- side and outside being 50 degrees, which is a high average. AIR. 149 There seems to be a simple relation, between the amount of heat necessary to maintain the temperature in a room, and the amount passed off in ventilation, no matter at what temperature the air passes the register entering the room, in indirect heating. For instance, let air enter at 20, and instead of rais- ing its temperature to 120, it is raised to 95 as it passes into the room. The difference between the temperature of the room (70") and 95 and 120, is as 1 and 2. Thus, if the windows, etc., cool a certain quantity of the air, from 120 to 70, they will cool iicice that quantity from 95 to 70, to maintain the same heat, and tiuice the quantity of air will have to pass out through the ventilator at half i\iQ greater difference, to make room for the fresh supply necessary to keep up the heat. So, the temper- ature at which air passes through the heat registers (of the same building) only affects the quantity of air moved and not the heat. This also points to another result — namely, the less the difference between the temperature the air leaves the heat register at, and the temj^erature the room is to be maintained at (so long as it proves sufficient), the more air there must be passed in a given time to keep the required warmth : which will of necessity make the air purer. A building heated altogether by indirect radiation, cannot be otJier than sufficiently ventilated. CHAPTEK XIX. HIGH PRESSURE STEAM USED EXPANSIVELY IN PIPES FOR HEATING. 137. It lias been customary, when speaking of steam- heating apparatus, to divide them into two kinds — called respectively liigh and low pressure ; but these names cannot now be accepted in their literal meaning, any more than high and low pressure would express the difference between non-condensing and condensing engines. Very high pressure steam is now used in the gravity apparatus, which some years ago was only constructed for low pressure steam. At that time, the terms low pressure apparatus and gravity apparatus were synony- mous; but since the gravity apparatus has been made to run at any pressure, the terms gravity system and expansion system have become common — to distinguish the two principal systems. Wlien steam has been let into pipes at any pressure, and run arbitrarily, to suit the convenience of one, who wants steam at a distance, under the supposition steam will run to any place where pipes can be put (as it will when certain conditions are complied with), such piping 150 HIGH PRESSURE STEAM, 151 amongst steam-fitters used to be called liirjh pressure, and is now synonymous with " expansion system," or steam used expansively for heating. The conditions alluded to are : the steam must be allowed to expand, — to blow through in fact ; if the pipes are not run on some system, that provides for the taking away of the water, at every low point in the piping ; and tlie quantity of steam used in a given time, must he sufficient to carry ahng the water of condensation which forms in tJie pipe during transmission. Scattered buildings, heated from one source, must be heated in this way ; if they have no basements, and are on different levels, and the condensed water must be taken care of by steam traps. It is usually attended with considerable waste of heat from imperfect steam-traps, etc., and requires the con- stant vigilance of the engineer, and should not be used in single buildings, when it is possible to make a gravity apparatus. 138. Lately, Mr. Holly has brought this system before the public on a large scale — the heating of towns and cities ; but it is only tlve old system on a larger and grander scale. Instead of heating three or four build- ings from one source, he heats hundreds. The magnitude of the apparatus prevents any attempt to take back the condensed water, which of necessity is wasted after it is cooled to its utmost practical limit ; and as the water becomes the property of the consumer it can be used in the house for culinary purposes, and in the laundry, if tlie rust from wrought iron p)ipe, carried along with the water, will not discolor clothes. The following quotation is from the Holly circular and explains the system in their own words : 152 STEAM HEATING FOB BTJILBINGS, " THE MECHANICAL DETAILS of this system we will present briefly, by detailing the course of the steam from the boilers through the various devices to control and regulate its use until it is finally condensed into pure distilled WATER FOR DOMESTIC PURPOSES. ^^ In this system of heating it is desirable to have as few plants as possible placed at central points, as convenient as may be, to coal and water. As the profit to those who supply the steam will depend upon its economical produc- tion, it will become of the first importance to admit nothing known to modern engineering art that will secure the largest amount of evaporation of water, at a minimum cost for coal, as steam is used merely as A CARRIER OP HEAT. " It is of course unnecessary to say, that the best and most economical boilers should be selected, and the most careful and competent engineers and assistants obtained. It is by no means an unimportant fact to be considered by cities with reference to this system, that the dangers and annoyances of boilers will be confined to a few localities, and their object- ionable features obviated in cities like New York, St. Louis and Cincinnati, where thousands of boilers are distributed through the city. *^ From the boilers the steam passes into THE MAIiTS AND LATERALS. The material used after experiments with cast iron and other substances, is the ordinary lap-welded, wrought iron HIGH PRESSURE STEAM, 153 steam-pipe. These are always tested by the manufacturers to a tension far above any joossible use, for example : a 12- Inch pipe of this kind J -inch thick, has a tensile strength of 60,000 lbs., and would bear a pressure of 2,500 lbs. to the square inch, as no pressure exceeding 100 lbs. will ever be required in this system. •^^ DANGER FROM EXPLOSION" of pipes can never become a subject for discussion, but con- densation is. For unless steam can be transmitted to con- siderable distances without too great loss by condensation, all devices to use it in buildings, however ingenious, would of course be useless. Condensation being caused by the radi- ation of heat from the pipes, the SUGGESTION OF COMMON SENSE would be to arrest the radiation, that is, keep in the heat by inclosing the pipes in the best non-conducting material that is attainable, and cheap enough. There is nothing new about it. Wool, hair, charcoal, brickdust, ashes, plaster, cotton, sawdust, gypsum, etc., have been used in various ways ever since metal pipes were used to convey steam. '^ The pipe is placed in a lathe and wound about, first, with asbestos, followed by hair felting, porous paper, manilla paper, finally thin strips of wood laid on lengthwise and the whole fastened together by a copper wire wound spirally over all. This is thrust into a wooden log, bored to Isave an intervening air-chamber between the pipe and w^ood, and of sufficient size to leave from three to five inches of wood covenng. The elasticity of the wrappings permits the free expansion and contraction of the pipe irrespective of the wood log which is securely anchored and made immovable. The whole is placed in a trench a short distance below the 154 STEAM HEATING FOR BUILDINGS, surface without regard to frost. At the bottom of the trench is laid an earthen tile drain to carry off any earth moisture, and in order further to insure the continuous dryness of the wood log inclosing the pipe, if desired, one and one-half inch plank are fastened around the log leaving an air space, and the whole daubed with coal tar and covered with earth never again within the experience of this generation to be disturbed. '* WE SAT NEVER, because the mains are never tapped for the attachment of service pipes, as in the case of gas and water mains, and be- cause the precautions taken to secure the wood against alter- nations of dryness and moisture will, according to experi- ence, preserve it indefinitely. "Pipes prepared in the manner described have been tho- roughly tested, and it is proven beyond doubt that conden- sation can be reduced to a point that renders the general transmission of steam not only practical, but profitable. At the risk of being tedious, we will quote, for the benefit of the curious, a well-attested experiment of Mr. Holly. In 1,600 feet of three-inch pipe, laid on a descending grade of 20 feet, the lower end trapped for water, steam pressure con- stant at 20 pounds at both ends, during 12 hours, water of condensation carefully weighed, amounted to 82 pounds per hour. The Holly boilers, accurately tested, evaporated 9 pounds of water per pound of coal. 82 pounds of water therefore represented 9 pounds of coal, or 2^ per cent. More clearly thus : Each pound of steam above 212° con- tains 960 units of heat ; the heat units lost in the conden- sation of 82 pounds of water were 78. 7-20, or at the rate of 1.312 units per minute. Now the capacity of a 3-inch pipe at 20 pounds pressure is 765 cubic feet per minute, containing 27.044 units of heat, of which only 1.312 were HIGH PRESSURE STEAM. 155 lost, yiz., 2J per cent. Experiment and practice, since veri- fied in 15 cities, show that the most economical pressure to be maintained in the mains is from 40 to GO pounds, although in some cities 70 pounds has been used. Experi- ence with large mains is yet limited, 8-incli being the largest in use. By calculation, the condensation at 60 pounds pressure is, in 3-inch pipes, per mile, 2. G ; in G-inch pipes, per mile, 2.0; in 12-inch pipes, per mile, 0.7. The condensation in large pipes is greater, but the relative per- centage less. *^ The experience of Detroit demonstrates the fact that GO pounds pressure could be maintained in four miles of lO-inch and G-inch pipes, against the drafts for power and heat along the line. The capacity of a 6-inch pipe at 60 pounds pressure may be estimated thus : a G-inch pipe at GO pounds pressure will discharge 102 cubic feet per second. A horse- power is one cubic foot of water, or 1712 cubic feet of steam, or 427 cubic feet of steam per second. Therefore a G-inch pipe at GO pounds pressure will supply 21 G horse-power per mile, and the same amount of steam will supply 3,000 CONSUMERS PER MILE, averaging 12,000 cubic feet of air space to be heated. "The next serious obstacle was found in the EXPAN^SIOI^ AND CONTRACTIOK of metallic pipes between the extremes of temperature, say 32", and the heat of steam at 60 lbs. pressure 307°. The expansion of wrought iron is -g}^ of its length, about 2^ inches in 100 feet. It was the inability to obviate this, that defeated the effort to inaugurate a general system of steam- heating in European cities. This difficulty was completely overcome by 156 STEAM HEATING FOR BUILDINGS. THE JUKCTIOK AI^D SERYICE-BOX. These are placed at convenient intervals along the line of 100 to 200 feet. The arriving-pipe from boilers is in- serted by a nickle-plated extension or telescopic Joint, made steam-tight by passing through a stuffing-box. The de- parting pipe is immovably attached to the box, so that one end of each 100 feet of pipe is fast and the other movable, affording free-play to the expansion and contrac- tion. " All service-pipes are taken from the junction-box, which is securely bolted to the masonry, and anchored to the pipes. The bottom of the box being placed lower than the pipes, all water of condensation is carried forward and deposited in it, to be taken up subsequently as ENTEAIiq-ED WATER, and reconverted into steam, at lower pressure, as the steam passes through the reduction valve.* The adjustable hoods are for the purpose of regulating the passage of dry or moist steam. The junction-box provides for the expansion of mains, tlie attachment of service-pipes and reception of water, no water is ever found therefore in the mains, and no provisions for trapping off water are required. The boxes are accessible by man-holes in the street ; from the junction- box, the steam passes to * From the above, one is likely to be led to believe- all the so-called entrained water flies into steam ; but this is not so! Only tiiat quantity of it is converted into steam at a low pressure, which can be evaporated, by the difference of the units of sensible heat of steam for the different pressures, which for the difference between 50 pounds and 2 pounds is equivalent to the re-evaporating of less than i^o of the water condensed under the high pressure ; the rest has to be forced through the pipes by the passage of the steam. — Remark by the Author. HIGH PRESSURE STEAM, I57 THE REGULATOR by means of which the pressure of steam is reduced, and the supply to the building regulated automatically. This is ac- complished by two diaphragms of rubber packing, acted upon by weighted levers, and moving two slide-valves. 'V\\e first valve is weighted to 10 lbs., and the second to 5 lbs., or 2 lbs. if required. When the steam arrives at the first valve of the regulator, it contains, suspended in minute particles, all the water which has been condensed in the mains, and brought forward to the junction-boxes. This is known as entrained water, which, under 60 lbs. pressure, cannot be- come steam, but does so at lower pressure of 10 lbs., and any further moisture remaining is further converted into steam, at a still lower pressure of 3 lbs., thence it passes at a uniform pressure through THE METER, placed, as seen in the plate, above the regulator. It resem- bles, and in fact is, the movements of a 55-day Yankee clock; as the steam passes, the movements are made to rotate a screw, upon which hangs a pointer moving along a dial, each revolution registers an arbitrary unit, the value of which has been previously ascertained by weighing the water. The clock marks the time and registers the quan- tity." When one building furnishes steam to several adja- cent buildings, or w^hen a cluster of buildings have a boiler house, it is not necessary to use junction boxes, or even common expansion joints ; the expansion may be provided for with right angle turns, or by throwing the expansion withinthe walls of the different buildings. 158 STEAM HEATING FOR BUILDINGS. Comparatively small piping can be used in an expan- sion system, and when there is no provision for draining the condensed water from the pipes, a size barely suf- ficient to carry the required steam along is preferable ; as in that case, the draft will carry the water out of the pipes ; whereas, if the pipes were larger, the draft of the steam would be so slow, the pipes would fill until the contracted passage increased the velocity of the steam to such a degree it forced itself through in irrgular pulsations, and caused pounding. CHAPTEK XX. EXHAUST STEAM AND ITS VALUE. 139. Among the many who own steam engines and the engineers who run them, there are few who have a just appreciation of the ihermal value of the clouds of ex- haust steam continually blown to the winds from the apparently numberless exhaust pipes, which can be seen from the top of a high building in any of our large cities. When I say that three-quarters of the practical thermal value of every pound of coal burned in the boiler fur- nace, is lost past recovery to the consumer, I am put- ting it at less than the actual loss ; and could this heat be converted into available motion, suitable for power purposes, it would be a boon indeed, and a fortune to the one who could do it. Perhaps there is a chance for the electrician to convert it into energy ; but as yet engineers can use it for heating purposes only, where ' its full value can be shown in the heating of water, air, or any tangible substance. The first purpose for which the exhaust steam is gen- erally employed is to warm the feed water, the object being to raise its temperature as high as possible, be- fore it enters the boiler, thereby to save fuel. 159 160 STEA3I HEATING FOR BUILDINGS. 140. The first question which nearly always sug- gests itself to the engineer is, How hot can feed water be made ? The second which he sometimes considers, but seldom arrives at a satisfactory conclusion about, is, What percentage of the coal does the heating of the feed water represent ? and the following, which rarely come under his notice, How much of the exhaust steam from an engine can be used in heating all the feed water necessary to supply the loss caused in the boiler by supplying steam to the same engine ? and how much of it is left for use elsewhere, partly or wholly, to heat the factory in winter or for drying purposes ? J?la^k2. The answer to the first question is: Water under the pressure of the atmosphere cannot be heated above 212"^ Fahr., and when the feed water passes the check valve at a temperature of 200^ it should be considered satis- factory, although it is possible to do better. Where water is forced through a heater, the tempera- ture can be raised higher than when drawn by a pump, from the heater, as the lessening of the pressure also lessens the capacity of the water for sensible heat. Some makers of feed water heaters claim they can heat the water above 212^, because it is under pressure; EXHAUST STEAM AND ITS VALUE, 161 but it is evidently a mistake to attempt it, as both the water to be heated, and the steam necessary to lieat it, should have a pressure above atmosphere, and anj at- tempt to keep a back pressure in the exhaust pipe for the simple purpose only of warming the feed water above 212^ is attended with a loss instead of a gain. The attempt to heat the feed water 5° above 212° by a back pressure of 2 pounds, the mean pressure in the cylinder being 50 pounds, is attended with a loss in energy, greater by more than ^lvq times the gain to the feed water. The answer to the second question is : That when the feed water is raised from mean temperature 39^ to 212° by the use of the exhaust steam at atmospheric press- ure, it is equivalent to very nearly two-thirteenths of the weight of the fuel necessary to convert water, at mean temperature, to steam at any pressure, and 15-18 per cent, of the coal is the greatest possible saving that can be made for this difference of temperature. /"IqJS To find the saving of other differences of temperature in the feed water, divide the difference between the temperature of the cold water as it enters the heater and that at which it enters the boiler into 1,146, less the 11 162 STEAM HEATma FOB BUILDINGS. difference between the cold water and 32, and the pro- duct is the fraction of the coal heap. 141. The answer to the third question is : That two- elevenths of the exhaust steam is the greatest quantity that can be utilized in the warming of the feed water, and making a generous allowance for loss by radiation, etc., there will still be three-fourths of all the exhaust steam for other j^urposes. The next general purpose for which the exhaust steam from an engine can be used is in the warming of the air of a building, to which purpose it is often applied, though not as much as it should he, as there appears to be an idea among many users of steam, that it is just as ic ell to take live steam from the hoiler as to cause one or two pounds back pressure on the engine for the purpose of getting a circulation, and driving the air from all parts of the coils. 142. The loss in power to an engine from back press- ure is very nearly directly as the difference between back pressure and mean pressure. Thus, in an engine of 50 pounds mean pressure, with a back pressure of 2 pounds, there is a loss of 4 per cent., and as the available energy of an engine cannot represent one-quarter of the 'practical thermal value of the coal, the loss caused by 2 pounds back pressure can- Bi M.,,im,ii;i„i,,,n„nmiiiiiiiiii ii i ii i i ii.ftiffli4ii»MiiiMifti^^ not represent more than 1 per cent of the coal, and as it is an incontrovertible fact that the exhaust steam con- tains more than three- fourths, or 75 per cent, of the 2^'^^cwtical thermal value of the coal, the balance is largely in favor of using the exhaust steam. The steam- EXHAUST STEAM AND ITS VALUE. 163 fitter when preparing to use the exhaust, usually places a hack pressure valve in the exhaust pipe, of such con- struction, that it can be loaded to suit, so as to reduce the back pressure to a minimum, when in use, and to hold it open when not required. Fig. 42 shows a section of a back pressure valve, with the weight hanging on the positive end of the lever, showing the position of the valve when the steam is turned into the coils. Fig. 43 shows the weight on the negative end of the lever, the position usually used in summer. Fig. 44 shows cross section on line a h, and stuffing-box and spindle. 143. Exhaust, and live steam, should never be used in the same coil at the same time. It is often attempted, but is very difficult to regulate, and the bet- ter way is to make the exhaust coils no larger than the steam will fill, and should this not prove sufficient for the space to be heated, add live steam coils, with entirely independent con- nections. Sometimes coils are furnished with two sets of connections, live and exhaust; but this re- quires constant attention to prevent workmen, etc., from thereby causing a waste. Another objection to having live and exhaust steam connections on the same coil, is the style of trapping used, for one is not fit for the other. A very good way to trap, and provide for the con- the steams. 164 STEAM HEATING FOB BUILDINOB. densed water from an exhaust steam coil, is to have an inverted water siphon to the sewer or tank, as shown in Fig. 45, with a vapor pipe to the roof, to remove an excess of pressure and the air. This pipe should have a check valve on it, to prevent the return of the air, between the strokes of the engine, and the water trap should be as deep as possible. CHAPTEE XXL BOILING AND COOKING BY STEAM, AND HINTS AS TO HOW THE APPARATUS SHOULD BE CONNECTED. 144. Large institutions with many inmates, find it almost impossible to cook without the aid of steam ; and manufacturers have long since abandoned all exter- nally fired kettles. Of the superiority of steam, as a means of drying and cooking, there is no question, and the occasional failures which occur, should not be attributed to steam, but to errors in the construction of apparatus, and an igno- rance of their use. Satisfactory appliances are with- in the reach of the steam-fitter, though frequently the ruinous competition in small things^ which compels the lowest bidder to neglect and omit everything possible, or in other words, " to do the least for the least money j"* ruins the effect of otherwise successful machines. The first and commonest kind of cooking by steam, is " steaming," which is again divided into steaming in the atmosphere (or at atmospheric pressure), and steaming under pressure, in closed tanks or boilers. Steaming can be used in the preparation of anything into which water cannot enter, or become part of, as oils ; or of substances which want an addition of water, but are capable of 165 166 STEAM BEATING FOR BUILDINGS. taking up only sufficient water to properly prepare them ; as vegetables, or substances which want to be bleached or disintegrated, as rags. The simplest form of steamer is the ordinary kitchen steamer ; a wire basket or tin pot with holes in the bot- tom of it, suspended in a larger pot with water in the bottom of the latter, the water not reaching the bottom of the basket, but the steam, rising and mixing with the air in the basket, gives a uniform heat, when the water in the lower pot is boiling. It is well known to the intelligent cook, that vegeta- bles cooked this way can be done through without break- ing, or without losing any of their starch. This cannot be done in boiling water, as the mechanical action of the water during ebullition breaks and washes out part of the substances, etc., before they can be sufficiently cooked in the center. The modification of this simplest kitchen steamer, BOILING AND COOKING BY STEAM. 167 used in large buildings, such as hotels and public insti- tutions, is shown in Fig. 46. The outside case. A, may be of cast iron, or sheet iron riveted and soldered with a cover of sheet iron. The hccskels, B B, rest inside the outer case, on a perforated shelf, (7, and are usually made of heavy tin plate, with holes in the bottom for the condensed steam to run oiT. The connections to these steamers require particular attention, far more than would appear from a super- ficial examination. The condensed water which gathers in the bottom of the outside case should be carried to the sewer or drain, and must be connected in such a way, that the foul air of the sewer cannot return into the steamer and con- taminate the food. And as much — and more — attention must be paid to the waste connection from a vegetable steamer, than is paid to the connections from a wash basin, even in a sleeping room. It is not only essential how the connections are run, but from ichat material they are composed, and further, -how the joints are made, and from what material. As the steam and hot water are capable of destroying lead pipes and traps, or working the lead joints out of cast iron pipes, it is best to use either wrought iron screwed pipe, or cast iron pipe with rust joints ; using a very deep S-trap, constructed of fittings, with plugs at every corner, so as to get straight openings at every part of the pipe, by simply removing the plugs. This is necessary to remove grease, or any obstruction that may pass into the pipe. The pipes should be of large diameter (about 3 ') with the trap sufficiently deep to pre- vent the pressure of steam within the steamer, from blow- ing it out, and connected with some contrivance, vacuum 168 STEAM HEATING FOR BUILDINGS. valve, or vent pipe, run on approved sanitary principles, to prevent its siphoning out, as is common to all soil pipes. There is another source of contamination or poison, in the connections of vegetable steamers, or any other steam boiler, which must have a vapor pipe ; these pipes should not be constructed of galvanized iron or copper, or any other substance whose salts are poison- ous, as the condensation which takes place within this vapor pipe, falls back into the kettle, continually wash- ing down carbonate or sulphate, or whatever may be formed that yields easily to the action of pure water. These pipes should be constructed of iron gas pipe, with screwed joints, or cast iron pipes, with rust joints. The live steam connection to an open steam box, or steamer, should be very small. Usually a J or J-inch pipe is used, and there is no discretion exercised in the manipulation, but an endeavor made to cook as rapidly as possible, regardless of steam. Beyond a certain quantity of steam admitted, nothing is gained in time, as just steam enough to expel the air is all that can be used ; a greater supply is only wasted through the vapor pipe, or escapes into the kitchen, under the edge of the cover. There is another point in the construction of open steamers worth considering — namely, a water seal around the edge of the cover. The seal consists of a groove or channel around the top edge of the case, into which a rib around the under side of the cover fits, as can be seen at a , Fig. 46. This seal should be as deep as possible, and to be effective should run around the whole cover, and not be dispensed with on the side of the hinges, as is fre- quently done. BOILING AND COOKING BY STEAM. 169 The objoct of this water trap, or seal, is to prevent steam from escaping into the kitchen and to force any excess of pressure out through the vapor pipe. To get the greatest economy, the water seal should be two inches or more deep, with a small sized vapor pipe with a valve in it, so it can be choked doivn^ to hold a pressure in the steamer, but not enough to force the water seal. Steaming under pressure must be done in a closed boiler or tight tank, capable of resisting high pressure steam. A common form of this class of stearders is the rag boiler in the paper mill. It is a horizontal cylinder, with conical ends, supported on trunions, and made to revolve by machinery, so as to use the mechanical motion in assisting the disintegration of the rags. This boiler is shown in Fig. 47, and should be constructed of exceedingly heavy iron, or it may explode, and do much injury. The pipe connections are made at the ends of the trunions (a), Avhich are provided with stuffing-boxes revolving around the pipe, thus leaving it stationary. Another form of high pressure steamer is an upright 170 STEAM BEATING EOR BUILDINGS. tank of strong construction, in which, fats are rendered and separated bj the action of high pressure steam. This tank is shown at Fig. 48, and is often 20 to 30 feet long. The fats and oils stratify, accord- ing to their gravity, with the water of condensation underneath, and are drawn off at the numerous cocks, according to their quality. 145. The steam connections on these tanks are made top and bot- tom, and they are sometimes con- structed with a spiral coil near the. bottom. Cooking and manufacturing, by the transmission of steam, heat through metal surfaces, and not by direct > ! I I contact, as in steaming, includes ap- paratus of varied designs, often the result of years of experimenting, the following modifications being the most common. Figs. 49 and 50 show sections of two of the ordinary forms of double- bottomed steam cooking kettles. The various uses to which these kettles are applied are wonderful. Differing very little in shape, the size alone adapts them to the special use. Small sizes, 20 to 40 gallons, can be used for glue melting, etc.; sizes running from 60 to 100 gallons are mostly used in hotels and institutions for cooking meats and farina- ceous foods, and larger ones, up to 500 gallons, are used in sugar-houses and soap boiling establishments. OAi^^TAJ BOILING AND COOKING BY STEAM. I7I Sizes to 200 gallons are usually cast iron, but larger ones are often made of Avrought iron, riveted and calked. The connections to these kettles are plain, but the steam pipe should be large, and the return water pipe sJiotdd not be put back into a return gravity circulation apparatus, but sJioidd be carried away by a good steam trap of approved pattern. Yapor pipes from these kettles should be of iron, for the same reason mentioned in connection with "steamers." The pipe from the inside of the kettle, which carries the contents to a receptacle, or sewer, should be large, with tees and plugs at every right angle, instead of elbows, to permit of easy and rapid cleaning, should it get stopped with grease, or any other substance which hardens on cooling. In these kettles steam cannot he ivasted unless it is 172 STEAM HEATING FOR BUILDINGS. passed through a defective steam trap, the consump- tion of steam depending on the amount of work to bo done, and the radiation from its sides. This radiation is often partly prevented by an out- side loose jacket, and if the space between the jacket and the kettle is filled with some non-conducting ma- terial, the loss of heat from the outside of the kettle will be reduced to a minimum. There is another class of kettles or pans which are not double-bottomed, but boil and cook by steam heat BOILING AND COOKING BY STEAM. I73 transmitted through spiral coils, passed around the inside of the bottom, the pan itself being partially exhausted of atmosphere ; that the contents may boil at a temperature much below 212^ Fahr. These kettles or pans are usually very large, and are principally used in sugar-houses and condensed milk establishments, or any place where boiling or evaporat- ing, at very low temperatures, is a desideratum. Fig. 51 shows a section of one of these pans, the principal points of importance to the steam-fitter, or coppersmith, are the sizes of the pipes, and the manner in which they should be run. When a quantity of water is to be raised from ordi- nary temperatures (35^ to 55 "" Fahr.) to boiling, it must be borne in mind by the fitter, or constructor, that it will take, in steam, at least | of the weight of the water in the pan, to raise it to the boiling point, and that when steam is first turned into the space, between the bottoms of jacketed kettles, or into the spiral coils of tanks, or vacuum pans, the shrinkage — i. e., condensa- tion of the steam, for the greatest difference of tem- perature, is something enormous ; and unless the supply of steam is continuous, and the pipe which conveys it ample for the greatest amount of work that can be put on it at any time, the result will be the filling up of the space or coil with water. This is caused by the absence of pressure of steam through the pipe, coming on the surface of the condensed water, to keep it down, and under some conditions the vacuum produced actually drawing water into the coil, from some other coil or the branch return pipes. To get a proper result, and economize in time, the pipe from the boiler must be sufficiently large, and all 174 STEAM HEATING FOR BUILDINGS. the connections and valves have area enough, to sup- ply the greatest quantity of steam required for the greatest work. Some have an idea they can waste steam, by giving a heating or boiling apparatus a full head of steam, but this is a mistake if they have proper steam traps, or return into, or are part of a return gravity apparatus. For the boiling of water, or the heating of air, can only use the steam it can con- dense, and the amount of steam used from first to last, is the same in any case, plus the loss by radiation for the time. It is not long coils of small diameter that are re- quired, but short coils of large diameter, with large piping throughout. With small long coils the apparatus, at first, takes a considerable time to heat up ; but when it is in " train," it seems to do very well. The reason of this being plain, when we consider that all the steam re- quired to keep a kettle boiling is exactly equal to what is given off in steam, from the surface of the water in the kettle. At first, while the great difference of temperature between the water and the steam lasts, the coil is warmed a comparatively short distance of its length, because all the steam that can pass in a given time, is condensed in this first part of the coil, consequently the ivhole coil is not doing duty, when it should be most efficient. Many have found that by turning on the steam first, and then letting in the water slowly, the kettle was boiling by the time it was full, and if they filled it with cold water first, it would not boil in an hour. Some might reason from this, if their pipe and coil BOILING AND COOKING BY STEAM. I75 were large enough to pass sufficient steam to boil tlie water in 15 minutes, by passing it in slowly, it should boil the whole in the same time, since it takes the same quantity of steam to boil a cubic foot of water, no matter how it is applied ; that this is not correct, as far as the size of the pipe is concerned, the following will show : In the first case, where the water is let in slowly, the coil or space is hot, and the quantity of water not being enough at any one time to condense the steam faster than it can pass, the whole coil is doing duty during the whole time. But when the large body of Avater is acted on by the steam, the latter rushes into the coil and is immediately condensed, /f??^??^/ the coil icitli water ^ the greatest part of its length, and leaving the first short heated part of the coil, to boil the water in the kettle, before the pressure of steam will pass through, to keep down the water of condensation. Many again think, this condensed water will run off by its own gravity ; but this is not so, as it cannot run off unless there is a pressure on its surface equal to the pressure of the atmosphere, if it connects with a trap, and equal to the pressure in the return pipe, if it connects wdth a gravity apparatus. The steam w^hich can be passed through a 2-inch pipe in an hour is capable of boiling about 4 tons of water, making allowance for loss of heat and friction, at a pressure of about 40 lbs. "When a pan has two or more coils in it, they may take their steam from the same source, provided it is sufficient, but the returns from these coils should be separate ; with a separate trap to each return, and tlie discharge from these traps should not be put into the 176 STEAM HEATING FOR BUILDINGS. same pipe, or into any confined space, where the dis^ charging of one of the ti^aps may cause pressure in the otherSy and cause them to discharge in advance of the proper moment. Long, flat wooden yats, with any convenient-shaped coil in the bottom, are often used for the evaporation of the water from brine by the salt manufacturer. Ex- haust steam from neighboring engines can be used here to advantage, thus utilizing heat that would other- wise be lost. 146. Another common way of warming or boiling water, when the object is not evaporation, but the warming of a tank of water for laundry purposes, or when the addition of the condensed steam is a benefit (provided it is not greasy), is to put the steam-pipe directly into the water, in the form of an open butt, or a perforated coil. This mode is usually attended with noise, but it is qincl{^ and effective. "When a perforated coil is used, it is usual for the fitter to have as many small holes in the coil as will aggregate equal to the area of cross-section of the pipe in the coil ; but in practice this is not nearly sufficient, if he wants to pass out all, or nearly all, of the steam and water which the supply-pipe is capable of passing. "Within an empty pipe, steam has a very high velocity, but striking the water, as it passes the holes, retards it so much that 5 to 10 times the area of the pipe in small holes has not been found too great in practice, the time of boiling lessening rapidly up to 10 times with shallow water and 40 lbs. of steam. The pressure of the steam and the depth of the water affects the time of heating; high pressure accelerates and deep water retards. BOILING AND COOKING BY STEA3I. 177 The lower the pressure of the steam that will pass out, as it strikes the water, the less the noise will be ; and a good way to avoid noise is to have a large diameter coil or pipe in the water, with a great many small holes in it, letting the high pressure steam expand into this perforated pipe through a " throttled'' valve, until the de- sired low pressure is attained. Another w^ay to prevent noise, is, to place a tin cylin- der, with wire-cloth ends, filled with shot, over the end of the steam-pipe, the pipe turned up into the cylinder, and the cylinder in a vertical position. (See Fig. 52.) E ^t^^SZ 147. Another way to warm water with steam is at the nozzle or cock where it is drawn. A very simple method is by mingling the steam and the water after they pass their respective cocks or valves (as shown at Fig. 53). There should be no cock or valve put in the bib, a\ for closing it will either force the water or steam (which ever has tho greatest pressure) into the other. There- fore it is necessary to have little resistance in the pipe after passing the valves. A very simple noiseless nozzle is shown in Fig. 54 It consists of an enlargement after passing the valves filled 12 178 STEAM HEATING FOR BUILDINGS. with shot, with a strainer to prevent the shot from pass- ing out ; or it may be filled with clean gravel, or anything the steam and water will have the least action on. By the regulation of the valves, a steady stream of water of almost any temperature between 212^ and the tempera- ture of the cold water can be had. 148. Often the pipe-fitter is called upon to construct means to warm water for bath-houses, laundries, or any place where they have no steam, and require no power, hence do not wish to have a steam boiler ; nevertheless use more water than can be warmed by the ordinary water back in the stove. The problem is, then, to warm the largest amount of water with the smallest expenditure of fuel. Fig. 55 shows an apparatus that for permanency and cost of maintenance is very satisfactory. A, is a tank of any convenient shape ; B^ a cast or wrought iron boiler, similar to that used for green-house heating ; (7, connection from top of boiler to the side of the tank, not very high tip, as all the water below the point it enters the tank cannot be estimated as part of the working capacity of the tank, for it is necessary to always keep this pipe covered with the water ; I), the return-pipe BOILINO AND COOKING BY STEAM. 179 from the tank to tlie boiler, its inner end being carried a few inches above the bottom of the tank, to prevent sediment from being carried into the boiler, and E, the pipe leading from the tank, for the distribu- tion of the hot water, the position it occupies being im- portant, as it must always be above the pipe (7, to prevent the possibility of drawing the water in the tank entirely down to that point. The tank may be furnished with a ball-cock, to the cold-water pipe, as shown at F, to keep a constant level of water. By feeding the water into the tank, instead of the boiler, impurities are deposited in the bottom of it, instead of being carried into the boiler. The same is true of all liot-imter apparatus, if the bottom of the tank is below the return-pipe, with capacity enough in the tank to prevent rapid currents. A coil of pipe is sometimes used in a stove instead of a boiler, but it soon fills with mud or lime, and burns out. CHAPTEK XXII. DRYING BY STEAM. 149. Thkee-fourths of all the manufacturers outside of tlie metal trades, and even many of tliem, use lieat for drying purposes ; and various as are the manufac- turers, so various are the modes of drying, in many instances satisfactory results being attained only by years of experience. No manufacturer of wooden articles can get along without a drying Mln. The laundry man or woman, the dyer, the hatter, the tobacconist, the piano and organ maker, the dried-fruit manufacturer, the japanner, the tanner, all must have a means of drying faster and more conveniently than can be had by exposure out-of- doors. Usually steam is used in drying rooms and drying kilns because of its cleanliness, its even distribution, its safety from fire, its easy and quick management, and the cheapness of its maintenance. The higher the temperature of a drying room, the cheaper can the articles be dried. This may not appear plain at first to those who have not studied the laws of equivalents, but nevertheless it is so, being caused by local conditions, which always prevent the utiliza- 180 DRYING BY STEAM. 181 Thus, the greater the difference in tion of all the heat, temperature and the slower the movement of the air compatible with the amount of moisture to be carried off, the better the result in the laundry or dry kiln, or any place where rapid drying only is the object. In no other place is the power of ra- diant heat (direct radiation) more manifest than in the drying room, and more failures can be traced to placing coils under skeleton floors, or flat on the floor, than any other cause, except, per- haps, an ignorance of the principles of piping, which so many consider can be done by any one who wears a pair of greasy overalls. The writer has proved, in many cases, that tl le same 182 STEAM HEATING FOR BUILDINGS. amount of pipe or plate surface, distributed around and between tlie materials to be dried, will do the work in half the time it takes the heated air from an indirect coil. This is no mistake ; and further, wooden blocks can be dried lighter (proving there is more water driven off) by direct radiation than by indirect radia- tion, the times and temperatures being the same. According to the above it is plain, that in the con- struction of drying houses, for most purposes, the heat- ing surfaces should be so placed and distributed that the direct heat rays from the iron could fall uninter- rupted, on the greatest surface possible, of the materials to be dried. 150. Fig. 56 shows a perspective of a good arrange- ment of a direct radiation laundry drying room coil. utilizing all the radiant heat that is thrown off, and giving a thoroughly uniform heat throughout the room. A A' are headers (often called manifolds), usually made of extra heavy pipe, to admit of tapping and threading, instead of using T's, for the cost of the heavy pipe and the drilling and tapping is very much less, as well as better and straighter, than a header composed of many DRYING BY STEAM. 183 short pieces of large pipe and tlie necessary T's. (These remarks apply to all large coils.) B B are the sjjring pieces, threaded right and left handed ; C C, the leaves cr sections of the coil ; and D D, the coil stands. The stands are always in pairs, to admit of giving the necessary division and inclina- tion to the pipes, and when viewed through the holes look like Fig. 57. The dotted lines are the centers of imaginary pipes to show the pitch. When coils are very wide in the direction of the length of the headers it is well to keep the coil stand 2 or 3 feet from the header at that end, to prevent the expansion from pull- ing the screws from the floor. The distance betvreen the holes in the standing coil header is usually about 12 inches, or as" wide as the clothes-horses are from center to center. The usual way to build these coils is to start at the bottom header, A\ Fig. 56, and to put each leaf, (7, to- gether continuously, working upward until you reach the elbow, E; when all the leaves are so far con- structed, with all the elbows looking up, with their left-handed thread uppermost, count in and jnark the right and left handed spring-pieces, B, then apply the upper header. A, and screw the whole up as nearly alike as possible. Do not be persuaded to do away witht he spring- pieces and the elbows through economy, so as to con- nect the upper headers straight, as in a box coil ; if you do you will have trouble should you want to take down a single leaf for repairs. Fig. 58 shows sectional perspective view through a laundry drying room : a being the coil ; h, the clothes- horse; c, the suspended rail, from w^hich the horses 184 STEAM HEATING FOR BUILDINGS. hang ; d, fresh-air inlet duct ; e, its damper or regulator ; /, ventilator with regulator, usually governed by a cord DRYING BY STEAM, 185 and bell crank, and drawn back by a spring ; and g, the space into which the horses are drawn, which of neces- sity must be as long as the horses. This style of drying room gives the direct radiation from both sides of the leaf of the coil to the fabrics to be dried, and also exposes both sides of a fabric to the direct radiation of a section or leaf. For high pressure steam 1-inch pipe is generally used in the coil ; but if exhaust steam is to be used the pipes should be not smaller than 1| inch, and the total length of any one leaf should not exceed 40 feet under a hack pressure of 2 pounds at the engine. For exhaust steam the upper header should be large, 3 inches for 12 leaves of 40 feet each, or about 500 feet in the coil gives satisfactory results ; this should be increased in proportion to the increase in leaves, a 4-inch pipe header being enough for a coil of from 900 to 1,000 feet, composed of leaves of 40 feet each. Unless the exhaust steam is carried a long distance horizontally, 50 feet or more, the pipe leading to the header may be one or two sizes smaller than the header, provided it is large enough for the engine. With steam of high tension, small pipe headers v^^ith T fitings may be used ; but where the pressure is variable, a large header insures an equal distribution of steam to all the leaves. Sometimes gridiron or floor coils are used on account of saving expense, but the same amount of j)ipe in this form will not dry clothes as fast as the standing section coil. Figs. 59 and 60 show gridiron coils of easy construc- tion, a a being the manifolds or headers; h h, right and left elbows ; c c, coil pipes right handed ; and d d, right and left handed spring-pieces. 186 STEAM HEATING FOR BUILDINGS. In Fig. 59 tlie pitch of the pipes and headers is in the direction of the arrows. 151. These coils are often used in lumber-drying ^Y- <^^ kilns, but the same amount of pipe arranged around the walls in miter or wall coils will give a far better result, and will not be a receptacle for dirt, as a floor coil is, DRYING BY STEA3I. 187 requiring a skeleton floor over it, to walk on and pile the lumber on. In large drying kilns, on the direct radiation princi- ple, where pipe enough cannot be put on the walls, and for the better distribution of the heat, rows of stanch- eons should be put up to hang the coils on, in such a manner as not to interfere with the gangways. The tobacconist prefers to dry without artificial heat, in a temperature of about 60^, with a rapid change of air through the windows. This appears to give dry- ness without brittleness, but at night and in damp weather they must close the windows, and to get their stock out in time recourse must be had to steam coils. In experimenting for a well-known tobacco manufac- turer in fine cut, it was found that radiators or box coils placed in the middle of the rooms gave the best result. Wall coils under the windows made the room warm, but did not dry quickly, and the tobacco felt wet when brought into a cold room and allowed to remain for a short time. A strong ventilation with a tempera- ture of 80° made it too crisp ; but the box coils placed in the middle of the room, with a temperature of 65"", with a small ventilation, and the currents of air in the room, up at the center and down at the windows (con- trary to the general principle of warming for comfort), gave a result which was declared satisfactory. In piano-case manufactories, and where specialties in glued and veneered furniture of the best quality are made, the workmen are generally supplied with a dry- ing cabinet, of a size suitable to the pieces to be dried, in which the work is heated before the glue is applied, and into which it is again placed to dry properly. These cabinets are usually rectangular boxes, with 188 STEAM HEATING FOR BUILDINGS. holes in the bottom and top, to allow the air from the room to circulate through them so as to carry off the moisture. Their steam coils are usually of the grid- iron pattern, flat on the bottom of the box, and with the valves on the outside. Sometimes they are heated indirectly by the warmed air conveyed in tin pipes from a large coil placed in some favorable position. Some manufacturers claim the quicker the work can be dried after gluing the better it v/ill be. It is not profitable to dry by forcing air, as with a fan or blov/er, in connection with a steam coil. High-pressure steam should be used in connection with a blower. A temperature of 130° is considered ample, and can be easily attained in a drying room. The additional quantity of pipe necessary to raise the temperature of a drying room from 120° to 130°, if again added, will not raise it from 130° to 140°. CHAPTEK XXIII. STEAM-TRAPS. A STEAM-TKAP IS an appliance attached to certain classes of steam apparatus, whose object is to remove the water of condensation without a waste of steam. A gravity apparatus does not require a steam-trap of any kind; and the proof of a perfect gravity circulation is shown by the proper working of the apparatus icith- out one. Traps may be separated into two principal classes — namely, traps which open to the atmosphere, or atmos- pheric traps, and direct return traps, returning the water to the boiler, without great loss of heat or any loss of water. Expansion systems of piping and heating require a steam-trap of some kind. When the water is to be saved, and returned to the boiler, the direct return trap is best. When the water is to be wasted, the atmos- pheric trap, which allows the water to cool to the loiuest temperature is the best. Cooking apparatus, such as meat kettles, or kettles or tanks with coils in them, which condense much steam in a short time, should not be connected with a low- pressure gravity apparatus ; but should have a separate 189 190 STEAM HEATING FOR BUILDINGS. pipe from the boiler, and be connected to a trap, in consequence of the great and sudden shrinkage of steam, which takes place when they are quickly filled with cold water. They may be connected with a high- pressure gravity apparatus when the supply-pipes are very large. An intended gravity apparatus, which proves too small in the mains, or not properly done, so part of the piping remains full of water, can often be made to answer by the use of a direct return steam-trap ; but it should only be used when it is actually necessary. Atmospheric steam-traps should not be attached to a gravity apparatus under any circumstances, as they make an opening which permits the escape of water. CONSTRUCTION AND OPERATION OF THE DIRECT RETURN STEAM-TRAP. These traps have come into use within ten years, and form a new departure in steam-traps. They must be automatic in action, and of simple construction, and positive ; for an interruption of an hour or two, will fill the coils and pipes with water, and in very cold weather may be the cause .of freezing ; so judgment must be ex- ercised in the selection of them. There are now two or three very good modifications of this trap before the public ; accomplishing all a steam-pump will do, in the way of returning water to the boiler, and with less loss of heat. Manufacturers of these traps may claim they should be used on gravity apparatus, for certain purposes— such as to regulate the heat to the weather ; but it is evident to a thoughtful man that an apparatus which is perfect, STEA2I-TRAPS. 191 and that will run for a life-time without interruption (if water is kept in the boiler and fire under it), or assis- tance from mechanical means, should not be put to the chance of an occasional interruption by the use of a , nicely adjusted machine which wears out. These traps are excellent in their right place, being capable of returning the condensed water from coils into the boiler, no matter where they are placed ; thus doing away with tanks and pumps, in expansion appara- tus, and thereby saving heat. Also when a building has no basement, or when the boiler cannot be placed low enough for all the water to return by gravity, they can be used on the low coils ; but in a case where the build- ing is high, it would be best to heat the upper floors by a separate gravity system, and the lower floor or basement by a pipe of its own ; so that if there ivas an interruption, the low coils only would be affected, and thus give less for the trap to do. The principle involved in these traps is simple, being alternately a vacuum and a pressure ; but, like the single acting reciprocating pump which has no fly-wheel to help it at the end of the stroke, it must have some kind of an auxiliary. With the aid of the diagram. Fig 61, the action of these traps may be explained, ^represents the trap , proper ; (7, the receiver, which holds a certain quantity of the return-water ; D, a steam-pipe from the boiler to ' the trap ; E, a pipe from the trap to below the water- line in the boiler ; and F, a pipe from the receiver to the trap carried up inside the globe. It will also be seen, these pipes are provided with valves ; the steam-pipe has a globe-valve, and the other two pipes, check- valves; the valve in the pipe F, opening toward the 192 STEAM HEATING FOR BUILDINGS. trap, and the valve in the pipe E, opening toward the boiler. Now, if the valve in the steam-pipe is opened and steam admitted to the globe {B), until all the air is ex- pelled, and the steam allowed to condense, as it will do in a short time after the valve is closed (by the loss of heat from the steam through the sides of the globe to the outside atmosphere), there will be a vacuum formed in the globe, more or less perfect, which will draw water from the receiver (C), when there is a press- ure in the pipe which comes from the coils, or else- STEAM-TRAPS, I93 where, and this water, passing the check- valve in F, will overflow into B, and cannot return to (7, for two reasons —because it cannot pass the check-valve backward and cannot get back over the top of the pipe F. Now, if the valve in the steam-pipe is opened, and the pressure of the boiler admitted into the top of the globe (B), the pressure will become equalized between the boiler and the globe, and allow the water to pass down the pipe (F), and into the boiler of its own gravity (precisely as it would if everything was opened to atmosphere), going through the other check- valve, which will not allow it to pass back again, when the valve in the steam-pipe is closed, and condensation will again form a vacuum ; which will once more draw the water from the receiver, to flow down into the boiler, when the steam-valve is again opened, and thus the action goes on, being simply that of a pump without a piston. This principle was understood and used, substantially as explained above, before the automatic traps were introduced; but as it was necessary to construct the two globes, or tanks, of large size, to avoid too frequent attendance ; and as it required manipulation, at irregu- lar intervals, which, if neglected, would fill the pipes with water, it was not much used. Now, since automatic contrivances have been invented, which takes the place of manipulation, and which can be depended on with some degree of certainty, these traps can be, and are, used on apparatus which otherwise would be almos!; useless. Thus the difficulty to be overcome in this class of traps as before mentioned, is to construct an automatic con- trivance for opening and dosing the steam-valve which can be relied on. Fig. 62 shows one of these traps, which has been 13 194 STEAM HEATING FOR BUILDINGS. selected as an example, not because the trap is con- sidered the best — for there are others equally good — but because the action of the auxiliary is so easily explained. It is a view of the trap when set up ; ZT is the steam- pipe ; G, the pipe from the receiver to the trap ; and F, the pipe from the trap to the boiler. The valve marked D is the steam- valve, which is automatically regulated, and is a rotary slide-valve ; E, a connecting rod, be- tween a crank on the valve stem, and an arm, with slack motion, and a part of the casting (7, which rocks on a stud ; (7, a track, on which rolls a ball, also a part of the casting, which rocks on the stud before mentioned, and which engages another stud, on the lever B ; the lever STEAM-TRAPS. 195 B and its weight are a counterpoise to a float inside the globe. Tlie action is as follows : when there has been a vacuum in the globe, the water will pass through the pipe G, and fill the trap, consequently it raises the float and lowers the lever and counter- poise, whose stud engaging C, draws it down, until the track passes the horizontal position, without affecting the connecting rod E, on account of the lost motion, until the track has passed the horizontal position, then the ball will roll along the track, and strike on the opposite end against the hook — a blow sufficient to move the valve on its seat, and open it to its full extent ; but not before the globe is full of water. The reverse motion is similar : the float lowering, but not affecting the valve, until the water is nearly all ou-t of the globe ; the slack motion allowing the valve to remain open, until the track again passes the hoizontal position, when the force exerted by the blow on the hook at the other end of the track closes the valve suddenly. Among the atmospheric traps are found the old ex- pansion traps, now little used ; and the open float-traps, which still form a necessary part of certain apparatus. Fig. 63 shows a well known form of open float-traps, used both in this country and in England, of which there are many modifications of minor importance ; the action and principle remaining the same. ^ is a cast-iron pot, sufficiently strong to withstand high-pressure steam,with an inlet at F; B is another pot (an open pot), inside the pot A, with a spike at the center of the bottom, and a guide to keep the inner pot in a central position. G is a brass tube screwed into the cover D, and forming a valve with a spike at the inside of the bottom of the 196 STEAM HEATING FOR BUILDINGS. pot B; J5' is a valve in the cover of pot A^ which, when opened, acts as an air- valve, or Uoiv-throiigh^ to hurry up the circulation when first heating up the coils. The pot-trap operates thus : the condensed water from the coils, etc., runs in at the pipe F, and fills the outer pot A with water, until it floats the inner pot B, against the stem (7, closing the valve formed by the f ^J/,V///^ spike and the tube, thus closing the outlet to the tank or sewer. The water, which still continues to flow into the outside pot, rises, and overflows into the inside pot. Then the latter sinks, and opens the valve which the spike forms with the hollow stem, and allows all the water in the inner pot to be forced up through the stem and out by the pressure of the steam in the upper part of the pot acting on the surface of the water. Thus, when the inner pot becomes bouyant again, by the discharge of its water, it closes the valve, and leaves it so, until the increase of the condensed water again overflows it. This action is intermittent, the frequency of it depending on the amount of work to be done. STEAM-TRAPS. 197 There is one point in the construction of this trap on which its icorking depends — namely, the area in square inches of the hole in the end of the hollow stem C must be no larger than the quotient obtained from dividing the weight in pounds of the inner pot when submerged, by the maximum pressure in pounds per square inch of the steam to be carried. Thus, if the inner pot weighs -12 J- pounds under water, and the greater pressure of the steam is to be 100 pounds per square inch, the hole must be a little smaller than I the area of a square inch, say a round hole \ of an inch in diameter, which leaves a factor of safety of -\ the weight of the pot. The reason for this is plain, when we consider that there is practically no pressure within the stem when the valve is closed ; and for the pot to sink, when it is full, it must be heavy enough to pull it- self away from the stem, and still be light enough to float ^ of its weight when empty. This ^?/j:>e of trap possesses a special point of excellence — it will discharge the water of condensation from coils, or from the cylinder of an engine, into a tank or sewer, at a very much higher level than that which it drains, and it will keep them as dry as if it discharged down- ward. It is the only trap opening to atmosphere ichich icill do this, except by blowing through continuously. It is peculiarly adapted to elevator engines, which stop and start frequently, and are operated from the car or an upper floor, as it removes the water at a high tem- perature, and will keep a steam-chest cZr?/ by removing the water which accumulates while the engine is standing with steam turned on ; which engines thus used require that they may be always ready for a call. There is another openfioat-trap. Fig. 64, which contains 198 STEAM HEATING FOR BUILDINGS. a special point of merit, the value of which is not yel generally understood, — namely, a trap capable of taking recognition, so to speak, of temperature, as well as quantity, and which will discharge its water down to atmospheric temperature and pressure, no matter what may be the temperature of the water in the coils due to high pressure. To make this clear, it is necessary to explain, that water which falls to the bottom side of a nearly horizon- tal pipe, with 50 pounds pressure of steam in it, has not fallen to a temperature of 212° Fahrenheit, as is very generally supposed, but has simply parted with the latent heat of the steam, incidental to the pressure, leav- ing the temperature of the water (when the flow and press- ure of the steam are maintained) a very little less than the temperature of the steam. This water will again give off some of its sensible heat, to be again made latent, making steam of a lower pressure when allowed to expand. But it must not be understood that all the water flies into steam. It does not — the quantity of water converted into steam being represented by the ratio the latent heat of the steam, at the different press- STEAM-TRAPS. 199 ures, bears to the sum of the latent heat and the sensi- ble heat of steam. Thus, when water is drawn directly from a high-press- ure coil into the receiver of a trap, and is discharged against atmosphere, before the water has cooled below 212°, it is attended with considerable loss of heat. This can be seen in the blowing of a gauge-cock, for, though the water is solid and dense in the boiler, when it is drawn some of it flies into steam, and makes a cloud which often deludes the novice into the belief that it is all steam, and that possibly he has low water. The construction of this trap is plain : it consists of an outside case with a loose cover, an open float with the mouth down, and a common plug-cock operated by the float. When steam or water above 212^ in temperature is discharged through the cock, and under the float, the latter is immediately raised by the pressure of the vapor underneath and between the float, and the water which cannot flow over the case. This action closes the cock, which will remain closed until the vapor condenses and allows the float to once more sink, when the cock again discharges the hot water behind it. If this water is below 212 \ it will pass rapidly out of the case under the edge of the float ; but when it again becomes hot enough to make a little steam, the float raises, and the cock is again shut. This trap cannot be used on an engine, as it will not discharge any considerable quantity of water until the temperature is below 212° ; but for an expansion sys- tem, or for exhaust, it would be a good one. CHAPTEE XXIV. BOILER CONNECTIONS AND ATTACHMENTS. 157. Feed-Pipes. — The feed-valve should be a globe or angle valve placed near the boiler, with the fewest possible joints in the feed-pipe between it and the boiler. If it is a loose or swivel disk valve, it should be secured with solder (sweated in) in the threads of the double part of the disk, so as to make it almost impossible to loose the disk from the stem ; a mark with a center punch or chisel is not enough. The valve should be so turned toward the boiler that the inflow- ing water will be under and against the disk, so that, in the case of the loss of the disk, it will not act as a check -valve against the influx of the feed-water. This arrangement will bring the pressure of the water in the boiler always against the stuffing-box of the valve ; but, all things considered, it is best. The check-valve should be close to and outside the feed- valve, with only a nipple between them. Always use horizontal check-valves, as they admit of easy cleaning. With the ordinary vertical check it is neces- sary to take down some part of the feed-pipe to clean it. When two or more boilers are fed from the same 200 BOILER CONNECTIONS AND ATTACHMENTS. 201 pump, or when the pump is used for pumping water for some other purpose, it is well to have a stoj^-valve on each side of the check- valve, as it will enable the engineer to get at his check without stopping the •water elsewhere. In passing through boiler walls or cast-iron fronts, care should be taken that the feed-j)ipe does not nest, or the settling of the boiler will break it off. Use a flange union on the feed-pipe instead of the common swivel union ; the engineer can take it apart with a monkey wrench, and it makes a more permanent job, and it will not leak. Never put a T in the feed-pipe inside the feed- valve for the purpose of a blow-off; but make a separate connection to the boiler. Blow-off Cocks. — Never use anything but a plug cock of the best steam metal throughout. The reasons for using a cock are, that the engineer is always sure when he looks at it whether it is shut or open ; it gives a straight opening ; if chips, packing, or dirt gets into the cock it will shear them off when closing, or if it does not, the engineer knows it is not shut. Do not use an iron-hodij cock tuitJi brass plug, for when the cock is opened to blow down a little, the hot water expands the plug of the cock more than the body, and it is almost impossible to close it. Do not use a globe or angle-valve, as you cannot always tell when it is shut ; a chip or dirt getting between the disk and seat will prevent its closing. I have seen two fine boilers destroyed from this cause. Gate or straight-way valves are subject to the same objections as globe or angle. When it is practicable there should be a T with a plug in it in the blow-off pipe outside the blow-off 202 STEAM HEATING FOR BUILDINGS. cock, the plug arranged so as to be removed wlien the cock is closed. By this means the engineer can always tell if he is losing water from his boiler. The blow-ofi pipe should be large, with few bends in it, and fire bends are better than elbows. It should be attached to the bottom of the shell of a horizontal boiler, and not tapped into the head a few inches up. When there is a mud-pipe, attach it at the opposite end from the feed-pipe. Safety -Valves. — They are the main-stay of the en- gineer, acting both as a relief and a warning signal. They should be attached to the steam-dome high up. At the side is better than the top, as they are not so liable to draw water when blowing off in that position. They should be large, and have a large pipe connection all to themselves. The ordinary cross-body safety- valve is very much to be condemned, and I think in some countries there are regulations against their use. They are constructed to save making an extra connec- tion for the main steam-pipe, thereby drawing the largest amount of steam directly from under the disk of the safety-valve. A weighted safety-valve is better than a spring- valve when it can be used, as the lifting of the valve makes practically no difference in the leverage ; not so with a spring- valve, for the higher it is lifted the more power it takes to compress the spring. Gauge or Try Cocks. — Gauge-cocks are various in style, the wood handle compression gauge-cock is a very good kind for all purposes. When setting gauge- cocks care should be taken that they are not too low, and that the drip will not flow over the person who tries them. Tliey should be tapped directly into the BOILER CONNECTIONS AND ATTACHMENTS. 203 boiler if possible ; but when it is necessary to use a piece of pipe to bring tliem through a boiler front or brick-work, give the pij^e an inclination backward, that the condensation may fun back and into the boiler. When the pipe inclines outward and down, the con- densation remains in it and the cock, and will deceive the unwary, giving the appearance of plenty of water with a short blow. Glass Water- Gauges. — Water-gauges are best set when attached to a vertical cylinder at the front of the boiler. The cylinder should be connected to the boiler with not less than 1-inch pipe, top and bottom ; the top or steam connection should be taken from the boiler shell near the front head, and not from the dome or steam-pipe, as the draught of steam in either will cause the glass to show more water than the boiler contains. The bottom or water connection should be taken from the front head at a point where about two thirds of the water in the boiler will be above it and one third below ; this wdll lessen the chances of the pipe stopping up with mud, etc., and it should also be provided with a half-inch pipe at the lowest point for a blow-out. When gauge glasses are set this way the condensation in the cylinder is downward, and the flow of water being toward the boiler through the bottom pipe, the tendency is to cleanse the glass and cylinder and keep them so. Steara- Gauges should never be set much above or below the boilers to which they are attached, as each two feet of fall or elevation from the direct connection is nearly equal to a difference of one pound on the steam-gauge ; it is always so when the gauge is below, for the condensation in the gauge-pipe fills it with water, 204 STEAM HEATING FOR BUILDINGS. whicli leaves a pressure on the steam-gauge equal to tlie hydrostatic head, which is a little over two feet per- pendicularly to the pound per steam-gauge, giving the gauge the appearance of being weak. When the gauge is above it is not so always, though generally so even then, for the pipes being long and of small diameter or trapped, which prevents a circulation of steam in them, they fill with water, which acts against the pressure from the boiler and gives a gauge the appearance of being strong. It is a good plan to connect the gauge- pipe to a boiler below the w^ater-line, say 12 or 18 inches, and have the gauge on the boiler about 12 inches above the water-line, using no water-trap or siphon, that the water may run back from the gauge when there is no pressure in the boiler, and thereby prevent the possibility of freezing or of getting steam to the spring of the gauge. Sometimes a steam-fitter has to run a gauge pipe a long distance to an office or engine room. When such a gauge is far above the boiler he should run a large pipe direct from the steam-dome, and give it sufficient pitch to clear itself of water ; it should be covered with some non-conducting material, and be of such size that the flow of steam through the pipe to supply the loss by condensation will be so slow as not to interfere with the flow of water along the bottom of the pipe in a con- trary direction, and it rjhould have a siphon imme- diately under the gauge. When it is necessary to have a gauge very much lower than a boiler, fill the pipe with water, but before doing so remove the glass and lift the hand or index over the stop-pin and mark where it remains station- ary ; now fill the pipe to its highest point with water, BOILER CONNECTIONS AND ATTACHMENTS. 205 then draw the index from its spindle and set it back to the mark where it remained stationary before the pipe was filled, and press it on; then bring it to its normal position on the stop-pin and adjust the glass. The Main Steam-Pipe for Heating Apparatus should be high up on a boiler, and any pipe larger than 2 inch should not be tapped in, but connected with a flange bolted or riveted to the boiler. Two and a half inch pipe and larger sizes have eight threads to the inch, and will not answer with a less number. Automatic water-feeders, combination water-gauges, or steam-gauges, should not be tapped into the steam- heating or engine pipe, as the draught of the steam through the pipe interferes with their proper working. Engine or pump pipes should not he taleii from the steam-heating pipe, as the draught they cause relieves the pressure in the heating apparatus and spoils the circulation, especially if it is a direct return gravity circulation. With an automatic return steam-trap, applied to an old job, if the steam-heating pipe is large enough, it will not be necessary to remove the engine pipe, but should the circulation be still defective, remove the engine pipe to the shell of the boiler, and remote from the heating pipe. CHAPTEE XXV. MISCELLANEOUS ARTICLES. CUTTING WALLS AND COVERING RISERS. 158. Architects often omit to leave a recess where required in tlie walls of a building, and the fitter has to cut one. In his anxiety to put up as much pipe as possible, and as he considers the cutting of the wall does not properly belong to him, he cuts it in the quickest and easiest manner he can, regardless of the appearance, and in some loosely put up walls it is a difficult task to make an attractive or even satisfactory piece of work. The proper way T\;ould be to have the openings left and cutting avoided ; but if it must be done, it should be well done. Let the fitter provide himself with sharp chisels, and a light hammer, and he can generally cut a brick, with- out disturbing it in the wall ; but it is also necessary for the master mechanic to consider wall cutting laboVi and to give the workman to understand he will be credited with cutting walls as well as for putting up pipe. The fitter should get the architect's permission before he commences to cut, for otherwise there may 206 TURNING EXHAUST STEA3I INTO CHIMNEYS. 207 be much injury done to a building, by having a recess cut from top to bottom, near a front wall or corner. The best way to cover a riser recess is with a board. Have the grounds put on before the plastering is done, and have the panel screwed on afterward. The panel may be fancy iron-work, with holes in it, which makes a very permanent method. A moveable panel admits of access to the pipes to make repairs without breaking the walls. Some architects require the recess to be plastered over, using slate, or coarse wire-cloth, to hold the plaster with, so as to entirely hide the appearance of a pipe, but even then they do not entirely succeed, for two or three reasons. When a slate is stuck over the recess with plaster-of-Paris, and plastered over all, the expansion of the slate cracks the plaster; when plas- tered on wire-cloth, it does very well, and will not crack, but it will turn a dark color in time, as will any thin covering when it becomes warm ; and the con- tinuous current of air passing up the wall at that par- ticular spot deposits more dust there than at any other point, and leaves a well-defined mark. For the same reason, the walls back of radiators get darker more rs.pidly than the walls of any other part of the room. The same is true of curtains which hang near a register. In parts of the country where soft coal is generally used this is very apparent. TURNING EXHAUST STEAM OR VAPOR INTO CHIMNEYS. 159. There is a custom among steam-fitters, and others, of turning the exhaust steam from an engine into the boiler chimney in buildings, ostensibly to 208 STEAM HEATING FOR BUILDINGS. make the draft better, but in reality to save running an exhaust pipe to the roof of the building. Exhaust steam, turned into a long or high brick chimney, will not improve the draft, but impair it. In locomotives the exhaust steam is turned into the stack to increase the draft, and in short iron stacks of portable engines it has the same effect, when properly put in; but it must be borne in mind, that to be effect- ive, it must have such proportions as to make it an injector, to increase the velocity of the air by contact with its own high velocity, before it has time to expand and fill the stack. In long iron stacks, a little steam turned into them may be of some use in warming the stack (which cools rapidly from contact with the wind and air in cold weather), and by assisting the upward current of smoke or air, by mixing with it. Under certain conditions, it makes a mixture of steam and air lighter than the air alone, while, if the increased velocity caused thereby more than compensates for the extra volume which has to pass it, may be an improvement. But usually the exhaust steam chokes a very long chimney, the latent heat of the steam passing through the sides of the chimney (especially an iron one), and leaving the condensation to run down the insides of the chimney in streams, and to be again partly re-evapor- ated by absorbing heat from the gases of combustion. In brick chimneys this is very apparent, condensing and soaking into the brick-work, and absorbing as much heat from the gases of combustion to evaporate and drive off a cubic foot of it as would cool 30,000 cubic feet of air 100 degrees Fahrenheit. It also destroys the chimney. SOLDERING OF PIPES AND BRASS FITTINGS. 209 SOLDEEING OF PIPES AND BRASS riTTIXGS. 160. Often it is necessary to solder or -' sweat " pipes into fittings, or male and female threads of brass work. The latter is no trouble, and can be done by tinning the parts to be put together, using only resin for a flux, if done while new, and then screwing them together while hot. When iron pipe has to be sweated into iron fittings, malleable iron fittings should be used, because they can bo tinned by using muriatic acid reduced with zinc ; cast iron does not solder well. "When about to sweat a pipe and fitting together, wipe the threads carefully, and run a carefully Aviped die over the male thread, to entirely clean it, using a clean tap, to remove any oxide or grease from the female thread in the fitting, then tin cleanly, using muriatic acid for a flux, and screw them together while both are hot. There is no advantage in soldering a frost burst in an iron pipe, through which steam or very hot water passes, /or it ivill not last. In iron water-pipe, rather than remove the pipe, it may be soldered, but it must be thoroughly cleaned and tinned, and a heavy icipe joint made on it ; holting is of no avail. . When cracks appear in brass or copper pipes, with- out any apparent cause, there is very little use in soldering, for they are usually caused by undue expan- sion or jarring, and are a fault of construction, which soft solder will remedy for a very short time. Parts of brass goods, such as valves, etc., which are 14 210 STEAM BEATING FOR BUILDINGS. liable to jar loose, should be sweated together in par- ticular places, such as the disk on a feed- valve, or main stop-valve. PAINTING PIPES. 161. Distributing pipes may be painted with any- thing that will arrest oxidation; lead paints are very good, for they are the poorest conductors of heat ; but lead paints should not be used on radiating surfaces, as they lessen the radiating and transmitting power, many coats applied, year after year continually, im- pair their efficiency greatly. Zinc paint is considered somewhat better, but there is good reason to say it should not be used. Raw linseed-oil, with ochre of the required color, and turpentine, form a good preparation for radiators, when they are to be bronzed, as it gathers and " fixes " any machine oil or dirt there may be on the pipes, and will make a good hack for the bronze. Black baking japan, or black air-drying japan, are very good substances for painting radiators with, as they appear to impair their efficiency but little, and two coats will give a good gloss, which does not re- quire to be renewed ; a wipe with a slightly oiled woolen cloth will give them a fresh appearance. Black paraffine varnish should not be used ; it is not permanent ; it cokes with heat, and has no body. Indirect coils, or coils or heaters which cannot be seen, it is best not to paint. Dust allowed to collect on heaters impairs them very much. CHAPTEK XXVI. MISCELLANEOUS NOTES AND TABLES. These notes and tables will be found of service in estimating. The avoirdupois pound is always to be used, unless otherwise specified. It contains 7,000 Troy grains ; the grain is always Troy. 16 drams = 1 ounce. oz. 16 ounces = 1 pound. lb. 25 pounds = 1 quarter. qr. 4 quarters = 1 hundred. cwt. 20 cwi, 2,000 lbs. = 1 ton. The gross ton (in which the quarter becomes 28 lbs., the hundredweight, 112 lbs., and the ton, 2,240 lbs.) is used in estimating English goods at the U. S. Custom- House ; in freighting ; in the wholesale coal trade ; and in the wholesale iron and plaster trades, and when specif ed. 1 lb. avoir. = 16 oz. avoir. = 7,000 grs. Troy. 1 " " = 4,37.5 " 27yV cubic inches of water weigh one pound avoir- dupois, at a temperature of 40^. 211 212 STEA3I HEATING FOR BUILDINGS. A cubic foot of water, at a temperature of 60^, weighs 999 ozs., and is taken as 1,000 ounces, or 62 J pounds, for all ordinary calculations. It weighs a little less than 60 pounds when the temperature is 212 \ A cubic foot of water contains very nearly 1\ gallons, and for rough calculations may be taken as such (7.4805 gallons is actual) number. A cubic inch of water, at its greatest density, weighs 252.693 grains; a cubic foot, 58,372.0 grains. 1 gal. = 231.0 cubic in. 1 cub. ft.. 1\ '' = 1728.0 1 bushel, IgV 9jV " -^ 2150.42 1 cord, 128.0 " a u 1 cub. yd., 27.0 '' = 46656.0 1 barrel,^ 421 " 31i " = 7276.5 * A flour barrel will hold 33.28 gallons, or 4.449 cubic feet, or 2.79 heaped bushels (called 2| bushels). In estimating quantities of water by barrels, 31^ standard gallons equals the barrel. TABLE NO. 9. WEIGHT OF A CUBIC IXCH OF VARIOUS METALS. Iron, cast „ . ... . .. 0.263 of a " wrought 0.23 Lead., 0.41 Copper 0.32 Nickel 0.30 Steel 0.28 Tin 0.2G5 Zinc, cast 0.24 " rolled 0.26 Brass, steam metal . 315 «' yellow 0.282 ound. MISCELLANEOUS NOTES AND TABLES. 213 TABLE NO. 10. WEIGHT OF A CUBIC FOOT OF YARIOuS BUILDING MATERIALS, IN POUNDS (approximate). G^ranite 1G8.0 pounds Marble 165 " Sandstone 135.0 " Blue-stone 165.0 '' Slate 180.0 " Mortar, dry. .* 80.0 to 100 pounds. Common Brick 113,0 pounds. I^iySand 100.0 " Fire-brick I35 '' One perch of stone-work, in walls or foundations, measures 24| cubic feet. One thousand common bricks, laid in a wall, makes about 50 cubic fest, varying a little for different bricks. Six fire-bricks to each square foot of lining, one brick thick, is sufficient ; 1,000 bricks will make 170 superficial feet of lining, laid in the ordinary way. To find the weight of iron castings by computation. — Find its solid contents, in inches, and multiply them by .26, and it will give the weight, in pounds. For rough calculations, it will do to divide the cubic inches by 4, and call the answer pounds. To find the weight of any other casting, or forging. — Find its solid contents in cubic inches, and multiply by the weight of a cubic inch of the metal, as given in the table, "Weight of a cubic inch of various metals." For irregular castings, which are difficult to measure, and cannot be conveniently weighed, a rough estimate of tJieir weight may be taken, provided they are not cored out, by weighing the pattern, if it is of soft pine, and allowing 13 times the weight of the pattern, if it 2U STEAM HEATING FOR BUILDINGS. is new, or just out of the sand, and 14 times if it has laid in the pattern loft for some time. A square foot of cast-iron, one inch thick, weighs 37. J pounds. To find what a square foot of any other thickness will weigh, multiply ST^ by the thickness in inches, or fractions of an inch. A square foot of rolled wrought-iron, one inch thick, weighs 40 lbs. To find the weight of boiler plates, or sheet-iron, per square foot, multiply 40 by the decimal of an inch in thickness the required plates are to be. TABLE NO. 11. THE FOLLOWING TABLE SHOWS THE DIFFERENCE BETWEEN AMERICAN AND ENGLISH WIRE GAUGES, AND THE THICKNESS OF PLATES, m DECIMALS OF AN INCH FOR EACH. No. of Gauge. American. Inches. English. Inches. 0000 0-46 0.454 000 0.4096 0.425 00 0.3648 0.38 0.3248 0.34 1 0.2893 0.3 2 0.2576 0.284 8 0.2294 0.259 4 0.2043 0.238 5 0.1819 0.32 6 0.1620 0.203 7 0.1443 0.18 8 0.1284 0.165 9 0.1144 0.148 10 0.1018 0.134 11 0.0007 0.12 12 0.0808 0.109 13 0.0719 0.0')5 14 0.0640 0.083 15 0.057 0.072 16 0.05 0.065 17 0.045 0.05S 18 0.04 0.019 19 0.035 0.043 20 0.031 0.035 MISCELLANEOUS NOTES AND TABLES. 215 To find the weight of a cast-iron pipe, for one foot of its length. — Multiply the diameter of the pipe in inches by 3.1416, and multiply the answer thus obtained, by the thickness of the pipe in inches, or decimals of an inch, then by 12 and 0.26 respectively ; or instead of the last two, use 3.15. This will give about the weight of the pipe, includ- ing the hubs, as the outside circumference of the pipe is not the mean length of the iron, according to its thickness. To be exact. Proceed as above, but take one thickness of the iron from the diameter of the pipe first, and it will give the weight of the pipe without hubs or flanges. Example.— Eequired the weight of a 12-inch pipe, J inch thick, for one foot of its length. Thus : 12 in. — 0.5 = 11.5 X 3.U16 = 36.127 x 0.5 ^ 18.063 x 3.15 = 56.89 pounds. The 3.15 is the sum of 12 inches for the length, and 0.263 for the weight. Definitions and computations in mensuration, re- quired by the steam-fitter. The perimeter of a figure is its outer boundary, with- out regard to shape. A true circle forms the shortest perimeter for the greatest area inclosed, and is called a circumference. A diameter is a right line, passing through the center of a circle. A diameter is very nearly ^^u of the circumference of the same circle, or, to he exact, 0.3183 of it. Kule.— Mul- tiply the circumference by 0.3183, and it will give the answer, in the same denomination. A circumference is 3iVo of the diameter of the same circle very nearly, or, to be exact, 3.1416. 216 STEAM HEATING FOR BUILDINGS. Tlie square of the diameter of a circle is multiplying it once by itself. Thus, if the diameter is 4, the square will be 16. (4 inches x 4 inches = 16 inches.) To find the area (the number of square inches) within a circle. — Multiply the square of the diameter by 0.7854, and it will give the answer in the same de- nomination as it was squared in. Thus, 4 " x 4 " = 16 ' X 0.7854 = 12.566 square inches, whose diameter is 4 inches. The cube of a number is the number multiplied by itself twice. Thus, 4 x 4 =: 16 x 4 = 64. When the cube of the diameter of a sphere is mul- tiplied by 0.5236, it gives the solid contents, in numbers of the same denomination as it was cubed in. Thus : 4" x 4" = 16 " X 4'= 64" x 0.5236 = 33.51 cubic inches, for a ball 4 inches in diameter ; and when multiplied again by 0.263 it gives 8.813, which will be the weight in pounds of a cast-iron ball of the same diameter. A cylinder of the same length as its diameter has the same surface as a sphere of equal diameter. To find the surface of a cylinder 4 inches in dia- meter and 4 inches long. — Multiply the diameter by 8.1416 and the product by the 4 inches in length. Thus, 4 X 3.1416 = 12.566 x 4 = 50.2656, the square inches on the outside of a 4 x 4 cylinder. To find the surface of a sphere, 4 inches in diameter. — Square the diameter, and multiply by 3.1416. Thus : 4x4 = 16x3.1416 = 50.2656. To find the outside surface of a pipe. — Multiply the outside diameter by 3.1416, and by the length in inches, and divide by 144, it will give the answer in square feet. To find the pressure, per square inch, a column of MISCELLANEOUS NOTES AND TABLES. 217 water of any height will exert. — Multiply the height of the column, in feet, by the weight of a cubic foot of water in pounds at the temperature the water may be, and divide by 144. Example. — Eequired the pressure, per square inch, of a head of water of 200 feet, and when the temperature of the water is 40° Fahr. (weight 62 J pounds). Thus, 200 X 62.5 = 12500^144 = 86.8 pounds per square inch. Required the pressure of the water at a temperature of 212^ Thus, 200 X 59.-80 = 119G -- 144 =.83.05 pounds per square inch. TABLE XO 12. THE FOLLOWIXG TABLE OF DIAMETERS, CIRCUMrERENCES, AND AREAS IS GIVEN FOR " READY-RECKONING." Diameter. Circumfer- Area. Diameter. Circumfer- Area. ence. ence tV 0.1003 0.0030 r^ 4.5160 1 . (;229 ^ 0.8027 0.0122 i 4.7124 1.7671 1 b 0.5800 0.0276 -h 4.9087 1.9175 i 0.7814 0.0190 i 5.1051 2.0739 ■h 0.0317 0.0767 A 5.3015 2.2865 'i 1.1781 0.1104 4 5.4978 2.4052 -h 1.8744 0.1508 4t 5.6941 2.5801 1.5708 0.1968 I 5.8905 2.7611 1^6- 1.7671 0.2485 n 0.0808 2.9483 5. 1.9385 0.3068 n 2. 1503 0.3712 2 in. 6.2832 3.1416 4 2.85()2 0.4417 fi) 6.4705 3 3411 i 2.5525 0.5185 i 6.6759 3.5465 X 2.7489 0.6013 .a. 1 () 6.8722 3.7582 If 2.9452 0.6903 i 7.0686 3.9760 ■h- 7.2()40 4.2001 1 in. 3.1416 7854 i 7.4613 4.4302 -.-'- 3.8870 0.8861 "iv 7.6576 4.6664 3.5343 0.0040 i 7.8540 4.0087 -^> 3.78.)6 1.1075 "1^6 8.0503 5.1573 i 3.9270 1.2271 ^ 8.2467 5.4119 -^. 4.1283 1.8520 H 8.4430 5.6727 i- 4.3197 1.4848 i 8.0394 5.9395 218 STEA3I HEATING FOB BUILDINGS. Diameter. Circumfer- Area. Diameter. Circnmfer- Area. ence. euce. i! 8.8357 0.2126 i 17.2788 23.7583 I 9.0321 6.4918 tg 17.4751 24.3014 it 9.2284 6.7772 f 17.6715 24.8505 n 17.8678 25.4058 3 in. 9.4248 7.0686 3. 4 18.0642 25.9672 \h 9.C211 7.3662 M 18.2605 26.5348 \ 9.8175 7.0699 i 18.4569 27.1085 -h 10.0138 7.9798 n 18.6532 27.6884 \ 10.2102 8.2957 ■h 10 40G5 8.6179 6 in. 18.8496 28.2744 8 10.6029 8.94G2 i\ 19.0459 28.8665 -1- 1 b 10.7992 9.2806 i 19.2423 29.4647 \ 10.9956 9.6211 -A 19.4386 30.0798 -A- 11.1919 9.9678 L 4 19.6350 30.6796 11.3883 10.3206 A 19.8313 31.2964 \k 11.5846 10.0796 i 20.0277 31.9192 f 11.7810 11.0446 A 20.2240 32.5481 it 11.9773 11.4159 i 20.4204 33.1831 i 12.1737 11.7932 'ra 20.6167 33.8244 •ft 12.3700 12.1768 f 20.8131 34.4717 u 21.0094 35.1252 4 in. 12.5664 12.5664 f 21.2058 35.7847 'h 12.7627 12.9622 n 21.4021 36.4505 \ 12.9591 13.3640 i 21.5985 37.1224 A 13.1554 13.7721 i§ 21.7948 37.8005 i 13.3518 14.1862 -IT 13.5481 14.6066 7 in. 21.9912 38.4846 f 13.7445 15.0331 ■k 22.1875 39.1749 -iV 13.9408 15.4C57 i 22.3839 39.8713 i 14.1372 15.9043 -.^6- 22.5802 40.5469 i'b- 14.3335 16.3492 22.7766 41.2825 ? 14.5299 16.8001 1 t) 22.9729 41.9974 H 14.7262 17.2573 1 23.1693 42.7184 f 14.9226 17.7205 fV 23.3656 43.4455 it 15.1189 18.1900 f 23.5620 44.1787 8 15.3153 18.6655 rV 23.7583 44.9181 n 15.5716 19.1472 t 23.9547 45.6636 U 24.1510 46.4153 5 in. 15.7080 19.6350 4 24.3474 47.1730 -.\ 15.9013 20.1290 i^ 24.5437 47.9370 i 16.1007 20.6290 1 24.7401 48.7070 -A- 16.2970 21 . 1252 15. 1 t) 24.9354 49.4833 i 16.4934 21 . 6475 -3^1 16.6897 22.1661 8 in. 25.1328 50.2056 f 16.8861 22.6907 -.\- 25.3291 51.0541 fe- 17.0824 23.2215 i 25.5255 51.8486 MISCELLANEOUS NOTES AND TABLES, 219 Diameter. Circnmfer- encc. Area. I .Diameter. Circumfer- ence. Area. i^ 20.7218 52.8994 4 30.9138 108.4342 \ 25.9182 53.45G2 I 37.3005 110.7580 -A. 1 ij 20.1145 54.2748 f 20.3109 55.0885 12 in. 37.0992 113.0970 ? 20.5072 55.9138 i 38.0919 115.4G00 t 20.7030 50.7451 \ 38.4840 117.8590 "iHi" 20.8999 57.5887 f 38.8773 120.27GG 1 27.0903 58.4204 i 39.27C0 122.7187 i^ 27.2920 59.77G2 f 38.0027 125.1854 3. 4 27.4890 00.1321 f 40.0554 127.0705 13 1 27 0853 00.9943 i 40.4481 130.1923 jL 8 27.8817 G1.8G25 it 28.0780 02.7309 13 in. 40.8408 132.7S2G i 41 2338 135.2974 9 in. 28.2744 03.0174 4 41 . 0202 137.8b07 .1 . 1 ti 28.4707 04.5041 f 42.0180 140.5007 i 28.0071 05.3908 i 42.4110 143.1391 VV 28.8034 CO. 2957 f 42.8044 145.8021 1 4 29.0598 07.2007 i 43.1970 148.4896 A 29.2501 08.1120 i 43.5857 151.2017 f 29.4525 09.0^93 Vb 29.0488 09.9528 14 in. 43.9824 153.9384 i 29.8452 70.8883 i 44.3751 150 . G995 l"6 30.0415 71.8121 \ 44.7070 159.4852 f 30.2379 72.7599 1 45.1005 102.2950 i^ 30.4342 73.7079 i 45.5532 105.1303 f 30.0300 74.0020 f 45.9459 107.9896 il 30.82G9 75.0223 i 40.3380 170.8735 1 31.0233 70.5887 i 40.7313 173.7820 tt 31.2190 77.5013 15 in. 47.1240 170.7150 10 in. 31.4100 78.5400 i 47.5107 179.0725 i 31.8087 80.5157 . i 47.9094 182.0545 ± 32.2014 82.5100 t 48.3021 185.0012 1 32.5941 84.5409 i 48.09^8 188.0923 i 32.9808 80.5903 f 49.0875 191.7480 i- 33.3795 88.0048 f 49.4802 194.8282 33.7722 90.7027 I 49.8729 197.9330 1 34.1049 92.8858 10 in. 50.2050 201.0024 11 in. 34.5570 95.0334 i 50.0583 204.2102 i 34.9503 97.2053 \ 51.0510 207.3946 1 4 35.3430 99.4121 1 51.4447 210.5976 f 35.7357 101.0234 i 51.8304 213.8251 i 30.1284 103.8091 1 52.2291 217.0772 i 30.5211 100.1394 i 52.0218 220.3537 220 STEA3I EEATIXG FOR BUILD mOS. Diameter. Circumfer- euce. Area. Diameter. Circumfer- ence. Area. 1 53.0145 223.6549 f 67.1517 358.8419 i 67.5444 363.0511 17 in. 53.4073 226.9806 f 67.9371 867.2849 i 5;j.7U99 230.3308 ■A 4 68.3298 371.5432 k 54.1926 233.7055 1 68.7225 875.8261 f 54.5853 237.1049 * 54.9780 240.5287 ■ 22 in. 69.1152 880.1336 1- 55.3707 243.9771 i 69.5079 384.4655 ^ 55.7034 247.4500 i 69.9003 388.8220 1 5G.15G1 250.9475 f 70.2933 893.2081 i 70.0860 397.6087 18 in. 50.5488 254.4696 1 71.0787 402.0388 i 56.9415 258.0161 71.4714 406.4935 4 57.8342 261.5872 1 71.8641 410.9728 f 57.7269 265.1829 ^ 58.1196 268.8031 23 in. 72.2508 415.4766 f 58.5123 272.4479 i 72 6495 420.0049 f 58.9053 276.1171 I 4 73.0422 424.5577 1 59.2977 279.8110 • f 72.4319 429.1352 i 73.8276 433.7371 19 in. 59.6904 283.5204 74.2203 438.36:;6 i 60 0831 287.2723 1 74.6130 443.0146 1 4 60.4758 291.0397 i 75.0057 447.6092 1 60.8385 294.8312 i 61.2612 298.6483 24 in. 75.8984 452.3904 f 61 . 6539 302.4804 i 75.7911 457.1150 i 62.0406 306.3550 4 76.1838 461.8642 1 62.4393 310.2452 f 76 . 5765 466.6380 i 76.9692 471 4363 20 in. 62.8320 314.1600 f 77.3619 476.2592 -1 63.2247 318.0992 ■i 77.7546 48 L. 1065 4 63.6174 322.0630 i 78.1473 485.9785 f 64.0101 326.0514 i 64.4023 330.0643 25 in. 78.5400 490.8750 f 64.7955 334.1018 i 78.9327 495.7960 ii 4 65.1882 338.1637. 1 4 79.3254 500.7415 i 65.5800 342.2503 i 79.7181 505.7117 i 80.1108 510.7063 21 in. 65.7936 346.3614 1 80.5035 515.7255 JL 66.3363 350.4970 1 80.8962 520.7692 4 66.7590 354.6571 i 81.2889 525.8375 To find the circumferences of larger circles, multiply the diameter by 8.1416. For areas, multiply the square of the diameter by 0.7854. MISCELLANEOUS NOTES AND TABLES. 221 TABLE NO. 13. SHOWING THE NUMBER OF FEET IX LENGTH OF VARIOUS SIZED PIPES WHICH WILL CONTAIN ONE CUBIC FOOT OF WATER. By multiplying tlie above lengths by tlie relative volume ^' of steam at any required pressure, it will give the length of pipe which will be necessary to contain a cubic foot of water when conyerted into steam at that pressure. * See Table No, 5. APPENDIX A. The foUoicing detaUed specification is here introduced to familiarize the reader ivith an ordinary form for a steam- heating ivorkf and will suggest much useful information to the fitter. SPECIFICATION FOE STEAM-HEATI:N"G apparatus, YEKTILATIOK, C00KIN"G, WASHING, DRYII^G, Ai^D PUMPS, FOR A HOTEL OR PUBLIC BUILDIN^G. Boilers. There will be required for heating and power .... horizontal multi-tubular boilers, each inches in diameter and feet long, with lap- welded tubes ; inches in diameter, of No. . . wire- gauge iron, no tube to be placed nearer than three (3) inches to shell. steam dome. Each boilcr will havc a steam-dome inches high, and inches in diameter. Mud-pipes. The mud-pipes for boilers, (if used,) will be inches in diameter by six (6) feet long, with heavy- cast-iron connections. The connecting-pipe to be eight (8) inches inside diameter cast metal, not less than one (1) inch in thickness ; the head and flange will also be of cast-iron. The flanges and connections to have turned faces, and to be 224 APPENDIX. fitted with tliree-fonrth (f ) inch bolts, not more than three (3) inches from centers. Lugs. Each boiler to have four (4) cast-iron lugs or brackets, one and one-fonrth (IJ) inch thick, and twelve (12) inches wide, and to project not less than twelve (12) inches from the sides of boilers. The lugs Avill be fastened to the shell of boilers with not less than ten (10) three-fourths (J) inch rivets each. Man-holes. The mau-liolcs of boilers will be twelve (12) by sixteen (IG) inches, with heavy plate and guard. Hand-holes. Euch boilcr will havc two (2) hand-holes, of the ordinary size, provided with heavy plates and guards. Material. The wliolc slicll, licads, domc, and mud-pipe to be of C. H. No. 1 iron (or boiler steel of the finest quality), each and every sheet used in construction of boilers must be stamped, showing the grade and quality of the iron or steel. The shell of boilers and domes will be five-sixteenths (j^^-) of an inch thick. Heads three-eighths (§) inch thick. Heads of dome, three-eighths (f ) inch. The mud-pipe (if used) will also be three-eighths (f ) of an inch thick. stavs and Each head of boilers above the tubes to have not braces ]ggg than braccs or stays, each brace or stay to have in its smallest diameter one square inch of the best refined iron, and to be fastened to the shell and heads by the best method for equalizing strain. Heads of domes (if made of wrought-iron) to have stays or braces, sub- ject to the same conditions as aforesaid stays or braces. Seams. Longitudinal seams to be double riveted. The vertical seams in dome, and flange of dome, to be double riveted. lS[o hole larger than six (6) inches to be made in shell of boiler under the dome, the aggregate area of said holes to be four times that of the steam-pipe. Rivets. No cupped or button -set rivets are to be al- lowed — they must be either hand or machine made, the latter APPENDIX, 225 preferred. Tlie use of the drift pin must be entirely clis- pensed tvith. The splitting or cracking of a hole or sheet will be cause for rejection. Calking. Whcrc the work is chipped and calked after being fitted and riveted, it must be done in such a manner that the inside sheets will not be marked or seamed by the chisel or calking-tool ; the edges must be driven in straight, and not against, or partly against, the inner sheet, hereby raising a shoulder on it. Testing. Eacli of Said boilers will be tested to one hun- dred and fifty (150) pounds cold-water pressure to the square inch before leaving the shops. The Supervising Engineer or Architect to have every facility for examining the work as it progresses. The boilers to be made in accordance with the drawings, special attention being paid to laying out the tubes. The non-compliance with any of the above will be cause for the rejection of any or all of the boilers. j3^,j,^^ The boiler to be substantially set up in brick- setiing. Y^ork ; walls inches thick, the foundation walls to be of stone, inches thick, laid in cement mortar. All exposed walls will be built of straight well-burned bricks, laid in fresh lime and sand mortar, all brick-work exposed to the fire to be lined with first-class fire-bricks, laid in fire-clay mortar, the floor of fire-pit will be paved with hard burned brick, and well grouted. Boiler fronts. Eacli boilcr. to havc a full cast-iron front, the metal to be five-eighths (§) inch thick. Said fronts will have flue doors, fire doors, and ash doors of sizes drawn, all neatly fitted. The fire doors will be lined with perforated plates to allow free circulation of air between tlie doors and linings. The boilers to be furnished with cleaning doors, covering-bars, anchors, bolts, tie-rods, buckstaves, and other castings usual and necessary. 226 APPENDIX. Smoke fines. Eacli fumace to have flues leading from the front-connection oi boiler, and connecting with a main flue to stack. Said flues to be of wrought-iron of an inch thick, thoroughly riveted and bolted at connections, the flues to be furnished with the required dampers. Grates. One sct of grate bars will be required for each boiler as drawn. Boiler trim- Each boilcr to be provided with a inch mings safety-valve, a two (2) inch blow-off cock, one eight (8) inch nickel-plated cased steam-gauge of approved con- struction, one three-fourths {%) inch water-gauge, three com- pression gauge-cocks, with wooden handles, a one and one- half (1|) inch feed-pipe, together with all necessary pipes, valves, fittings, etc., to make the whole complete in all its parts ; the boilers to be so connected that they may be sepa- rately or together used for heating and all other purposes. Small pnmp. Providc and set up where specified or shown, two of Wortliington's Duplex boiler feed*pumps, (or any other j)ump of approved qnalities.) Diameter of steam cylinders, inches ; diameter of water cylinder, , . , inches ; length of stroke, inches. Pump con- ^^^^ pumps to be so connected and cross connect- nectious. q^^ ]j\^q^'^ either can be used for the work of the other. steam-pipes. All the pipcs uscd for steam to be of wrought- iron, of standard weight and dimensions. Said pipes to be screwed together with heavy cast-iron fittings, and wrought- iron sockets. Cast-iron flange-unions to be used on all pipes larger than two (2) inches, and right-and-left couplings for pipes less than two and a half (2J) inches. The main steam-pipes to start from the dome of each boiler with a inch pipe and valve, and run to a cross-main, said cross-main to be inches. The main distributing-pipe for heating apparatus is to start from cross-main of inches in diameter, and APPENDIX, 227 be run in or about the position shown on plans, and of the sizes tliere mar]:ed, and to be out less than two inches at each of its extremes, and furthermore, no engine-pipe, or elevator-pump pipe, must be taken from the same cross- main ; but must have separate connections to the domes of boilers, when used. Steam-mains to be supplied with all fittings, valves, etc., usual and necessary for the proper completion of the appar- atus. The further distribution of the steam-pipes and re- turns can be seen by consulting plans. Expansion '^^^^ "^'^^^ Supply aud return pipes, also branch joints, niains and returns, will be supplied with the nec- essary expansion joints, when the expansion cannot bo com- pensated for by right- angle turns. Rising mains. Each perpendicular line of coils or radiators will have a separate rising main. Not more than two (2) radia- tors to be supplied from one rising main on the same floor. The mains to be accompanied by a return-pip3,said return-i:>ipG will be one size smaller than supply-pipe. The rising mains and return-pipes will each have a brass globe or angle-valve same size as pipes, at their lower ends, so that steani may be let on or off one or more sections without interfering with any other. Relief piiK-s. The main steam-pipes to be properly drained in suitable places, so that no water of condensation can at any time remain in pipes above the water-line. All pipes to be secured to walls, arches, etc., with expansion hangers and hooks, as may be required. Return pipes. The main rctum-pipes for collecting the water of condensation from the coils, radiators, and relief-pipes, must be of sufficient capacity to collect all the water and conduct it back. All return pipes must be supplied with valves, fittings, etc., to correspond to the main steam-pipe. 228 APPENDIX. Summer Summer supph^-pipe will be required for the supply, •^gg qI w^q laundry, kitchen, drying room, venti- lating shafts and hot-water tanks, said pipe to be connected to boilers direct, and so arranged that it can be supplied by steam from either boiler, separately and together. Tliis pipe will extend to kitchen etc., inches in diameter, and will have globe-valves same size of pipes on each con- nection, etc., and the above specified pipe to have branches as drawn, with a brass globe-valve connecting each branch to main. Summer re- Fumisli and fit up rctum-pipes for collecting turn pipes. |]^g water of Condensation from laundry, kitchen, coils in drying room, hot-water tanks, and coils in ventilating shafts, and return the same to boilers (or condensed steam-tank in boiler room,) with all connections, valves, and everything necessary to finish the work. The return-pipes to be one size smaller than supply-pipes, each to be furnislied with a brass Yalve same size of pipe. The whole system of sum- mer supply and return pipes to be entirely independent of the general steam-heating pipes. Valves. Valves of two (2) inches and under, to be made of the best steam-metal. The bodies of all valves, two and a half (2 1) inches and upward, to be made of the best soft cast-iron, with valves, seats, and stems of steam-metal. Fittings. The fittings throughout the entire work, unless otherwise specified, must be of the best quality of cast-iron, neatly finished. Radiators. All radiators used must be vertical Uibe radia- tors, made of wrought or cast iron with ornamental cast-iron tops and bases. All rooms in building, with radiators sliowu on plans, to have one or more of the above style of radiators, situated as near as possible to position marked on plan, and to have not less heating surface in squai'e feet than is marked in figures APFEXDIX. 229 on plan of radiator, in each room. Each radiator above, and including eighty (80) square feet of heating surface, to have one and one-fourth (IJ) inch steam-valves and connections, and one (1) inch return- valves and connections. Each ra- diator less than eighty (80) square feet, and more than forty (40) square feet of heating surface, to have one (1) inch steam-valves and connections, and three-fourths (f ) inch return-valves and connections ; all smaller radiators to have three-fourths (f) inch steam and one-half (|) inch return valves and connections. Each radiator and coil throughout the work must be provided with an air-valve. Each radi- ator to be bronzed with the best quality of gold bronze. All radiator-valves to be nickel plated, and have wooden handles. Coils. ^ The.... floor will be heated with ornamental coil radiators of size and capacity marked on plan, and will have . . inch steam and . . inch return pipes and valves, the valves to be nickel plated. These coils will be finished with blaclv baking japan, relieved with gold as may be directed. Horizontal ^^^^ chapcl and dining-rooms will be heated coils. ^,j|.|j horizontal coils of one (1) inch pipe, with amount of heating surface marked on plans in square feet, with spring-pieces at inlet ends, all to be provided with the necessary manifolds. The coils to rest on cast-iron ring plates not less than eight feet apart, said ring plates to be screwed to neat wooden strips, the strips being well fastened to walls and partitions, the brick walls to be plugged. All coils to be placed on the outside walls under windows. There will be put up in each ventilating shaft a coil of one (1) inch pipe equal to square feet of heating surface, with supply and return connections, also steam and return valves. The coils will be supported upon the re- quired hook plate. All the coils and pipes, both mains and 230 APPENDIX. returns, will be painted with black baking jtipan, in best manner. „ ,. The maximum pressure of steam is not to exceed Heating ^ capacity. ;gfty (50) pounds to the square inch^ and should the amount of heating surface figured on plans be deemed insufficient in any location of the building, through more than ordinary exposure, the heating surface may be in- creased to the necessary amount. The extra cost to be gov- erned by prices in schedule. VEKTILATIOIif. Chapel and ^"^ ^^^^ ^^ ^^^^^^ ('^) ^^^^^^ Ventilating shafts in wings, rotunda building will be placed square feet of heating surface, in one coil of one (1) inch internal diameter steam-pipo, fastened to the inside of shafts with the necessary hook plates and battens. Registers. To fumisli the ncccssary registers, of the re- quired size, finished in black japan, and properly set up, and secured in the wall. Into these shafts the rooms will be ventilated ; as shown on drawings. All ventilating coils to be united to the summer supply and return pipes. Drying room. The drying room will be ventilated by a shaft with entrance from ceiling over clothes rack and connected by a lateral duct to boiler smoke stack (or elswhere). The supply of fresh air being admitted beneath the floor of drying-room by openings in the wall (between joists), through the floor, by perforations one and one-fourth (1^) inch in diameter under drying-coils. KITCHEIS'. Meat kettles. To fumish and set up in the kitchen four (4) APPENDIX, 231 steam kettles, for cooking meats, etc., each of seventy-five (75) gallons capacity, with all the cocks and valves necessary to complete the same. Make all connections for cold-water, steam, and return pipes of the full size of tapped hole, said pipes to be supplied with brass valves. Ve'^etabie ^^ fumisli and set up four (4) vegetable steam- ketties. gpg qI thirty-three (33) gallons capacity, with the necessary tin baskets, etc. Make the necessary connections with water, steam, and waste pipe, with valves and cocks of required sizes. Sinks. To furnish and set up four (4) cast iron sinks 3 feet by 3 ft. 6 in., and 10 inches deep, to be set as drawn, with f inch hot and cold water connections, provided with compression cocks of brass, and waste connection to sewer, 2 inches internal diameter. coffce-nm. To fumisli and set up one steam jacket tea and coffee maker or urn, of eighty (80) gallons capacity, w^ith all the necessary steam and water connections, valves, etc. Hot-water To fumish and set up one hot-w^ater boiler, two ^^^^' feet six inches in diameter by five feet high, made of one-fourth inch boiler plate, the top end to be riveted in, the bottom to be of cast-iron, bolted to wrought-iron flange. The boiler to be riveted, chipped, and calked, and to be tested to a pressure of one hundred and fifty (150) pounds per square inch. Said boiler to be provided with a vertical coil of one hundred and fifty (150) lineage feet of one (1) inch internal diameter steam-pipe, for supplying steam heat. Said coil to be connected to the cast-iron bottom of boiler, and to have the necessary supply and return pijies and valves. Vapor-pipe. Each stcam kettle or steamer to have a vapor pipe, three (3) inches in diameter, connected to a six (6) inch main ; said main to be carried to the roof. 232 APPENDIX. LAUNDKY. Washing- ^^® laundry will be fitted up to run witli steam- machines. power. To fumish (2) large laundry-size wasli- ing-machines with wringer and counter-shaft with the necessary belting, etc., to connect with line-shaft, machines, and wringers ; make all water connections (hot and cold), steam and sewer connections. Soak-tabs. Furnisli and set up (2) soak-tubs, six (6) feet long by two feet eight inches (2 ft. 8. in.) wide, and two feet four inches (2 ft. 4 in.) deep. Soak-tubs to be made of two inch pine plank matched together, the joints being set in white lead ; the angles to be well spiked and secured with wrought- iron straps screwed on in best manner. The tubs to be made water-tight. The wash and soak tubs to be supplied with hot and cold water, and to be provided with a two- inch waste and overflow pipe connected with drain. The hot and cold water supply will be one (1) inch in diameter, with brass compression bibbs. Washing-machines and soak- tubs to have steam connections with at least four (4) feet of one-half (J) inch perforated brass pipe to each machine and tub, for the purpose of boiling the clothes, with all the necessary valves and fittings to properly finish the work. Mangle. To fumish and set up one (1) box or French mangle securely fastened to the floor of laundiy, with the necessary counter- shaft, leather belting, pulleys, etc. Mangle pulley to be 14 inches in diameter, by 3 J inches face, and to have a 3 inch leather driving belt, 'i'he mangle to be prop- erly loaded and balanced ; speed of mangle pulley to be not less than seventy (70) revolutions per minute, nor over ninety (90). DEYING ROOM. ' Steam-pipes. There will be required in the drying room of APPENDIX. 233 laundry thirty-one (31) coils of one (1) inch pipe ten (10) feet long, and four (4) pipes high, set on hook stands, and each connected into a three (3) inch manifold, to be supplied with a one and one-half inch steam pipe and yalve on feed end, and a one (1) inch pipe and valve on return end; said steam- pipes to be connected with summer supply-pipe. Clothes Furnish thirty-two (32) clothes racks, together racks, -^rj^]^ rollers, guides, handles, linos, and thirty-two (32) wrought-iron tracks for the same, to be made of three- sixteenths (y"V) inch by three-fourths (J) inch rolled T-iron, twenty feet long, each, and to be screwed to the floor. All to be finished and set up, in accordance with the drawing, in good working order. The wood-work of clothes racks to be furnished and put up by the joiner, the work being done under the direction of the contractor, who will be held responsible for the proper working of the same. FIXALLY. Mason and '^'^^® brick and mason work, and all excavations brickwork, ^-iii ]3Q ^q^q j^y ^j^^ jji^ijider (excepting the brick and mason work of boilers), and all material belonging to such work will be furnished by the same. The materials for boiler setting will be provided by the contractor. Carpenter ^^^^ carpcutcr work for the entire apparatus will work. jjigQ ijQ ^Q^^Q jjy ^j-^Q joiner, and materials therein used furnished by the same. The contractor will be held to furnish all of the different kinds of pipe herein stated, and the necessary quantities of each kind; he will furnish all other materials as licrein specified ; he will do all work which is required of him in these specifications. All materials and all work must be of the best quality and done in the most workmanlike manner. All openings or slats in the walls required to be cut for any pipe, must be done by the contractor, and any injury to 234 APPENDIX, plastering, or wood- work, in the different buildings, must be borne by him, and made good at his own expense, and in no case shall any cutting be allowed without the permission of the architect. It is to be distinctly understood, that the true meaning and intent of these specifications are, that the whole work shall be performed in the finest and most secure manner. All disputes arising from these specifications to be sub- mitted to a board of 3, selected as follows: — The contractor to select one, the owner or architect to select one, and the two thus selected to choose a third — the decision of the majority to be binding on both parties. FflE NASOtf No. 71 Eeekman and Fulton Sts., N. Y. LEADBNG DEPOT IN NEW YORK MARKET FOR Steam and Gas Fitters, Machinists, Railroad and Factory Supplies. Nason's Patent Fiee- End Tubular Boilers. Nason's Patent Veitical Wrought- Iron Welded Tube Radiators. Nason's Patent Steam Trap Condensers. Nason's Patent Open Jaw Pipe Vise— will take Pipe at any j^oint. Nason's Patent Improv- ed Glue or Paste Heater. Nason's Patent Combi- nation Boiler, with Worth- ington Steam Pump. Nason's Improved Draft or Damper Regulators. Nason's Improved Feed Water Heaters. [ Nason's Improved Foot Rail Brackets. J Nason's Improved Ven- tilating Fans, for ITosi)itals and Public Buildings. Nason's Improved Boiler Feed Pumps. Nason's Improved Foot Valves with Strainers. Nason's Improved Water Columns, new design. The Worthington Steam Pumps. Water Meter. Bailey's Fire Hydrant. Wrouglit and Cast-iron Pipe, all varieties, Valves, Cocks, Fittings, etc., for Steam, Gas. Water and Oil. ^ ' ' > ». Heating Apparatus for Public Buildings, Apart, ment Houses, Residences, etc. Established by Joseph NasoD, 1840. Incorporated by The TTason Manufacturing Co., 1874. Carleton W. Nason, Frest. Harry F. Worthington. Vice-Frcat. John W. Carrington, Trcas. M UU MANUFACTURERS OF Fcr Steam, Gas and "Water, LAP WELDED BOILER TUBES, ass ail! Iron Valves anil Gocks, CAST IRON RADIATORS, Fitters' Tools and Supplies OF EVERY DESCRIPTION. 142 k 144 Centre St. and 117 Walker St, NEVS^ YORK. Malleable Iron Fittings a Specialty. ■Vt^- S- XJI^'T'^ IMPROVED UNIVERSAL FORGE PUMPS. The undersigned bogs to offer a new line of the above Pumps, wliich combine all the im- provements that a long experience has sug- gested. These Pumps have an increased stroke, greater power, superior finish, and beauty of design. They can be placed in any desired position, as the working head rotates. The upper nozzle offers a straight water-way through the pump, saving much friction when filling a tank. Hose can be used at either nozzle if desired. A full assortment of these Pumps constantly on hand, for the house and for out-door wells of the greatest depth. For power and reliability, these pumps cannot be surpassed. Complete outfits furnished to order, and ad- vice given on all questions relating to water supply. Send for circulars. 94 Beekman St., N. Y. WROUGHT-IRON PIPE lallcalle Iron fittings If Steam Heating. CHAPMAN VALVES PAHCOAST k TARE, MANUFACTURER'S AGENTS, ^S JPZatt Street, JVew ITovli WALWORTH fflANOFACTURINU OOiPAM. Established 1842. {rrwT.lL?.''i''6o.\ Capital, $400,000. Steam Engineers and Contractors. Plans and Estimates prepared for every description of Steam and Hot- Water Warming and Ventilating Apparatus. OFFICE, ^^.^^^^a FOUNDRIES Salesroom and Engineer's Dep't, 69 WHI St., I30ST0JV. C^ Warming of Dwelling houses and Green-houses by - Hot Water a specialty. And MACHINE SHOPS City Point, ^@mtM ^@ei®m .n^ '^-t^-.. Wrought- Iron Radiators. ^ u^ We manufacture all Radiators, Valves and Fit- tings used by us. GASKELL, GREENLIE & CO. SUCCESSORS TO R. S. PLACE, Screw Bolt Manufactufers, Machinists and Sliipsmilhs, 409 WATER &253 SOUTH STS., NEW YORK. Bolts, Nuts, Wood Screws, Tap Bolts, Set Screws. Rivets, Wasliers, etc.. otc. constantlj' on hand and made to order at the shortest notice. Also, General Smith Work. Estimates given on Heavy and Light Forging, All kinds of" Repairs promptly attended to. E. HOLLOWAY, SteaiTL ^ipe SendeT. Coils ijf ail Im it Un for Oil Eeiorifis, Soap IKettxes, Heaters for Steam Uoilers. RESIDENCE, 38 DIVISION ST., near Myrtle Ave., BROOKLYN. ANNIN & CO. IMPROVED STEAM HEATER. chTngeAS^'^^ov'eSfiJ'tl^ ^^^8 induced \,s to Hiake'snch" market, at a -rektly reduced c»st Xfwf^^^^ vl^^fPF^'^^"^- ^\^^ ^"'^'^'^ "^ to pl.ice on tlie omlcal Heater in /se for'|?eam VeattrPn^pS ""tH S V'^t^Tll'^'T'''''- ""'' ^^V'" twelve years without getting out of renair i^ n J^mJlv^ ^ having been m u8o for construction. ^ *= P "^ ^^ ^ sufficient guarantee of its durability of toa „V^,;S'o&&,7r„f ?h'/nfL^T''"<="^ 0' management, we ,vo„W refer ll,e public the Bhapo of ,he HeJer T e Hre P?t'i' of cS iro"1n fon? nV't "l'""'^'"'"-,;" '""f'"-™ "> For further particulars and circular address, "*^uiar. -A. 3M" INT X 2>r c*5 00-, Brooklyn Tube Works, Foot Adams Street, Brooklyn., THE RUSSELL VALVE. It IS needless to remind steam users of the annoyance and actual loss entailed by the great quantities of cheap and worthless articles sold and put in as Globe Valves. Unless specified, no contractor can be expected to pay the cost of a reliable article. The It VSSET.L VA I. IE has stood the test for nine years. It has a composition mov- able disk that usually will last about two years, and can any time be readily replaced. MANUFACIUKED ONLY BY T. R. McMANN & BRO, (Successors to McMann & Russell,) MANUFACTURERS AND DEALERS IN UmiW-h Fip d Im d Irso Fitiim FOR WATER AND STEAM, Arcliitects, and others interested, are requested to send for Descriptive Catalogues. 83 Beekman St., N. T., 64 Union St., Boston. D. SAUNDERS' SONS Manufacturers of Pipe Cutting and Threading Machines, TAPPING MACHINES, STEAM AND GAS FITTEES' HAND TOOLS, as to 31 -a.tlLorto:n^ St., ■K-o:icH«.ors, jsr. "ST. BATES & JOHNSON, (Successors to WYLLYS H. WARNER,) MANrrPACTCTRERS OP STEAM WARMING APPARATUS, HIGH AND LOW PRESSURE. BOILSES, EADIATOES, AUTOMATIC WATEE FEBDSES, DEAFT EEGULATOES, Etc. Sectional view of Magazine Boiler. Sole mannfacturers for New Eni^land, Eastern New York, Pennsylvania and New Jersey, of DUNNING'S Fatent Im Bming Ifagagine Boilers. No. 114 Leonard St., New York. Also, 33 We?t Railroad Street, Syracuse ; 310 Broadway, Albany. STEAM HEATING LOW OR HIGH PRESSURE. TWENTY-FIYE YEARS EXPERIENCE, Many hundred examples of our work may be seen in New York and vicinity ; including the Stock Exchange Building and Drexel Building, Broad and Wall Sts.; the Catholic Cathedral, 50th St. and 5th Ave.; the Kelly Building, Beek- man and Nassau Sts.; and the J. J. Astor Block, Broadway and Prince St. also stores public buildings and private houses in Troy, Albany, Washington, and Memphis, Tenn. aiLLIS & aEOaHEGAN, 116 & nS WOOSTER STREET, ABOVE SPRING STREET N E T^ Y O R K:. MAJfUFACTURERS OF BEST QUALITY Wnii-hPijHiTite, FROM i TO 15 INCHES DIAMETER. We mam a specialty of Wroughi-Iron (Pij,, and (Boiler Tules for Steam Heating. Extra and Double Extra Strong Pipe for Coils and Heavy Pressure. MACK'S PATENflNJECTo7oR~BOILER FEEDER. )mOES : 104 and 106 ^^^^^::^:Z^~rz^.^^^^,^ Square, Boston. 159 Lake Street, Chicago. MoEeesport, Pa. Pittsburg, Pa. WOEZJ : Boston, Mass. McKees-jort; Pa, Frederick Townsend, Pres't. Jas. H. Blessing, Sec'y and Treas. Mhmj Stsim f mp 60.' GRAVITATING -AND- BucKET Trap. BUCKET RETURN STEAM TRAPS For ReMflE tie Waters of Coiteati. These Traps automatically drain the water of condensation from Heati2s^g Coils, and return the same to the Boiler, whether the Coils are above or below the water level in Boiler, thus doing away with pumps gravitating Trap. and other mechanical devices for such purposes. They return the escaping steam of the brew-kettle, and thus effect a great saving in fuel. "Write for Circulars and prices to THE ALBANY STEAM TRAP COMPABl THE M. T. DAYIDSOH STEAM PUMP, MANUFACTURED BY DAVIDSOP STEAM PUMP CO, 4.1 to 4.7 Keap St., Brooklyn, N. Y. The above cut represents our regular Pressure or Boiler Feed Pump. We make pumps for any situation where one can be used, and ive positively assert that the M. T. Davidson Steam Pump is the only one made^ Single or Duplex, that can be run at high piston speed without shock and with safety to machine. This feature makes it the most desirable for Hotels, Hospitals, Apartment Houses, or any situation where quiet is a desideratum. American laundry lachinery Co., 8 New Church St., New York "Asiiifi Maciiiis. steam, Cas and Cold Mangles, Centrifugal and Roll Wnngers, Collar, Cuff and Shirt Ironing Machinery LAUNDRIES FITTED UP COMPLETE. EAST RIVER SCREW BOLT WORKs" williaFgaskell MAJiUFACTTJRER OF Str8iB)lts,tt,TajBjlts,S!tlS[rsBs,ItL No. 433 EAST 25th STREET Kear First Avenue, "T. ' ^ NEW YORK. FRED. STONE & CO., 62 Gold St., New York. \ LDfllowTalTesamlflyilraDts, I PIPE TONGS, I Globe and Radiator Valves, Steam Cocks, etc J JohUng Trade Solicited. Send for Price List. ' JOHN Vy^ILEY &i SONS 15 ASTOJR PLACE, NEW YORK, ^ PUBLISHERS OF ^CIEPIFIC ^P P^CTO^Ii WeMS ''"i ng! D$St"Et'?tt^v' ^E""^-^'C»Pentr7, Chemistry. Drawing. Paint- Building, Steam Engines, Ventilation, Etc, Etc ^ vf\ F ^ 3 A ^.r"; Deacidified using the Bookkeeper pre Neutralizing agent; Magnesium Oxide Treatment Date: June 2004 PreservationTechnologies A WORLD LEADER IN PAPER PRESERVATIOr' 1 1 1 Thomson Park Drive Cranberry Township, PA 16066 (724)779-2111 . LIBRARY OF CONGRESS 012 208 638