The person charging this material is re¬ 
 sponsible for its return to the library from 
 which it was withdrawn on or before the 
 Latest Date stamped below. 
 
 Theft, mutilation, and underlining of books are reasons 
 for disciplinary action and may result in dismissal from 
 the University. 
 
 To renew call Telephone Center, 333-8400 
 
 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN 
 
 MG i 1 1981 
 
 jul 2 i lira 
 
 B 
 
 o ’n 
 
 L161—0-1096 
 
LIBRARY 
 OF THE 
 
 UNIVERSITY OF ILLINfil'' 
 
 THE 
 
 BOILER BOOK 
 
 The Hartford Steam Boiler 
 Inspection and Insurance 
 Company 
 
 A Collection of Reliable Data 
 For Use in the Design and 
 Installation of Boilers and 
 Other Pressure Vessels. 
 
 Compiled by H. E. DART, Superintendent 
 of Engineering Department 
 
 The Hartford Steam Boiler Inspection 
 and Insurance Co., Hartford, Conn. 
 
 1920 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Copyright 1920 
 
 The Hartford Steam Boiler inspection and Insurance Company 
 
 
 
 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
\i\M< 
 
 MTb 
 
 PREFACE 
 
 F 
 
 OR MORE than forty years the designs of the Engineering Department of 
 this Company have been accepted as standards throughout the United 
 States and have been copied into the most authoritative engineering hand¬ 
 
 books and textbooks as well as the trade catalogs of the best-known boiler makers 
 
 and dealers in materials required for boiler construction. We comply with a 
 great many requests for data on boiler design and installation, the sources of 
 inquiry ranging from college professors to firemen, from well-known steel com¬ 
 panies-and large boiler-shops to steam-fitters, plumbers and brick-masons in 
 small towns, from Canadian Government commissions and English boiler¬ 
 makers to Cuban sugar plantations, and from wood-pulp mills in Maine to saw¬ 
 mills in Oregon and cotton plantations in Louisiana. 
 
 Our designs and standards have been disseminated principally in the form 
 of blue-prints, over 83,000 prints having been sent out since the Engineering 
 . Department was established. As a rule, however, each blue-print covers only 
 one single phase of some particular subject and we have often thought that it 
 r would be worth while to assemble some of the more commonly used data in the 
 form of a pamphlet. This idea has been more forcibly brought to our attention 
 since the promulgation of the Boiler Code of the American Society of Mechanical 
 Engineers and its adoption by several states and cities. We adopted the Code 
 as a standard as soon as it was published and made such minor changes in our 
 old drawings, as were needed to comply with its requirements. All our newer 
 drawings, tables, and other data have been designed in accordance with the 
 provisions of the Code and, in view of the many inquiries which we receive 
 regarding the Code and its application, it seems that such data ought to be 
 especially valuable to those who are trying to follow the Code requirements. 
 
 With these ideas in mind we have collected and published the data which 
 appears on the following pages for the use of our friends. This little book is not 
 intended as a treatise on boiler design but merely as a collection in convenient 
 form, of data which we have found valuable in our Engineering Department and 
 
 which we hope will prove of equal value to those who may have occasion to use 
 
 it. The designs contained herein represent our ideas as to good practice in 
 < boiler construction but it should be understood that we necessarily insure many 
 v-~ boilers which do not comply therewith. 
 
 
 THE HARTFORD STEAM BOILER INSPECTION 
 AND INSURANCE COMPANY 
 
 November 20, 1920. 
 
 Hartford, Conn. 
 
 1022174 
 
 3 
 
4 
 
 The Hartford Steam Boiler Inspection and Insurance Co 
 
 INDEX 
 
 A 
 
 American Standard, Drilling and other 
 details for Flanges and Fittings.. 
 
 Areas of Circles,. 
 
 Areas of Segments to be stayed in H. T. 
 boiler heads,. 
 
 B 
 
 Basic Principles. 
 
 Braces, Arrangement in H. T. boilers.. 
 
 Diagonal Crowfoot, Proportions 
 
 of. 
 
 Spacing.... 
 
 Stresses and 
 Areas sup¬ 
 ported by. 
 
 Through, Proportions of. 
 
 Stresses and Areas 
 supported by. 
 
 Bracing Heads of H. T. boilers,. 
 
 Bricks, Number required for H. T. boil¬ 
 er settings,. 
 
 Bumped Heads, Allowable pressures on 
 Butt-Joints. See “Joints.” 
 
 C 
 
 Circles, Circumferences and Areas of. . 
 
 Circumferential Seams. See “Girth 
 Seams.” 
 
 Columns for Supporting H. T. boilers, 
 Cast Iron, Round and Square,. 
 
 Steel, H-Beams. 
 
 Plate-and-Angle,. 
 
 Connections, Boiler. Minimum num¬ 
 ber of Pipe Threads in. 
 
 Cylindrical Shells, Girth seams of. 
 
 Allowable Pressures 
 on. 
 
 D 
 
 Decimal Equivalents of Common Frac¬ 
 tions, . 
 
 Dished Heads, Allowable Pressures on, 
 
 F 
 
 Flanges and Fittings, Drilling and other 
 Details,. 
 
 Fractions, Decimal Equivalents of,.... 
 
 Furnaces, Unstayed. Allowable Pres¬ 
 sures on.. 
 
 G 
 
 Girth Seams, H. T. boilers,. 
 
 Cylindrical Vessels with 
 Solid Unstayed Heads. 
 Grates, Size of, for H. T. boilers,. 
 
 
 J 
 
 Page 
 
 Page 
 
 Joints, Butt. Double-riveted,. 
 
 7 
 
 56 
 
 Triple-riveted,. 
 
 8, 9 
 
 57 to 65 
 
 Quadruple-riveted. 
 
 10, 11 
 
 20, 21, 22 
 
 Lap. Double-riveted. 
 
 13 
 
 Girth Seams. 
 
 14, 15 
 
 
 Single-riveted,. 
 
 12 
 
 5 
 
 Joints, Riveted. 
 
 6 
 
 17, 18, 19 
 
 L 
 
 
 23 
 
 23 
 
 Lap Joints. See “Joints.” 
 
 P 
 
 
 
 Plates, Steel. Weight per square foot, 
 
 47 
 
 24 
 
 Pressures, Allowable on Cylindrical 
 
 Shells,. 
 
 16 
 
 25 
 
 on Spherical Heads, 
 
 31 to 35 
 
 26, 27 
 
 on Unstayed Fur¬ 
 naces. 
 
 36, 37 
 
 17 to 22 
 
 43 
 
 R 
 
 Rivets, Shearing Strength of,. 
 
 5 
 
 31 to 35 
 
 Rivet Heads, Proportions for,. 
 
 6 
 
 57 to 65 
 
 Riveted Joints. See “Joints.” 
 
 S 
 
 Safety Valves for Power Boilers,. 
 
 51 
 
 Number and size of for 
 Fire-tube boilers. 
 
 52, 53 
 
 49 
 
 50 
 
 Number and size of for 
 Water-tube boilers,... 
 
 54, 55 
 
 Size of boiler connections 
 for two or three. 
 
 51 
 
 50 
 
 Settings for H. T. boilers, 
 
 
 
 Dimensions,. 
 
 42 
 
 56 
 
 General description. 
 
 40, 41 
 
 15 
 
 Number of bricks required for,. 
 
 43 
 
 16 
 
 Shearing Strength of rivets,. 
 
 5 
 
 Smoke-Openings, Size of for H. T. boilers 
 
 44 
 
 
 Spherical Heads, Allowable pressures on 
 
 31 to 35 
 
 
 Staybolts, Allowable loads on,. 
 
 29 
 
 57 
 
 Least angle for given number 
 of threads. 
 
 30 
 
 31 to 35 
 
 Maximum pitch,. 
 
 28 
 
 
 Stays and Staying. See “Braces” and 
 “Bracing”. 
 
 Steel Plates, Weights per square foot. . 
 
 47 
 
 56 
 
 Suspension of H. T. boilers,. 
 
 48 to 50 
 
 57 
 
 T 
 
 
 36, 37 
 
 Threads, Pipe. Minimum number in 
 boiler connections. 
 
 56 
 
 
 Staybolt. Least angle for 
 given number of,. 
 
 30 
 
 14 
 
 Tubes, Arrangement of in H. T. boilers 
 
 17, 18, 19, 46 
 
 15 
 
 44 
 
 For Fire-tube boilers, Standard 
 dimensions,. 
 
 38 
 
 For Water-tube boilers and sup¬ 
 erheaters, . 
 
 39 
 
 H 
 
 H-Beams as Columns for Supporting H. 
 
 T. boilers. 50 
 
 Heads, Bracing of in H. T. boilers. 17 to 22 
 
 Spherical,. 31 to 35 
 
 Heating Surface of H. T. boilers,. 46 
 
 Heights for Setting H. T. boilers. 45 
 
 Horsepower of H. T. boilers. 46 
 
 I 
 
 I-Beams for Suspending H. T. boilers, 
 
 Sizes of. 48 
 
 U 
 
 Uptakes, Size of for H. T. boilers. 44 
 
 Unstayed Furnaces, Allowable Pres¬ 
 sures on,. 36, 37 
 
 V 
 
 Valves, Safety. See “Safety Valves.” 
 
 W 
 
 Weights of boiler tubes. 38 
 
 of H. T. boilers,. 47 
 
 of Steel plates per square foot, 47 
 
 Water, Weight of in H. T. boilers. 47 
 
 November, 1920. 
 
The H artf or d Steam Boiler Inspection and Insurance Co. 
 
 5 
 
 BASIC PRINCIPLES. 
 
 The general rules and working stresses used in calculating the tables which 
 appear on the following pages, are given below. These values are used in all 
 the work of our Engineering Department. 
 
 Minimum factor of safety = 5. 
 
 Tensile strength of steel plates = 55000 lbs. per sq. in. 
 
 Resistance of steel plates to crushing = 95000 lbs. per sq. in. 
 
 Strength of rivets in single shear = 44000 lbs. per sq. in. 
 
 Strength of rivets in double shear = 88000 lbs. per sq. in. 
 
 The cross-sectional area of rivets is taken as the area of the rivet holes, it 
 being assumed that all rivets will be properly driven so as to entirely fill the holes. 
 
 All calculations are based on the use of steel rivets conforming to the 
 requirements of the A. S. M. E. Boiler Code; no figures are given for iron rivets. 
 
 Allowable Shearing Strength of Steel Rivets. 
 
 Diameter of Rivet After 
 Driving 
 
 Cross-Sectional Area of 
 Rivet After Driving 
 
 Shearing Strength 
 
 Single Shear 
 
 Double Shear 
 
 1 he"—0.6875" 
 
 0.37122 sq. in. 
 
 16334 lbs. 
 
 32668 lbs. 
 
 K"—0.7500" 
 
 0.44179 “ “ 
 
 19439 “ 
 
 3887S “ 
 
 .8125" 
 
 0.51849 “ “ 
 
 22814 “ 
 
 45628 “ 
 
 —0.8750" 
 
 0.60132 “ “ 
 
 26458 “ 
 
 52916 “ 
 
 1 he"—0.9375" 
 
 0.69029 “ “ 
 
 30373 “ 
 
 60746 “ 
 
 1" —1.0000" 
 
 0.78540 “ “ 
 
 34558 “ 
 
 69116 “ 
 
 1 14"—1.0625" 
 
 0.88664 “ “ 
 
 39012 “ 
 
 78024 “ 
 
 1 he"—1 • 1875" 
 
 1.1075 “ “ 
 
 48730 “ 
 
 97460 “ 
 
 1 he"—1-3125" 
 
 1.3530 “ “ 
 
 59532 “ 
 
 119064 “ 
 
 1 he"—1.4375" 
 
 1.6230 “ “ 
 
 71412 “ 
 
 142824 “ 
 
6 
 
 The H a rtf or d Steam Boiler Inspection and Insurance Co. 
 
 STANDARD PROPORTIONS FOR RIVET HEADS 
 
 r 
 
 Straight Base Cone Head Pan Head Button Head 
 
 Button Head 
 
 Double Radius Steeple Head Countersunk Head Flat Head 
 
 Button Head 
 
 Dimensions May Be Larger Or '/\o Smaller Than Those Shown. 
 
 f 
 
 RIVETED JOINTS 
 
 Our designs for riveted joints have probably been copied and used more 
 widely than any other data which we have issued. About four years ago we 
 decided to make a complete new set of detail drawings for these joints because 
 the tracings were getting worn so badly that it was impossible to make good 
 blue prints from them. It seemed that this would be a good time to make any 
 changes'in design which might be desirable on account of variations in boiler- 
 shop practices and customs, so we wrote to several boiler-makers, asking for 
 copies of the tables which they were using and inviting suggestions for changes. 
 In practically every case the boiler-maker returned a nearly exact copy of the 
 standards which we had adopted years before and no suggestions were offered 
 for any radical changes. In making the new drawings, however, we simplified 
 the designs in some cases by eliminating some of the small fractions of an inch 
 in pitch dimensions, and in some of the designs we had to increase the back- 
 pitch slightly to comply with the requirements of the A. S. M. E. Boiler Code. 
 
 The tables which follow on Pages 7 to 13 show the various standard types 
 of riveted joints with complete dimensions and with efficiencies computed in 
 accordance with our usual practice as outlined on Page 5. Detail drawings are 
 available for all of the butt-joint designs. 
 
 Designs are included for lap-joints though we seldom use this style of joint 
 for longitudinal seams except in the cases of small vessels or vessels which will 
 not be subjected to heat. Special designs will be found on Pages 14 and 15 for 
 lap-joints to be used in circumferential seams. 
 
The H a rtf or d Ste am Boiler Inspection and Insurance Co. 
 
 7 
 
 DOUBLE-RIVETED BUTT-JOINTS 
 
 Typical Details of Design. 
 
 (See table below for dimensions, efficiencies, etc.) 
 
 Thickness 
 
 of 
 
 Plate 
 
 Thickness 
 
 of 
 
 Straps 
 
 Diameter 
 
 of 
 
 Rivet Hole 
 
 Efficiency 
 
 % 
 
 Long 
 
 Pitch 
 
 Short 
 
 Pitch 
 
 A 
 
 B 
 
 C 
 
 E 
 
 A" 
 
 A" 
 
 n As" 
 
 82.8 
 
 4" 
 
 2" 
 
 SA" 
 
 4 A" 
 
 l As" 
 
 2H" 
 
 W 
 
 A 
 
 'As" 
 
 82.8 
 
 4" 
 
 2" 
 
 8 A* 
 
 4X" 
 
 l As" 
 
 2 A" 
 
 As" 
 
 9 . 4 " 
 
 'As" 
 
 ■ 81.9 
 
 4 A" 
 
 2 A" 
 
 9 A" 
 
 5" 
 
 l A" 
 
 2As" 
 
 n /32" 
 
 
 1 As " 
 
 81.9 
 
 4 A" 
 
 2A" 
 
 9A" 
 
 5" 
 
 l A" 
 
 2 As" 
 
 H” 
 
 As' 
 
 ' As " 
 
 81.9 
 
 4 A" 
 
 2 A" 
 
 9As" 
 
 5" 
 
 l A" 
 
 2 As" 
 
 'W 
 
 As" 
 
 'As" 
 
 81.9 
 
 4 A" 
 
 2 A" 
 
 9A" 
 
 5" 
 
 1 A" 
 
 2 As" 
 
 As" 
 
 Vs" 
 
 'As" 
 
 81.3 
 
 5" 
 
 2 A" 
 
 11 A" 
 
 5 A" 
 
 lAs" 
 
 2 A" 
 
 
 H" 
 
 'As" 
 
 81.3 
 
 5" 
 
 2 A" 
 
 nA" 
 
 5 A" 
 
 lAs" 
 
 2 A" 
 
 A" 
 
 ‘As" 
 
 'As" 
 
 81.3 
 
 5" 
 
 2 A" 
 
 11 A* 
 
 5 A" 
 
 l As" 
 
 2 A" 
 
 NOTE—All joints in the above table fail by tearing the plate between rivet 
 holes in the outer naw. 
 
 For convenience in driving rivets the back-pitch (dimension E) may be 
 increased, if desired, without affecting the joint efficiency, but it should not 
 be decreased. 
 
8 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 TRIPLE-RIVETED BUTT-JOINTS 
 
 External View 
 
 Typical Details of Design 
 
 I" or dimensions, efficiencies, etc., see table on opposite page. 
 
The H a r tf or d Steam Boiler I ns p ection and Insurance Co 
 
 9 
 
 TRIPLE-RIVETED BUTT-JOINTS 
 
 Table of Dimensions and Efficiencies 
 
 (Letters refer to sketch on opposite page.) 
 
 Thickness 
 
 of 
 
 Plate 
 
 Thickness 
 
 of 
 
 Straps 
 
 Diameter 
 
 of 
 
 Rivet Hole 
 
 Efficiency 
 
 % 
 
 * 
 
 Long 
 
 Pitch 
 
 Short 
 
 Pitch 
 
 A 
 
 B 
 
 c 
 
 D 
 
 E 
 
 4" 
 
 4" 
 
 “4" 
 
 87.5 
 
 54" 
 
 24" 
 
 12" 
 
 734" 
 
 1 Vie" 
 
 14" 
 
 24" 
 
 9 4" 
 
 X" 
 
 n 4t 
 
 87.5 
 
 54" 
 
 234" 
 
 12" 
 
 734" 
 
 1 He" 
 
 14" 
 
 24 " 
 
 4o" 
 
 4" 
 
 13 4" 
 
 87.5 
 
 64" 
 
 34" 
 
 134" 
 
 834" 
 
 1 4" 
 
 14" 
 
 2Vfe" 
 
 n 4" 
 
 At 
 
 13 4" 
 
 87.5 
 
 64" 
 
 34" 
 
 134" 
 
 84" 
 
 1 4" 
 
 14" 
 
 24" 
 
 4" 
 
 *At 
 
 13 4" 
 
 88.4 
 
 7" 
 
 34" 
 
 134" 
 
 84" 
 
 1 4" 
 
 14" 
 
 2 Vie" 
 
 13 4" 
 
 
 13 4" 
 
 88.4 
 
 7" 
 
 34" 
 
 134" 
 
 834" 
 
 1 4" 
 
 14" 
 
 2 Vie" 
 
 W 
 
 4" 
 
 15 4" 
 
 87.9 
 
 7 4" 
 
 34" 
 
 154" 
 
 94" 
 
 1 Vie" 
 
 2" 
 
 24" 
 
 
 H" 
 
 15 4" 
 
 87.9 
 
 74" 
 
 34" 
 
 154" 
 
 94" 
 
 1 7 4e" 
 
 2" 
 
 234" 
 
 4" 
 
 W 
 
 15 4" 
 
 88.3 
 
 8" 
 
 4" 
 
 154" 
 
 94" 
 
 1 7 4e" 
 
 2" • 
 
 234" 
 
 11 At 
 
 7 4e" 
 
 15 4" 
 
 88.3 
 
 8" 
 
 4" 
 
 154" 
 
 934 " 
 
 1 Vfe" 
 
 2" 
 
 234" 
 
 %" 
 
 7 4e" 
 
 1 At 
 
 86.7 
 
 8" 
 
 4" 
 
 17" 
 
 11" 
 
 1 4" 
 
 24" 
 
 3" 
 
 19 4" 
 
 4" 
 
 l 14" 
 
 86.7 
 
 8" 
 
 4" 
 
 17" 
 
 11" 
 
 1 4" 
 
 24 " 
 
 3" 
 
 4" 
 
 4" 
 
 1 14" 
 
 86.7 
 
 8" 
 
 4" 
 
 17" 
 
 11" 
 
 1 4" 
 
 24 " 
 
 3" 
 
 
 4" 
 
 l 14" 
 
 86.7 
 
 8" 
 
 4" 
 
 17" 
 
 11" 
 
 1 34 " 
 
 24 " 
 
 3" 
 
 n Ac>" 
 
 4" 
 
 l Vie" 
 
 85.6 
 
 84" 
 
 44" 
 
 184" 
 
 12" 
 
 l 13 4e" 
 
 23/6" 
 
 34" 
 
 23 4>" 
 
 X” 
 
 1 14" 
 
 85.6 
 
 84" 
 
 44" 
 
 184" 
 
 12" 
 
 I’Vfe" 
 
 24" 
 
 34" 
 
 4" 
 
 , 4" 
 
 l *4" 
 
 85.5 
 
 84" 
 
 44" 
 
 184" 
 
 12" 
 
 1 13 4e" 
 
 24 " 
 
 . 34" 
 
 25 4>" 
 
 %" 
 
 1 14" 
 
 84.6 
 
 84" 
 
 44" 
 
 204 " 
 
 134" 
 
 2" 
 
 24 " 
 
 34 " 
 
 n At 
 
 9 fe" 
 
 i 4" 
 
 84.6 
 
 8 X" 
 
 44" 
 
 20 4 " 
 
 134" 
 
 2" 
 
 24" 
 
 34" 
 
 21 At 
 
 9/'' 
 
 -'16 
 
 1 14" 
 
 84.2 
 
 84" 
 
 44" 
 
 204" 
 
 134" 
 
 2" 
 
 24" 
 
 34 " 
 
 4" 
 
 4" 
 
 1 5 4"* 
 
 84.1 
 
 84" 
 
 434" 
 
 204" 
 
 134" 
 
 2" 
 
 24 " 
 
 34" 
 
 29 4" 
 
 4" 
 
 l 14" 
 
 83.6 
 
 834" 
 
 44 " 
 
 204" 
 
 134" 
 
 2" 
 
 24" 
 
 34" 
 
 15 4e" 
 
 l %" 
 
 l 14" 
 
 83.7 
 
 9" 
 
 44" 
 
 204 " 
 
 134" 
 
 2" 
 
 24" 
 
 34" 
 
 3 14" 
 
 n A&" 
 
 1 14" 
 
 83.2 
 
 9" 
 
 44 " 
 
 204" 
 
 134" 
 
 2" 
 
 24" 
 
 34 " 
 
 r 
 
 X" 
 
 l 14" 
 
 83.4 
 
 94" 
 
 44" 
 
 22" 
 
 14 4" 
 
 9 3/ " 
 
 ^ /16 
 
 24" 
 
 34" 
 
 NOTE—Joints for plate thicknesses from 2 %" to 1" (both inclusive) fail by 
 tearing the plate between rivet holes in the second row and shearing a rivet in 
 the outer row; this also applies to the joint for the Y" plate. All other joints in 
 the above table fail by tearing the plate between rivet holes in the outer row. 
 
 For convenience in driving rivets, either of the dimensions for back-pitch 
 (D and E) may be increased without affecting the joint efficiency, but they 
 should not be decreased. 
 
10 
 
 The H a rtf or d Steam Boiler Inspection and Insurance Co. 
 
 QUADRUPLE-RIVETED BUTT-JOINTS 
 
 External View 
 
 Typical Details of Design 
 
 For dimensions, efficiencies, etc., see table on opposite page. 
 
The Hartford Steam Boiler Inspection and Insurance Co 
 
 11 
 
 QUADRUPLE-RIVETED BUTT-JOINTS 
 Table of Dimensions and Efficiencies 
 
 Thick¬ 
 
 ness 
 
 of 
 
 Plate 
 
 Thick¬ 
 
 ness 
 
 of 
 
 Straps 
 
 Diam. 
 
 of 
 
 Rivet 
 
 Hole 
 
 Effici¬ 
 
 ency 
 
 % 
 
 Long 
 
 Pitch 
 
 Middle 
 
 Pitch 
 
 Short 
 
 Pitch 
 
 A 
 
 B 
 
 C 
 
 D 
 
 E 
 
 F 
 
 X" 
 
 X" 
 
 X VY 
 
 93.8 
 
 11 " 
 
 5X" 
 
 2X" 
 
 16X" 
 
 7X" 
 
 1 Ye" 
 
 IX" 
 
 2X" 
 
 2 X" 
 
 \Y 
 
 X" 
 
 l Ye" 
 
 93.8 
 
 11 " 
 
 5 X" 
 
 2X" 
 
 16X" 
 
 7X" 
 
 1 Ye" 
 
 IX" 
 
 2YY 
 
 2 X" 
 
 VY 
 
 9 4" 
 
 l Ye" 
 
 93.8 
 
 13" 
 
 6 X" 
 
 3X" 
 
 18X" 
 
 8 X" 
 
 1 X" 
 
 i YY 
 
 2VY 
 
 2 X" 
 
 X VY 
 
 vy 
 
 x Ye" 
 
 93.8 
 
 13" 
 
 6 X" 
 
 3X" 
 
 18 YY 
 
 8 X" 
 
 1 X" 
 
 l YY 
 
 2VY 
 
 2 X" 
 
 YY 
 
 Ye" 
 
 l Ye" 
 
 94.2 
 
 14" 
 
 7" 
 
 3X" 
 
 19X" 
 
 8 X" 
 
 1 X" 
 
 1 YY 
 
 We" 
 
 2 X" 
 
 X VY 
 
 Ye" 
 
 l Ye" 
 
 94.2 
 
 14" 
 
 7" 
 
 3X" 
 
 19X" 
 
 8 X" 
 
 l X" 
 
 IYY 
 
 We" 
 
 2 X" 
 
 Ye" 
 
 H" 
 
 l Ye" 
 
 94.0 
 
 15X" 
 
 7X" 
 
 3 VY 
 
 21 YY 
 
 9X" 
 
 1 Ye" 
 
 2 " 
 
 2X" 
 
 3 VY 
 
 X W 
 
 H" 
 
 l Ye" 
 
 94.0 
 
 15X" 
 
 7X" 
 
 3 VY 
 
 21 YY 
 
 9X" 
 
 1 Ye" 
 
 2 " 
 
 2X" 
 
 3 VY 
 
 X" 
 
 Ye" 
 
 x Ye" 
 
 94.1 
 
 16" 
 
 8 " 
 
 4" 
 
 21 X" 
 
 9 X" 
 
 1 Ye" 
 
 2 " 
 
 2X" 
 
 3 VY 
 
 VY 
 
 Ye" 
 
 X VY 
 
 94.1 
 
 16" 
 
 8 " 
 
 4" 
 
 21 YY 
 
 9X" 
 
 1 Ye" 
 
 2 " 
 
 2 X" 
 
 3 YY 
 
 Ye" 
 
 Ye" 
 
 l Ye" 
 
 94.1 
 
 16" 
 
 8 " 
 
 4" 
 
 21 X" 
 
 9X" 
 
 1 Ye" 
 
 2 " 
 
 23X" 
 
 3 VY 
 
 l *h” 
 
 X" 
 
 1 Ye" 
 
 93.4 
 
 16" 
 
 8 " 
 
 4" 
 
 23X" 
 
 11 " 
 
 1 X" 
 
 2 X" 
 
 3" 
 
 3 VY 
 
 YY 
 
 X" 
 
 1 Ye" 
 
 93.4 
 
 16" 
 
 8 " 
 
 4" 
 
 23 VY 
 
 11 " 
 
 1 YY 
 
 2 X" 
 
 3" 
 
 3 VY 
 
 
 X" 
 
 1 Ye" 
 
 93.4 
 
 16" 
 
 8 " 
 
 4" 
 
 23 YY 
 
 11 " 
 
 1 YY 
 
 2X" 
 
 3" 
 
 3 VY 
 
 1 Ye" 
 
 X" 
 
 1 Ye" 
 
 92.8 
 
 16X" 
 
 8 X" 
 
 4X" 
 
 25 X" 
 
 12 " 
 
 We" 
 
 2 X" 
 
 3X" 
 
 3 VY 
 
 2 VY 
 
 X" 
 
 1 Ye" 
 
 92.8 
 
 16X" 
 
 8 X" 
 
 4X" 
 
 25X" 
 
 12 " 
 
 We" 
 
 2 YY 
 
 3X" 
 
 3 VY 
 
 YY 
 
 X" 
 
 1 Ye" 
 
 92.7 
 
 16X" 
 
 8 X" 
 
 ' 4X" 
 
 25X" 
 
 12 " 
 
 We" 
 
 2YY 
 
 3X" 
 
 3 VY 
 
 
 Ye" 
 
 1 Ye" 
 
 92.3 
 
 17" 
 
 8 X" 
 
 4X" 
 
 2,1 YY 
 
 13X" 
 
 2" 
 
 2 YY 
 
 3X" 
 
 3 X VY 
 
 l Ye" 
 
 *16 
 
 1 Ye" 
 
 92.3 
 
 17" 
 
 8 X" 
 
 4X" 
 
 .21 YY 
 
 13X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3 13 4" 
 
 
 Ye" 
 
 1 Ye" 
 
 91.8 
 
 17" 
 
 8 X" 
 
 4X" 
 
 21 YY 
 
 13X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3 X VY 
 
 YY 
 
 YY- 
 
 1 Ye" 
 
 91.2 
 
 17 YY 
 
 8 X" 
 
 4X" 
 
 28" 
 
 13 X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3 VY 
 
 YY 
 
 YY 
 
 1 Ye" 
 
 90.5 
 
 17 X* 
 
 8 X" 
 
 4X" 
 
 28" 
 
 13X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3 YY 
 
 X VY 
 
 x Ye" 
 
 1 Ye" 
 
 90.1 
 
 18" 
 
 9" 
 
 4X" 
 
 28X" 
 
 13X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3WY 
 
 3 VY 
 
 l Ye" 
 
 1 Ye" 
 
 89.5 
 
 18" 
 
 9" 
 
 4 X" 
 
 28 YY 
 
 13X" 
 
 2 " 
 
 2 YY 
 
 3X" 
 
 3 X VY 
 
 1" 
 
 X" ’ 
 
 1 Ye" 
 
 90.2 
 
 19" 
 
 9X" 
 
 4X" 
 
 30 X" 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 l W 
 
 X" 
 
 1 Ye" 
 
 89.6 
 
 19" 
 
 9X" 
 
 4X" 
 
 30X" 
 
 14 X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 1 Ye" 
 
 X" 
 
 1 Ye" 
 
 89.0 
 
 19" 
 
 9X" 
 
 4X" 
 
 30X" 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 l VY 
 
 X" 
 
 1 Ye" 
 
 88.5 
 
 19" 
 
 9 X" 
 
 4X" 
 
 30X" 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 1 X" 
 
 X" 
 
 1 Ye" 
 
 88.0 
 
 19" 
 
 9X" 
 
 4X" 
 
 30X" 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 1 VY 
 
 X" 
 
 1 Ye" 
 
 87.5 
 
 19" 
 
 9X" 
 
 4X // 
 
 30 YY 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 X" 
 
 1 Ye" 
 
 VY 
 
 1 Ye" 
 
 87.7 
 
 20" 
 
 10" 
 
 5" 
 
 30X" 
 
 14 X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 VY 
 
 1 VY 
 
 l Ye" 
 
 1 Ye 
 
 87.2 
 
 20" 
 
 10" 
 
 5" 
 
 30X" 
 
 14 X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 VY 
 
 l X" 
 
 VY 
 
 ' 1 Ye" 
 
 86.8 
 
 20" 
 
 10" 
 
 5" 
 
 30 YY 
 
 14X" 
 
 2 Ye" 
 
 2 YY 
 
 3X" 
 
 4 VY 
 
 NOTE—Joints for plate thicknesses from to 1 y A " (both inclusive) fail 
 by tearing the plate between rivet holes in the third row and shearing the rivets 
 in the two outer rows; this also applies to the joint for the Ti" plate. All other 
 joints in the above table fail by tearing the plate between rivet holes in the 
 outer row. 
 
 For convenience in driving rivets, any of the dimensions for back-pitch 
 (dimensions D, E, and F) may be increased, if desired, without affecting the joint 
 efficiency, but they should not be decreased. 
 
12 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 SINGLE-RIVETED LAP-JOINTS 
 
 Typical Details of Design 
 
 (See table below for dimensions, efficiencies, etc.) 
 
 Thickness 
 of Plate 
 
 Diameter of 
 Rivet Holes 
 
 Efficiency % 
 
 Pitch 
 
 A 
 
 Method of 
 Failure 
 
 X" 
 
 
 60.7 
 
 IX" 
 
 l%" 
 
 T. P. 
 
 
 l W 
 
 60.3 
 
 IX" 
 
 lWe" 
 
 S. R. 
 
 
 13 4 " 
 
 59.4 
 
 2" 
 
 IX" 
 
 T. P. 
 
 U A" 
 
 
 59.4 
 
 2" 
 
 IX" 
 
 T. P. 
 
 X" 
 
 1S A" 
 
 58.3 
 
 2X" 
 
 
 T. P. 
 
 w 
 
 l %" 
 
 58.3 
 
 2X" 
 
 m* 
 
 T. P. 
 
 W' 
 
 i %" 
 
 57.5 
 
 2X" 
 
 IX" 
 
 T. P. 
 
 U A* 
 
 i %>" 
 
 57.5 
 
 2X" 
 
 IX" 
 
 T. P. 
 
 y*" 
 
 i w 
 
 56.7 
 
 2X" 
 
 IX" 
 
 S. R. 
 
 NOTE—In the column headed “Method of Failure,” “T. P.” indicates that 
 the joint will fail by tearing the plate in the net section between rivet holes; 
 “S. R.” means that the failure will be due to shearing rivets. 
 
The Hartford Steam Boiler Inspection and Insurance Co. 
 
 13 
 
 DOUBLE-RIVETED LAP-JOINTS 
 
 Typical Details of Design 
 
 (See table below for dimensions, efficiencies, etc.) 
 
 Thickness of 
 Plate 
 
 Diameter of 
 Rivet Holes 
 
 Efficiency 
 
 % 
 
 Pitch 
 
 A 
 
 B 
 
 A" 
 
 
 69.5 
 
 2^" 
 
 l%" 
 
 l A" 
 
 Ik" 
 
 1 We" 
 
 69.5 
 
 2X" 
 
 IWe" 
 
 l A" 
 
 A," 
 
 
 69.1 
 
 2H" 
 
 1A" 
 
 1 H" 
 
 
 
 69.1 
 
 2H" 
 
 1A" 
 
 1H" 
 
 H" 
 
 
 68.9 
 
 3" 
 
 VAS 
 
 2" 
 
 'AS 
 
 15 4" 
 
 68.9 
 
 3" 
 
 w 
 
 2" 
 
 W 
 
 l W 
 
 68.5 
 
 sy&" 
 
 1H" 
 
 2A" 
 
 15 4" 
 
 l W 
 
 68.5 
 
 
 1H" 
 
 2As" 
 
 K" 
 
 1 %" 
 
 68.5 
 
 3 H” 
 
 l H" 
 
 2'A" 
 
 NOTE—All joints described by the above table will fail by tearing the 
 plate in the net section between rivet holes. 
 
14 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 LAP-RIVETED JOINTS FOR GIRTH SEAMS OF HORIZONTAL 
 
 TUBULAR BOILERS 
 
 In cases like that usually found in horizontal tubular boilers where 50% 
 or more of the load which would act on an unstayed solid head of the same 
 diameter as the shell, is relieved by the effect of tubes or through stays, the 
 strength of the circumferential joints in the shell should be at least 35% of that 
 required for the longitudinal joints; and when such circumferential joints are 
 exposed to the products of combustion, the shearing strength of the rivets should 
 be not less than 50% of the full strength of the plate corresponding to the thick¬ 
 ness at the joint. The following table of single-riveted lap-joints is designed to 
 meet the above conditions, using rivets of the same size as those in our standard 
 designs for butt-joints. We do not advise the use of plates thicker than 
 when the girth seams, under pressure, are exposed to. the fire or products of com¬ 
 bustion and the table is therefore not extended beyond this limit. 
 
 Thickness 
 of Plate 
 
 Diameter of 
 
 Rivet Holes 
 
 Pitch of Rivets 
 
 ' \ 
 
 Efficiency 
 
 1 of Joint 
 
 Shearing Strength of 
 Rivets in per cent of 
 Solid Plate 
 
 K" 
 
 
 IK" 
 
 60.7 
 
 67.9 
 
 
 u /6" 
 
 IK" 
 
 60.3 
 
 60.3 
 
 
 x *4" 
 
 IK" 
 
 56.7 
 
 70.8 
 
 
 13 4" 
 
 IK" 
 
 56.7 
 
 64.4 
 
 K" 
 
 
 IK" 
 
 56.7 
 
 59.1 
 
 
 13 4" 
 
 IK" 
 
 54.5 
 
 54.5 
 
 W 
 
 15 /fc" 
 
 2K" 
 
 55.9 
 
 59.4 
 
 'W 
 
 15 Te" 
 
 2K" 
 
 55.4 
 
 55.4 
 
 K" 
 
 15 4" 
 
 2K" 
 
 52.0 
 
 52.0 
 
 
 '■bo" 
 
 2 Kg" 
 
 50.4 
 
 50.4 
 
 %" 
 
 1 %" 
 
 2K" 
 
 53.3 
 
 53.3 
 
 In portions of girth seams which will be subjected to the hot fire, the rivet¬ 
 ing should be started at the bottom of the boiler and carried up continuously 
 on both sides, reaming the holes anew as the seam is riveted up to the full 
 diameter of the boiler. 
 
 I 
 
15 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 LAP-RIVETED JOINTS FOR GIRTH SEAMS OF CYLINDRICAL 
 VESSELS WITH SOLID UNSTAYED HEADS 
 
 In horizontal tubular boilers, tanks and similar vessels it is customary for 
 the sake of convenience, to use the same size of rivets in the girth seams as in 
 the longitudinal seams. Where the heads of such vessels are not stayed by tubes 
 or through braces the strength of the circumferential joints should be at least 
 50% of that required for the longitudinal joints of the vessel. The joints in the 
 table below are designed to meet the above requirements and it should be under¬ 
 stood that a higher efficiency could be obtained in some instances by using a 
 different size of rivets. It is assumed in each case that the efficiency of the 
 corresponding longitudinal joint is not greater than that of our standard design 
 for Quadrupled-Riveted Butt-Joints as shown on Page 11. 
 
 Thickness 
 of Plate 
 
 Diameter of 
 Rivet Holes 
 
 Single-Riveted Lap Joints 
 
 Double-Riveted Lap Joints 
 
 Pitch of Rivets 
 
 Efficiency of Joint 
 
 Pitch of Rivets 
 
 Efficiency of Joint 
 
 K" 
 
 u 4" 
 
 IK" 
 
 60.7 
 
 
 
 9 4" 
 
 u 4" 
 
 IK" 
 
 60.3 
 
 
 
 5 4" 
 
 13 4" 
 
 IK" 
 
 56.7 
 
 
 
 “K" 
 
 13 4" 
 
 IK" 
 
 56.7 
 
 
 
 H" 
 
 13 4" 
 
 IK" 
 
 56.7 
 
 
 
 i3 4" 
 
 13 4" 
 
 IK" 
 
 54.5 
 
 
 
 7 4" 
 
 15 4" 
 
 2 K" 
 
 55.9 
 
 
 
 
 ,5 4" 
 
 2K" 
 
 55.4 
 
 
 
 K" 
 
 15 -4" 
 
 2K" 
 
 52.0 
 
 
 
 17 4" 
 
 15 4" 
 
 214" 
 
 50.4 
 
 3" 
 
 68.8 
 
 9 ,6" 
 
 1 Kb" 
 
 2 K" 
 
 53.3 
 
 3K" 
 
 67.3 
 
 19 
 
 *32 
 
 1 Wb" > 
 
 
 
 3K" 
 
 67.3 
 
 K" 
 
 l 14" 
 
 
 
 3K" 
 
 67.3 
 
 21 4" 
 
 1 14" 
 
 
 
 3K" 
 
 66 .5 
 
 u 4" 
 
 l %* 
 
 
 
 3K" 
 
 68.3 
 
 2S 4" 
 
 1 Vb" 
 
 
 
 3K" 
 
 65.8 
 
 K" 
 
 l 3 4" 
 
 
 
 3K" 
 
 63.0 
 
 25 4" 
 
 i 5 4" 
 
 
 
 4" 
 
 67.2 
 
 13 4" 
 
 l %!' 
 
 
 
 4" 
 
 66.6 
 
 27 4" 
 
 1 5 4" 
 
 
 
 4" 
 
 64.1 
 
 K" 
 
 1 5 4" 
 
 
 
 4" 
 
 61.9 
 
 29 4" 
 
 1 5 4" 
 
 
 
 4" 
 
 59.7 
 
 15 4" 
 
 l 14" 
 
 
 
 4" 
 
 57.7 
 
 3 *4" 
 
 l 5 4" 
 
 
 
 4" 
 
 55.9 
 
 l" 
 
 l 7 4" 
 
 
 
 4 K" 
 
 57.7 
 
 l 14" 
 
 l 7 4" 
 
 
 
 4K" 
 
 56.0 
 
 i Kb" 
 
 l 7 4" 
 
 
 
 4K" 
 
 54.3 
 
 l 3 4" 
 
 1 7 4" 
 
 
 
 4K" 
 
 52.S 
 
 i k" 
 
 l 7 4" 
 
 
 
 4K" 
 
 51.3 
 
 l /4" 
 
 l 7 4" 
 
 
 
 4K" 
 
 49.9 
 
 1 3 4" 
 
 l 7 4" 
 
 
 
 4K" 
 
 48.6 
 
 l w 
 
 1 7 4" 
 
 
 
 4K" 
 
 47.4 
 
 1 K" 
 
 l 14" 
 
 
 
 4K" 
 
 46.2 
 
ALLOWABLE WORKING PRESSURES ON CYLINDRICAL SHELLS 
 
 16 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
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 The Hartford Steam Boiler Inspection and Insurance Co. 
 
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 4 - 3" Tubes 52-3^" Tubes 46-4" Tubes 
 
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 Arrangement Of Tubes And Braces In 60 Inch Horizontal Tubular Boilers 
 
18 The Hartford Steam Boiler Inspection and Insurance Co. 
 
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 Arrangement Of Tubes And Braces In 72 Inch Horizontal Tubular Boilers 
 
The H a rtf or d Steam Boiler Inspection and Insurance Co. 19 
 
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 176-3" Tubes 138-3^" Tubes 108-4" Tub 
 
 Arrangement Of Tubes And Braces In 84 Inch Horizontal Tubular Boilers 
 
20 The H a rtf or d Steam Boiler Inspection and Insurance Co. 
 
 AREAS TO BE STAYED IN HEADS OF HORIZONTAL TUBULAR 
 
 BOILERS 
 
 A 
 
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 i 
 
 " t 
 
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 The diagram above shows a typical layout of tubes in the head of a hori¬ 
 zontal tubular boiler, the areas which require bracing being indicated by shading. 
 The distance of two inches (2") from the tubes where bracing is not required is 
 taken as a constant for all sizes of boilers, all pressures and all head thicknesses 
 but the distance supported by the flange of the head (indicated by the letter d) 
 is dependent upon the pressure and the thickness of the head in each case. 
 Values of d may be determined from the following table which is based on the 
 formula: 
 
 d_«i 
 
 v p 
 
 where d = unstayed distance from shell in inches. 
 
 P = maximum allowable working pressure in pounds per sq. in. 
 
 T = number of sixteenths of an inch in head thickness (T = 8 for head, 
 9 for head, etc.) 
 
The Hartford Steam Boiler Inspection and Insurance Co. 
 
 21 
 
 AREAS TO BE STAYED IN HEADS OF HORIZONTAL TUBULAR 
 
 BOILERS—(Continued) 
 
 Value of d or Distance Supported by Flange of Head 
 
 Wrkng 
 Pres.— 
 
 Thickness of Head (Inches) 
 
 ids. per 
 sq. in. 
 
 H 
 
 14 
 
 K 
 
 % 
 
 H 
 
 n 4 
 
 V* 
 
 13 4 
 
 V* 
 
 
 1.0 
 
 50 
 
 4.24 
 
 4.95 
 
 5.66 
 
 6.36 
 
 7.07 
 
 7.78 
 
 8.49 
 
 9.19 
 
 9.90 
 
 10.61 
 
 11.31 
 
 60 
 
 3.87 
 
 4.52 
 
 5.16 
 
 5.81 
 
 6.46 
 
 7.10 
 
 7.75 
 
 8.39 
 
 9.04 
 
 9.68 
 
 10.33 
 
 70 
 
 3.59 
 
 4.18 
 
 4.78 
 
 5.38 
 
 5.98 
 
 6.57 
 
 7.17 
 
 7.77 
 
 8.37 
 
 8.96 
 
 9.56 
 
 SO 
 
 3.35 
 
 3.91 
 
 4.47 
 
 5.03 
 
 5.59 
 
 6.15 
 
 6.71 
 
 7.27 
 
 7.83 
 
 8.39 
 
 8.94 
 
 90 
 
 3.16 
 
 3.69 
 
 4.22 
 
 4.74 
 
 5.27 
 
 5.80 
 
 6.33 
 
 6.85 
 
 7.38 
 
 7.91 
 
 8.43 
 
 100 
 
 3.00 
 
 3.50 
 
 4.00 
 
 4.50 
 
 5.00 
 
 5.50 
 
 6.00 
 
 6.50 
 
 7.00 
 
 7.50 
 
 8.00 
 
 110 
 
 2.86 
 
 3.33 
 
 3.81 
 
 4.29 
 
 4.77 
 
 5.24 
 
 5.72 
 
 6.20 
 
 6.67 
 
 7.15 
 
 7.63 
 
 120 
 
 2.75 
 
 3.21 
 
 3.66 
 
 4.12 
 
 4.58 
 
 5.04 
 
 5.50 
 
 5.96 
 
 6.42 
 
 6.88 
 
 7.33 
 
 125 
 
 2.68 
 
 3.13 
 
 3.58 
 
 4.03 
 
 4.47 
 
 4.92 
 
 5.37 
 
 5.81 
 
 6.26 
 
 6.71 
 
 7.16 
 
 130 
 
 2.63 
 
 3.07 
 
 3.50 
 
 3.95 
 
 4.38 
 
 4.82 
 
 5.26 
 
 5.70 
 
 6.14 
 
 6.57 
 
 7.00 
 
 140 
 
 2.53 
 
 2.95 
 
 3.38 
 
 3.80 
 
 4.22 
 
 4.64 
 
 5.07 
 
 5.49 
 
 5.91 
 
 6.33 
 
 6.76 
 
 150 
 
 2.45 
 
 2.85 
 
 3.26 
 
 3.67 
 
 4.08 
 
 4.49 
 
 4.90 
 
 5.31 
 
 5.71 
 
 6.12 
 
 6.53 
 
 160 
 
 2.37 
 
 2.77 
 
 3.16 
 
 3.56 
 
 3.95 
 
 4.35 
 
 4.74 
 
 5.14 
 
 5.53 
 
 5.93 
 
 6.32 
 
 170 
 
 2.30 
 
 2.68 
 
 . 3.06 
 
 3.44 
 
 3.83 
 
 4.22 
 
 4.60 
 
 4.98 
 
 5.37 
 
 5.75 
 
 6.13 
 
 180 
 
 2.23 
 
 2.60 
 
 2.98 
 
 3.35 
 
 3.72 
 
 4.10 
 
 4.47 
 
 4.84 
 
 5.21 
 
 5.59 
 
 5.96 
 
 190 
 
 2.17 
 
 2.54 
 
 2.90 
 
 3.26 
 
 3.63 
 
 3.99 
 
 4.35 
 
 4.72 
 
 5.08 
 
 5.44 
 
 5.80 
 
 200 
 
 2.12 
 
 2.47 
 
 2.83 
 
 3.18 
 
 3.54 
 
 3.89 
 
 4.24 
 
 4.59 
 
 4.95 
 
 5.30 
 
 5.66 
 
 The outside radius of the flange of the head may be used for d if such radius 
 is greater than the value given in the above table for the required pressure and 
 thickness of head, except that the value obtained in this manner must not be 
 greater than eight (8) times the thickness of the head. 
 
 Referring again to the diagram on Page 20, the area of the rectangle shown 
 by the wide cross-hatching can be easily determined from its length and width 
 and the area of either segment can be calculated from the formula 
 
 . 4(H-d-2) 2 / 2(R-d) 77 no 
 
 Area ~ 3 V (H-d-2) °' 608 
 
 where H = distance from top (or bottom) of tubes to shell in inches. 
 
 R = radius of the boiler head in inches, 
 d = unstayed distance from shell in inches. 
 
 Our Engineering Department can furnish blue-prints of a table giving areas 
 of segments based on this formula for different values of the two terms (H-d-2) 
 and (R-d) but the table is too large to print conveniently in a book of this size. 
 On the following page, however, will be found a table giving areas of segments 
 for cases where d (as defined above) is equal to three inches (3"). It will be 
 found that the calculated value of d is usually greater than 3 inches and, in 
 such cases, the areas given in the table will therefore be somewhat larger than 
 actually required so that they will be on the safe side. 
 
22 The Hartford Steam Boiler Inspection and Insurance Co 
 
 AREAS TO BE STAYED IN HEADS OF HORIZONTAL TUBULAR 
 
 BOILERS—(Concluded) 
 
 Table Showing Net Areas of Segments of Heads Where d (as defined on 
 Pages 20 and 21) is Equal to Three Inches (3") 
 
 Height 
 
 from 
 
 Tubes 
 
 to 
 
 Diameter of Boiler (Inches) 
 
 24 
 
 30 
 
 36 
 
 42 
 
 48 
 
 54 
 
 60 
 
 66 
 
 72 
 
 7S 
 
 84 
 
 90 
 
 96 
 
 Shell, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Ins.) 
 
 
 
 
 
 Area to be stayed, Sq. In. 
 
 
 
 
 
 8 
 
 28 
 
 33 
 
 37 
 
 40 
 
 43 
 
 47 
 
 51 
 
 53 
 
 55 
 
 58 
 
 60 
 
 63 
 
 65 
 
 8 K 
 
 35 
 
 41 
 
 46 
 
 51 
 
 55 
 
 59 
 
 63 
 
 66 
 
 70 
 
 74 
 
 76 
 
 80 
 
 82 
 
 9 
 
 42 
 
 49 
 
 56 
 
 62 
 
 67 
 
 72 
 
 76 
 
 82 
 
 86 
 
 90 
 
 92 
 
 95 
 
 98 
 
 9K 
 
 50 
 
 58 
 
 66 
 
 70 
 
 80 
 
 86 
 
 91 
 
 96 
 
 101 
 
 105 
 
 111 
 
 116 
 
 119 
 
 10 
 
 57 
 
 68 
 
 77 
 
 85 
 
 93 
 
 99 
 
 106 
 
 112 
 
 117 
 
 123 
 
 129 
 
 132 
 
 137 
 
 10K 
 
 66 
 
 78 
 
 89 
 
 98 
 
 107 
 
 114 
 
 123 
 
 131 
 
 135 
 
 142 
 
 147 
 
 153 
 
 160 
 
 11 
 
 74 
 
 88 
 
 100 
 
 111 
 
 121 
 
 130 
 
 138 
 
 147 
 
 155 
 
 161 
 
 169 
 
 174 
 
 183 
 
 11K 
 
 83 
 
 99 
 
 112 
 
 124 
 
 137 
 
 146 
 
 156 
 
 165 
 
 173 
 
 181 
 
 189 
 
 196 
 
 204 
 
 12 
 
 91 
 
 109 
 
 125 
 
 139 
 
 151 
 
 163 
 
 174 
 
 184 
 
 194 
 
 203 
 
 213 
 
 219 
 
 230 
 
 12K 
 
 
 120 
 
 138 
 
 153 
 
 167 
 
 180 
 
 193 
 
 204 
 
 216 
 
 224 
 
 234 
 
 243 
 
 252 
 
 13 
 
 
 132 
 
 151 
 
 168 
 
 183 
 
 197 
 
 211 
 
 224 
 
 235 
 
 247 
 
 256 
 
 267 
 
 279 
 
 13K 
 
 
 143 
 
 164 
 
 183 
 
 200 
 
 216 
 
 230 
 
 246 
 
 258 
 
 270 
 
 282 
 
 293 
 
 302 
 
 14 
 
 
 155 
 
 178 
 
 199 
 
 217 
 
 234 
 
 250 
 
 266 
 
 280 
 
 294 
 
 305 
 
 319 
 
 331 
 
 14^ 
 
 
 167 
 
 192 
 
 215 
 
 235 
 
 254 
 
 271 
 
 287 
 
 303 
 
 318 
 
 333 
 
 345 
 
 360 
 
 15 
 
 
 178 
 
 206 
 
 231 
 
 252 
 
 273 
 
 291 
 
 309 
 
 326 
 
 343 
 
 357 
 
 372 
 
 386 
 
 15K 
 
 
 
 220 
 
 247 
 
 271 
 
 291 
 
 312 
 
 332 
 
 350 
 
 368 
 
 382 
 
 400 
 
 417 
 
 16' " 
 
 
 
 235 
 
 263 
 
 289 
 
 312 
 
 334 
 
 355 
 
 374 
 
 394 
 
 411 
 
 423 
 
 443 
 
 16^ 
 
 
 
 249 
 
 281 
 
 308 
 
 332 
 
 357 
 
 380 
 
 399 
 
 420 
 
 436 
 
 457 
 
 475 
 
 17' 
 
 
 
 264 
 
 297 
 
 326 
 
 353 
 
 378 
 
 402 
 
 425 
 
 447 
 
 467 
 
 486 
 
 502 
 
 17K 
 
 
 
 
 314 
 
 345 
 
 374 
 
 400 
 
 426 
 
 449 
 
 471 
 
 494 
 
 516 
 
 536 
 
 18' " 
 
 
 
 
 331 
 
 365 
 
 396 
 
 424 
 
 450 
 
 476 
 
 500 
 
 520 
 
 543 
 
 564 
 
 18U 
 
 
 
 
 349 
 
 384 
 
 417 
 
 448 
 
 476 
 
 501 
 
 526 
 
 552 
 
 577 
 
 598 
 
 19 
 
 
 
 
 366 
 
 404 
 
 439 
 
 470 
 
 500 
 
 529 
 
 555 
 
 580 
 
 604 
 
 631 
 
 19K 
 
 
 ► • • • 
 
 
 384 
 
 424 
 
 461 
 
 496 
 
 528 
 
 558 
 
 584 
 
 613 
 
 641 
 
 663 
 
 20' 
 
 
 
 
 401 
 
 444 
 
 483 
 
 519 
 
 552 
 
 583 
 
 613 
 
 642 
 
 667 
 
 699 
 
 20 K 
 
 
 
 
 
 464 
 
 505 
 
 543 
 
 578 
 
 613 
 
 643 
 
 675 
 
 706 
 
 729 
 
 21 
 
 
 
 
 
 485 
 
 528 
 
 568 
 
 604 
 
 640 
 
 673 
 
 705 
 
 733 
 
 766 
 
 21K 
 
 
 
 
 
 505 
 
 551 
 
 594 
 
 632 
 
 669 
 
 703 
 
 739 
 
 766 
 
 797 
 
 22' 
 
 
 
 
 
 526 
 
 574 
 
 618 
 
 658 
 
 697 
 
 734 
 
 769 
 
 800 
 
 835 
 
 22 K 
 
 
 
 
 
 
 597 
 
 643 
 
 687 
 
 726 
 
 765 
 
 800 
 
 835 
 
 867 
 
 23 
 
 
 
 
 
 
 620 
 
 668 
 
 713 
 
 754 
 
 796 
 
 830 
 
 869 
 
 906 
 
 23 K 
 
 
 
 
 
 
 642 
 
 695 
 
 740 
 
 784 
 
 827 
 
 866 
 
 904 
 
 945 
 
 24' 
 
 
 
 
 
 
 667 
 
 719 
 
 768 
 
 814 
 
 859 
 
 897 
 
 939 
 
 978 
 
 24 K 
 
 
 
 
 
 
 689 
 
 745 
 
 797 
 
 843 
 
 892 
 
 934 
 
 975 
 
 1018 
 
 25 
 
 
 
 
 
 
 714 
 
 771 
 
 825 
 
 875 
 
 922 
 
 966 
 
 1010 
 
 1051 
 
 25 K 
 
 
 
 
 
 
 737 
 
 798 
 
 855 
 
 907 
 
 956 
 
 1003 
 
 1047 
 
 1092 
 
 26' 
 
 
 
 
 
 
 761 
 
 824 
 
 882 
 
 936 
 
 987 
 
 1035 
 
 1083 
 
 1126 
 
 26K 
 
 
 
 
 
 
 
 850 
 
 909 
 
 968 
 
 1024 
 
 1073 
 
 1120 
 
 1167 
 
 27 
 
 
 
 
 
 
 
 877 
 
 939 
 
 998 
 
 1053 
 
 1106 
 
 1157 
 
 1202 
 
 27 K 
 
 
 
 
 
 
 
 904 
 
 968 
 
 1030 
 
 1089 
 
 1145 
 
 1195 
 
 1243 
 
 28' 
 
 
 
 
 
 
 
 . .930 
 
 997 
 
 1060 
 
 1120 
 
 1177 
 
 1232 
 
 1279 
 
 28 K 
 
 
 
 
 
 
 
 
 1028 
 
 1092 
 
 1157 
 
 1211 
 
 1270 
 
 1321 
 
 29 
 
 
 
 
 
 
 
 
 1056 
 
 1123 
 
 1187 
 
 1248 
 
 1305 
 
 1360 
 
 29 K 
 
 
 
 
 
 
 
 
 1084 
 
 1155 
 
 1221 
 
 1284 
 
 1347 
 
 1400 
 
 30 
 
 
 
 
 
 
 
 
 1115 
 
 1187 
 
 1255 
 
 1321 
 
 1382 
 
 1442 
 
 30K 
 
 
 
 
 
 
 
 
 1218 
 
 1290 
 
 1358 
 
 1424 
 
 1480 
 
 31 
 
 
 
 
 
 
 
 
 
 1252 
 
 1324 
 
 1394 
 
 1459 
 
 1523 
 
 31K 
 
 
 
 
 
 
 
 
 
 1286 
 
 1359 
 
 1433 
 
 1496 
 
 1561 
 
 32 
 
 
 
 
 
 
 
 
 
 1317 
 
 1394 
 
 1467 
 
 1538 
 
 1605 
 
 32K 
 
 
 
 
 
 
 
 
 
 1430 
 
 1508 
 
 1575 
 
 1650 
 
 33 
 
 
 
 
 
 
 
 
 
 
 1465 
 
 1542 
 
 1617 
 
 1687 
 
 33 K 
 
 
 
 
 
 
 
 
 
 
 1500 
 
 1578 
 
 1655 
 
 1733 
 
 34 
 
 
 
 
 
 
 
 
 
 
 1536 
 
 1617 
 
 1695 
 
 1770 
 
 34 K 
 
 
 
 
 
 
 
 
 
 
 1654 
 
 1735 
 
 1816 
 
 35 
 
 
 
 
 
 
 
 
 
 
 
 1692 
 
 1775 
 
 1856 
 
 35H 
 
 
 
 
 
 
 
 
 
 
 
 1810 
 
 1900 
 
 36 
 
 
 
 
 
 
 
 
 
 
 
 
 1857 
 
 1941 
 
 36K 
 
 
 
 
 
 
 
 
 
 
 
 
 1984 
 
 37 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2026 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The H ar tf or d Ste am Boiler Inspection and Insurance Co. 23 
 
 PROPORTIONS OF DIAGONAL CROWFOOT STAYS 
 
 Diagonal crowfoot stays should be made of solid, weldless mild steel. Each 
 branch of a crowfoot should be designed to carry two-thirds of the total 
 load for which the stay is designed, the fulfilment of-this requirement being 
 proved by tests, if necessary. To develop the full strength of a stay, the com¬ 
 bined cross-sectional area of the two rivets at each end should be at least one and 
 one-quarter (lf4) times the cross-sectional area of the body of the stay. The 
 net cross-sectional area through the center of each rivet hole in the blade of the 
 stay should also be at least equal to one and one-quarter (1}4) times the cross- 
 sectional area of the body of the stay, and the net area through the center of 
 each rivet hole in the crowfoot should be at least one-half (}4) of the net area 
 through a rivet hole in the blade. The following table has been calculated to 
 meet the above requirements. 
 
 Diameter 
 
 Cross-sectional area 
 
 Minimum Diam. 
 
 Minimum cross-sectional 
 
 Minimum cross-sectional 
 
 of stay 
 
 of body of stay 
 
 of rivet holes 
 
 area at A-A 
 
 area at B-B 
 
 1 H* 
 
 0.9940 sq. in. 
 
 15 Ae" 
 
 1.2425 sq. in. 
 
 1.3844 “ “ 
 
 0.6213 sq. in.. 
 
 1%" 
 
 1.1075 “ “ 
 
 1" 
 
 0.6922 “ “ 
 
 IJ4" 
 
 1.2272 “ “ 
 
 1" 
 
 1.5340 “ “ 
 
 0.7670 “ “ 
 
 SPACING OF CROWFOOT STAYS 
 
 The number of crowfoot stays needed in any case is determined by spacing 
 requirements as well as by the size of the area to be supported. In general the 
 spacing should conform to the following requirements: 
 
 ( 1 ) The maximum spacing between the centers of rivets attaching the 
 
 crowfeet of braces to the stayed surface should be determined by 
 the value of p in the formula: j 135T 2 
 
 p = V-p~ 
 
 ( 2 ) The distance between the edges of tube holes and the centers of rivets 
 
 attaching the crowfeet of braces to the stayed surface should not 
 exceed the value of p in the above formula. 
 
 (3) The maximum spacing between the inner surface of the shell and lines 
 
 parallel to the surface of the shell passing through the centers of 
 rivets attaching the crowfeet of braces to the head should be deter¬ 
 mined by the value of p in the formula: / 175^2 
 
 p=v— 
 
 In the above formulae, P = maximum allowable working pressure, lbs. per 
 
 sq. in. 
 
 T = the number of sixteenths of an inch in the thick¬ 
 ness of the stayed surface. (T = 8 for yl" 
 plate, 9 for plate, etc.) 
 
24 The H artf or d Steam Boiler Inspection and Insurance Co . 
 
 STRESSES IN DIAGONAL CROWFOOT STAYS AND AREAS 
 
 SUPPORTED THEREBY 
 
 Because of the angularity of diagonal crowfoot stays with reference to the 
 direction in which the load acts, greater cross-sectional areas are required than 
 would be the case with direct stays. If a is the required area of a direct stay for 
 any given conditions and A is the corresponding area for a diagonal stay, then 
 
 A: a = L: l or A = —-—- 
 
 L and l being measured as indicated in the sketch above. 
 
 In horizontal tubular boilers L is usually not more than 1.15 times l and in 
 such cases diagonal stays may be calculated as direct stays, allowing ninety per 
 cent (90%) of the stress which would be permitted for such stays. For weldless 
 mild steel direct stays not more than 120 diameters in length a stress of 9500 
 pounds per square inch is permissible so that the allowable stress for such diag¬ 
 onal stays would be 8550 pounds per square inch; this is usually taken as 8500 
 pounds for easy figuring. In any unusual case the relation of L to / should be 
 checked and the required area should be figured from the formula given if L is 
 greater than 1.15 times /. The following table has been calculated to show the 
 maximum areas supported by the usual sizes of diagonal stays under various 
 pressures. It is based on a stress of 8500 pounds per square inch which is equiva¬ 
 lent to 8449 pounds for 1 y& inch stays, 9414 pounds for l^fg inch stays and 10431 
 pounds for 1 Ti inch stays. 
 
 Maximum Areas in Square Inches Supported by Weldless Mild Steel 
 
 Diagonal Crowfoot Stays 
 
 Pressure 
 
 Lbs. per sq. in. 
 
 Diameter of Stay 
 
 Pressure 
 
 Lbs. per sq. in. 
 
 Diameter of Stay 
 
 1X" 
 
 1*4" 
 
 IX" 
 
 IX" 
 
 1 %" 
 
 IX" 
 
 100 
 
 84 
 
 94 
 
 104 
 
 180 
 
 46 
 
 52 
 
 58 
 
 105 
 
 80 
 
 89 
 
 99 
 
 185 
 
 45 
 
 50 
 
 56 
 
 110 
 
 76 
 
 85 
 
 94 
 
 190 
 
 44 
 
 49 
 
 54 
 
 115 
 
 73 
 
 81 
 
 90 
 
 195 
 
 43 
 
 48 
 
 53 
 
 120 
 
 70 
 
 78 
 
 87 
 
 200 
 
 42 
 
 47 
 
 52 
 
 125 
 
 67 
 
 75 
 
 83 
 
 210 
 
 40 
 
 44 
 
 49 
 
 130 
 
 65 
 
 72 
 
 80 
 
 220 
 
 38 
 
 42 
 
 47 
 
 135 
 
 62 
 
 69 
 
 77 
 
 230 
 
 36 
 
 40 
 
 45 
 
 140 
 
 60 
 
 67 
 
 74 
 
 240 
 
 35 
 
 39 
 
 43 
 
 145 
 
 58 
 
 64 
 
 72 
 
 250 
 
 33 
 
 37 
 
 41 
 
 150 
 
 56 
 
 62 
 
 69 
 
 260 
 
 32 
 
 36 
 
 40 
 
 155 
 
 54 
 
 60 
 
 67 
 
 270 
 
 31 
 
 34 
 
 38 
 
 160 
 
 52 
 
 58 
 
 65 
 
 280 
 
 30 
 
 33 
 
 37 
 
 165 
 
 51 
 
 57 
 
 63 
 
 290 
 
 29 
 
 32 
 
 36 
 
 170 
 
 49 
 
 55 
 
 61 
 
 300 
 
 28 
 
 31 
 
 34 
 
 175 
 
 48 
 
 53 
 
 59 
 
 310 
 
 27 
 
 30 
 
 33 
 
The H a rtf or d Ste am Boiler Inspection and Insurance Co. 25 
 
 PROPORTIONS OF THROUGH STAYS 
 
 Through stays should be upset on the threaded end so that the net cross- 
 sectional area at the root of the thread will be at least equal to the cross-sectional 
 area of the body of the stay. The diameter of the outside washer should be at 
 least 2yl times the diameter of the stay; in certain cases a greater diameter will 
 be necessary to meet spacing requirements. The eye on the opposite end of the 
 stay should be made by upsetting and drilling a hole for the pin rather than by 
 welding. To develop the full strength of a stay, the cross-sectional area of the 
 pin should be at least three-fourths (3^) of the area through the body of the stay 
 and the cross-sectional area through the center of the eye should be at least 
 twenty-five per cent (25%) greater than the area through the body of the brace. 
 The pin should be turned to make a neat fit in the hole. The combined cross- 
 sectional area of the rivets attaching each stay to the head should be at least 
 twenty-five per cent (25%) greater than the area through the body of the stay. 
 The following table shows the proportions of weldless steel through stays neces¬ 
 sary to meet the above requirements. 
 
 D 
 
 Diameter 
 of stay 
 
 Cross-sectional 
 area of body. 
 
 (sq. in.) 
 
 U 
 
 Diameter 
 of Upset* 
 
 Minimum 
 diameter 
 of Washer 
 
 Diameter 
 of Pin 
 
 Minimum 
 cross-sectional 
 area at A-A 
 (sq. in.) 
 
 Minimum 
 combined area 
 of rivets 
 (sq. in.) 
 
 1" 
 
 0.7854 
 
 IK" 
 
 2K" 
 
 K" 
 
 0.9S2 
 
 0.982 
 
 1 X" 
 
 0.9940 
 
 IK" 
 
 2K" 
 
 1" 
 
 1.243 
 
 1.243 
 
 IK" 
 
 1.2272 
 
 IK" 
 
 3K" 
 
 IK" 
 
 1.534 
 
 1.534 
 
 l K" 
 
 1.4849 
 
 IK" 
 
 3K" 
 
 IK" 
 
 1.856 
 
 1.856 
 
 IK" 
 
 1.7672 
 
 IK" 
 
 3K" 
 
 IK" 
 
 2.209 
 
 2.209 
 
 IK" 
 
 2.0739 
 
 2 " 
 
 4K" 
 
 IK" 
 
 2.592 
 
 2.592 
 
 IK" 
 
 2.4053 
 
 2K" 
 
 4K" 
 
 IK" 
 
 3.007 
 
 3.007 
 
 IK" 
 
 2.7612 
 
 2K" 
 
 . 4K" 
 
 l— 4 
 
 \Ol 
 
 oo\ 
 
 3.452 
 
 3.452 
 
 2 " 
 
 3.1416 
 
 2K" 
 
 5" 
 
 IK" 
 
 3.927 
 
 3.927 
 
 2K" 
 
 3.5466 
 
 2K" 
 
 5 K" 
 
 IK" 
 
 4.433 
 
 4.433 
 
 2K" 
 
 3.9761 
 
 2K" 
 
 5K" 
 
 v- 2" 
 
 4.970 
 
 4.970 
 
 2K" 
 
 4.4301 
 
 23K" 
 
 6" 
 
 2K" 
 
 5.538 
 
 5.538 
 
 2K" 
 
 4.9087 
 
 3" 
 
 6K" 
 
 2K" 
 
 6.136 
 
 6.136 
 
 *Based on Sellers Standard Threads. 
 
26 The H a rtf or d Steam Boiler Inspection and Insurance Co. 
 
 STRESSES IN THROUGH STAYS AND AREAS SUPPORTED THEREBY 
 
 For unwelded steel through-stays the allowable stresses should be figured 
 in accordance with the following: 
 
 
 Lengths not exceeding 120 diameters 
 
 Lengths exceeding 120 diameters 
 
 Diameters not exceeding IX" 
 
 9500 lbs. per sq. in. 
 
 8500 lbs. per sq. in. 
 
 Diameters exceeding 1 X" 
 
 10400 lbs. per sq. in. 
 
 9000 lbs. per sq. in. 
 
 On the above basis the following table has been prepared to show the maxi¬ 
 mum areas in square inches which can be supported by through stays of different 
 diameters and lengths under varying pressures, it being assumed that the stays 
 will be proportioned in accordance with the requirements stated on Page 25. 
 
 Maximum Areas in Square Inches Supported by Weldless Steel Through 
 
 Stays 
 
 Pres¬ 
 sure 
 (Lbs. 
 per sq. 
 
 IX" 
 
 Diam. 
 
 IX" 
 
 Diam. 
 
 IX" 
 
 Diam. 
 
 IX" 
 
 Diam. 
 
 IX" Diam. 
 
 ir-3" 
 
 Over 
 
 12'-6" 
 
 Over 
 
 13'-9" 
 
 Over 
 
 15'-0" 
 
 Over 
 
 16'-3" 
 
 Over 
 
 in.) 
 
 or less 
 
 ll'-3" 
 
 or less 
 
 12'-6" 
 
 or less 
 
 13'-9" 
 
 or less 
 
 15'-0" 
 
 or less 
 
 16'-3" 
 
 100 
 
 94 
 
 84 
 
 116 
 
 104 
 
 141 
 
 126 
 
 167 
 
 150 
 
 215 
 
 186 
 
 105 
 
 89 
 
 SO 
 
 111 
 
 99 
 
 134 
 
 120 
 
 159 
 
 143 
 
 205 
 
 177 
 
 110 
 
 85 
 
 76 
 
 105 
 
 94 
 
 128 
 
 114 
 
 152 
 
 136 
 
 196 
 
 169 
 
 115 
 
 82 
 
 73 
 
 101 
 
 90 
 
 122 
 
 109 
 
 145 
 
 130 
 
 187 
 
 162 
 
 120 
 
 78 
 
 70 
 
 97 
 
 86 
 
 117 
 
 105 
 
 139 
 
 125 
 
 179 
 
 155 
 
 125 
 
 75 
 
 67 
 
 93 
 
 83 
 
 112 
 
 100 
 
 134 
 
 120 
 
 172 
 
 149 
 
 130 
 
 72 
 
 64 
 
 89 
 
 80 
 
 108 
 
 97 
 
 129 
 
 115 
 
 165 
 
 143 
 
 135 
 
 69 
 
 62 
 
 86 
 
 77 
 
 104 
 
 93 
 
 124 
 
 111 
 
 159 
 
 138 
 
 140 
 
 67 
 
 60 
 
 83 
 
 74 
 
 100 
 
 90 
 
 119 
 
 107 
 
 154 
 
 133 
 
 145 
 
 65 
 
 58 
 
 80 
 
 71 
 
 97 
 
 87 
 
 115 
 
 103 
 
 148 
 
 128 
 
 150 
 
 62 
 
 56 
 
 77 
 
 69 
 
 94 
 
 84 
 
 111 
 
 100 
 
 143 
 
 124 
 
 155 
 
 60 
 
 54 
 
 75 
 
 67 
 
 91 
 
 81 
 
 108 
 
 96 
 
 139 
 
 120 
 
 160 
 
 59 
 
 52 
 
 72 
 
 65 
 
 88 
 
 78 
 
 104 
 
 93 
 
 134 
 
 116 
 
 165 
 
 57 
 
 51 
 
 70 
 
 63 
 
 85 
 
 76 
 
 101 
 
 91 
 
 130 
 
 113 
 
 170 
 
 55 
 
 49 
 
 68 
 
 61 
 
 82 
 
 74 
 
 98 
 
 88 
 
 126 
 
 109 
 
 175 
 
 53 
 
 48 
 
 66 
 
 59 
 
 80 
 
 72 
 
 95 
 
 85 
 
 123 
 
 106 
 
 180 
 
 52 
 
 46 
 
 64 
 
 57 
 
 78 
 
 70 
 
 93 
 
 83 
 
 119 
 
 103 
 
 185 
 
 51 
 
 45 
 
 63 
 
 56 
 
 76 
 
 68 
 
 90 
 
 81 
 
 116 
 
 100 
 
 190 
 
 49 
 
 44 
 
 61 
 
 54 
 
 74 
 
 66 
 
 88 
 
 79 
 
 113 
 
 98 
 
 195 
 
 48 
 
 43 
 
 59 
 
 53 
 
 72 
 
 64 
 
 86 
 
 77 
 
 110 
 
 95 
 
 200 
 
 47 
 
 42 
 
 58 
 
 52 
 
 70 
 
 63 
 
 83 
 
 75 
 
 107 
 
 93 
 
 210 
 
 44 
 
 40 
 
 55 
 
 49 
 
 67 
 
 60 
 
 79 
 
 71 
 
 102 
 
 88 
 
 220 
 
 42 
 
 38 
 
 53 
 
 47 
 
 64 
 
 57 
 
 76 
 
 68 
 
 98 
 
 84 
 
 230 
 
 41 
 
 36 
 
 50 
 
 45 
 
 61 
 
 54 
 
 72 
 
 65 
 
 93 
 
 81 
 
 240 
 
 39 
 
 35 
 
 48 
 
 43 
 
 58 
 
 52 
 
 69 
 
 62 
 
 89 
 
 77 
 
 250 
 
 37 
 
 33 
 
 46 
 
 41 
 
 56 
 
 50 
 
 67 
 
 60 
 
 86 
 
 74 
 
 260 
 
 36 
 
 32 
 
 44 
 
 40 
 
 54 
 
 48 
 
 64 
 
 57 
 
 82 
 
 71 
 
 270 
 
 34 
 
 31 
 
 43 
 
 38 
 
 52 
 
 46 
 
 62 
 
 55 
 
 79 
 
 69 
 
 280 
 
 33 
 
 30 
 
 41 
 
 37 
 
 50 
 
 45 
 
 59 
 
 53 
 
 77 
 
 66 
 
 290 
 
 32 
 
 29 
 
 40 
 
 35 
 
 48 
 
 43 
 
 57 
 
 51 
 
 74 
 
 64 
 
 300 
 
 31 
 
 28 
 
 38 
 
 34 
 
 47 
 
 42 
 
 55 
 
 50 
 
 71 
 
 62 
 
27 
 
 The Hartford Steam Boiler Inspection and Insurance Co 
 
 Maximum Areas in Square Inches Supported by Weldless Steel Through 
 
 Stays (Concluded) 
 
 Pressure 
 (Lbs. per 
 sq. in.) 
 
 124" Diam. 
 
 V/&" Diam. 
 
 2" Diam. 
 
 2 yi" Diam. 
 
 2 24" Diam. 
 
 17'-6" 
 
 Over 
 
 18'-9" 
 
 Over 
 
 20'-0" 
 
 Over 
 
 21'-3" 
 
 Over 
 
 22'-6" 
 
 Over 
 
 or less 
 
 17'-6" 
 
 or less 
 
 18'-9" 
 
 or less 
 
 20'-0" 
 
 or less 
 
 21'-3" 
 
 or less 
 
 22'-6" 
 
 100 
 
 250 
 
 216 
 
 287 
 
 248 
 
 326 
 
 282 
 
 368 
 
 319 
 
 413 
 
 357 
 
 105 
 
 238 
 
 206 
 
 273 
 
 236 
 
 311 
 
 269 
 
 350 
 
 303 
 
 393 
 
 340 
 
 110 
 
 227 
 
 196 
 
 261 
 
 225 
 
 297 
 
 257 
 
 335 
 
 290 
 
 376 
 
 325 
 
 115 
 
 217 
 
 188 
 
 249 
 
 216 
 
 284 
 
 245 
 
 320 
 
 277 
 
 359 
 
 311 
 
 120 
 
 208 
 
 180 
 
 239 
 
 207 
 
 272 
 
 235 
 
 307 
 
 265 
 
 344 
 
 298 
 
 125 
 
 200 
 
 173 
 
 229 
 
 198 
 
 261 
 
 226 
 
 294 
 
 255 
 
 330 
 
 286 
 
 130 
 
 192 
 
 166 
 
 220 
 
 191 
 
 251 
 
 217 
 
 283 
 
 245 
 
 318 
 
 275 
 
 135 
 
 185 
 
 160 
 
 212 
 
 184 
 
 242 
 
 209 
 
 273 
 
 236 
 
 306 
 
 264 
 
 140 
 
 178 
 
 154 
 
 205 
 
 177 
 
 233 
 
 201 
 
 263 
 
 227 
 
 295 
 
 255 
 
 145 
 
 172 
 
 149 
 
 198 
 
 171 
 
 225 
 
 194 
 
 254 
 
 220 
 
 285 
 
 246 
 
 150 
 
 166 
 
 144 
 
 191 
 
 165 
 
 217 
 
 188 
 
 245 
 
 212 
 
 275 
 
 238 
 
 155 
 
 161 
 
 139 
 
 185 
 
 160 
 
 210 
 
 182 
 
 237 
 
 205 
 
 266 
 
 230 
 
 160 
 
 156 
 
 135 
 
 179 
 
 155 
 
 204 
 
 176 
 
 230 
 
 199 
 
 258 
 
 223 
 
 165 
 
 151 
 
 131 
 
 174 
 
 150 
 
 198 
 
 171 
 
 223 
 
 193 
 
 250 
 
 216 
 
 170 
 
 147 
 
 127 
 
 16S 
 
 146 
 
 192 
 
 166 
 
 216 
 
 187 
 
 243 
 
 210 
 
 175 
 
 142 
 
 123 
 
 164 
 
 142 
 
 186 
 
 161 
 
 210 
 
 182 
 
 236 
 
 204 
 
 180 
 
 138 
 
 120 
 
 159 
 
 138 
 
 181 
 
 157 
 
 204 
 
 177 
 
 229 
 
 198 
 
 185 
 
 135 
 
 116 
 
 155 
 
 134 
 
 176 
 
 152 
 
 199 
 
 172 
 
 223 
 
 193 
 
 190 
 
 131 
 
 113 
 
 151 
 
 130 
 
 171 
 
 148 
 
 194 
 
 167 
 
 217 
 
 188 
 
 195 
 
 128 
 
 110 
 
 147 
 
 127 
 
 167 
 
 144 
 
 189 
 
 163 
 
 212 
 
 183 
 
 200 
 
 125 
 
 108 
 
 143 
 
 124 
 
 163 
 
 141 
 
 184 
 
 159 
 
 206 
 
 178 
 
 210 
 
 119 
 
 103 
 
 136 
 
 118 
 
 155 
 
 134 
 
 175 
 
 151 
 
 196 
 
 170 
 
 220 
 
 113 
 
 98 
 
 130 
 
 112 
 
 148 
 
 128 
 
 167 
 
 145 
 
 187 
 
 162 
 
 230 
 
 108 
 
 94 
 
 124 
 
 108 
 
 142 
 
 122 
 
 160 
 
 138 
 
 179 
 
 155 
 
 240 
 
 104 
 
 90 
 
 119 
 
 103 
 
 136 
 
 117 
 
 153 
 
 132 
 
 172 
 
 149 
 
 250 
 
 100 
 
 86 
 
 114 
 
 99 
 
 130 
 
 113 
 
 147 
 
 127 
 
 1 165 
 
 143 
 
 260 
 
 96 
 
 83 
 
 110 
 
 95 
 
 125 
 
 108 
 
 141 
 
 122 
 
 159 
 
 137 
 
 270 
 
 92 
 
 80 
 
 106 
 
 92 
 
 121 
 
 104 
 
 136 
 
 118 
 
 153 
 
 132 
 
 280 
 
 89 
 
 77 
 
 102 
 
 88 
 
 116 
 
 100 
 
 131 
 
 113 
 
 147 
 
 127 
 
 290 
 
 86 
 
 74 
 
 99 
 
 85 
 
 112 
 
 97 
 
 127 
 
 110 
 
 142 
 
 123 
 
 300 
 
 83 
 
 72 
 
 95 
 
 82 
 
 108 
 
 94 
 
 122 
 
 106 
 
 137 
 
 119 
 
28 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 MAXIMUM PITCH IN INCHES FOR SCREWED STAYBOLTS WITH 
 
 ENDS RIVETED OVER 
 
 (For Flat Surfaces) 
 
 Thickness of Plate (Inches) 
 
 Pressure 
 
 Lbs. per 
 sq.inch 
 
 Pi 
 
 
 We 
 
 XX A 
 
 Pi 
 
 u /6 
 
 Vi 
 
 X V4 
 
 Pi 
 
 'Vi 
 
 Vi 
 
 '% 
 
 pi 
 
 2 V4 
 
 X V4 
 
 23 4 
 
 25 
 
 8 We 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 30 
 
 7 Pi 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 35 
 
 7 pi 
 
 8 V4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 40 
 
 6' We 
 
 7 pi 
 
 8 We 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 45 
 
 6 We 
 
 7 Vi 
 
 7 Pi 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 50 
 
 6 
 
 6 y 
 
 7 Pi 
 
 8 Pi 
 
 
 
 
 
 
 
 
 
 
 
 
 
 55 
 
 5'We 
 
 6 14 
 
 7 Pi 
 
 7!P4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 60 
 
 5 We 
 
 6 ^ 
 
 6 13 /4 
 
 7 Pi 
 
 8 Vi 
 
 
 
 
 
 
 
 
 
 
 
 
 65 
 
 5 pi 
 
 5 y 
 
 6 Vi 
 
 7 P4 
 
 7 pi 
 
 
 
 
 
 
 
 
 
 
 
 
 70 
 
 5 14 
 
 5'We 
 
 6 We 
 
 6'Pi 
 
 7 Pi 
 
 8 3 /4 
 
 
 
 
 
 
 
 
 
 
 
 75 
 
 4 
 
 5 pi 
 
 6 We 
 
 6 1 /4 
 
 7 5 /4 
 
 7'We 
 
 
 
 
 
 
 
 
 
 
 
 80 
 
 4 y 
 
 5 We 
 
 5 pi 
 
 6 Pi 
 
 7 Pi 
 
 7'We 
 
 8 Pi 
 
 
 
 
 
 
 
 
 
 
 85 
 
 4 pi 
 
 5 Pi 
 
 5 y 
 
 6 '14 
 
 6 Pi 
 
 7 We 
 
 8 
 
 
 
 
 
 
 
 
 
 
 90 
 
 4 We 
 
 5 
 
 5 ®4 
 
 6 Pi 
 
 6 n /4 
 
 7 Pi 
 
 7'We 
 
 
 
 
 
 
 
 
 
 
 95 
 
 4 We 
 
 4 pi 
 
 5 We 
 
 6 
 
 6 Pi 
 
 7 Vi 
 
 7 pi 
 
 8 We 
 
 
 
 
 
 
 
 
 
 100 
 
 4 X 
 
 4 pi 
 
 5 We 
 
 5 13 4 
 
 6 pi 
 
 6 pi 
 
 7 Vi 
 
 8 *4 
 
 
 
 
 
 
 
 
 
 105 
 
 4 pi 
 
 4 pi 
 
 5 We 
 
 5!14 
 
 6 3 /4 
 
 5'We 
 
 7 Pi 
 
 8 
 
 
 
 
 
 
 
 
 
 110 
 
 4 
 
 4 % 
 
 5 We 
 
 5 We 
 
 6 We 
 
 « Vi 
 
 7 V4 
 
 7'We 
 
 8 Pi 
 
 
 
 
 
 
 
 
 115 
 
 3 15 /4 
 
 4 We 
 
 4'We 
 
 5 We 
 
 5'We 
 
 6 Vi 
 
 6 pi 
 
 7 Pi 
 
 8 We 
 
 
 
 
 
 
 
 
 120 
 
 3 pi 
 
 4 Pi 
 
 4'We 
 
 5 We 
 
 5'We 
 
 6 Pi 
 
 6 Pi 
 
 7 K 
 
 8 
 
 8 Pi 
 
 
 
 
 
 
 
 125 
 
 3 Pi 
 
 4 X 
 
 4 Pi 
 
 5 We 
 
 5'We 
 
 6 Pi 
 
 6 pi 
 
 7 Pi 
 
 7 'We 
 
 8 We 
 
 
 
 
 
 
 
 130 
 
 3'V4 
 
 4 We 
 
 4 pi 
 
 5 Pi 
 
 5 We 
 
 6 
 
 6 Pi 
 
 7 3 /4 
 
 7'We 
 
 8 We 
 
 
 
 
 
 
 
 135 
 
 3 pi 
 
 4 Pi 
 
 4 Pf 6 
 
 5 
 
 5 Pi 
 
 5'We 
 
 6 pi 
 
 7 We 
 
 7 We 
 
 8 
 
 8 Pi 
 
 
 
 
 
 
 140 
 
 3 We 
 
 4 
 
 4 pi 
 
 4'We 
 
 5 Pi 
 
 5'We 
 
 6 We 
 
 5'We 
 
 7 Pi 
 
 7 pi 
 
 8 We 
 
 
 
 
 
 
 145 
 
 3 pi 
 
 3 l5 y fi 
 
 4 Pi 
 
 4 13 ^6 
 
 5 y 
 
 5'We 
 
 6 Pi 
 
 5'We 
 
 7 Pi 
 
 7 Pi 
 
 8 We 
 
 
 
 
 
 
 150 
 
 
 3 Pi 
 
 4 P4 
 
 4 P< 
 
 5 We 
 
 5 Pi 
 
 6 Vi 
 
 6 u /4 
 
 7 li 
 
 7 Pi 
 
 8 Vi 
 
 8 Pi 
 
 
 
 
 
 160 
 
 
 3 Pi 
 
 4 P4 
 
 4 Pi 
 
 5 
 
 5 We 
 
 5 Pi 
 
 6 Pi 
 
 5'We 
 
 7 Pi 
 
 7»Vi 
 
 8 Pi 
 
 
 
 
 
 170 
 
 
 3 Pi 
 
 4 14 
 
 4 14 
 
 4 Pi 
 
 5 Pi 
 
 ^Vi 
 
 6 We 
 
 6 Pi 
 
 7 Pi 
 
 7 We 
 
 8 
 
 8 Pi 
 
 
 
 
 175 
 
 
 3 Pi 
 
 4 
 
 4 pi 
 
 4 13 /4 
 
 5 We 
 
 5 pi 
 
 6 V4 
 
 6 pi 
 
 7 Vfe 
 
 7 We 
 
 7 pi 
 
 8 5 i 
 
 
 
 
 180 
 
 
 3 We 
 
 S'We 
 
 4 Vi 
 
 4 Pi 
 
 5 Pi 
 
 5 Pi 
 
 6 Pi 
 
 6 Pi 
 
 5'We 
 
 7 Pi 
 
 7 Pi 
 
 8 We 
 
 
 
 
 190 
 
 
 
 3 13 /ffi 
 
 4 We 
 
 4 pi 
 
 5 
 
 5 pi 
 
 3'We 
 
 6 Pi 
 
 6 Pi 
 
 7 Pi 
 
 7 9 4 
 
 7'We 
 
 8 We 
 
 
 
 200 
 
 
 
 3 Pi 
 
 4 Pi 
 
 4 pi 
 
 4 Pi 
 
 5 Pi 
 
 5'We 
 
 6 We 
 
 6 9 /4 
 
 6'Vi 
 
 7 Pi 
 
 7 Pi 
 
 8 Pi 
 
 
 
 210 
 
 
 
 3 Pi 
 
 4 
 
 4 Pi 
 
 4 Pi 
 
 5 Pi 
 
 5'We 
 
 6 We 
 
 6 We 
 
 6'Vi 
 
 7 Pi 
 
 7 We 
 
 7 15 /4 
 
 8 5 /4 
 
 
 220 
 
 
 
 3 P4 
 
 3 15 /4 
 
 4 Vi 
 
 4 Pi 
 
 5 
 
 5 We 
 
 5 pi 
 
 6 Pi 
 
 6 pi 
 
 7 
 
 7 Pi 
 
 7 Pi 
 
 8 Pi 
 
 8 Pi 
 
 230 
 
 
 
 3 Pi 
 
 3 13 y« 
 
 4 Vi 
 
 4 9 /4 
 
 4 pi 
 
 5 We 
 
 5 Pi 
 
 6 Pi 
 
 6 Pi 
 
 6 Pi 
 
 7 Vi 
 
 7 ?i 
 
 7'We 
 
 8 We 
 
 240 
 
 
 
 
 3 Pi 
 
 4 Pi 
 
 4 Vi 
 
 4 Pi 
 
 5 We 
 
 5 Pi 
 
 6 
 
 6 pi 
 
 6'Pi 
 
 7 Vi 
 
 7 Vi 
 
 7 y 
 
 8 Pi 
 
 250 
 
 
 
 
 3 u /4 
 
 4 
 
 4 Pi 
 
 4'V4 
 
 5 We 
 
 5 Vi 
 
 5 pi 
 
 6 Pi 
 
 6 9 /i 
 
 6'Vi 
 
 7 Pi 
 
 7 Pi 
 
 7'Vi 
 
 The above table for pitch of staybolts on flat surfaces is based on the formula: 
 
 ,-v? 
 
 where p = maximum pitch between centers of staybolts, inches. 
 
 P = maximum allowable working pressure, lbs. per sq. in. 
 
 T = the number of sixteenths of an inch in the plate thickness. 
 
 C = 112 for plates not over thick. 
 
 C = 120 for plates more than 1 /(§ thick. 
 
 For cylindrical furnaces which require staying, the pitch may be increased 
 somewhat over that allowed for flat surfaces, the formula for such cases being 
 
 P = 
 
 C T 2 R 
 P R —250 T 
 
 where R = the internal radius of the furnace in inches and the other letters 
 have the same significance as above. 
 
The Hartford Steam Boiler Inspection and Insurance Co. 
 
 29 
 
 ALLOWABLE LOADS ON SOLID STAYBOLTS WITH 12 V-THREADS 
 
 PER INCH OF LENGTH 
 
 The following table is based on a stress of 7500 pounds per square inch of 
 net cross-sectional area and is intended for use with staybolts less than twenty 
 (20) diameters long, screwed through plates, with ends riveted over. For use in 
 boilers having a grate area in excess of fifteen (15) square feet, it is recommended 
 that the outside ends of solid staybolts which have a length of eight inches (8") 
 or less shall be drilled with a hole % inch in diameter to a depth of at least 
 inch beyond the inside of the plate. The area of this hole must be deducted in 
 figuring the net cross-sectional area of the staybolt and the table shows the allow¬ 
 able loads under this condition as well as the allowable loads for solid staybolts 
 which are not drilled. In each case the area is figured from the diameter at the 
 bottom of the thread. 
 
 Diameter of Staybolt 
 (Inches) 
 
 Diameter at 
 Bottom of 
 Thread 
 (Inches) 
 
 AREA AT BOTTOM OF THREAD 
 (square INCHES) 
 
 ALLOWABLE LOAD (LBS.) 
 
 Not 
 
 Drilled 
 
 We" Hole 
 Deducted 
 
 Not 
 
 Drilled 
 
 Drilled 
 (We" Hole) 
 
 X 
 
 0.7500 
 
 0.6057 
 
 0.2881 
 
 0.2605 
 
 2160 
 
 1953 
 
 x We 
 
 0.8125 
 
 0.6682 
 
 0.3507 
 
 0.3231 
 
 2630 
 
 2423 
 
 H 
 
 0.8750 
 
 0.7307 
 
 0.4193 
 
 0.3917 
 
 3144 
 
 2937 
 
 l We 
 
 0.9375 
 
 0.7932 
 
 0.4941 
 
 0.4665 
 
 3705 
 
 3498 
 
 1 
 
 1.0000 
 
 0.8557 
 
 0.5751 
 
 0.5475 
 
 4313 
 
 4106 
 
 1 We 
 
 1.0625 
 
 0.9182 
 
 0.6622 
 
 0.6346 
 
 4966 
 
 4759 
 
 l H 
 
 1.1250 
 
 0.9807 
 
 0.7554 
 
 0.7278 
 
 5665 
 
 5458 
 
 1 We 
 
 1.1875 
 
 1.0432 
 
 0.8547 
 
 0.8271 
 
 6410 
 
 6203 
 
 1 K 
 
 1.2500 
 
 1.1057 
 
 0.9602 
 
 0.9326 
 
 7201 
 
 6994 
 
 1 We 
 
 1.3125 
 
 1.1682 
 
 1.0718 
 
 1.0442 
 
 8038 
 
 • 7831 
 
 l H 
 
 1.3750 
 
 1.2307 
 
 1.1897 
 
 1.1621 
 
 8922 
 
 8715 
 
 1 We 
 
 1.4375 
 
 1.2932 
 
 1.3135 
 
 1.2859 
 
 9851 
 
 9644 
 
 1 K 
 
 1.5000 
 
 1.3557 
 
 1.4435 
 
 1.4159 
 
 10826 
 
 10619 
 
 To figure the allowable pressure on a flat surface supported by staybolts 
 the gross area supported by each stay should be determined from the full pitch 
 dimensions and the net area can then be obtained by deducting the area occu¬ 
 pied by the staybolt itself. The allowable working pressure in pounds per square 
 inch is the quotient of the allowable load as given in the table divided by the 
 net area supported. For example: With 1-inch staybolts pitched 5 inches on 
 centers in each direction the gross area supported by each staybolt is 25 square 
 inches and the net area is 25 minus 0.5751=24.4249 square inches. If each 
 staybolt is drilled with a ^fg-inch hole the allowable load as given in the table 
 is 4106 pounds and the allowable pressure will be 4106 divided by 24.4249 or 
 168 pounds per square inch. Of course the spacing and plate thickness must 
 conform to the requirements as given on the opposite page for the stated pressure. 
 
30 i The H artf or d Ste am Boiler Inspection and Insurance Co 
 
 TABLES SHOWING THE LEAST ANGLE WHICH A STAYBOLT MAY 
 MAKE WITH A PLATE TO SECURE A GIVEN NUMBER OF 
 
 FULL THREADS 
 
 (Based on V-threads, 12 to the inch) 
 
 Table 1. 4 Full Threads 
 
 
 DIAMETER OF STAYBOLT 
 
 
 
 
 
 
 
 
 
 
 of Plate 
 
 X" 
 
 X" 
 
 X" 
 
 X" 
 
 1 " 
 
 IX" 
 
 IX" 
 
 IX' 
 
 X" 
 
 
 
 
 
 
 
 
 
 5,4" 
 
 
 
 
 
 
 
 
 
 H" 
 
 
 
 90° * 
 
 
 
 
 
 
 W 
 
 90° 
 
 89° 
 
 88.5° 
 
 89.5° 
 
 89° 
 
 0 
 
 00 
 
 90° 
 
 90° 
 
 X" 
 
 83° 
 
 84° 
 
 83° 
 
 84° 
 
 84° 
 
 85° 
 
 85° 
 
 87° 
 
 9 4" 
 
 76° 
 
 78° 
 
 78° 
 
 81° 
 
 84° 
 
 83° 
 
 83° 
 
 85° 
 
 X" 
 
 54° 
 
 68 ° 
 
 71° 
 
 75° 
 
 770 
 
 79° 
 
 80° 
 
 82° 
 
 X" 
 
 
 48° 
 
 56° 
 
 64° 
 
 68 ° 
 
 71° 
 
 73° 
 
 770 
 
 X" 
 
 
 
 O 
 
 cc 
 
 <N 
 
 51° 
 
 60° 
 
 64° 
 
 67° 
 
 72° 
 
 1 " 
 
 
 
 
 30° 
 
 48° 
 
 61° 
 
 60° 
 
 64° 
 
 Table II. 3 Full Threads 
 
 
 DIAMETER OF STAYBOLT 
 
 
 
 
 
 
 
 
 
 
 of Plate 
 
 X" 
 
 X" 
 
 X" 
 
 X" 
 
 1" 
 
 IX" 
 
 IX" 
 
 IX' 
 
 X" 
 
 
 
 
 
 
 
 
 
 54 " 
 
 
 90° * 
 
 90° 
 
 
 
 90° 
 
 90° * 
 
 
 X" 
 
 87° 
 
 85° 
 
 85° 
 
 88° 
 
 88° 
 
 86° 
 
 89° 
 
 90° 
 
 W 
 
 80° 
 
 80° 
 
 82° 
 
 84° 
 
 85° 
 
 83° 
 
 85° 
 
 88° 
 
 X" 
 
 70° 
 
 72° 
 
 75° 
 
 79° 
 
 80° 
 
 80° 
 
 83° 
 
 85° 
 
 %• 
 
 62° 
 
 66° 
 
 71° 
 
 75° 
 
 78° 
 
 78° 
 
 80° 
 
 82° 
 
 X" 
 
 
 55° 
 
 63° 
 
 69° 
 
 71° 
 
 71° 
 
 77° 
 
 78° 
 
 X" 
 
 
 
 46° 
 
 59° 
 
 64° 
 
 65° 
 
 70° 
 
 73° 
 
 X" 
 
 
 
 
 43° 
 
 55° 
 
 5S° 
 
 65° 
 
 68° 
 
 r 
 
 
 
 
 
 42° 
 
 48° 
 
 57° 
 
 61° 
 
 Table III. 2 Full Threads 
 
 
 DIAMETER OF STAYBOLT 
 
 
 
 
 
 
 
 
 
 
 of Plate 
 
 X" 
 
 X" 
 
 X" 
 
 X" 
 
 1 " 
 
 IX" 
 
 IX" 
 
 IX" 
 
 X" 
 
 
 
 90° * 
 
 90° 
 
 90° * 
 
 90° 
 
 90° 
 
 
 %" 
 
 85° 
 
 85° 
 
 86° 
 
 86° 
 
 87° 
 
 85° 
 
 87° 
 
 88 ° 
 
 X" 
 
 78° 
 
 78° 
 
 81° 
 
 81° 
 
 84° 
 
 82° 
 
 84° 
 
 87° 
 
 w 
 
 69° 
 
 73° 
 
 76° 
 
 78° 
 
 80° 
 
 79° 
 
 82° 
 
 83° 
 
 X" 
 
 57° 
 
 65° 
 
 69° 
 
 72° 
 
 74° 
 
 75° 
 
 78° 
 
 81° 
 
 *4" 
 
 48° 
 
 60° 
 
 64° 
 
 68° 
 
 72° 
 
 73° 
 
 75° 
 
 77° 
 
 X" 
 
 
 44° 
 
 55° 
 
 60° 
 
 66° 
 
 67° 
 
 73° 
 
 76° 
 
 X" 
 
 
 
 36° 
 
 50° 
 
 57° 
 
 61° 
 
 67° 
 
 69° 
 
 X" 
 
 
 
 
 35° 
 
 48° 
 
 53° 
 
 60° 
 
 64° 
 
 r 
 
 
 
 
 
 35° 
 
 44° 
 
 52° 
 
 57° 
 
 An asterisk (*) signifies that the specified number of threads will be scant. 
 
The Hartford Steam Boiler Inspection and Insurance Co. 31 
 
 SPHERICAL HEADS, “PLUS” AND “MINUS” 
 
 (A “Hartford” Idea in Nomenclature) 
 
 Much confusion has resulted in the use of the terms “bumped/’ “dished,” 
 “concave” and “convex” as applied to spherical heads of cylindrical vessels 
 such as boilers, tanks, drums, etc. The terms “bumped” and “dished” are used 
 interchangeably by many people and the terms “concave” and “convex” are 
 not sufficiently definite unless some explanatory phrase is added to indicate 
 whether the observer is supposed to be on the outside looking in, or on the inside 
 looking out. In the case of a head which curves outwardly from the shell and 
 which is concave to the pressure, the volume enclosed by the head is added to 
 the volume of the shell, thus making a larger vessel than would be the case if a 
 flat head were used; such heads are called “plus" heads in our Engineering 
 Department. Similarly, if a head is convex to the pressure, curving inwardly 
 from the shell, its volume will be subtracted from that which the vessel would 
 have with a flat head and it would be called a “minus" head. 
 
 The tables on Pages 32, 33, 34 and 35 show the allowable working pressure 
 on spherical heads of various thicknesses and diameters. The table for Plus 
 heads without manholes is based on the formula: 
 
 5.5XPXL. (2XT. S.) (t- pi) 
 
 t= 2XT.S7 + * ° r P= -5^XL - 
 
 Where t = the thickness of the head in inches. 
 
 P = the maximum allowable working pressure in pounds per sq. in. 
 
 T.S. = the tensile strength of the steel in pounds per sq. in. = 55000. 
 
 L = the radius to which the head is bumped, in inches. 
 
 Substituting the value of the tensile strength, the formula reduces to: 
 
 20000t - 2500 
 L 
 
 For Plus heads containing manholes the formula is: 
 
 (2 XT. S.) (t - yf) _ 20000 t - 5000 
 5.5 XL ~ L 
 
 For Minus heads the maximum pressure is figured at sixty per cent (60%) 
 of that allowed on Plus heads of the same dimensions. 
 
 In using the tables a radius equal to at least eighty per cent (80%) of the shell 
 diameter should be employed in any case where the actual radius to which the head 
 is bumped or dished is less than this amount. 
 
ALLOWABLE WORKING PRESSURES ON SPHERICAL HEADS 
 Plus Heads (Concave to Pressure) Without Manhole 
 
 32 The H a rtf or d Steam Boiler Inspection and Insurance Co 
 
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ALLOWABLE WORKING PRESSURES ON SPHERICAL HEADS 
 Plus Heads (Concave to Pressure) With Manhole 
 
 The H a r tf o r d Steam Boiler Inspection and Insurance Co 
 
 33 
 
 
 108 
 
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36 The II a rtf or d Steam Boiler Inspection and Insurance Co 
 
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38 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 / 
 
 % 
 
 TUBES FOR FIRE-TUBE BOILERS 
 Standard Dimensions 
 
 Outside 
 
 Diameter 
 
 (Inches) 
 
 Standard 
 
 Thickness 
 
 (Inches) 
 
 Birming¬ 
 ham Wire 
 Gage. 
 (Number)- 
 
 Inside 
 
 Diam. 
 
 (Inches) 
 
 Inside 
 
 Circum¬ 
 
 ference 
 
 (Inches) 
 
 Outside 
 
 Circum¬ 
 
 ference 
 
 (Inches) 
 
 Length 
 of Tube 
 per Sq. 
 Ft. of 
 Inside 
 Surface 
 (Feet) 
 
 Length 
 of Tube 
 per Sq. 
 Ft. of 
 Outside 
 Surface 
 (Feet) 
 
 Cross 
 Sectional 
 Area 
 Inside 
 (Sq. In.) 
 
 Cross 
 Sectional 
 Area 
 Outside 
 (Sq. In.) 
 
 Nominal 
 Weight 
 per Foot. 
 (Pounds) 
 
 1 
 
 0.072 
 
 15 
 
 0.85 
 
 2.68 
 
 3.14 
 
 4.46 
 
 3.81 
 
 0.57 
 
 0.78 
 
 0.70 
 
 IK 
 
 0.072 
 
 15 
 
 1.10 
 
 3.47 
 
 3.92 
 
 3.45 
 
 3.05 
 
 0.96 
 
 1.22 
 
 0.90 
 
 IK 
 
 0.083 
 
 14 
 
 1.33 
 
 4.19 
 
 4.71 
 
 2.86 
 
 2.54 
 
 1.39 
 
 1.76 
 
 1.24 
 
 2 
 
 0.095 
 
 13 
 
 1.80 
 
 5.66 
 
 6.28 
 
 2.11 
 
 1.90 
 
 2.55 
 
 3.14 
 
 1.91 
 
 2K 
 
 0.109 
 
 12 
 
 2.28 
 
 7.17 
 
 7.85 
 
 1.67 
 
 1.52 
 
 4.09 
 
 4.90 
 
 2.75 
 
 3 
 
 0.109 
 
 12 
 
 2.78 
 
 8.74 
 
 9.42 
 
 1.37 
 
 1.27 
 
 6.08 
 
 7.06 
 
 3.33 
 
 3K 
 
 0.120 
 
 11 
 
 3.26 
 
 10.24 
 
 10.99 
 
 1.17 
 
 1.09 
 
 8.35 
 
 9.62 
 
 4.28 
 
 4 
 
 0.134 
 
 10 
 
 3.74 
 
 11.75 
 
 12.56 
 
 1.02 
 
 0.95 
 
 10.99 
 
 12.56 
 
 5.47 
 
 4 K 
 
 0.134 
 
 10 
 
 4.24 
 
 13.32 
 
 14.13 
 
 0.90 
 
 0.84 
 
 14.12 
 
 15.90 
 
 6.17 
 
 5 
 
 0.148 
 
 9 
 
 4.72 
 
 14.81 
 
 15.70 
 
 0.80 
 
 0.76 
 
 17.49 
 
 19.63 
 
 7.58 
 
 6 
 
 0.165 
 
 8 
 
 5.69 
 
 17.90 
 
 18.84 
 
 0.67 
 
 0.63 
 
 25.50 
 
 28.27 
 
 10.16 
 
 Tubes of the standard thicknesses given in the above table are suitable for 
 pressures up to 175 pounds per square inch. For higher pressures the thickness 
 of tubes should be increased in accordance with the following: For each increase 
 of one gage in thickness above the standard gage shown in the table, the allow¬ 
 able working pressure in pounds per square inch may be increased by an amount 
 equal to the quotient of 200 divided by the diameter of the tube in inches. 
 
The H a rtf or d Steam Boiler I nspection and Insurance Co. 
 
 39 
 
 TUBES FOR WATER TUBE BOILERS AND SUPERHEATERS 
 
 In water tube boilers and superheaters the maximum allowable working 
 pressures for tubes should be determined from the formula: 
 
 P = 
 
 18000-250 
 
 where P = maximum allowable working pressure in pounds per sq.'in. 
 t = thickness of tube wall in inches. 
 
 D = outside diameter of tube in inches. 
 
 The following table, based on the above formula, shows the maximum 
 allowable working pressures for tubes of various diameters and thicknesses. 
 
 Gage Number on Birmingham Wire Gage 
 
 Outside 
 
 diameter of 
 tube, in 
 inches 
 
 D 
 
 17 
 
 16 
 
 15 
 
 14 
 
 13 
 
 12 
 
 11 
 
 10 
 
 9 
 
 8 
 
 7 
 
 6 
 
 5 
 
 t = 
 0.058 
 
 t = 
 0.065 
 
 t = 
 0.072 
 
 t = 
 0.083 
 
 t = 
 0.095 
 
 t = 
 0.109 
 
 t = 
 0.120 
 
 t = 
 0.134 
 
 t = 
 0.148 
 
 t = 
 0.165 
 
 t = 
 0.180 
 
 t = 
 0.203 
 
 t = 
 0.220 
 
 K 
 
 434 
 
 686 
 
 938 
 
 1334 
 
 
 
 
 
 
 
 
 
 
 X 
 
 206 
 
 374 
 
 542 
 
 806 
 
 i094 
 
 .... 
 
 
 .... 
 
 .... 
 
 .... 
 
 .... 
 
 .... 
 
 
 l 
 
 
 218 
 
 344 
 
 542 
 
 758 
 
 1010 
 
 
 
 
 
 
 
 
 IK 
 
 
 166 
 
 278 
 
 454 
 
 646 
 
 870 
 
 1046 
 
 .... 
 
 .... 
 
 .... 
 
 • • • • 
 
 .... 
 
 
 IK 
 
 
 124 
 
 225 
 
 383 
 
 557 
 
 758 
 
 916 
 
 1118 
 
 
 .... 
 
 • • • • 
 
 .... 
 
 
 IK 
 
 
 
 146 
 
 278 
 
 422 
 
 590 
 
 722 
 
 890 
 
 i058 
 
 .... 
 
 .... 
 
 .... 
 
 
 IK 
 
 
 
 
 203 
 
 326 
 
 470 
 
 583 
 
 727 
 
 871 
 
 1046 
 
 .... 
 
 .... 
 
 .... 
 
 2 
 
 
 
 
 146 
 
 254 
 
 380 
 
 479 
 
 605 
 
 731 
 
 884 
 
 1019 
 
 
 
 2K 
 
 
 
 
 
 198 
 
 310 
 
 398 
 
 510 
 
 622 
 
 758 
 
 878 
 
 i062 
 
 
 2X 
 
 
 
 
 
 153 
 
 254 
 
 333 
 
 434 
 
 535 
 
 657 
 
 765 
 
 931 
 
 1053 
 
 2K 
 
 
 
 
 
 117 
 
 208 
 
 280 
 
 372 
 
 464 
 
 575 
 
 673 
 
 824 
 
 935 
 
 3 
 
 
 
 
 
 
 170 
 
 236 
 
 320 
 
 404 
 
 506 
 
 596 
 
 734 
 
 836 
 
 3K 
 
 
 
 
 
 
 
 199 
 
 276 
 
 354 
 
 448 
 
 531 
 
 658 
 
 752 
 
 3K 
 
 
 
 
 
 
 
 167 
 
 238 
 
 310 
 
 398 
 
 475 
 
 594 
 
 681 
 
 3K 
 
 
 
 
 
 .... 
 
 .... 
 
 139 
 
 206 
 
 273 
 
 355 
 
 427 
 
 537 
 
 619 
 
 4 
 
 
 
 
 
 
 
 
 178 
 
 240 
 
 317 
 
 385 
 
 488 
 
 565 
 
 4K 
 
 
 
 
 
 .... 
 
 .... 
 
 .... 
 
 .... 
 
 186 
 
 254 
 
 314 
 
 406 
 
 474 
 
 5 
 
 1 
 
 
 
 .... 
 
 .... 
 
 .... 
 
 
 
 142 
 
 204 
 
 ■ 258 
 
 340 
 
 402 
 
40 The H artf or d Steam Boiler Inspection and Insurance Co. 
 
 HORIZONTAL TUBULAR BOILER SETTINGS 
 
 Our setting plans for horizontal tubular boilers have recently been revised 
 and the new drawings show certain features in greater detail than was formerly 
 the case. For each of the common sizes of boilers we have four separate draw¬ 
 ings, this number being necessary in order to clearly illustrate the difference 
 between boilers with flush fronts and overhanging fronts and between boilers 
 supported on the side walls and boilers suspended from overhead. Upon appli¬ 
 cation to our Engineering Department blue-prints of any of these drawings will 
 be furnished for use in setting boilers which we insure. In asking for such blue¬ 
 prints it is necessary to state the diameter of the boiler, the length of tubes, the 
 style of front (flush or overhanging) and the method of support. 
 
 Our setting plans illustrate four different types of wall construction, as shown 
 below: 
 
 The design shown by Type I is probably used more extensively than any of 
 the others. While it costs but little more than Type II, it has a distinct ad¬ 
 vantage over that type as regards the prevention of air leakage into the furnace 
 because the cracks will occur principally in the inner wall, leaving the outer wall 
 intact. With a solid wall like that of Type II the cracks will extend clear through 
 the brickwork, thus increasing the probability of air leaks with a resulting excess 
 of air and a lower furnace efficiency. The air space has no virtue as a heat 
 insulator; a double wall of this type will transmit just as much heat under given 
 conditions as a solid wall of the same total thickness. 
 
 Type III makes use of insulating bricks to reduce the amount of heat that is 
 transmitted through the wall and thereby lost. These insulating bricks are 
 made of different materials by different manufacturers and they are cut to the 
 proper size so that they will lay up evenly with ordinary bricks. They have 
 little mechanical strength in themselves so that it is best to use metal ties, as 
 shown in the cut, for bonding the inner fire-brick section to the common brick on 
 the outside. It is also advisable to use a uniform thickness of nine inches for 
 the fire-brick lining in place of the 4^-inch lining with header courses as shown 
 
41 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 for the other types. This type of construction makes a very good setting, 
 costing somewhat more than either Type I or Type II. 
 
 Type IV may be considered as similar to Type I with a steel casing substi¬ 
 tuted for the outer wall and the air space filled with magnesia or other good 
 insulating material. This makes a most excellent form of setting, the only 
 drawback to its more general use being its greater cost as compared with other 
 types. The insulating material reduces the heat radiation loss to a minimum 
 and the steel casing prevents the even greater loss due to air leakage through 
 the setting walls. Furthermore, a setting of this kind presents a very neat ap¬ 
 pearance and requires less space than any of the other types illustrated. 
 
 The sections shown are intended to apply to the side walls at the rear of 
 the bridge wall. For the furnace section in front of the bridge wall, we advise 
 that the walls be battered from the grate level to the closing-in line near the 
 middle of the boiler shell. Our drawings show a batter of six inches in this 
 height, thus making the walls that much thicker at the bottom. 
 
 The illustration below is a typical longitudinal section through the center 
 of a setting. On the four following pages will be found data on overall dimen¬ 
 sions of settings, approximate numbers of bricks required for the various sizes 
 and types, sizes of grates and the heights for setting boilers with different kinds 
 of coal. These tables have been made up from our standard setting plans and 
 it should be understood that they are inter-dependent. They are intended for 
 use with hand-fired horizontal tubular boilers where the combustion rate does 
 not exceed twenty-five (25) pounds of coal per square foot of grate surface per 
 hour and the output is not more than twenty-five per cent (25%) above the 
 nominal rating. 
 
 -TWOVALVE5 of THE OUT6IDE-5CREW-ANO-VOKE 
 
 TYPE 5HOULO BE USED IF BOILER IS CONNECTED 
 TO A COnnON 5TEAM MAIN WITH ONE OR MORE 
 QTHER BOILER*.Valve NEAREST BOILER SHOULD 
 BE PRE FE RABLY OF TmE NON-RETURN TYPE. 
 
 Escape Pipe shoulo 
 
 BE OR AIMED BY A DRIP 
 E LL OR OTHER SUITABLE 
 MEANS WITH OPENING AT 
 LEAST »"1N DIAMETER.^ 
 
 ✓ StopValve SHOULD 
 BE PLACED AS NEAR 
 THE BOILER AS 
 PRACTICABLE . 
 
 H tN Sipe Vv* 
 
 Set REAR EMOOiFSpiLER 
 I INCH LOWER th^n front 
 END. 
 
 Union 
 
 2'oh 2j“ Biiow Off Pipe. 
 Extra]he|avy Pipe and 
 Fittings. 
 
 Cover this 
 trench with 
 STEEL PLATE 
 OR LOOSC 
 BRIC K .N 
 
 Steam Pipe should 
 drain away from valve- 
 
 Downward Pitch _ 
 
 Drain required if two valves are 
 USED. DRAIN PIPE Should have open 
 END VISIBLE WHILE OPERATING MAIN 
 VALVES- -—--’"** 
 
 -IF ESCAPE PIPE IS USED IT SHOULD 
 
 HAVE A DIAMETER AT LEAST EQUAL 
 TO THAT OF THE SAFETY VALVE TO 
 WHICH IT IS ATTACHED AND IF |T IS 
 OVER SIX FEE T LONG IT SHOULO BE 
 SUPPORTS O INOE PENOENTLY OF THE 
 SAFETY VALVE WITH SUCH ARRANGE¬ 
 MENT THAT NO STRAIN WILL COME 
 ON THE VALVE BOOY. 
 
 i — Damper with provision for 
 
 (HAND OPERATION FROM FLOOR. 
 
 ^Connection 
 
 - , ■ : ■ FOR DRAFT GAGE. 
 
 Center of fusible 
 plug 2"above line 
 of upper surface 
 
 OF TUBES-—' " 
 
 BlowOffPipe 
 
 ShOULO HAVE TWO 
 VALVES, OR VALVE 
 ANO COCK IF PRES¬ 
 SURE EXCEEDS 
 123 LBS.flOO LBS. I N 
 
 Massachusetts). 
 Clearance oft l 
 
 ALL AROUND PIPE 1 
 INSIDE OF SLEEVE. L 
 
 Space filled in 
 with ASBESTOS / 
 TO PREVENT AIR/" 
 LEAKAGE. - / T 
 
 —Sampling tube 
 
 FOR FLUE-GAS 
 ANALYSIS. 
 
 .--Gate Valve 
 
 OROINARILY LEFT 
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 — Check Valve. 
 
 y Globe Valve 
 
 VlTH BOILER 
 PRESSURE ON 
 TOP OF DISK. 
 
 s Asbestos Rope. 
 
 Floor Level. 
 
 Typical Longitudinal Section Through Center of Horizontal 
 
 Tubular Boiler Setting. 
 
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 See Pages 40 and 41 for description of different types. 
 
APPROXIMATE NUMBERS OF BRICKS REQUIRED FOR SETTING HORIZONTAL TUBULAR BOILERS 
 
 IN ACCORDANCE WITH STANDARD SETTING PLANS 
 
 Overhanging Fronts 
 
 The Hartford Steam Boiler Inspection and Insurance Co 
 
 43 
 
 
 Type IV. 
 
 Fire 
 
 Brick 
 
 4,900 
 
 5,300 
 
 5,500 
 
 5,900 
 
 6,300 
 
 6,700 
 
 6.900 
 
 7,400 
 
 7.900 
 
 7,600 
 
 8,200 
 
 8,700 
 
 9,200 
 
 9,800 
 
 
 Com. 
 
 Brick 
 
 16,000 
 
 17,400 
 
 18,500 
 
 19,900 
 
 20,100 
 
 21,600 
 
 22,200 
 
 23,800 
 
 25,500 
 
 24,400 
 
 26,200 
 
 28,000 
 
 28,600 
 
 30,300 
 
 CO 
 
 Pi 
 
 W 
 
 4 
 
 HH 
 
 O 
 
 PC 
 
 Type III. 
 
 Fire 
 
 Brick 
 
 5,700 
 
 6,250 
 
 6,850 
 
 7,400 
 
 7,750 
 
 8,300 
 
 8,650 
 
 9,300 
 
 9,950 
 
 9,500 
 
 10,200 
 
 10,850 
 
 11,500 
 
 12,150 
 
 Com. 
 
 Brick 
 
 17,000 
 
 18,400 
 
 19,600 
 
 21,100 
 
 21,200 
 
 22,800 
 
 23,100 
 
 24,800 
 
 26,400 
 
 25,400 
 
 27,300 
 
 29,100 
 
 29,900 
 
 31,700 
 
 O 
 
 £ 
 
 H 
 
 t-H 
 
 I-H 
 
 a 
 
 
 Fire 
 
 Brick 
 
 4,900 
 
 5,300 
 
 5,500 
 
 5,900 
 
 6,300 
 
 6,700 
 
 6.900 
 7,400 
 
 7.900 
 
 7,600 
 
 8,200 
 
 8,700 
 
 9,200 
 
 9,800 
 
 
 cl 
 
 >< 
 
 H 
 
 
 Com 
 
 Brick 
 
 22,100 
 
 24,000 
 
 25.800 
 
 27.800 
 
 27,800 
 
 29,900 
 
 30,600 
 
 32,800 
 
 35,000 
 
 33,700 
 
 36,100 
 
 38,500 
 
 39,300 
 
 41,800 
 
 
 HH 
 
 W 
 
 
 Fire 
 
 Brick 
 
 4,900 
 
 5,300 
 
 5,500 
 
 5,900 
 
 6,300 
 
 6,700 
 
 6.900 
 7,400 
 
 7.900 
 
 7,600 
 
 8,200 
 
 8,700 
 
 9,200 
 
 9,800 
 
 
 cu 
 
 > 
 
 H 
 
 
 Com. 
 
 Brick 
 
 23.100 
 
 25.100 
 
 27,000 
 
 29,000 
 
 29,000 
 
 31,200 
 
 31,700 
 
 34,000 
 
 36,200 
 
 35,000 
 
 37,500 
 
 40,000 
 
 40,800 
 
 43,300 
 
 
 
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 2,650 
 
 2,750 
 
 2,950 
 
 3,150 
 
 3,350 
 
 3,450 
 
 3,700 
 
 3,950 
 
 3,800 
 
 4,100 
 
 4,350 
 
 4,600 
 
 4,900 
 
 
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 10,500 
 
 11,100 
 
 12,000 
 
 12,000 
 
 13,000 
 
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 14.200 
 15,300 
 
 14,600 
 
 15,700 
 
 16,900 
 
 17,100 
 
 18,300 
 
 
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 Brick 
 
 3,350 
 
 3,650 
 
 3,900 
 
 4,250 
 
 4,350 
 
 4,700 
 
 4,900 
 
 5,300 
 
 5,700 
 
 5,350 
 
 5,800 
 
 6,200 
 
 6,450 
 
 6,850 
 
 4 
 
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 11.500 
 
 12,100 
 
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 13.100 
 
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 17,900 
 
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 3,950 
 
 3,800 
 
 4,100 
 
 4,350 
 
 4,600 
 
 4,900 
 
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 16,300 
 
 17,400 
 
 18,800 
 
 18,700 
 
 20,300 
 
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 22,000 
 
 23,700 
 
 22,500 
 
 24,300 
 
 26,100 
 
 26,400 
 
 28,300 
 
 
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 19,700 
 
 21,300 
 
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 23,000 
 
 24,600 
 
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 27,200 
 
 27,600 
 
 29,500 
 
 
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44 
 
 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 DIMENSIONS OF GRATES FOR HORIZONTAL TUBULAR BOILERS 
 
 (As Shown on Standard Setting Plans) 
 
 Diameter of Boiler 
 
 Length of Tubes 
 
 Size of Grates 
 
 Width 
 
 Length 
 
 Area (sq. ft.) 
 
 54" 
 
 14' 
 
 4'—0" 
 
 4'—0" 
 
 16 
 
 54" 
 
 16' 
 
 4'—0" 
 
 4'-0" 
 
 16 
 
 60" 
 
 16' 
 
 4'-6" 
 
 4'—6" 
 
 20 K 
 
 60" 
 
 18' 
 
 4'—6" 
 
 5'-0" 
 
 22 & 
 
 66 " 
 
 16' 
 
 5'-0" 
 
 5'-0" 
 
 25 
 
 66 " 
 
 18' 
 
 5'-0" 
 
 5'-6" 
 
 27 K 
 
 72" 
 
 16' 
 
 5'-6" 
 
 5'—6" 
 
 30 X 
 
 72" 
 
 18' 
 
 5'-6" 
 
 6 '-0" 
 
 33 
 
 72" 
 
 20 ' 
 
 .5'—6" 
 
 6 '—6" 
 
 35K 
 
 78" 
 
 16' 
 
 6 '-0" 
 
 6 '-0" 
 
 36 
 
 78" 
 
 18' 
 
 6 '-0" 
 
 6 '—6" 
 
 39 
 
 78" 
 
 20 ' 
 
 6 '-0" 
 
 7'-0" 
 
 42 
 
 84" 
 
 18' 
 
 6 '—6" 
 
 7'-0" 
 
 45 K 
 
 84" 
 
 20 ' 
 
 6 '-6" 
 
 7'-0" 
 
 45K 
 
 (For hand-fired boilers with combustion rate not exceeding 25 pounds of coal 
 
 per square foot of grate surface per hour) 
 
 Dimensions of Uptakes or Smoke-Openings for Horizontal 
 
 Tubular Boilers 
 
 Diameter of Boiler 
 
 Uptake or Smoke Opening 
 
 Width 
 
 Length 
 
 Area (sq. in.) 
 
 54" 
 
 10" 
 
 3'-4" 
 
 400 
 
 60" 
 
 10" 
 
 4'—6" 
 
 540 
 
 66 " 
 
 12" 
 
 4'—6" 
 
 648 
 
 72" 
 
 14" 
 
 5'-0" 
 
 S40 
 
 78" 
 
 14 K" 
 
 5'-6" 
 
 957 
 
 84" 
 
 17" 
 
 6'-0" 
 
 1224 
 
RECOMMENDED HEIGHTS FROM GRATES TO SHELL AND FROM BRIDGE-WALL TO SHELL FOR HORI¬ 
 ZONTAL TUBULAR BOILER SETTINGS WITH DIFFERENT KINDS OF COAL 
 
 The Hartford Steam Boiler Inspection and Insurance Co 
 
 45 
 
 S-i 
 
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 For bituminous coals containing more than 35% volatile matter. (Illinois) 
 
 For bituminous coals containing from 18% to 35% volatile. (Pittsburgh) 
 
 For anthracite coal and semi-bituminous coal, containing less than 18% volatile. (Pocahontas, George’s Creek, etc.) 
 
46 The Hartford Ste am Boiler Inspection and Insurance Co 
 
 TABLE OF HEATING SURFACE AND HORSEPOWER FOR STANDARD 
 SIZES OF HORIZONTAL TUBULAR BOILERS WITH 
 
 MANHOLES BELOW TUBES 
 
 Diameter 
 
 of 
 
 Boiler 
 
 TUBES 
 
 • 
 
 HEATTNG SURFACE (Sq. Ft.) 
 
 Horse- 
 
 Power 
 
 Length 
 
 Diameter 
 
 Number 
 
 Tubes 
 
 Shell 
 
 Rear Head 
 
 Total 
 
 54" 
 
 14' 
 
 3" 
 
 52 
 
 531 
 
 99 
 
 8 
 
 638 
 
 64 
 
 54" 
 
 16' 
 
 3" 
 
 52 
 
 607 
 
 113 
 
 8 
 
 728 
 
 73 
 
 54" 
 
 14' 
 
 3 K" 
 
 44 
 
 526 
 
 99 
 
 8 
 
 633 
 
 63 
 
 54" 
 
 16' 
 
 3K" 
 
 44 
 
 602 
 
 113 
 
 8 
 
 723 
 
 72 
 
 54" 
 
 14' 
 
 4" 
 
 36 
 
 494 
 
 99 
 
 7 
 
 601 
 
 60 
 
 54" 
 
 16' 
 
 4" 
 
 36 
 
 565 
 
 113 
 
 7 
 
 686 
 
 69 
 
 60" 
 
 16' 
 
 3" 
 
 74 
 
 864 
 
 125 
 
 9 
 
 998 
 
 100 
 
 60" 
 
 18' 
 
 3" 
 
 74 
 
 972 
 
 141 
 
 9 
 
 1122 
 
 112 
 
 60" 
 
 16' 
 
 3K" 
 
 52 
 
 711 
 
 125 
 
 10 
 
 846 
 
 85 
 
 60" 
 
 18' 
 
 3K" 
 
 52 
 
 800 
 
 141 
 
 10 
 
 951 
 
 95 
 
 60" 
 
 16' 
 
 4" 
 
 46 
 
 722 
 
 125 
 
 9 
 
 856 
 
 86 
 
 60" 
 
 18' 
 
 4" 
 
 46 
 
 812 
 
 141 
 
 9 
 
 962 
 
 96 
 
 66 " 
 
 16' 
 
 3" 
 
 94 
 
 1098 
 
 138 
 
 11 
 
 1247 
 
 125 
 
 66 " 
 
 18' 
 
 3" 
 
 94 
 
 1235 
 
 156 
 
 11 
 
 1402 
 
 140 
 
 66 " 
 
 16' 
 
 3 K" 
 
 74 
 
 1012 
 
 138 
 
 11 
 
 1161 
 
 116 
 
 66 " 
 
 18' 
 
 3 K" 
 
 74 
 
 1138 
 
 156 
 
 11 
 
 1305 
 
 131 
 
 66 " 
 
 16' 
 
 4" 
 
 56 
 
 878 
 
 138 
 
 11 
 
 1027 
 
 103 
 
 66 " 
 
 18' 
 
 4" 
 
 56 
 
 988 
 
 156 
 
 11 
 
 1155 
 
 115 
 
 72" 
 
 16' 
 
 3" 
 
 122 
 
 1425 
 
 151 
 
 13 
 
 1589 
 
 159 
 
 72" 
 
 18' 
 
 3" 
 
 122 
 
 1603 
 
 170 
 
 13 
 
 1786 
 
 179 
 
 72" 
 
 20' 
 
 3" 
 
 122 
 
 1781 
 
 188 
 
 13 
 
 1982 
 
 198 
 
 72" 
 
 16' 
 
 3 K" 
 
 98 
 
 1340 
 
 151 
 
 12 
 
 1503 
 
 150 
 
 72" 
 
 18' 
 
 3K" 
 
 98 
 
 1508 
 
 170 
 
 12 
 
 1690 
 
 169 
 
 72" 
 
 20' 
 
 3K" 
 
 98 
 
 1675 
 
 188 
 
 12 
 
 1875 
 
 188 
 
 72" 
 
 16' 
 
 4" 
 
 74 
 
 1161 
 
 151 
 
 12 
 
 1324 
 
 132 
 
 72" 
 
 18' 
 
 4" 
 
 74 
 
 1306 
 
 170 
 
 12 
 
 1488 
 
 149 
 
 72" 
 
 20' 
 
 4" 
 
 74 
 
 1451 
 
 188 
 
 12 
 
 1651 
 
 165 
 
 78" 
 
 16' 
 
 3" 
 
 146 
 
 1705 
 
 163 
 
 15 
 
 1883 
 
 188 
 
 78" 
 
 18' 
 
 3" 
 
 146 
 
 1918 
 
 184 
 
 15 
 
 2117 
 
 212 
 
 78" 
 
 20' 
 
 3" 
 
 146 
 
 2131 
 
 204 
 
 15 
 
 2350 
 
 235 
 
 78" 
 
 16' 
 
 3K" 
 
 112 
 
 1532 
 
 163 
 
 15 
 
 1710 
 
 171 
 
 78" 
 
 18' 
 
 3 K" 
 
 112 
 
 1723 
 
 184 
 
 15 
 
 1922 
 
 192 
 
 78" 
 
 20' 
 
 3K" 
 
 112 
 
 1915 
 
 204 
 
 15 
 
 2134 
 
 213 
 
 78" 
 
 16' 
 
 4" 
 
 91 
 
 1427 
 
 163 
 
 14 
 
 1604 
 
 160 
 
 78" 
 
 18' 
 
 4" 
 
 91 
 
 1606 
 
 184 
 
 14 
 
 1804 
 
 180 
 
 78" 
 
 20' 
 
 4" 
 
 91 
 
 1784 
 
 204 
 
 14 
 
 2002 
 
 200 
 
 84" 
 
 18' 
 
 3" 
 
 176 
 
 2312 
 
 198 
 
 17 
 
 2527 
 
 253 
 
 84" 
 
 20 ' 
 
 3" 
 
 176 
 
 2569 
 
 220 
 
 17 
 
 2806 
 
 281 
 
 84" 
 
 18' 
 
 3X" 
 
 138 
 
 2123 
 
 198 
 
 16 
 
 2337 
 
 234 
 
 84" 
 
 20' 
 
 3y 2 " 
 
 138 
 
 2359 
 
 220 
 
 16 
 
 2595 
 
 260 
 
 84" 
 
 18' 
 
 4" 
 
 108 
 
 1906 
 
 198 
 
 16 
 
 2120 
 
 212 
 
 84" 
 
 20' 
 
 4" 
 
 108 
 
 2118 
 
 220 
 
 16 
 
 2354 
 
 235 
 
 The above table is figured on the basis of ten (10) square feet of heating 
 surface per boiler horsepower; the heating surface as calculated includes all of 
 the inside tube area, one-half the area of the cylindrical portion of the shell, and 
 two-thirds of the area of the rear head minus the combined cross-sectional area 
 of the tubes. 
 
The Hartford Steam Boiler Inspection and Insurance Co 
 
 47 
 
 APPROXIMATE WEIGHTS OF HORIZONTAL TUBULAR BOILERS 
 
 The weights of bare boilers as given in the following table are taken from 
 data of the American Boiler Manufacturers’ Association, figures being given 
 for boilers designed to operate at pressures of 125 pounds and 150 pounds. 
 These weights do not include fronts, trimmings, grates or other castings. The 
 amount of water contained in a boiler of given diameter and length will vary 
 with the number of tubes and their diameter. The weights given in the last 
 column are figured for average cases, with the boiler entirely filled and allowing 
 62.5 pounds per cubic foot of water. These weights should be added to the 
 weights of the bare boilers in order to determine the total maximum weight of 
 a boiler as installed, due allowance being made also for the weight of trimmings 
 and other parts which are attached directly to the boiler and supported thereby. 
 
 • 
 
 Diameter of Boiler 
 
 Length of Tubes 
 
 Weight of Bare Boiler, Lbs. 
 
 Weight of Water 
 
 125 lbs. Pressure 
 
 150 lbs. Pressure 
 
 54" 
 
 14' 
 
 9100 
 
 9700 
 
 11700 
 
 54" 
 
 16' 
 
 10100 
 
 10800 
 
 13400 
 
 60" 
 
 16' 
 
 12400 
 
 13400 
 
 16300 
 
 60" 
 
 18' 
 
 13600 
 
 14800 
 
 18400 
 
 66 " 
 
 16' 
 
 14900 
 
 16300 
 
 19100 
 
 66 " 
 
 18' 
 
 16400 
 
 17800' 
 
 21500 
 
 72" 
 
 16' 
 
 18400 
 
 20000 
 
 22500 
 
 72" 
 
 18' 
 
 20000 
 
 21700 
 
 25300 
 
 72" 
 
 20 ' 
 
 21700 
 
 23300 
 
 28100 
 
 78" 
 
 18' 
 
 25000 
 
 26400 
 
 29600 
 
 78" 
 
 20 ' 
 
 27100 
 
 28600 
 
 32900 
 
 Approximate Weights in Pounds per Square Foot of Flat Steel Plates 
 
 Thickness (Inches) 
 
 Weight (Lbs.) 
 
 Thickness (Inches) 
 
 Weight (Lbs.) 
 
 l A 
 
 10.20 
 
 S A 
 
 25.50 
 
 9 4 
 
 11.48 
 
 
 26.78 
 
 % 
 
 12.75 
 
 
 28.05 
 
 
 14.03 
 
 
 29.33 
 
 H 
 
 15.30 
 
 H 
 
 30.60 
 
 I3 ^2 
 
 16.58 
 
 2 % 
 
 31.88 
 
 7 /f 6 
 
 17.85 
 
 ls /fe 
 
 33.15 
 
 
 19.13 
 
 2 % 
 
 34.43 
 
 K 
 
 20.40 
 
 7 A 
 
 35.70 
 
 17 /£> 
 
 21.68 
 
 2 9 32 
 
 36.98 
 
 % 
 
 22.95 
 
 15 ^6 
 
 38.25 
 
 19 & 
 
 24.23 
 
 *V6 
 
 1 
 
 39.53 
 
 40.80 
 
 The above table is based on a weight of 0.2833 pound per cubic inch for 
 steel plate; this corresponds with a specific gravity of 7.854. 
 
48 The H a rtf or d Steam Boiler Inspection and Insurance Co. 
 
 I-BEAMS FOR SUSPENDING HORIZONTAL TUBULAR BOILERS 
 
 The following table shows the sizes of I-beams which we recommend for the 
 suspension of horizontal tubular boilers of the more common sizes. It is based 
 on a maximum fiber stress of 12500 pounds per square inch, this conservative 
 figure being used because of the fact that such I-beams are often required to 
 carry loads in excess of those due to the boilers. In computing the table, the 
 limiting spans and the locations of the points of suspension were taken from our 
 standard setting plans. It should be understood that four I-beams are required 
 in each case, the beams being bolted together in pairs as shown in the sketch 
 below the table. 
 
 Diameter of 
 Boilers 
 
 Length of 
 Tubes 
 
 Depth of I-Beams and Weight per Foot 
 
 One Boiler 
 
 Two Boilers 
 
 Three Boilers 
 
 54" 
 
 16' 
 
 6"-12X lbs. 
 
 10"-30 lbs. 
 
 15"-42*lbs. 
 
 60" 
 
 16' 
 
 7"-15 
 
 12"-31K “ 
 
 18"-55 “ 
 
 60" 
 
 18' 
 
 7"-15 
 
 12"-35 
 
 18"-55 “ 
 
 66" 
 
 16' 
 
 7"-15 
 
 12"-40 
 
 18"-55 “ 
 
 66" 
 
 18' 
 
 8"-18 
 
 15"-42 
 
 lS"-60 “ 
 
 72" 
 
 16' 
 
 8"-18 
 
 15"-42 
 
 20"-65 “ 
 
 72" 
 
 18' 
 
 8"-18 
 
 15"—42 
 
 20"-65 “ 
 
 72" 
 
 20' 
 
 8"-18 
 
 18"-55 
 
 24"-80 “ 
 
 78" 
 
 16' 
 
 8"-18 
 
 18"-55 
 
 24"-80 “ 
 
 78" 
 
 18' 
 
 9"-21 
 
 18"-55 
 
 24"-80 “ 
 
 78" 
 
 20' 
 
 9"-21 
 
 18"-55 
 
 24"-80 “ 
 
 84" 
 
 18' 
 
 9"-21 
 
 18"-55 
 
 24"-80 “ 
 
 84" 
 
 20' 
 
 9"-21 
 
 20"-65 
 
 24"-90 “ 
 
The Hartford Ste am Boiler Inspection and Insurance Co . 
 
 49 
 
 COLUMNS FOR SUPPORTING HORIZONTAL TUBULAR BOILERS 
 
 On this page and page 50 will be found tables to show the proper sizes 
 of columns for suspended horizontal tubular boilers. Four types of columns are 
 included, viz:—square cast-iron columns, round cast-iron columns, structural 
 steel H-beams and built-up columns of the plate-and-angle type. No table is 
 given for I-beam columns because the I-beam shape is poorly adapted for use as 
 a column and is not recommended for this purpose. We also have designs for 
 reinforced concrete columns and beams for the usual sizes of horizontal tubular 
 boilers and can furnish copies of the same on application. 
 
 The tables for column sizes in structural steel handbooks cannot be applied 
 to the support of boilers, as a rule, because such tables are based on the assump¬ 
 tion that the loads are direct and equally distributed over the cross-section of 
 the column, or else balanced on opposite sides thereof, whereas in boiler installa¬ 
 tions the loads are usually applied entirely at one side, thus introducing bend¬ 
 ing stresses which must be taken into consideration. There is no simple solu¬ 
 tion of the problem but it is a matter of much importance and allowance has 
 therefore been made for this condition in the tables which follow. In these tables 
 it is assumed that the columns are not built into the brickwork or braced in any 
 other way against flexure. The maximum ratio of slenderness ( = the quotient 
 of the unsupported length of the column divided by its radius of gyration) is 
 taken at 120 for steel and 70 for cast iron. The maximum length as given in 
 the tables for each case should not be exceeded. 
 
 We realize that the designs are heavier than those used by some boiler¬ 
 makers but we do not believe that lighter columns should be used except in 
 cases where the loading is non-eccentric or where the columns are braced laterally 
 so as to reduce the effective unsupported length. 
 
 Sizes of Round Cast Iron Columns for Suspended Horizontal 
 
 Tubular Boilers 
 
 Diameter of 
 Boilers 
 (Inches) 
 
 Length of 
 Tubes 
 (Feet) 
 
 Maximum 
 Length of 
 Columns 
 
 Diameter and Thickness of Columns 
 
 One Boiler 
 
 Two Boilers 
 
 Three Boilers 
 
 54 
 
 16 
 
 10'-6" 
 
 7" x 
 
 A" 
 
 7" x y 
 
 7" x 1" 
 
 60 
 
 16 
 
 ll'-0" 
 
 7" x 
 
 A" 
 
 7" x y 
 
 7" x 1" 
 
 60 
 
 18 
 
 ll'-0" 
 
 7" x 
 
 A" 
 
 7" x y 
 
 7" x 1" 
 
 66 
 
 16 
 
 12'—0" 
 
 8" x 
 
 A" 
 
 8" x 1" 
 
 8" x lyy 
 
 66 
 
 18 
 
 12'-0" 
 
 8" x 
 
 A" 
 
 8" x 1" 
 
 8" x 1H" 
 
 72 
 
 16 
 
 13'-0" 
 
 9" x 
 
 y 
 
 9" x 1" 
 
 9" x i yy 
 
 72 
 
 IS 
 
 13'-0" 
 
 9" x 
 
 H" 
 
 9" x 1" 
 
 9" x 1 y 
 
 72 
 
 20 
 
 13'-0" 
 
 9" x 
 
 A" 
 
 9" x 1" 
 
 9" x lyy 
 
 78 
 
 16 
 
 13'-6" 
 
 9" x 
 
 V*" 
 
 9" x 1" 
 
 9" x i yy 
 
 78 
 
 18 
 
 13'-6" 
 
 9" x 
 
 H" 
 
 9" x 1" 
 
 9" x 1 H" 
 
 78 
 
 20 
 
 13'-6" 
 
 9" x 
 
 A" 
 
 9" x 1" 
 
 9" x 1 X" 
 
 84 
 
 18 
 
 14'-0 // 
 
 9" x 
 
 l 
 
 9" x 1 yy 
 
 9" x \yy 
 
 84 
 
 20 
 
 14'-0" 
 
 10" x 
 
 l" 
 
 10" x 1" 
 
 io" x i yy 
 
 Sizes of Square Cast Iron Columns for Suspended Horizontal 
 
 Tubular Boilers 
 
 Diameter of 
 Boilers 
 (Inches) 
 
 Length of 
 Tubes 
 (Feet) 
 
 Maximum 
 Length of 
 Columns 
 
 Width and Thickness of Columns 
 
 One Boiler 
 
 Two Boilers 
 
 Three Boilers 
 
 54 
 
 16 
 
 10'-6" 
 
 6" 
 
 X 
 
 A" 
 
 6" 
 
 X 
 
 yy 
 
 6" 
 
 X 
 
 1" 
 
 60 
 
 16 
 
 ll'-O" 
 
 6" 
 
 X 
 
 A" 
 
 6" 
 
 X 
 
 yy 
 
 6" 
 
 X 
 
 1" 
 
 60 
 
 18 
 
 ll'-0" 
 
 6" 
 
 X 
 
 A" 
 
 6" 
 
 X 
 
 yy 
 
 6" 
 
 X 
 
 1" 
 
 66 
 
 16 
 
 12'-0" 
 
 7" 
 
 X 
 
 A" 
 
 7" 
 
 X 
 
 yy 
 
 7" 
 
 X 
 
 1" 
 
 66 
 
 18 
 
 12 , -0" 
 
 7" 
 
 X 
 
 A" • 
 
 7" 
 
 X 
 
 yy 
 
 7" 
 
 X 
 
 1" 
 
 72 
 
 16 
 
 13'-0" 
 
 8" 
 
 X 
 
 A" 
 
 8" 
 
 X 
 
 y 
 
 8" 
 
 X 
 
 1" 
 
 72 
 
 18 
 
 13'-0" 
 
 8" 
 
 X 
 
 A" 
 
 8" 
 
 X 
 
 y 
 
 8" 
 
 X 
 
 1" 
 
 72 
 
 20 
 
 13'-0" 
 
 8" 
 
 X 
 
 A" 
 
 8" 
 
 X 
 
 y 
 
 8" 
 
 X 
 
 1" 
 
 78 
 
 • 16 
 
 13'-6" 
 
 8" 
 
 X 
 
 A " 
 
 8" 
 
 X 
 
 y 
 
 8" 
 
 X 
 
 1" 
 
 78 
 
 18 
 
 13'—6" 
 
 8" 
 
 X 
 
 A" 
 
 8" 
 
 X 
 
 yy 
 
 8" 
 
 X 
 
 1" 
 
 78 
 
 20 
 
 13'-6" 
 
 8" 
 
 X 
 
 A" 
 
 8" 
 
 X 
 
 y 
 
 8" 
 
 X 
 
 1" 
 
 84 
 
 18 
 
 14'-0" 
 
 8" 
 
 X 
 
 l" 
 
 8" 
 
 X 
 
 i" 
 
 8" 
 
 X 
 
 ly 
 
 84 
 
 20 
 
 14'-0" 
 
 8" 
 
 X 
 
 l" 
 
 8" 
 
 X 
 
 i" 
 
 8" 
 
 X 
 
 i y 
 
 
50 The Hartford Steam Boiler Inspection and Insurance Co 
 
 Sizes of H-Beams for Suspended Horizontal Tubular Boilers 
 
 Diameter 
 
 of 
 
 Boilers 
 
 Length 
 
 of 
 
 Tubes 
 
 Maximum 
 Length of 
 Columns 
 
 Depth of H- 
 
 Beams and Weight per Foot 
 
 One Boiler 
 
 Two Boilers 
 
 Three Boilers 
 
 54" 
 
 16' 
 
 10 '—6" 
 
 5"-18.7 lbs. 
 
 5"-18.7 lbs. 
 
 6"-23.8 lbs. 
 
 60" 
 
 16' 
 
 ll'-O" 
 
 5"-18.7 “ 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 60" 
 
 18' 
 
 ll'-O" 
 
 5"-18.7 “ 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 66 " 
 
 16' 
 
 12 '-0" 
 
 5"-18.7 “ 
 
 8"-34.0 “ 
 
 8"-34.0 “ 
 
 66 " 
 
 18' 
 
 12 '-0" 
 
 5"-18.7 “ 
 
 8"-34.0 “ 
 
 
 72" 
 
 16' 
 
 13'-0" 
 
 6"-23.8 “ 
 
 S"-34.0 “ 
 
 
 72" 
 
 18' 
 
 13'-0" 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 
 72" 
 
 20 ' 
 
 13'-0" 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 
 78" 
 
 16' 
 
 13'-6" 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 
 78" 
 
 18' 
 
 13'—6" 
 
 6"-23.8 “ 
 
 8"-34.0 “ 
 
 
 78" 
 
 20 ' 
 
 13'-6" 
 
 8"-34.0 “ 
 
 
 
 84" 
 
 18' 
 
 14'-0" 
 
 8"-34.0 “ 
 
 
 
 84" 
 
 20 ' 
 
 14'-0" 
 
 8"-34.0 “ 
 
 
 
 See explanatory notes on Page 49. 
 
 Sizes of Plate-and-Angle Columns for Suspended Horizontal 
 
 Tubular Boilers 
 
 Diameter 
 
 of 
 
 Boilers 
 
 Length 
 
 of 
 
 Tubes 
 
 Maximum 
 Length of 
 Columns 
 
 Sizes of Plates-and-Angles 
 
 One Boiler 
 
 Two Boilers 
 
 Three Boilers 
 
 54" 
 
 16' 
 
 10' -6" 
 
 6" x 
 
 3" x 2" x y 
 
 6" x y 
 
 3" x 2" x y" 
 
 8" x y 
 
 3 y x 2 yx y 
 
 60" 
 
 16' 
 
 ll'-O" 
 
 6" x y 
 
 3" x 2" x y" 
 
 8" x y 
 
 3" x 2 y" x %" 
 
 8" x y A ,f 
 
 3 y x 2 y x 54" 
 
 60" 
 
 18' 
 
 ll'-O" 
 
 6" x y 
 
 3" x 2" x y" 
 
 8" x y 
 
 3" x2K"x %" 
 
 8" x 54" 
 
 3 y x 2y 2 " x H" 
 
 66" 
 
 16' 
 
 12'-0" 
 
 8" x X" 
 
 3" x 2 K" x %" 
 
 8" x y" 
 
 3K" X 2y" X 54" 
 
 8" x %" 
 
 4" x 3" x 54" 
 
 66" 
 
 18' 
 
 12'-0" 
 
 8" x y 
 
 3" x2M"x 
 
 8" x y 
 
 3 y x 2 W'x 54" 
 
 8" x y 
 
 4" x 3" x H" 
 
 72" 
 
 16' 
 
 13'-0" 
 
 8" x X" 
 
 3K" x 2 y" x y" 
 
 8" x %" 
 
 3K" x2K"x H" 
 
 8" x y 
 
 4" x 3" x !4" 
 
 72" 
 
 18' 
 
 13'-0" 
 
 8" x y" 
 
 3 y" x2K"x y 
 
 8" x 54" 
 
 3 y x 2 y x y 
 
 8" x y 
 
 4" x 3" x 14" 
 
 72" 
 
 20' 
 
 13'-0" 
 
 8" X X" 
 
 3 y"x 2 y"x y" 
 
 8" x 54" 
 
 4" X 3" x 54" 
 
 8" x y 
 
 4" x 3" x y 
 
 78" 
 
 16' 
 
 13'-6" 
 
 8" x y" 
 
 3y x2K"x y" 
 
 8" x y 
 
 4" x 3" x 54" 
 
 s" x y 
 
 4" x 3" x y 
 
 * 
 
 GO 
 
 18' 
 
 13'-6" 
 
 8" x X" 
 
 3 y x 2 y x y 
 
 8" x 54" 
 
 4" x 3" x yi" 
 
 10" x y 
 
 5" x 3 y x y 
 
 <1 
 
 00 
 
 20' 
 
 13'-6" 
 
 3 K" x 2 yf' x ®4" 
 
 8" x y 
 
 4" x 3" x 7 /4" 
 
 10" x y 
 
 5" x 3 y x 14" 
 
 Tf« 
 
 00 
 
 18' 
 
 14'-0" 
 
 8" x y" 
 
 3%" x 2K" X 54" 
 
 8" X yi" 
 
 4" x 3" x Ffg" 
 
 10" x y 
 
 5" X 3K" X !4" 
 
 00 
 
 20' 
 
 14'-0" 
 
 » 
 
 8" x y" 
 
 3 y* x 2%" x 54" 
 
 8" x y 
 
 4" x 3" x y 
 
 10" X y" 
 
 6" x 4" x y& n 
 
 NOTE: The columns described in 
 this table are intended to be constructed 
 in accordance with the detail sketch at the 
 left. For each size of boiler the size of the 
 web plate is given above with the size of 
 the angles underneath. Four angles are 
 required in every case. Overall dimensions 
 of the various column cross-sections may 
 be determined by reference to the sketch. 
 
 See explanatory notes on Page 49. 
 
The H artf or d Steam Boiler Inspection and Insurance Co . 
 
 51 
 
 SAFETY VALVES FOR POWER BOILERS 
 
 The tables on the next four pages give data in regard to the sizes of flat-seat 
 and 45-degree bevel-seat safety valves required for various pressures and for 
 different sizes of boilers as determined by the nominal horsepower rating, this 
 rating in each case being figured on the basis of ten (10) square feet of boiler 
 heating surface per horsepower. "(See table on Page 46 for ratings of horizontal 
 tubular boilers). The required relieving capacity of safety valves is based on 
 six (6) pounds of steam per square foot of boiler heating surface per hour for 
 water-tube boilers, five (5) pounds for other types when the pressure exceeds 
 100 pounds per square inch, and three (3) pounds for such types when the 
 pressure varies between the limits of 15 pounds and 100 pounds per square inch, 
 inclusive. Relieving capacities for intermediate sizes not given in the tables 
 should be figured on the above basis. 
 
 The required number and size of safety valves in any case should be deter¬ 
 mined primarily from the relieving capacity which is dependent upon the lift of 
 the valve as well as its diameter. As a matter of convenience, the tables show 
 the number and diameter of valves required for various conditions based upon 
 assumed lifts as given below: 
 
 Diameter of Valve Assumed Lift 
 
 1" 
 
 IK". 
 
 IK" 
 
 2 " 
 
 2K" 
 
 3" 
 
 3K" 
 
 4" 
 
 4K" 
 
 0.04" 
 0.04" 
 0.05" 
 0.06" 
 0.06" 
 0.08" 
 0.09" 
 0 . 10 " 
 0 . 11 " 
 
 The valve diameters given should be used with caution, the actual lift being 
 considered in each case. When the lift differs from that assumed in the tables 
 the relieving capacity of a valve can be calculated from one of the following 
 formulae: 
 
 W = 155(P+14.7) XD XL for flat-seat valves. 
 
 W= 110(P + 14.7) XDXL for 45-degree bevel-seat valves. 
 
 W = 50(P + 14.7) A for valves with seats of any angle, 
 where W = the relieving capacity in pounds per hour. 
 
 P = gage pressure in pounds per square inch. 
 
 D = inside diameter of valve seat, inches. 
 
 L = vertical lift of valve disk measured with 3% excess pressure, inches. 
 
 A = relieving area in square inches = 3.1416XD XLXsine of seat angle. 
 
 Sizes of Boiler Connections for Two or Three Safety Valves Mounted on a 
 
 Single Base or Enclosed in a Single Casing 
 
 Diameter 
 of Each 
 
 Valve 
 
 Diameter of Opening to Boiler 
 
 Two Valves 
 
 Three Valves 
 
 1" 
 
 IK" 
 
 2" 
 
 IK" 
 
 2" 
 
 2K" 
 
 IK" 
 
 2 K" 
 
 3" 
 
 2" 
 
 3" 
 
 3K" 
 
 2K" 
 
 4" 
 
 4K" 
 
 3" 
 
 4K" 
 
 6" 
 
 3K" 
 
 5" 
 
 7" 
 
 4" 
 
 6" 
 
 7" 
 
 4K" 
 
 7" 
 
 8" 
 
The H a rtf or d Steam Boiler Inspection and Insurance Co 
 
 SAFETY VALVES FOR FIRE-TUBE BOILERS 
 (Pressure Range from 15 lbs. to 100 lbs. Inclusive) 
 
 Nominal 
 
 Requirec 
 
 NUMBER AND DIAMETER OF SAFETY VALVES REQUIRED WITH AVERAGE LIFT 
 
 I1UI5C- 
 
 povver 
 
 Rating 
 
 (Lbs. per 
 Hr.) 
 
 BEVEL SEAT 
 
 FLAT SEAT 
 
 15 lbs. 
 
 25 lbs. 
 
 50 lbs. 
 
 75 lbs. 
 
 100 lbs. 
 
 15 lbs. 
 
 25 lbs. 
 
 50 lbs. 
 
 75 lbs. 
 
 100 lbs. 
 
 50 
 
 1500 
 
 1-4K' 
 
 1-4" 
 
 1-3" 
 
 1-3" 
 
 1-2" 
 
 1-4" 
 
 1-3 X" 
 
 1-3" 
 
 1-2" 
 
 1-2" 
 
 55 
 
 1650 
 
 2-3 K" 
 
 1-4" 
 
 1-3" 
 
 1-3" 
 
 1-2X" 
 
 1-4" 
 
 1-3 X" 
 
 1-3" 
 
 1-2" 
 
 1-2" 
 
 60 
 
 1800 
 
 2-3X" 
 
 1-4 K" 
 
 1-3 x' 
 
 1-3" 
 
 1-2X" 
 
 1-4" 
 
 1-3 K" 
 
 1-3" 
 
 1-2X" 
 
 1-2" 
 
 65 
 
 1950 
 
 2-3K" 
 
 1-4 K" 
 
 1-3X' 
 
 1-3" 
 
 1-3" 
 
 1-4 X" 
 
 1-4" 
 
 1-3" 
 
 1-2X" 
 
 1-2" 
 
 70 
 
 2100 
 
 2-4" 
 
 2-3K" 
 
 2-2X* 
 
 2-2" 
 
 2-2" 
 
 2-3" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 2-1K' 
 
 75 
 
 2250 
 
 2-4" 
 
 2-3 K" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 2-3X" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 2-1X" 
 
 80 
 
 2400 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 2-2 K" 
 
 2-2" 
 
 2-3 X" 
 
 2-3" 
 
 2-2K" 
 
 2-2" 
 
 2-1K" 
 
 85 
 
 2550 
 
 2-4" 
 
 2-3 K" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 2-3X" 
 
 2-3" 
 
 2-2X" 
 
 2-2" 
 
 2-1K" 
 
 90 
 
 2700 
 
 2-4^" 
 
 2-3K" 
 
 2-3" 
 
 2-2K" 
 
 2-2" 
 
 2-3K" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 2-1K" 
 
 95 
 
 2850 
 
 2-4>4" 
 
 2-4" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 2-3X" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 100 
 
 3000 
 
 2-4 K" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 105 
 
 3150 
 
 2-4 K" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 110 
 
 3300 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 2-2" 
 
 2-2" 
 
 115 
 
 3450 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-2X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 120 
 
 3600 
 
 3-4" 
 
 2-4 K" 
 
 2-3X" 
 
 2-3" 
 
 2-2 K" 
 
 2-4" 
 
 2-3X" 
 
 2-3" 
 
 2-2K" 
 
 2-2" 
 
 125 
 
 3750 
 
 3-4" 
 
 2-4K" 
 
 2-3 X* 
 
 2-3" 
 
 2-2K" 
 
 2-4 X" 
 
 2-3X" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 130 
 
 3900 
 
 3-4" 
 
 2-4 K" 
 
 2-3X" 
 
 2-3" 
 
 2-3" 
 
 2-4 X" 
 
 2-4" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 135 
 
 4050 
 
 3-4K" 
 
 2-4K" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-4X" 
 
 2-4" 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 140 
 
 4200 
 
 3-4 K" 
 
 2-4 K" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-4X" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2" 
 
 145 
 
 4350 
 
 3-4 y 2 " 
 
 3-4" 
 
 2-3K" 
 
 2-3" 
 
 2-3" 
 
 2-4 X" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2K" 
 
 150 
 
 4500 
 
 3-4K" 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-4 X" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2K" 
 
 155 
 
 4650 
 
 3-4 K" 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 160 
 
 4800 
 
 3-4 K" 
 
 3-4" 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-2K' 
 
 165 
 
 4950 
 
 4-4" 
 
 3-4" 
 
 2-4" 
 
 2-3 K" 
 
 2-3" 
 
 3-4" 
 
 2-4X" 
 
 2-3X" 
 
 2-3" 
 
 2-2K' 
 
 170 
 
 5100 
 
 4-4" 
 
 3-4" 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 3-4" 
 
 2-4 K" 
 
 2-3K" 
 
 2-3" 
 
 2-2X" 
 
 175 
 
 5250 
 
 4-4 K" 
 
 3-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 3-4" 
 
 2-4 X" 
 
 2-3X" 
 
 2-3" 
 
 2-2X' 
 
 180 
 
 5400 
 
 4-4K" 
 
 3-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 3-4" 
 
 2-4K" 
 
 2-3^2 " 
 
 2-3" 
 
 2-2K' 
 
 185 
 
 5550 
 
 4-4 K" 
 
 3-4K" 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-3K" 
 
 2-3" 
 
 2-2K" 
 
 190 
 
 5700 
 
 4-4 ys 
 
 3-4X' 
 
 2-4 X" 
 
 2-3 X* 
 
 2-3" 
 
 3-4X" 
 
 2-4 X* 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 195 
 
 5850 
 
 4-4 K" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-3 X* 
 
 2-3" 
 
 3-4K" 
 
 2-4 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 200 
 
 6000 
 
 4-4K" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-3 K" 
 
 2-3" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 205 
 
 6150 
 
 4-4^2 " 
 
 3-4 X" 
 
 2-4 X" 
 
 2-3 X" 
 
 2-3 X* 
 
 3-4 x" 
 
 3-4" 
 
 2-3K" 
 
 2-3" 
 
 2-3" 
 
 210 
 
 6300 
 
 4-4 K" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 3-4 X" 
 
 3-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 215 
 
 6450 
 
 4-4K" 
 
 3-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 3-4K" 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 220 
 
 6600 
 
 5-4 K" 
 
 4-4" 
 
 2-4 >4" 
 
 2-4" 
 
 2-3 X" 
 
 3-4 x" 
 
 3-4" 
 
 2-4" 
 
 2-3" 
 
 2-3" 
 
 225 
 
 6750 
 
 5-4 K' 
 
 4-4" 
 
 2-4 X" 
 
 2—4" 
 
 2-3K" 
 
 3-4 K" 
 
 3-4" 
 
 2-4" 
 
 2-3K" 
 
 2-3" 
 
 230 
 
 6900 
 
 5-4 K" 
 
 4-4" 
 
 2-4 X" 
 
 2-4" 
 
 2-3 X' 
 
 4-4" 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 235 
 
 7050 
 
 5-4K" 
 
 4-4K" 
 
 3-4" 
 
 2-4" 
 
 2-3X" 
 
 4-4" 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 240 
 
 7200 
 
 5-4 ys 
 
 4-4 X" 
 
 3-4" 
 
 2-4" 
 
 2-3K" 
 
 4-4" 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 245 
 
 7350 
 
 5-4K' 
 
 4-4 X' 
 
 3-4" 
 
 2-4" 
 
 2-3 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 250 
 
 7500 
 
 5-4 K" 
 
 4-4 X" 
 
 3-4" 
 
 2-4" 
 
 2-3K' 
 
 4-4 X" 
 
 3-4X" 
 
 2-4" 
 
 2-3X' 
 
 2-3" 
 
 See explanatory notes on Page 51 
 
The Hartford Steam Boiler Inspection and Insurance Co 
 
 53 
 
 SAFETY VALVES FOR FIRE TUBE BOILERS 
 (For Pressures in Excess of 100 lbs.) 
 
 Nom- 
 
 Re¬ 
 
 quired 
 
 NUMBER AND DIAMETER OF SAFETY VALVES REQUIRED WITH AVERAGE LIFT 
 
 
 Cilpcl- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H. P. 
 
 city 
 
 
 
 BEVEL SEAT 
 
 
 
 
 
 FLAT SEAT 
 
 
 
 
 /T Ko 
 
 
 
 
 
 
 
 
 
 
 
 
 
 XVd.1- 
 
 \.L/DS. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ing 
 
 per hr.) 
 
 125 lbs. 
 
 150 lbs. 
 
 175 lbs. 
 
 200 lbs. 
 
 225 lbs. 
 
 250 lbs. 
 
 125 lbs. 
 
 150 lbs. 
 
 175 lbs. 
 
 200 lbs. 
 
 225 lbs. 
 
 250 lbs 
 
 50 
 
 2500 
 
 2-2" 
 
 2-1K" 
 
 2-1K" 
 
 2-1K" 
 
 2-1X" 
 
 2-1X" 
 
 2-1K" 
 
 2-lY" 
 
 2-1K" 
 
 2-1' 
 
 2-1" 
 
 2-1' 
 
 55 
 
 2750 
 
 2-2“ 
 
 2-2" 
 
 2-1 Y' 
 
 2-1Y" 
 
 2-1 Y" 
 
 2-1K" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-1K" 
 
 2-1 Y" 
 
 2-1" 
 
 2-1" 
 
 60 
 
 3000 
 
 2-2" 
 
 2-2" 
 
 2-1K" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-1 Y" 
 
 2-1 X" 
 
 2-1 Y" 
 
 2-1" 
 
 65 
 
 3250 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1Y" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-1Y" 
 
 2-lY" 
 
 2-1" 
 
 70 
 
 3500 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1K" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-2" 
 
 2-1Y" 
 
 2-1 Y" 
 
 2-1K" 
 
 2-1Y" 
 
 2-1Y 
 
 75 
 
 3750 
 
 2-2%” 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-2" 
 
 2-1Y" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1Y" 
 
 2-1Y 
 
 SO 
 
 4000 
 
 2-2K" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1Y" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1Y 
 
 85 
 
 4250 
 
 2-2K" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1Y" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1K" 
 
 2-1 Y" 
 
 2-1Y 
 
 90 
 
 4500 
 
 2-2 Y" 
 
 2-2 K" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1Y 
 
 95 
 
 4750 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1 Y" 
 
 2-1Y 
 
 100 
 
 5000 
 
 2-3" 
 
 2-2 K" 
 
 2-2 K" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y" 
 
 2-1 Y 
 
 105 
 
 5250 
 
 2-3“ 
 
 2-2 Y” 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y' 
 
 2-1 Y 
 
 110 
 
 5500 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1K" 
 
 2-1Y 
 
 115 
 
 5750 
 
 2-3" 
 
 2-3" 
 
 2-2 Y” 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 Y 
 
 120 
 
 6000 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1Y 
 
 125 
 
 6250 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 130 
 
 6500 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 135 
 
 6750 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y” 
 
 2-2 Y" 
 
 2-2" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 140 
 
 7000 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 145 
 
 7250 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 •2-2" 
 
 2-2" 
 
 150 
 
 7500 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 155 
 
 7750 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 160 
 
 8000 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2' 
 
 2-2" 
 
 165 
 
 8250 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 170 
 
 8500 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 175 
 
 8750 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 . 2-3" 
 
 2-2 Y" 
 
 2-2" 
 
 2-2" 
 
 180 
 
 9000 
 
 2-3 K" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2K" 
 
 2-2' 
 
 185 
 
 9250 
 
 2-314" 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 190 
 
 9500 
 
 2-3 Y“ 
 
 2-3K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 195 
 
 9750 
 
 2-4" 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y" 
 
 2-2" 
 
 200 
 
 10000 
 
 2-4" 
 
 2-3 K" 
 
 2-3 Y" 
 
 2-3' 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y 
 
 205 
 
 10250 
 
 2-4" 
 
 2-3%" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y 
 
 210 
 
 10500 
 
 2-4" 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y' 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y 
 
 215 
 
 10750 
 
 2-4" 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2 Y 
 
 220 
 
 11000 
 
 2-4" 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y" 
 
 2-2% 
 
 225 
 
 11250 
 
 2-4' 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2Y 
 
 230 
 
 11500 
 
 2-4" 
 
 2-4" 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3' 
 
 2-3" 
 
 2-3' 
 
 2-2 Y 
 
 235 
 
 11750 
 
 2-4" 
 
 2-4" 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 Y 
 
 240 
 
 12000 
 
 2-4' 
 
 2-4' 
 
 2-3 Y" 
 
 2-3 K" 
 
 2-3" 
 
 2-3" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3' 
 
 2-3' 
 
 2-2 Y 
 
 245 
 
 12250 
 
 2-4" 
 
 2-4' 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3' 
 
 2-3 Y" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3' 
 
 2-3' 
 
 2-3" 
 
 250 
 
 12500 
 
 2-4K" 
 
 2-4" 
 
 2-3 K" 
 
 2-3 Y" 
 
 2-3" 
 
 2-3" 
 
 2-3 K" 
 
 2-3 Y" 
 
 2-3' 
 
 2-3" 
 
 2-3' 
 
 2-3" 
 
 See explanatory notes on Page 51 
 
54 The H a rtf or d Steam Boiler I nspection and Insurance Co 
 
 SAFETY VALVES FOR WATER TUBE BOILERS 
 
 Bevel Seat 
 
 Nominal 
 
 Rated 
 
 Horse¬ 
 
 power 
 
 Required 
 Capacity 
 (Lbs. per 
 Hr.) 
 
 Number and Diameter of Safety Valves Require 
 
 d with Average Lift 
 
 100 lbs. 
 
 125 lbs. 
 
 150 lbs. 
 
 175 lbs. 
 
 200 lbs. 
 
 225 lbs. 
 
 250 lbs. 
 
 275 lbs. 
 
 300 lbs. 
 
 100 
 
 6000 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 125 
 
 7500 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 150 
 
 9000 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 175 
 
 10500 
 
 2-4 X" 
 
 2-4" 
 
 2-3X" 
 
 2-3X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 200 
 
 12000 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 225 
 
 13500 
 
 3-4" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 250 
 
 15000 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3X" 
 
 2-3" 
 
 2-3" 
 
 275 
 
 16500 
 
 3-4 X" 
 
 3-4" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X* 
 
 2-3X" 
 
 2-3" 
 
 300 
 
 18000 
 
 3-4 X* 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3 X" 
 
 325 
 
 19500 
 
 4-4" 
 
 3-4K" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 350 
 
 21000 
 
 4-4 X" 
 
 3-4 K" 
 
 3-4" 
 
 3-4 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 375 
 
 22500 
 
 4-4X" 
 
 4-4" 
 
 3-4X" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-4" 
 
 400 
 
 24000 
 
 4-4 X" 
 
 4-4" 
 
 3-4K" 
 
 3-4" 
 
 3-4" 
 
 2-4X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 425 
 
 25500 
 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 450 
 
 27000 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 475 
 
 28500 
 
 
 4-4X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X* 
 
 3-4" 
 
 2—IX* 
 
 2-4 X” 
 
 2-4 X" 
 
 500 
 
 30000 
 
 
 4-4K" 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 525 
 
 31500 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 550 
 
 33000 
 
 
 
 4-4> 2 " 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 575 
 
 34500 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X* 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 3-4" 
 
 600 
 
 36000 
 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 625 
 
 37500 
 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 650 
 
 39000 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 675 
 
 40500 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 700 
 
 42000 
 
 
 
 
 
 4-4X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 725 
 
 43500 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 750 
 
 45000 
 
 
 
 
 
 4-4 X" 
 
 4-4 X* 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 775 
 
 46500 
 
 
 
 
 
 4-4 X" 
 
 4-4X" 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X r/ 
 
 800 
 
 48000 
 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 825 
 
 49500 
 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 850 
 
 51000 
 
 
 
 
 
 
 4-4 X* 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 875 
 
 52500 
 
 
 
 
 
 
 
 4-4X" 
 
 4-4X" 
 
 4-4" 
 
 900 
 
 54000 
 
 
 
 
 
 
 
 4-4X" 
 
 4-4 X* 
 
 4-4 X" 
 
 925 
 
 55500 
 
 
 
 
 
 
 
 4-4X" 
 
 4-4 X" 
 
 4-4X" 
 
 950 
 
 57000 
 
 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 4-4 X* 
 
 975 
 
 58500 
 
 
 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 1000 
 
 60000 
 
 
 
 
 
 
 
 
 4-4X" 
 
 4-4 X" 
 
 See explanatory notes on Page 51 
 
55 
 
 The H artj or d Steam Boiler Inspection and Insurance Co 
 
 SAFETY VALVES FOR WATER-TUBE BOILERS (Concluded) 
 
 Flat Seat 
 
 Nominal 
 
 Rated 
 
 Horse¬ 
 
 power 
 
 Required 
 Capacity 
 (Lbs. per 
 Hr.) 
 
 Number and Diameter of Safety Valves Required with Average Lift 
 
 100 lbs. 
 
 125 lbs. 
 
 150 lbs. 
 
 175 lbs. 
 
 200 lbs. 
 
 225 lbs. 
 
 250 lbs. 
 
 275 lbs. 
 
 300 lbs. 
 
 100 
 
 6000 
 
 2-3" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-1 X" 
 
 2-1X" 
 
 2-1X" 
 
 125 
 
 7500 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 2-2" 
 
 150 
 
 9000 
 
 2-3 X w 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 175 
 
 10500 
 
 2-3 H" 
 
 2-3 ^2 " 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2" 
 
 2-2" 
 
 200 
 
 12000 
 
 2-4" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 2-2 X" 
 
 2-2 X" 
 
 225 
 
 13500 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-2 X" 
 
 250 
 
 15000 
 
 2-4 x" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 *2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 275 
 
 16500 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 300 
 
 18000 
 
 3-4" 
 
 2-4 X" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 325 
 
 19500 
 
 3-4" 
 
 2-4 K" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 2-3" 
 
 350 
 
 21000 
 
 3-4" 
 
 2-4K" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 2-3" 
 
 375 
 
 22500 
 
 3-4K" 
 
 3-4" 
 
 2-4 K" 
 
 2-4" 
 
 2-4" 
 
 2-3X" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3" 
 
 400 
 
 24000 
 
 3-4 X" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3X" 
 
 2-3 X" 
 
 2-3X" 
 
 425 
 
 25500 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 x" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 2-3 X" 
 
 450 
 
 27000 
 
 4-4" 
 
 3-4 K" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 2-3 X" 
 
 475 
 
 28500 
 
 4-4 K" 
 
 3-4 X" 
 
 3-4" 
 
 2-4X" 
 
 2-4 x" 
 
 2-4" 
 
 2-4" 
 
 2-4" 
 
 2-3X" 
 
 500 
 
 30000 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 K" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-3 X" 
 
 525 
 
 31500 
 
 4-4 K" 
 
 3-4 X" 
 
 3-4 X w 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 2-4" 
 
 550 
 
 33000 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X ,; 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 575 
 
 34500 
 
 4-4 X" 
 
 4-4X" 
 
 3-4X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 2-4" 
 
 600 
 
 36000 
 
 
 4-4 X" 
 
 3-4X" 
 
 3-4 X" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4" 
 
 625 
 
 37500 
 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2—4" 
 
 650 
 
 39000 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 2-4 X" 
 
 675 
 
 40500 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 700 
 
 42000 
 
 
 4-4 X" 
 
 4-4 K" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4 X" 
 
 725 
 
 43500 
 
 
 
 4-4 x" 
 
 4-4" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4 X" 
 
 2-4X" 
 
 750 
 
 45000 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 x" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4X" 
 
 775 
 
 46500 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 2-4X" 
 
 800 
 
 48000 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 3-4" 
 
 825 
 
 49500 
 
 
 
 
 4-4X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 850 
 
 51000 
 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4" 
 
 3-4" 
 
 875 
 
 52500 
 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X* 
 
 3-4X" 
 
 3-4" 
 
 3-4" 
 
 900 
 
 54000 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4 X* 
 
 3-4" 
 
 925 
 
 55500 
 
 
 
 
 4-4 X" 
 
 4-4X" 
 
 4-4" 
 
 3-4 X* 
 
 3-4 X" 
 
 3-4" 
 
 950 
 
 57000 
 
 
 
 
 4-4X" 
 
 4-4K" 
 
 4-4" 
 
 3-4 X" 
 
 3-4X" 
 
 3-4" 
 
 975 
 
 58500 
 
 
 
 
 
 4-4 X" 
 
 4-4" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 1000 
 
 60000 
 
 
 
 
 
 4-4 X" 
 
 4-4 X" 
 
 3-4 X" 
 
 3-4 X" 
 
 3-4X" 
 
 See explanatory notes on Page 51 
 
56 The H artf or d Steam Boiler Inspection and I nsur ance Co 
 
 Drilling and Other Details for Flanges and Fittings 
 
 (American Standard) 
 
 Pressures Not Exceeding 125 Lbs. 
 
 Pipe 
 
 Size 
 
 Diameter of 
 Flanges 
 
 Thickness of 
 Flanges 
 
 Number of 
 Holes 
 
 Siz e of 
 Holes 
 
 Diameter of 
 Bolt Circle 
 
 Size of 
 
 Gaskets 
 
 1" 
 
 4" 
 
 K" 
 
 4 
 
 K" 
 
 3" 
 
 1" x 2K" 
 
 1 K" 
 
 4K" 
 
 K" 
 
 4 
 
 K" 
 
 3K" 
 
 IK" x 2K' 
 
 IK" 
 
 5" 
 
 %" 
 
 4 
 
 K" 
 
 3K" 
 
 IK" x 3K' 
 
 2" 
 
 6" 
 
 K" 
 
 4 
 
 K" 
 
 4K" 
 
 2" x 4" 
 
 2K' 
 
 7" 
 
 “K" 
 
 4 
 
 K" 
 
 5K" 
 
 2K"x 4K" 
 
 3* 
 
 7K" 
 
 K" 
 
 4 
 
 K" 
 
 6" 
 
 3" x 5K" 
 
 3K" 
 
 SK" 
 
 
 4 
 
 K" 
 
 7" 
 
 3K"x 6K' 
 
 4" 
 
 9" 
 
 
 8 
 
 K" 
 
 7K" 
 
 4" x 6K' 
 
 4K" 
 
 9K" 
 
 15 K" 
 
 8 
 
 K" 
 
 7K" 
 
 4K"x 6K' 
 
 5" 
 
 10" 
 
 u i4" 
 
 8 
 
 K" 
 
 8K" 
 
 5" x 7K" 
 
 6' 
 
 11" 
 
 l" 
 
 0 
 
 8 
 
 K" 
 
 9K" 
 
 6" x 8K" 
 
 V 
 
 12K" 
 
 l H’ 
 
 8 
 
 K* 
 
 10K" 
 
 7" x 9K" 
 
 8" 
 
 13K" 
 
 l K" 
 
 8 
 
 K" 
 
 UK" 
 
 8" x 10K" 
 
 9" 
 
 15" 
 
 l K" 
 
 12 
 
 K" 
 
 13K" 
 
 9" x 12K" 
 
 10" 
 
 16" 
 
 l %' 
 
 12 
 
 1" 
 
 14K* 
 
 10" x 13K" 
 
 12" 
 
 19" 
 
 l K" 
 
 12 
 
 1' 
 
 17" 
 
 12" x 16" 
 
 14" 
 
 21" 
 
 • l K" 
 
 12 
 
 IK" 
 
 18K" 
 
 14" x 17K' 
 
 125 Lbs. to 250 Lbs. Pressure 
 
 Pipe 
 
 Size 
 
 Diameter of 
 Flanges 
 
 Thickness of 
 Flanges 
 
 Number of 
 Holes 
 
 Size of 
 Holes 
 
 Diameter of 
 Bolt Circle . 
 
 Size of 
 
 Gaskets 
 
 1" 
 
 4K" 
 
 “/«' 
 
 4 
 
 K" 
 
 3K" 
 
 1" x 2K" 
 
 IK" 
 
 5" 
 
 K" 
 
 4 
 
 K" 
 
 3K" 
 
 IK" x 3K" 
 
 IK" 
 
 6" 
 
 
 4 
 
 K" 
 
 4K" 
 
 IK" x 3K" 
 
 2' 
 
 6K" 
 
 K" 
 
 4 
 
 K" 
 
 5" 
 
 2" x 4K" 
 
 2K" 
 
 7K" 
 
 l" 
 
 4 
 
 K" 
 
 5K" 
 
 2K" x 5" 
 
 3" 
 
 . 8K" 
 
 l K" 
 
 8 
 
 K" 
 
 6K" 
 
 3" x 5K" 
 
 3K" 
 
 9" 
 
 1 Ke" 
 
 8 
 
 K" 
 
 7K" 
 
 3K"x 6K" 
 
 4» 
 
 10" 
 
 l K" 
 
 8 
 
 K" 
 
 7K" 
 
 4" x 7" 
 
 4K" 
 
 ioK" 
 
 l 
 
 8 
 
 K" 
 
 8 K" 
 
 4K" x 7K" 
 
 5" 
 
 ii" 
 
 l K" 
 
 8 
 
 K 
 
 9K" 
 
 5" x 8K" 
 
 6" 
 
 12K" 
 
 l Ke" 
 
 12 
 
 K" 
 
 10K" 
 
 6" x 9K" 
 
 7" 
 
 14" 
 
 1 K" 
 
 12 
 
 l" 
 
 11K" 
 
 7" x 10K" 
 
 8" 
 
 15" 
 
 l K" 
 
 12 
 
 l" 
 
 13" 
 
 8" x 12" 
 
 9" 
 
 16K" 
 
 l K" 
 
 12 
 
 IK" 
 
 14" 
 
 9" x 12K" 
 
 10" 
 
 17K" 
 
 l K" 
 
 16 
 
 IK" 
 
 15K' 
 
 10" x 14K" 
 
 12" 
 
 20K" 
 
 2' 
 
 16 
 
 IK" 
 
 17K" 
 
 12" x 16K" 
 
 14" 
 
 23" 
 
 2 K" 
 
 20 
 
 IK" 
 
 20K" 
 
 13K" x 19" 
 
 Minimum Number of Pipe Threads for Connections to Boilers 
 
 Size of Pipe Connection 
 (Inches) 
 
 1 and K 
 
 IK and 2 
 
 2K to 4 
 Inclusive 
 
 4K to 6 
 Inclusive 
 
 7 and 8 
 
 9 and 10 
 
 12 
 
 Number of threads per inch 
 
 UK 
 
 11K 
 
 8 
 
 8 
 
 8 
 
 S 
 
 8 
 
 Minimum number of threads 
 required in opening 
 
 4 
 
 5 
 
 7 
 
 8 
 
 10 
 
 12 
 
 13 
 
 Minimum thickness of material 
 required to give above num¬ 
 ber of threads (Inches) 
 
 0.348 
 
 0.435 
 
 0.875 
 
 1.000 
 
 1.250 
 
 1.500 
 
 1.625 
 
The Hartford Steam Boiler Inspection and Insurance Co 
 
 57 
 
 Decimal Equivalents of Common Fractions 
 
 Common 
 
 Fraction 
 
 Decimal 
 
 Equivalent 
 
 Common 
 
 Fraction 
 
 Decimal 
 
 Equivalent 
 
 Common 
 
 Fraction 
 
 Decimal 
 
 Equivalent 
 
 Common 
 
 Fraction 
 
 Decimal 
 
 Equivalent 
 
 We 
 
 0.0625 
 
 !4 
 
 0.03125 
 
 w 
 
 0.015625 
 
 S3 4t 
 
 0.515625 
 
 X 
 
 .1250 
 
 Wi 
 
 .09375 
 
 Wi 
 
 .046875 
 
 "44 
 
 .546875 
 
 We 
 
 .1875 
 
 Wi 
 
 .15625 
 
 Wi 
 
 .078125 
 
 37 4 
 
 .578125 
 
 X 
 
 .2500 
 
 7 /?2 
 
 .21875 
 
 Wi 
 
 .109375 
 
 3 % 
 
 .609375 
 
 We 
 
 0.3125 
 
 9 ^2 
 
 0.28125 
 
 % 
 
 0.140625 
 
 4 14 
 
 0.640625 
 
 X 
 
 .3750 
 
 "42 
 
 .34375 
 
 "4i 
 
 .171875 
 
 
 .671875 
 
 We 
 
 .4375 
 
 13 42 
 
 .40625 
 
 'W 
 
 .203125 
 
 43 4 
 
 .703125 
 
 X 
 
 .5000 
 
 'W 2 
 
 .46875 
 
 n 4i 
 
 .234375 
 
 47 /64 
 
 .734375 
 
 We 
 
 0.5625 
 
 "42 
 
 0.53125 
 
 17 4i 
 
 0.265625 
 
 4 % 
 
 0.765625 
 
 X 
 
 .6250 
 
 19 4 
 
 .59375 
 
 'W 
 
 .296875 
 
 5 '4i 
 
 .796875 
 
 1 We 
 
 .6875 
 
 21 4 
 
 .65625 
 
 "4a 
 
 .328125 
 
 53 4 
 
 .828125 
 
 X 
 
 .7500 
 
 23 M 2 
 
 .71875 
 
 n 4i 
 
 .359375 
 
 5 Wi 
 
 .859375 
 
 'We 
 
 0.8125 
 
 2 % 
 
 0.78125 
 
 
 0.390625 
 
 57 4i 
 
 0.890625 
 
 X 
 
 .8750 
 
 2 % 
 
 .84375 
 
 "A* 
 
 .421875 
 
 59 4i 
 
 .921875 
 
 1 We 
 
 .9375 
 
 29 4 
 
 .90625 
 
 2 ?4 
 
 .453125 
 
 e W 
 
 .953125 
 
 1 
 
 1.0000 
 
 *W» 
 
 .96875 
 
 
 .484375 
 
 
 .984375 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 V6 
 
 0.0982 
 
 0.00077 
 
 116 
 
 3.2398 
 
 0.8352 
 
 2 W 2 
 
 6.3814 
 
 3.2405 
 
 We 
 
 .1964 
 
 .00307 
 
 1 We 
 
 3.3379 
 
 .8866 
 
 2 We 
 
 6.4795 
 
 3.3410 
 
 W 2 
 
 .2945 
 
 .00690 
 
 1 3 M 2 
 
 3.4361 
 
 .9396 
 
 2 *4 
 
 6.5777 
 
 3.4430 
 
 X 
 
 .3927 
 
 .01227 
 
 1 X 
 
 3.5343 
 
 .9940 
 
 2 X 
 
 6.6759 
 
 3.5466 
 
 W 2 
 
 0.4909 
 
 0.01918 
 
 1 % 
 
 3.6325 
 
 1.0500 
 
 2 W 2 
 
 6.7741 
 
 3.6516 
 
 We 
 
 .5890 
 
 .02761 
 
 1 We 
 
 3.7306 
 
 1.1075 
 
 2 We 
 
 6.8722 
 
 3.7583 
 
 W 2 
 
 .6872 
 
 .03758 
 
 1 7 42 
 
 3.8288 
 
 1.1666 
 
 2 W 2 
 
 6.9704 
 
 3.8664 
 
 X 
 
 .7854 
 
 .04909 
 
 1 X 
 
 3.9270 
 
 1.2272 
 
 2 X 
 
 7.0686 
 
 3.9761 
 
 W 2 
 
 0.8836 
 
 0.06213 
 
 1 % 
 
 4.0252 
 
 1.2893 
 
 2 ?4 
 
 7.1668 
 
 4.0873 
 
 We 
 
 .9818 
 
 .07670 
 
 1 We 
 
 4.1233 
 
 1.3530 
 
 2 Me 
 
 7.2649 
 
 4.2000 
 
 "42 
 
 1.0799 
 
 .09281 
 
 1 "42 
 
 4.2215 
 
 1.4182 
 
 2"4t 
 
 7.3631 
 
 4.3143 
 
 H 
 
 1.1781 
 
 .11045 
 
 1 X 
 
 4.3197 
 
 1.4849 
 
 2 X 
 
 7.4613 
 
 4.4301 
 
 'W 2 
 
 1.2763 
 
 0.12962 
 
 l 13 4 
 
 4.4179 
 
 1.5532 
 
 2 'W 2 
 
 7.5595 
 
 4.5475 
 
 We 
 
 1.3744 
 
 .15033 
 
 1 We 
 
 4.5160 
 
 1.6230 
 
 2 We 
 
 7.6576 
 
 4.6664 
 
 "42 
 
 1.4726 
 
 .17258 
 
 l'W2 
 
 . 4.6142 
 
 1.6943 
 
 2'V%2 
 
 7.7558 
 
 4.7868 
 
 X 
 
 1.5708 
 
 .19635 
 
 1 X 
 
 4.7124 
 
 1.7672 
 
 2 X 
 
 7.8540 
 
 4.9087 
 
 "42 
 
 1.6690 
 
 0.22166 
 
 1 "42 
 
 4.8106 
 
 1.8415 
 
 2"42 
 
 7.9522 
 
 5.0322 
 
 We 
 
 1.7671 
 
 .24850 
 
 1 We 
 
 4.9087 
 
 1.9175 
 
 2 We 
 
 8.0503 
 
 5.1572 
 
 'W 2 
 
 1.8653 
 
 .27688 
 
 I'lii 
 
 5.0069 
 
 1.9949 
 
 2 "42 
 
 8.1485 
 
 5.2838 
 
 X 
 
 1.9635 
 
 .30680 
 
 l X 
 
 5.1051 
 
 2.0739 
 
 2 X 
 
 8.2467 
 
 5.4119 
 
 21 Ai 
 
 2.0617 
 
 0.33824 
 
 1 2 V6 
 
 5.2033 
 
 2.1545 
 
 2"4i 
 
 8.3449 
 
 5.5415 
 
 "Ae 
 
 2.1598 
 
 .37122 
 
 I'We 
 
 5.3014 
 
 2.2365 
 
 2 "Ae 
 
 8.4430 
 
 5.6727 
 
 "4i 
 
 2.2580 
 
 .40574 
 
 V-W 2 
 
 5.3996 
 
 2.3202 
 
 2 23 4 
 
 8.5412 
 
 5.8054 
 
 X 
 
 2.3562 
 
 .44179 
 
 1 x 
 
 5.497S 
 
 2.4053 
 
 2 X 
 
 8.6394 
 
 5.9396 
 
 "42 
 
 2.4544 
 
 0.47937 
 
 VW 2 
 
 5.5960 
 
 2.4920 
 
 2 "42 
 
 8.7376 
 
 6.0753 
 
 'We 
 
 2.5525 
 
 .51849 
 
 I'We 
 
 5.6941 
 
 2.5802 
 
 2'We 
 
 8.8357 
 
 6.2126 
 
 "42 
 
 2.6507 
 
 .55914 
 
 1 "42 
 
 5.7923 
 
 2.6699 
 
 2"4i 
 
 8.9339 
 
 6.3515 
 
 X> 
 
 2.7489 
 
 .60132 
 
 1 X 
 
 5.8905 
 
 2.7612 
 
 2 X 
 
 9.0321 
 
 6.4918 
 
 2 % 
 
 2.8471 
 
 0.64504 
 
 
 5.9887 
 
 2.8540 
 
 2 "42 
 
 9.1303 
 
 6.6337 
 
 "We 
 
 2.9452 
 
 .69029 
 
 I'We 
 
 6.0868 
 
 2.9483 
 
 2'We 
 
 9.2284 
 
 6.7771 
 
 
 3.0434 
 
 .73708 
 
 1*16 
 
 6.1850 
 
 3.0442 
 
 2 "42 
 
 9.3266 
 
 6.9221 
 
 1 
 
 3.1416 
 
 .78540 
 
 2 
 
 6.2832 
 
 3.1416 
 
 3 
 
 9.4248 
 
 7.0686 
 
58 The Hartford Steam Boiler Inspection and Insurance Co. 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 
 ference 
 
 
 
 ference 
 
 
 
 ference 
 
 
 3 
 
 9.4248 
 
 7.0686 
 
 5 
 
 15.7080 
 
 19.6350 
 
 7 
 
 21.9911 
 
 38.4845 
 
 3 We 
 
 9.6211 
 
 7.3662 
 
 5 We 
 
 15.9043 
 
 20.1289 
 
 7 We 
 
 22.1875 
 
 39.1748 
 
 3 x 
 
 9.8175 
 
 7.6699 
 
 5 X 
 
 16.1007 
 
 20.6290 
 
 7 X 
 
 22.3838 
 
 39.8712 
 
 3 We 
 
 10.0138 
 
 7.9798 
 
 5 X 
 
 16.2970 
 
 21.1352 
 
 7 We 
 
 22.5S02 
 
 40.5738 
 
 3 x 
 
 10.2102 
 
 8.2958 
 
 5 X 
 
 16.4934 
 
 21.6475 
 
 7 X 
 
 22.7765 
 
 41.2825 
 
 3 We 
 
 10.4065 
 
 8.6179 
 
 5 We 
 
 16.6897 
 
 22.1660 
 
 7 We 
 
 22.9729 
 
 41.9973 
 
 3 X 
 
 10.6029 
 
 8.9462 
 
 5 X 
 
 16.8861 
 
 22.6906 
 
 7 X 
 
 23.1692 
 
 42.7183 
 
 3 We 
 
 10.7992 
 
 9.2806 
 
 5 We 
 
 17.0824 
 
 23.2214 
 
 7 We 
 
 23.3656 
 
 43.4454 
 
 3 X 
 
 10.9956 
 
 9.6211 
 
 5 X 
 
 17.2788 
 
 23.7583 
 
 7 X 
 
 23.5619 
 
 44.1786 
 
 3 % 
 
 11.1919 
 
 9.9678 
 
 5 We 
 
 17.4751 
 
 24.3013 
 
 7 We 
 
 23.7583 
 
 44.9180 
 
 3 x 
 
 11.3883 
 
 10.3206 
 
 5 X 
 
 17.6715 
 
 24.8505 
 
 7 X 
 
 23.9546 
 
 45.6635 
 
 VWe 
 
 11.5846 
 
 10.6796 
 
 5' We 
 
 17.8678 
 
 25.4058 
 
 7 1 We 
 
 24.1510 
 
 46.4152 
 
 3 x 
 
 11.7810 
 
 11.0447 
 
 5X 
 
 18.0642 
 
 25.9672 
 
 7 X 
 
 24.3473 
 
 47.1730 
 
 3 13 /4 
 
 11.9773 
 
 11.4159 
 
 5 13 4 
 
 18.2605 
 
 26.5348 
 
 7 13 4 
 
 24.5437 
 
 47.9369 
 
 3 X 
 
 12.1737 
 
 11.7932 
 
 5 X 
 
 18.4569 
 
 27.1085 
 
 7 X 
 
 24.7400 
 
 48.7070 
 
 3’54 
 
 12.3700 
 
 12.1767 
 
 5'We 
 
 18.6532 
 
 27.6884 
 
 7'We 
 
 24.9364 
 
 49.4831 
 
 4 
 
 12.5664 
 
 12.5664 
 
 6 
 
 18.8496 
 
 28.2743 
 
 8 
 
 25.1327 
 
 50.2655 
 
 4 We 
 
 12.7627 
 
 12.9621 
 
 6 We 
 
 19.0459 
 
 28.8665 
 
 8 We 
 
 25.3291 
 
 51.0539 
 
 4 X 
 
 12.9591 
 
 13.3640 
 
 6 X 
 
 19.2423 
 
 29.4647 
 
 8 X 
 
 25.5254 
 
 51.8486 
 
 4 ^4 
 
 13.1554 
 
 13.7721 
 
 6X6 
 
 19.4386 
 
 30.0691 
 
 8 We 
 
 25.7218 
 
 52.6493 
 
 4 X 
 
 13.3518 
 
 14.1863 
 
 6 X 
 
 19.6350 
 
 30.6796 
 
 8 X 
 
 25.9181 
 
 53.4562 
 
 4 *4 
 
 13.5481 
 
 14.6066 
 
 6 We 
 
 19.8313 
 
 31.2963 
 
 8 We 
 
 26.1145 
 
 54.2692 
 
 4 X 
 
 13.7445 
 
 15.0330 
 
 6 X 
 
 20.0277 
 
 31.9191 
 
 8 X 
 
 26.3108 
 
 55.0883 
 
 4 Xe 
 
 13.9408 
 
 15.4656 
 
 6X6 
 
 20.2240 
 
 32.5480 
 
 8 We 
 
 26.5072 
 
 55.9136 
 
 4 X 
 
 14.1372 ' 
 
 15.9043 
 
 6 X 
 
 20.4204 
 
 33.1831 
 
 8 X 
 
 26.7035 
 
 56.7450 
 
 We 
 
 14.3335 
 
 16.3492 
 
 6 We 
 
 20.6167 
 
 33.8243 
 
 8 We 
 
 26.8999 
 
 57.5826 
 
 4 X 
 
 14.5299 
 
 16.8002 
 
 6 X 
 
 20.8131 
 
 34.4716 
 
 8 X 
 
 27.0962 
 
 58.4263 
 
 4 u /4 
 
 14.7262 
 
 17.2573 
 
 6 1 Xe 
 
 21.0094 
 
 35.1251 
 
 &We 
 
 27.2926 
 
 59.2761 
 
 4 X 
 
 14.9226 
 
 17.7205 
 
 6 X 
 
 21.2058 
 
 35.7847 
 
 8 X 
 
 27.4889 
 
 60.1320 
 
 4 13 /4 
 
 15.1189 
 
 18.1899 
 
 6' 3 46 
 
 21:4021 
 
 36.4504 
 
 8 13 4 
 
 27.6853 
 
 60.9941 
 
 4 X 
 
 15.3153 
 
 18.6655 
 
 6 X 
 
 21.5984 
 
 37.1223 
 
 8 X 
 
 27.8816 
 
 61.8624 
 
 4 15 4e 
 
 15.5116 
 
 19.1472 
 
 6 15 X 
 
 21.7948 
 
 37.8004 
 
 8 l We 
 
 28.0780 
 
 62.7367 
 
 5 
 
 15.7080 
 
 19.6350 
 
 7 
 
 21.9911 
 
 38.4845 
 
 9 
 
 i 
 
 28.2743 
 
 63.6173 
 
The H art ford Steam Boiler Inspection and Insurance Co 
 
 59 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 9 
 
 28.2743 
 
 63.6173 
 
 11 
 
 34.5575 
 
 95.0332 
 
 13 
 
 40.8407 
 
 132.7323 
 
 9 14 
 
 9 yi 
 
 9 We 
 
 28.4707 
 
 28.6670 
 
 28.8634 
 
 64.5039 
 65.3967 
 66.2956 
 
 U We 
 
 11 X 
 
 11 We 
 
 34.7539 
 
 34.9502 
 
 35.1466 
 
 96.1162 
 
 97.2053 
 
 98.3006 
 
 13 We 
 
 13 X 
 
 13 We 
 
 41.0371 
 
 41.2334 
 
 41.4298 
 
 134.0116 
 
 135.2971 
 
 136.5887 
 
 9 X 
 
 29.0597 
 
 67.2006 
 
 H X 
 
 35.3429 
 
 99.4020 
 
 13 X 
 
 41.6261 
 
 137.8865 
 
 9 We 
 
 9 H 
 
 9 We 
 
 29.2561 
 
 29.4524 
 
 29.6488 
 
 68.1118 
 
 69.0291 
 
 69.9526 
 
 11 We 
 u X 
 
 U We 
 
 35.5393 
 
 35.7356 
 
 35.9320 
 
 100.5095 
 
 101.6232 
 
 102.7430 
 
 13 We 
 
 13 X 
 
 13 We 
 
 41.8225 
 
 42.0188 
 
 42.2152 
 
 139.1903 
 
 140.5004 
 
 141.8165 
 
 9 X 
 
 29.8451 
 
 70.8822 
 
 11 X 
 
 36.1283 
 
 103.8689 
 
 13 X 
 
 42.4115 
 
 143.1388 
 
 9 We 
 
 9 X 
 
 9 x We 
 
 30.0415 
 
 30.2378 
 
 30.4342 
 
 71.8179 
 
 72.7598 
 73.7078 
 
 11 We 
 
 li x 
 
 ll 1 We 
 
 36.3247 
 
 36.5210 
 
 36.7174 
 
 105.0010 
 106.1392 
 107.2835 
 
 13 We 
 
 13 X 
 
 13 x We 
 
 42.6078 
 
 42.8042 
 
 43.0005 
 
 144.4672 
 
 145.8018 
 
 147.1425 
 
 9 X 
 
 30.6305 
 
 74.6619 
 
 11 X 
 
 36.9137 
 
 108.4340 
 
 13 X 
 
 43.1969 
 
 148.4893 
 
 9 x We 
 
 9 H 
 
 9 x We 
 
 30.8269 
 31.0232 
 31.2196 
 
 75.6222 
 76.5886 
 77.5611 
 
 ll x W> 
 
 li X 
 IDWe 
 
 37.1101 
 
 37.3064 
 37.5028 
 
 109.5907 
 110.7534 
 111.9223 
 
 13i We 
 
 13 X 
 13‘We 
 
 43.3932 
 
 43.5896 
 43.7859 
 
 149.8423 
 
 151.2014 
 
 152.5667 
 
 10 
 
 31.4159 
 
 78.5398 
 
 12 
 
 37.6991 
 
 113.0973 
 
 14 
 
 43.9823 
 
 153.9380 
 
 10 We 
 
 10 X 
 
 10 We 
 
 31.6123 
 
 31.8086 
 
 32.0050 
 
 79.5246 
 
 80.5156 
 81.5127 
 
 12 We 
 
 12 X 
 
 12 We 
 
 37.8955 
 
 38.0918 
 
 38.2882 
 
 114.2785 
 
 115.4658 
 
 116.6592 
 
 14 We 
 
 14 X 
 
 14 We 
 
 44.1786 
 
 44.3750 
 
 44.5713 
 
 155.3156 
 
 156.6992 
 
 158.0890 
 
 io X 
 
 32.2013 
 
 82.5159 
 
 12 X 
 
 38.4845 
 
 117.8588 
 
 14K 
 
 44.7677 
 
 159.4849 
 
 10 We 
 
 10 3/8 
 
 io We 
 
 32.3977 
 
 32.5940 
 32.7904 
 
 83.5253 
 
 84.5407 
 85.5624 
 
 12 We 
 
 12 H 
 
 12 We 
 
 38.6809 
 
 38.8772 
 
 39.0736 
 
 119.0645 
 
 120.2764 
 
 121.4943 
 
 14 We 
 
 14 X 
 
 14 We 
 
 44.9640 
 
 45.1604 
 45.3567 
 
 160.8870 
 
 162.2952 
 
 163.7095 
 
 io X 
 
 32.9867 
 
 86.5901 
 
 12 X 
 
 39.2699 
 
 122.7185 
 
 14 X 
 
 45.5531 
 
 165.1300 
 
 io We 
 
 10 x 
 
 10 iWe 
 
 33.1831 
 
 33.3794 
 
 33.5758 
 
 87.6240 
 
 88.6641 
 
 89.7103 
 
 12 We 
 
 12 X 
 12 x We 
 
 39.4663 
 
 39.6626 
 
 39.8590 
 
 123.9487 
 
 125.1851 
 
 126.4276 
 
 14 We 
 
 14 X 
 
 14‘We 
 
 45.7494 
 
 45.9458 
 
 46.1421 
 
 166.5566 
 
 167.9893 
 
 169.4282 
 
 10 x 
 
 33.7721 
 
 90.7626 
 
 12 X 
 
 40.0553 
 
 127.6763 
 
 14 X 
 
 46.3385 
 
 170.8732 
 
 10 iWe 
 
 10 X 
 
 10 iWe 
 
 33.9685 
 
 34.1648 
 34.3612 
 
 91.8210 
 
 92.8856 
 
 93.9563 
 
 12i We 
 
 12 X 
 12 1 We 
 
 40.2517 
 
 40.4480 
 
 40.6444 
 
 128.9311 
 
 130.1920 
 
 131.4591 
 
 14iWe 
 
 14 X 
 
 14iWe 
 
 46.5348 
 
 46.7312 
 
 46.9275 
 
 172.3243 
 
 173.7816 
 
 175.2450 
 
 11 
 
 34.5575 
 
 95.0332 
 
 13 
 
 40.8407 
 
 132.7323 
 
 15 
 
 47.1239 
 
 176.7146 
 
60 The H ar tf or d Steam Boiler Inspection and Insurance Co 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 
 ference 
 
 
 
 ference 
 
 
 
 ference 
 
 
 15 
 
 47.124 
 
 176.715 
 
 20 
 
 62.832 
 
 314.159 
 
 25 
 
 78.540 
 
 490.874 
 
 X 
 
 47.517 
 
 179.672 
 
 X 
 
 63.225 
 
 318.099 
 
 X 
 
 78.933 
 
 495.795 
 
 X 
 
 47.909 
 
 182.654 
 
 X 
 
 63.617 
 
 322.062 
 
 X 
 
 79.325 
 
 500.740 
 
 X 
 
 48.302 
 
 185.661 
 
 x& 
 
 64.010 
 
 326.051 
 
 X 
 
 79.718 
 
 505.710 
 
 X 
 
 48.695 
 
 188.692 
 
 X 
 
 64.403 
 
 330.064 
 
 X 
 
 80.111 
 
 510.705 
 
 X 
 
 49.087 
 
 191.748 
 
 X 
 
 64.795 
 
 334.101 
 
 X 
 
 80.503 
 
 515.724 
 
 X 
 
 49.480 
 
 194.828 
 
 X 
 
 65.188 
 
 338.163 
 
 X 
 
 80.896 
 
 520.768 
 
 X 
 
 49.873 
 
 197.933 
 
 X 
 
 65.581 
 
 342.250 
 
 X 
 
 81.289 
 
 525.836 
 
 16 
 
 50.265 
 
 201.062 
 
 21 
 
 65.973 
 
 346.361 
 
 26 
 
 81.681 
 
 530.929 
 
 X 
 
 50.658 
 
 204.216 
 
 X 
 
 66.366 
 
 350.496 
 
 X 
 
 82.074 
 
 536.046 
 
 X 
 
 51.051 
 
 207.394 
 
 X 
 
 66.759 
 
 354.656 
 
 X 
 
 82.467 
 
 541.188 
 
 X 
 
 51.444 
 
 210.597 
 
 X 
 
 67.152 
 
 358.841 
 
 X 
 
 82.860 
 
 546.355 
 
 X 
 
 51.836 
 
 213.825 
 
 X 
 
 67.544 
 
 363.050 
 
 X 
 
 83.252 
 
 551.546 
 
 X 
 
 52.229 
 
 217.077 
 
 X 
 
 67.937 
 
 367.284 
 
 X 
 
 83.645 
 
 556.761 
 
 Va 
 
 52.622 
 
 220.353 
 
 X 
 
 68.330 
 
 371.542 
 
 X 
 
 84.038 
 
 562.001 
 
 X 
 
 53.014 
 
 223.654 
 
 X 
 
 68.722 
 
 375.825 
 
 X 
 
 84.430 
 
 567.266 
 
 17 
 
 53.407 
 
 226.980 
 
 22 
 
 69.115 
 
 380.133 
 
 27 
 
 84.823 
 
 572.555 
 
 X 
 
 53.800 
 
 230.330 
 
 X 
 
 69.508 
 
 384.465 
 
 x 
 
 85.216 
 
 577.869 
 
 Va 
 
 54.192 
 
 233.705 
 
 X 
 
 69.900 
 
 388.821 
 
 X 
 
 85.608 
 
 583.207 
 
 X 
 
 54.585 
 
 237.104 
 
 X 
 
 70.293 
 
 393.202 
 
 X 
 
 86.001 
 
 588.570 
 
 X 
 
 54.978 
 
 240.528 
 
 X 
 
 70.686 
 
 397.608 
 
 X 
 
 86.394 
 
 593.957 
 
 X 
 
 55.371 
 
 243.977 
 
 X 
 
 71.079 
 
 402.038 
 
 X 
 
 86.786 
 
 599.369 
 
 Va 
 
 55.763 
 
 247.450 
 
 X 
 
 71.471 
 
 406.493 
 
 X 
 
 87.179 
 
 604.805 
 
 X 
 
 56.156 
 
 250.947 
 
 X 
 
 71.864 
 
 410.972 
 
 X 
 
 87.572 
 
 610.266 
 
 18 
 
 56.549 
 
 254.469 
 
 23 
 
 72.257 
 
 415.476 
 
 28 
 
 87.965 
 
 615.752 
 
 yk 
 
 56.941 
 
 258.016 
 
 X 
 
 72.649 
 
 420.004 
 
 yk 
 
 88.357 
 
 621.262 
 
 Xa 
 
 57.334 
 
 261.587 
 
 X 
 
 73.042 
 
 424.557 
 
 X, 
 
 88.750 
 
 626.797 
 
 X • 
 
 57.727 
 
 265.182 
 
 X 
 
 73.435 
 
 429.134 
 
 X 
 
 89.143 
 
 632.356 
 
 X 
 
 58.119 
 
 268.802 
 
 X 
 
 73.827 
 
 433.736 
 
 X 
 
 89.535 
 
 637.940 
 
 X 
 
 58.512 
 
 272.447 
 
 X 
 
 74.220 
 
 438.363 
 
 X 
 
 89.928 
 
 643.548 
 
 Va 
 
 58.905 
 
 276.117 
 
 X 
 
 74.613 
 
 443.014 
 
 X 
 
 90.321 
 
 649.180 
 
 X 
 
 59.298 
 
 279.811 
 
 X 
 
 75.006 
 
 447.689 
 
 X 
 
 90.714 
 
 654.838 
 
 19 
 
 59.690 
 
 283.529 
 
 24 
 
 75.398 
 
 452.389 
 
 29 
 
 91.106 
 
 660.520 
 
 X 
 
 60.083 
 
 287.272 
 
 X 
 
 75.791 
 
 457.114 
 
 X 
 
 91.499 
 
 666.226 
 
 X 
 
 60.476 
 
 291.039 
 
 X 
 
 76.184 
 
 461.863 
 
 X 
 
 91.892 
 
 671.957 
 
 X 
 
 60.868 
 
 294.831 
 
 X 
 
 76.576 
 
 466.637 
 
 X 
 
 92.284 
 
 677.713 
 
 X 
 
 61.261 
 
 298.648 
 
 X 
 
 76.969 
 
 471.435 
 
 X 
 
 92.677 
 
 683.493 
 
 X 
 
 61.654 
 
 302.489 
 
 X 
 
 77.362 
 
 476.258 
 
 X 
 
 93.070 
 
 689.297 
 
 X 
 
 62.046 
 
 306.355 
 
 X 
 
 77.754 
 
 481.105 
 
 X 
 
 93.462 
 
 695.126 
 
 X 
 
 62.439 
 
 310.245 
 
 X 
 
 78.147 
 
 485.977 
 
 X 
 
 93.855 
 
 700.980 
 
 20 
 
 62.832 
 
 314.159 
 
 25 
 
 78.540 
 
 490.874 
 
 30 
 
 94.248 
 
 706.858 
 
 ( 
 
The Hartford Steam Boiler I nspection and Insurance Co 
 
 61 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 30 
 
 94.248 
 
 706.86 
 
 35 
 
 109.956 
 
 962.11 
 
 40 
 
 125.664 
 
 1256.64 
 
 A 
 
 94.640 
 
 712.76 
 
 A 
 
 110.348 
 
 969.00 
 
 A 
 
 126.056 
 
 1264.50 
 
 A 
 
 95.033 
 
 718.69 
 
 Va 
 
 110.741 
 
 975.91 
 
 A 
 
 126.449 
 
 1272.39 
 
 A 
 
 95.426 
 
 724.64 
 
 A 
 
 111.134 
 
 982.84 
 
 A 
 
 126.842 
 
 1280.31 
 
 A 
 
 95.819 
 
 730.62 
 
 A 
 
 111.526 
 
 989.80 
 
 A 
 
 127.234 
 
 1288.25 
 
 A 
 
 96.211 
 
 736.62 
 
 A 
 
 111.919 
 
 996.78 
 
 A 
 
 127.627 
 
 1296.21 
 
 Va 
 
 96.604 
 
 742.64 
 
 Va 
 
 112.312 
 
 1003.79 
 
 A 
 
 128.020 
 
 1304.20 
 
 A. 
 
 96.997 
 
 748.69 
 
 A 
 
 112.705 
 
 1010.82 
 
 A 
 
 128.413 
 
 1312.22 
 
 31 
 
 97.389 
 
 754.77 
 
 36 
 
 113.097 
 
 1017.88 
 
 41 
 
 128.805 
 
 1320.25 
 
 A 
 
 97.782 
 
 760.87 
 
 A 
 
 113.490 
 
 1024.96 
 
 A 
 
 129.198 
 
 1328.32 
 
 Va 
 
 98.175 
 
 766.99 
 
 A 
 
 113.883 
 
 1032.06 
 
 A 
 
 129.591 
 
 1336.40 
 
 A 
 
 98.568 
 
 773.14 
 
 A 
 
 114.275 
 
 1039.19 
 
 A 
 
 129.983 
 
 1344.52 
 
 A 
 
 98.960 
 
 779.31 
 
 A 
 
 114.668 
 
 1046.35 
 
 A 
 
 130.376 
 
 1352.65 
 
 A 
 
 99.353 
 
 785.51 
 
 A 
 
 115.061- 
 
 1053.53 
 
 A 
 
 130.769 
 
 1360.81 
 
 Va 
 
 99.746 
 
 791.73 
 
 Va 
 
 115.454 
 
 1060.73 
 
 A 
 
 131.162 
 
 1369.00 
 
 A 
 
 100.138 
 
 797.98 
 
 7 A 
 
 115.846 
 
 1067.96 
 
 A 
 
 131.554 
 
 1377.21 
 
 32 
 
 100.531 
 
 804.25 
 
 37 
 
 116.239 
 
 1075.21 
 
 42 
 
 131.947 
 
 1385.44 
 
 a 
 
 100.924 
 
 810.54 
 
 A 
 
 116.632 
 
 1082.49 
 
 A 
 
 132,340 
 
 1393.70 
 
 Va 
 
 101.316 
 
 816.86 
 
 A 
 
 117.024 
 
 1089.79 
 
 A 
 
 132.732 
 
 1401.98 
 
 H 
 
 101.709 
 
 823.21 
 
 A 
 
 117.417 
 
 1097.12 
 
 A 
 
 133.125 
 
 1410.29 
 
 A 
 
 102.102 
 
 829.58 
 
 A 
 
 117.810 
 
 1104.47 
 
 A 
 
 133.518 
 
 1418.62 
 
 
 102.494 
 
 835.97 
 
 A 
 
 118.202 
 
 1111.84 
 
 A 
 
 133.910 
 
 1426.98 
 
 Va 
 
 102.887 
 
 842.39 
 
 A 
 
 118.595 
 
 1119.24 
 
 A 
 
 134.303 
 
 1435.36 
 
 A 
 
 103.280 
 
 848.83 
 
 A 
 
 118.988 
 
 1126.66 
 
 A 
 
 134.696 
 
 1443.77 
 
 33 
 
 103.673 
 
 855.30 
 
 38 
 
 119.381 
 
 1134.11 
 
 43 
 
 135.088 
 
 1452.20 
 
 H 
 
 104.065 
 
 861.79 
 
 A 
 
 119.773 
 
 1141.59 
 
 A. 
 
 135.481 
 
 1460.66 
 
 Va 
 
 104.458 
 
 868.31 
 
 A 
 
 120.166 
 
 1149.09 
 
 A 
 
 135.874 
 
 1469.14 
 
 H 
 
 104.851 
 
 874.85 
 
 A 
 
 120.559 
 
 1156.61 
 
 A 
 
 136.267 
 
 1477.64 
 
 A 
 
 105.243 
 
 881.41 
 
 A 
 
 120.951 
 
 1164.16 
 
 A 
 
 136.659 
 
 1486.17 
 
 A 
 
 105.636 
 
 888.00 
 
 A 
 
 121.344 
 
 1171.73 
 
 A 
 
 137.052 
 
 1494.72 
 
 Va 
 
 106.029 
 
 894.62 
 
 A 
 
 121.737 
 
 1179.32 
 
 A 
 
 137.445 
 
 1503.30 
 
 A 
 
 106.422 
 
 901.26 
 
 A 
 
 122.129 
 
 1186.94 
 
 A 
 
 137.837 
 
 1511.90 
 
 34 
 
 106.814 
 
 907.92 
 
 39 
 
 122.522 
 
 1194.59 
 
 44 
 
 138.230 
 
 1520.53 
 
 H 
 
 107.207 
 
 914.61 
 
 A 
 
 122.915 
 
 1202.26 
 
 As 
 
 138.623 
 
 1529.18 
 
 Va 
 
 107.600 
 
 921.32 
 
 A 
 
 123.308 
 
 1209.96 
 
 A 
 
 139.016 
 
 1537.86 
 
 A 
 
 107.992 
 
 928.06 
 
 A 
 
 123.700 
 
 1217.67 
 
 y& 
 
 139.408 
 
 1546.56 
 
 A 
 
 108.385 
 
 934.82 
 
 A 
 
 124.093 
 
 1225.42 
 
 A 
 
 139.801 
 
 1555.28 
 
 Az 
 
 108.778 
 
 941.61 
 
 A 
 
 124.486 
 
 1233.19 
 
 A 
 
 140.194 
 
 1564.03 
 
 Va 
 
 109.170 
 
 948.42 
 
 A 
 
 124.878 
 
 1240.98 
 
 A 
 
 140.586 
 
 1572.81 
 
 A 
 
 109.563 
 
 955.25 
 
 A 
 
 125.271 
 
 1248.80 
 
 A 
 
 140.979 
 
 1581.61 
 
 35 
 
 109.956 
 
 962.11 
 
 40 
 
 125.664 
 
 1256.64 
 
 45 
 
 141.372 
 
 1590.43 
 
62 The H a rtf or d Steam Boiler Inspection and Insurance Co 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 45 
 
 141.372 
 
 1590.43 
 
 50 
 
 157.080 
 
 1963.50 
 
 55 
 
 172.788 
 
 2375.83 
 
 A 
 
 141.764 
 
 1599.28 
 
 As 
 
 157.472 
 
 1973.33 
 
 As 
 
 173.180 
 
 2386.64 
 
 y 
 
 142.157 
 
 1608.15 
 
 A 
 
 157.865 
 
 1983.18 
 
 A 
 
 173.573 
 
 2397.48 
 
 A 
 
 142.550 
 
 1617.05 
 
 As 
 
 158.258 
 
 1993.06 
 
 A 
 
 173.966 
 
 2408.34 
 
 A 
 
 142.942 
 
 1625.97 
 
 K 
 
 158.650 
 
 2002.96 
 
 A 
 
 174.358 
 
 2419.22 
 
 A 
 
 143.335 
 
 1634.92 
 
 As 
 
 159.043 
 
 2012.89 
 
 As 
 
 174.751 
 
 2430.13 
 
 y 
 
 143.728 
 
 1643.89 
 
 A 
 
 159.436 
 
 2022.84 
 
 A, 
 
 175.144 
 
 2441.07 
 
 As 
 
 144.121 
 
 1652.88 
 
 A 
 
 159.828 
 
 2032.82 
 
 As 
 
 175.536 
 
 2452.03 
 
 46 
 
 144.513 
 
 1661.90 
 
 51 
 
 160.221 
 
 2042.82 
 
 56 
 
 175.929 
 
 2463.01 
 
 A 
 
 144.906 
 
 1670.95 
 
 A 
 
 160.614 
 
 2052.85 
 
 As 
 
 176.322 
 
 2474.02 
 
 A 
 
 145.299 
 
 1680.02 
 
 A 
 
 161.007 
 
 2062.90 
 
 A 
 
 176.715 
 
 2485.05 
 
 A 
 
 145.691 
 
 1689.11 
 
 As 
 
 161.399 
 
 2072.97 
 
 As 
 
 177.107 
 
 2496.11 
 
 A 
 
 146.084 
 
 1698.23 
 
 A 
 
 161.792 
 
 2083.07 
 
 K 
 
 177.500 
 
 2507.19 
 
 A 
 
 146.477 
 
 1707.37 
 
 As 
 
 162.185 
 
 2093.20 
 
 As 
 
 177.893 
 
 2518.29 
 
 3 A 
 
 146.870 
 
 1716.54 
 
 A. 
 
 162.577 
 
 2103.35 
 
 A 
 
 178.285 
 
 2529.42 
 
 A 
 
 147.262 
 
 1725.73 
 
 As 
 
 162.970 
 
 2113.52 
 
 As 
 
 178.678 
 
 2540.58 
 
 47 
 
 147.655 
 
 1734.94 
 
 52 
 
 163.363 
 
 2123.72 
 
 57 
 
 179.071 
 
 2551.76 
 
 A 
 
 148.048 
 
 1744.19 
 
 As 
 
 163.756 
 
 2133.94 
 
 As 
 
 179.464 
 
 2562.96 
 
 A 
 
 148.440 
 
 1753.45 
 
 A, 
 
 164.148 
 
 2144.19 
 
 A, 
 
 179.856 
 
 2574.19 
 
 H 
 
 148.833 
 
 1762.74 
 
 As 
 
 164.541 
 
 2154.46 
 
 A 
 
 180.249 
 
 2585.45 
 
 A 
 
 149.226 
 
 1772.05 
 
 A* 
 
 164.934 
 
 2164.75 
 
 A 
 
 180.642 
 
 2596.73 
 
 A 
 
 149.618 
 
 1781.39 
 
 A 
 
 165.326 
 
 2175.08 
 
 As 
 
 181.034 
 
 2608.03 
 
 A 
 
 150.011 
 
 1790.76 
 
 A 
 
 165.719 
 
 2185.42 
 
 A 
 
 181.427 
 
 2619.35 
 
 A 
 
 150.404 
 
 1800.14 
 
 As 
 
 166.112 
 
 2195.79 
 
 As 
 
 181.820 
 
 2630.70 
 
 48 
 
 150.796 
 
 1809.56 
 
 53 
 
 166.504 
 
 2206.18 
 
 58 
 
 182.212 
 
 2642.08 
 
 A 
 
 151.189 
 
 1818.99 
 
 A 
 
 166.897 
 
 2216.60 
 
 As 
 
 182.605 
 
 2653.48 
 
 A 
 
 151.582 
 
 1828.46 
 
 A 
 
 167.290 
 
 2227.05 
 
 A 
 
 182.998 
 
 2664.91 
 
 H 
 
 151.974 
 
 1837.94 
 
 As 
 
 167.682 
 
 2237.52 
 
 A 
 
 183.390 
 
 2676.36 
 
 A 
 
 152.367 
 
 1847.45 
 
 A 
 
 168.075 
 
 2248.01 
 
 A 
 
 183.783 
 
 2687.83 
 
 A 
 
 152.760 
 
 1856.99 
 
 As 
 
 168.468 
 
 2258.53 
 
 A 
 
 184.176 
 
 2699.33 
 
 A 
 
 153.153 
 
 1866.55 
 
 A 
 
 168.861 
 
 2269.07 
 
 A 
 
 184.569 
 
 2710.85 
 
 A 
 
 153.545 
 
 1876.13 
 
 As 
 
 169.253 
 
 2279.63 
 
 As 
 
 184.961 
 
 2722.40 
 
 49 
 
 153.938 
 
 1885.74 
 
 54 
 
 169.646 
 
 2290.22 
 
 59 
 
 185.354 
 
 2733.97 
 
 A 
 
 154.331 
 
 1895.37 
 
 As 
 
 170.039 
 
 2300.84 
 
 A 
 
 185.747 
 
 2745.57 
 
 A 
 
 154.723 
 
 1905.03 
 
 A, 
 
 170.431 
 
 2311.48 
 
 A 
 
 186.139 • 
 
 2757.19 
 
 As 
 
 155.116 
 
 1914.72 
 
 As 
 
 170.824 
 
 2322.14 
 
 As 
 
 186.532 
 
 2768.84 
 
 A 
 
 155.509 
 
 1924.42 
 
 A 
 
 171.217 
 
 2332.83 
 
 A 
 
 186.925 
 
 2780.51 
 
 A 
 
 155.902 
 
 1934.15 
 
 A 
 
 171.610 
 
 2343.54 
 
 As 
 
 187.318 
 
 2792.20 
 
 A 
 
 156.294 
 
 1943.91 
 
 A 
 
 172.002 
 
 2354.28 
 
 A, 
 
 187.710 
 
 2803.92 
 
 A 
 
 156.687 
 
 1953.69 
 
 As 
 
 172.395 
 
 2365.04 
 
 As 
 
 188.103 
 
 2815.67 
 
 50 
 
 157.080 
 
 1963.50 
 
 55 
 
 172.788 
 
 2375.83 
 
 60 
 
 188.496 
 
 2827.43 
 
The Hartford Steam Boiler Inspection and Insurance Co 
 
 63 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 
 ference 
 
 
 
 ference 
 
 
 
 ference 
 
 > 
 
 
 60 
 
 188.496 
 
 2827.43 
 
 65 
 
 204.204 
 
 3318.31 
 
 70 
 
 219.911 
 
 3848.45 
 
 X 
 
 188.888 
 
 2839.23 
 
 X 
 
 204.596 
 
 3331.08 
 
 X 
 
 220.304 
 
 3862.21 
 
 X 
 
 189.281 
 
 2851.04 
 
 X 
 
 204.989 
 
 3343.88 
 
 X 
 
 220.697 
 
 3875.99 
 
 X 
 
 189.674 
 
 2862.89 
 
 X 
 
 205.382 
 
 3356.71 
 
 X 
 
 221.090 
 
 3889.80 
 
 X 
 
 190.066 
 
 2874.75 
 
 X 
 
 205.774 
 
 3369.55 
 
 X 
 
 221.482 
 
 3903.63 
 
 X 
 
 190.459 
 
 2886.65 
 
 X 
 
 206.167 
 
 3382.43 
 
 X 
 
 221.875 
 
 3917.48 
 
 X 
 
 190.852 
 
 2898.56 
 
 X 
 
 206.560 
 
 3395.33 
 
 X 
 
 222.268 
 
 3931.36 
 
 X 
 
 191.244 
 
 2910.50 
 
 X 
 
 206.952 
 
 3408.25 
 
 X 
 
 222.660 
 
 3945.26 
 
 61 
 
 191.637 
 
 2922.47 
 
 66 
 
 207.345 
 
 3421.19 
 
 71 
 
 223.053 
 
 3959.19 
 
 x 
 
 192.030 
 
 2934.46 
 
 X 
 
 207.738 
 
 3434.17 
 
 X 
 
 223.446 
 
 3973.15 
 
 x 
 
 192.423 
 
 2946.47 
 
 X 
 
 208.130 
 
 3447.17 
 
 X 
 
 223.838 
 
 3987.12 
 
 X 
 
 192.815 
 
 2958.51 
 
 X 
 
 208.523 
 
 3460.18 
 
 X 
 
 224.231 
 
 4001.13 
 
 X 
 
 193.208 
 
 2970.57 
 
 X 
 
 208.916 
 
 3473.23 
 
 X 
 
 224.624 
 
 4015.15 
 
 X 
 
 193.601 
 
 2982.66 
 
 X 
 
 209.309 
 
 3486.30 
 
 X 
 
 225.017 
 
 4029.20 
 
 X 
 
 193.993 
 
 2994.77 
 
 X 
 
 209.701 
 
 3499.39 
 
 X 
 
 225.409 
 
 4043.28 
 
 X 
 
 194.386 
 
 3006.91 
 
 X 
 
 210.094 
 
 3512.51 
 
 X 
 
 225.802 
 
 4057.38 
 
 62 
 
 194.779 
 
 3019.07 
 
 67 
 
 210.487 
 
 3525.65 
 
 72 
 
 226.195 
 
 4071.50 
 
 X 
 
 195.172 
 
 3031.26 
 
 X 
 
 210.879 
 
 3538.82 
 
 X 
 
 226.587 
 
 4085.65 
 
 X 
 
 195.564 
 
 3043.47 
 
 X 
 
 211.272 
 
 3552.01 
 
 X 
 
 226.980 
 
 4099.83 
 
 X 
 
 195.957 
 
 3055.70 
 
 X 
 
 211.665 
 
 3565.23 
 
 X 
 
 227.373 
 
 4114.03 
 
 X 
 
 196.350 
 
 3067.96 
 
 X 
 
 212.058 
 
 3578.47 
 
 X 
 
 227.766 
 
 4128.25 
 
 X 
 
 196.742 
 
 3080.25 
 
 X 
 
 212.450 
 
 3591.74 
 
 X 
 
 228.158 
 
 4142.50 
 
 X 
 
 197.135 
 
 3092.56 
 
 X 
 
 212.843 
 
 3605.03 
 
 X 
 
 228.551 
 
 4156.77 
 
 X 
 
 197.528 
 
 3104.89 
 
 X 
 
 213.236 
 
 3618.34 
 
 X 
 
 228.944 
 
 4171.07 
 
 63 
 
 197.920 
 
 3117.25 
 
 68 
 
 213.628 
 
 3631.68 
 
 73 
 
 229.336 
 
 4185.39 
 
 X 
 
 198.313 
 
 3129.63 
 
 X 
 
 214.021 
 
 3645.05 
 
 X 
 
 229.729 
 
 4199.73 
 
 X 
 
 198.706 
 
 3142.03 
 
 X 
 
 214.414 
 
 3658.43 
 
 X 
 
 230.122 
 
 4214.10 
 
 X 
 
 199.098 
 
 3154.47 
 
 X 
 
 214.806 
 
 3671.85 
 
 X 
 
 230.514 
 
 4228.50 
 
 X 
 
 199.491 
 
 3166.92 
 
 X 
 
 215.199 
 
 3685.28 
 
 X 
 
 230.907 
 
 4242.92 
 
 X 
 
 199.884 
 
 3179.40 
 
 X 
 
 215.592 
 
 3698.75 
 
 X 
 
 231.300 
 
 4257.36 
 
 X 
 
 200.276 
 
 3191.91 
 
 X 
 
 215.984 
 
 3712.23 
 
 X 
 
 231.692 
 
 4271.83 
 
 X 
 
 200.669 
 
 3204.44 
 
 X 
 
 216.377 
 
 3725.75 
 
 X 
 
 232.085 
 
 4286.32 
 
 r 
 
 64 
 
 201.062 
 
 3216.99 
 
 69 
 
 216.770 
 
 3739.28 
 
 74 
 
 232.478 
 
 4300.84 
 
 X 
 
 201.455 
 
 3229.57 
 
 X 
 
 217.163 
 
 3752.84 
 
 X 
 
 232.871 
 
 4315.38 
 
 X 
 
 201.847 
 
 3242.17 
 
 X 
 
 217.555 
 
 3766.43 
 
 X 
 
 233.263 
 
 4329.95 
 
 X 
 
 202.240 
 
 3254.80 
 
 X 
 
 217.948 
 
 3780.04 
 
 X 
 
 233.656 
 
 4344.54 
 
 X 
 
 202.633 
 
 3267.45 
 
 X 
 
 218.341 
 
 3793.67 
 
 X 
 
 234.049 
 
 4359.16 
 
 X 
 
 203.025 
 
 3280.13 
 
 X 
 
 218.733 
 
 3807.33 
 
 X 
 
 234.441 
 
 4373.80 
 
 X 
 
 203.418 
 
 3292.83 
 
 X 
 
 219.126 
 
 3821.01 
 
 X 
 
 234.834 
 
 4388.46 
 
 X 
 
 203.811 
 
 3305.56 
 
 X 
 
 219.519 
 
 3834.72 
 
 X 
 
 235.227 
 
 4403.15 
 
 65 
 
 204.204 
 
 3318.31 
 
 70 
 
 219.911 
 
 3848.45 
 
 75 
 
 235.619 
 
 4417.86 
 
64 The Hartford Steam Boiler Inspection and I nsur ance Co 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 Diameter 
 
 Circum- 
 
 Area ' 
 
 Diameter 
 
 Circum- 
 
 Area 
 
 
 ference 
 
 
 
 ference 
 
 
 
 ference 
 
 
 75 
 
 235.619 
 
 4417.86 
 
 80 
 
 251.327 
 
 5026.55 
 
 85 
 
 267.035 
 
 5674.50 
 
 x 
 
 236.012 
 
 4432.60 
 
 X 
 
 251.720 
 
 • 5042 .'27 
 
 X 
 
 267.428 
 
 5691.20 
 
 X 
 
 236.405 
 
 4447.37 
 
 X 
 
 252.113 
 
 5058.01 
 
 X 
 
 267.821 
 
 5707.93 
 
 X 
 
 236.798 
 
 4462.15 
 
 X 
 
 252.506 
 
 5073.78 
 
 X 
 
 268.214 
 
 5724.68 
 
 X 
 
 237.190 
 
 4476.97 
 
 X 
 
 252.89S 
 
 5089.58 
 
 X 
 
 268.606 
 
 5741.46 
 
 x 
 
 237.583 
 
 4491.80 
 
 X 
 
 253.291 
 
 5105.39 
 
 X 
 
 268.999 
 
 5758.26 
 
 X 
 
 237.976 
 
 4506.66 
 
 X 
 
 253.684 
 
 5121.24 
 
 X 
 
 269.392 
 
 5775.08 
 
 X 
 
 238.368 
 
 4521.55 
 
 X 
 
 254.076 
 
 5137.10 
 
 X 
 
 269.784 
 
 5791.93 
 
 76 
 
 238.761 
 
 4536.46 
 
 81 
 
 254.469 
 
 5153.00 
 
 86 
 
 270.177 
 
 5808.80 
 
 X 
 
 239.154 
 
 4551.39 
 
 X 
 
 254.862 
 
 5168.91 
 
 X 
 
 270.570 
 
 5825.70 
 
 X 
 
 239.546 
 
 4566.35 
 
 X 
 
 255.254 
 
 5184.85 
 
 X 
 
 270.962 
 
 5842.63 
 
 X 
 
 239.939 
 
 4581.34 
 
 X 
 
 255.647 
 
 5200.82 
 
 X 
 
 271.355 
 
 5859.57 
 
 X 
 
 240.332 
 
 4596,35 
 
 X 
 
 256.040 
 
 5216.81 
 
 X 
 
 271.748 
 
 5876.55 
 
 X 
 
 240.724 
 
 4611.38 
 
 X 
 
 256.432 
 
 5232.83 
 
 X 
 
 272.140 
 
 5893.54 
 
 X 
 
 241.117 
 
 4626.44 
 
 X 
 
 256.825 
 
 5248.86 
 
 X 
 
 272.533 
 
 5910.56 
 
 X 
 
 241.510 
 
 4641.52 
 
 X 
 
 257.218 
 
 5264.93 
 
 X 
 
 272.926 
 
 5927.61 
 
 77 
 
 241.903 
 
 4656.63 
 
 82 
 
 257.611 
 
 5281.02 
 
 87 
 
 273.319 
 
 5944.68 
 
 X 
 
 242.295 
 
 4671.76 
 
 X 
 
 258.003 
 
 5297.13 
 
 X 
 
 273.711 
 
 5961.77 
 
 X 
 
 242.688 
 
 . 4686.91 
 
 X 
 
 258.396 
 
 5313.27 
 
 X 
 
 274.104 
 
 5978.89 
 
 X 
 
 243.081 
 
 4702.09 
 
 X 
 
 258.789 
 
 5329.43 
 
 X 
 
 274.497 
 
 5996.04 
 
 X 
 
 243.473 
 
 4717.30 
 
 X 
 
 259.181 
 
 5345.62 
 
 X 
 
 274.889 
 
 6013.20 
 
 X 
 
 243.866 
 
 4732.53 
 
 X 
 
 259.574 
 
 5361.83 
 
 X 
 
 275.282 
 
 6030.40 
 
 X 
 
 244.259 
 
 4747.78 
 
 X 
 
 259.967 
 
 5378.06 
 
 X 
 
 275.675 
 
 6047.62 
 
 X 
 
 244.652 
 
 4763.06 
 
 X 
 
 260.360 
 
 5394.32 
 
 X 
 
 276.068 
 
 6064.86 
 
 78 
 
 245.044 
 
 4778.36 
 
 83 
 
 260.752 
 
 5410.61 
 
 88 
 
 276.460 
 
 i 6082.12 
 
 X 
 
 245.437 
 
 4793.69 
 
 X 
 
 261.145 
 
 5426.92 
 
 X 
 
 276.853 
 
 6099.41 
 
 X 
 
 245.830 
 
 4809.04 
 
 X 
 
 261.538 
 
 5443.25 
 
 X 
 
 277.246 
 
 6116.73 
 
 X 
 
 246.222 
 
 4824.42 
 
 X 
 
 261.930 
 
 5459.61 
 
 X 
 
 277.638 
 
 6134.07 
 
 X 
 
 246.615 
 
 4839.82 
 
 X 
 
 262.323 
 
 5475.99 
 
 X 
 
 278.031 
 
 6151.44 
 
 X 
 
 247.008 
 
 4855.25 
 
 X 
 
 262.716 
 
 5492.40 
 
 X 
 
 278.424 
 
 6168.82 
 
 X 
 
 247.400 
 
 4870.70 
 
 X 
 
 263.108 
 
 5508.83 
 
 X 
 
 278.816 
 
 6186.24 
 
 X 
 
 247.793 
 
 4886.17 
 
 X 
 
 263.501 
 
 5525.29 
 
 X 
 
 279.209 
 
 6203.68 
 
 79 
 
 248.186 
 
 4901.67 
 
 84 
 
 263.894 
 
 5541.77 
 
 89 
 
 279.602 
 
 6221.14 
 
 X 
 
 248.578 
 
 4917.19 
 
 X 
 
 264.286 
 
 5558.28 
 
 X 
 
 279.994 
 
 6238.63 
 
 X 
 
 248.971 
 
 4932.74 
 
 X 
 
 264.679 
 
 5574.81 
 
 X 
 
 280.387 
 
 6256.14 
 
 X 
 
 249.364 
 
 4948.32 
 
 X 
 
 265.072 
 
 5591.36 
 
 X 
 
 280.780 
 
 6273.67 
 
 X 
 
 249.757 
 
 4963.91 
 
 X 
 
 265.465 
 
 5607.94 
 
 X 
 
 281.172 
 
 6291.24 
 
 X 
 
 250.149 
 
 4979.54 
 
 X 
 
 265.857 
 
 5624.54 
 
 X 
 
 281.565 
 
 6308.82 
 
 X 
 
 250.542 
 
 4995.18 
 
 X 
 
 266.250 
 
 5641.17 
 
 X 
 
 281.958 
 
 6326.43 
 
 X 
 
 250.935 
 
 5010.85 
 
 X 
 
 266.643 
 
 5657.82 
 
 X 
 
 282.351 
 
 6344.07 
 
 80 
 
 251.327 
 
 5026.55 
 
 85 
 
 267.035 
 
 5674.50 
 
 90 
 
 282.743 
 
 6361.73 
 
The Hartford Steam Boiler I nspcction and Insurance Co 
 
 65 
 
 Circumferences and Areas of Circles 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 Diameter 
 
 Circum¬ 
 
 ference 
 
 Area 
 
 90 
 
 282.743 
 
 6361.73 
 
 95 
 
 298.451 
 
 7088.22 
 
 100 
 
 314.159 
 
 7853.98 
 
 y 
 
 283.136 
 
 6379.41 
 
 y 
 
 298.844 
 
 7106.88 
 
 y 
 
 314.552 
 
 7873.63 
 
 y 
 
 283.529 
 
 6397.12 
 
 y 
 
 299.237 
 
 7125.57 
 
 y 
 
 314.945 
 
 7893.30 
 
 H 
 
 283.921 
 
 6414.85 
 
 y 
 
 299.629 
 
 7144.29 
 
 y 
 
 315.337 
 
 7913.00 
 
 y 
 
 284.314 
 
 6432.61 
 
 y 
 
 300.022 
 
 7163.03 
 
 y 
 
 315.730 
 
 7932.72 
 
 y 
 
 284.707 
 
 6450.39 
 
 y 
 
 300.415 
 
 7181.79 
 
 y 
 
 316.123 
 
 7952.46 
 
 K 
 
 285.100 
 
 6468.20 
 
 y 
 
 300.80S 
 
 7200.58 
 
 y 
 
 316.516 
 
 7972.23 
 
 14. 
 
 285.492 
 
 6486.03 
 
 14 
 
 301.200 
 
 7219.39 
 
 y 
 
 316.908 
 
 7992.03 
 
 91 
 
 285.885 
 
 6503.88 
 
 96 
 
 301.593 
 
 7238.23 
 
 101 
 
 317.301 
 
 8011.85 
 
 y 
 
 286.278 
 
 6521.76 
 
 y 
 
 301.986 
 
 7257.09 
 
 y 
 
 317.694 
 
 8031.69 
 
 y 
 
 286.670 
 
 6539.67 
 
 y 
 
 302.378 
 
 7275.98 
 
 y 
 
 318.086 
 
 S051.56 
 
 y 
 
 287.063 
 
 6557.60 
 
 y 
 
 302.771 
 
 7294.89 
 
 y 
 
 318.479 
 
 8071.45 
 
 K 
 
 287.456 
 
 6575.55 
 
 y 
 
 303.164 
 
 7313.82 
 
 y 
 
 318.872 
 
 8091.37 
 
 y 
 
 287.848 
 
 6593.53 
 
 y 
 
 303.556 
 
 7332.78 
 
 y 
 
 319.264 
 
 8111.31 
 
 y 
 
 288.241 
 
 6611.53 
 
 y 
 
 303.949 
 
 7351.77 
 
 y 
 
 319.657 
 
 8131.28 
 
 H 
 
 288.634 
 
 6629.56 
 
 14 
 
 304.342 
 
 7370.78 
 
 y 
 
 320.050 
 
 8151.27 
 
 92 
 
 289.027 
 
 6647.61 
 
 97 
 
 304.734 
 
 7389.81 
 
 102 
 
 320.442 
 
 8171.28 
 
 l A 
 
 289.419 
 
 6665.69 
 
 y 
 
 305.127 
 
 7408.87 
 
 y 
 
 320.835 
 
 8191.32 
 
 y 
 
 289.812 
 
 6683.79 
 
 y 
 
 305.520 
 
 7427.95 
 
 y 
 
 321.228 
 
 8211.39 
 
 H 
 
 290.205 
 
 6701.91 
 
 y 
 
 305.913 
 
 7447.06 
 
 y 
 
 321.620 
 
 8231.48 
 
 y 
 
 290.597 
 
 6720.06 
 
 y 
 
 306.305 
 
 7466.19 
 
 y 
 
 322.013 
 
 8251.59 
 
 H 
 
 290.990 ' 
 
 6738.24 
 
 y 
 
 306.698 
 
 7485.35 
 
 y 
 
 322.406 
 
 8271.73 
 
 y 
 
 291.383 
 
 6756.44 
 
 y 
 
 307.091 
 
 7504.53 
 
 y 
 
 322.799 
 
 8291.89 
 
 14 
 
 291.775 
 
 6774.66 
 
 14 
 
 307.483 
 
 7523.73 
 
 y 
 
 323.191 
 
 8312.08 
 
 93 
 
 292.168 
 
 6792.91 
 
 98 
 
 307.876 
 
 7542.96 
 
 103 
 
 323.584 
 
 8332.29 
 
 y 
 
 292.561 
 
 6811.18 
 
 y 
 
 308.269 
 
 7562.22 
 
 y 
 
 323.977 
 
 8352.53 
 
 y 
 
 292.954 
 
 6829.48 
 
 y 
 
 308.662 
 
 7581.50 
 
 y 
 
 324.369 
 
 8372.79 
 
 H 
 
 293.346 
 
 6847.80 
 
 y 
 
 309.054 
 
 7600.80 
 
 y 
 
 324.762 
 
 8393.07 
 
 y 
 
 293.739 
 
 6866.15 
 
 y 
 
 309.447 
 
 7620.13 
 
 y 
 
 325.155 
 
 8413.38 
 
 y 
 
 294.132 
 
 6884.52 
 
 y 
 
 309.840 
 
 7639.48 
 
 y 
 
 325.548 
 
 8433.72 
 
 y 
 
 294.524 
 
 6902.91 
 
 y 
 
 310.232 
 
 7658.86 
 
 y 
 
 325.940 
 
 8454.08 
 
 y 
 
 294.917 
 
 6921.33 
 
 y 
 
 310.625 
 
 7678.26 
 
 y 
 
 326.333 
 
 8474.46 
 
 94 
 
 295.310 
 
 6939.78 
 
 99 
 
 311.018 
 
 7697.69 
 
 104 
 
 326.726 
 
 8494.87 
 
 
 295.702 
 
 6958.25 
 
 y 
 
 311.410 
 
 7717.14 
 
 y 
 
 327.118 
 
 8515.30 
 
 y 
 
 296.095 
 
 6976.74 
 
 y 
 
 311.803 
 
 7736.61 
 
 y 
 
 327.511 
 
 8535.76 
 
 y 
 
 296.488 
 
 6995.26 
 
 y 
 
 312.196 
 
 7756.11 
 
 y 
 
 327.904 
 
 8556.24 
 
 y 
 
 296.880 
 
 7013.80 
 
 y 
 
 312.588 
 
 7775.64 
 
 y 
 
 328.296 
 
 8576.74 
 
 y 
 
 297.273 
 
 7032.37 
 
 y 
 
 312.981 
 
 7795.19 
 
 y 
 
 328.689 
 
 8597.28 
 
 y 
 
 297.666 
 
 7050.96 
 
 y 
 
 313.374 
 
 7814.76 
 
 y 
 
 329.082 
 
 8617.83 
 
 14 
 
 298.059 
 
 7069.58 
 
 y 
 
 313.767 
 
 7834•36 
 
 y 
 
 329.474 
 
 8638.41 
 
 95 
 
 298.451 
 
 7088.22 
 
 ! 00 
 
 314.159 
 
 7853.98 
 
 105 
 
 329.867 
 
 8659.01