Document xjgQNNNbVY4y5KG9OkDDJREOE

American Society of Heating and Ventilating Engineers Guide, 1935 where L = length of pipe, feet. D = outside diameter of the pipe used, inches. A = the amount of expansion to be taken up, inches. This formula, based on the use of mild-steel pipe with wall thicknesses not heavier than extra-strong, assumes a. maximum.safe value of fiber stress of 167000 lb per square inch. When square type bends are used, the width of the bend should not exceed about two times the height. It is Table 3. Dimensions of Welded Wrought-Iron Pipe Nominal Pipe Size H M Vi K H 1 114 lfi 2' 214 3 314 4 5 6 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 0. D. Outside Dlameteb 0.405 0.540 0.675 0.840 1.050 1.315 1.660 1.900 2.375 2.875 3.5 4.0 4.5 5.563 6.625 8.625 10.75 12.75 14.0 16.0 18.0 20.0 Nominal Wall Thicknesses fob Schedule Numbebs Schedule 10 0.250 0.250 0.250 Schedule 20 0.312 0.312 0.312 0.375 Schedule 30 Schedule 40 0.283* 0.313* 0.336* 0.375 0.375 0.437 0.500 0.070* 0.090* 0.093* 0.111* 0.115* 0.136* 0.143* 0.148* 0.158* 0.208* 0.221* 0.231* 0.242* 0.263* 0.286* 0.329* 0.372* -0,414 0.437 0.500 0.562 0.562 Schedule 60 Schedule 80 0.QQ8* 0.1??* ft 1?Q* 0.151* 0.157* 0.183* 0.195* 0.204* 0.223* . 0.282* 0.306* 0.325* 0.344* 0.383* 0.441* 0.510* 0.510* 0.606 0.574 0.702 0.625 0.750 0.687 0.750 AO dimensions are given in inches. The decimal thtckneses listed for the respective pipe sizes represent their nominal or average wall dimensions and include an allowance for mill tolerance of 12.5 per cent under the nominal thickness. "Rudenesses marked with an asterisk in Schedules 30 and 40 are identical with thicknesses for itandard-iDdght pipe in former lists; those in Schedules 60 ami 80 are identical with thicknesses for exlra-tirong pipe in former lists. The Schedule Numbers indicate approximate values of the expression 1000 x P/S. further assumed that the corners are made with screwed or flanged elbows or with arcs of circles having radii five to six times the pipe diameter. All risers must be anchored and safeguarded so that the difference in length when hot from the length when cold shall not disarrange the normal and orderly provisions for drainage of the branches. It is especially necessary with light-weight radiators so to anchor the piping and so to give it freedom for expansion that no strain therefrom shall be allowed to distort the radiators. When expansion strains from the pipes are permitted to reach these light metal heaters they usually emit sounds of distress which are exceedingly troublesome. 584 Chapter 34--Pipe,Fittings, Welding PIPE THREADS All threaded pipe for heating and ventilating installations uses the American Standard taper pipe thread which is made with a taper of 1 in 16 measured on the diameter of the pipe so as to secure a tight joint. Threads of fittings are tapped to the same taper. The number of threads Table 4. Nominal Weights of Welded Wrought-Iron Pipe Nominal Pipe Size (Inches) Va l/B \z a\7 \\/ 114 2 ?U 3 \\4 4 5 <$ 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 O. D. SCHED. Scbed. 10- - ' 20-- Schedule --------- 30" Schedule 40 Plain Ends Plain Ends Plain Ends Threads and Couplings Plain Ends Threads and Couplings 36.0 41.3 46.5 44.8 51.4 57.9 77.0 24.7* 34.3* 43.8* 53.6 61.4 80.5 103.0 25.0* 35.0* 45.0* 0.25* 0.43* 0.57* 0.86* 1.14* 1.68* 2.28* 2.72* 3.66* 5.80* 7.58* 9.11* 10.8* 14.7* 19.0* 28.6* 40.5* 53.6 62.2 81.2 103.0 115.0 0.25* 0.43* 0.57* 0.86* 1.14* 1.69* 2.29* 2.74* 3.68* 5.82* 7.62* 9.21* 10.9* 14.9* 19.2* 28.8* 41.2* 55.0 Schedule 60 Schedule. 80 Plain Ends Plain Ends 54.8* 73.2 87.6 111.0 136.0 0.32* 0.54* 0.74* 1.09* 1.48* 2.18* 3.00* 3.64* 5.03* 7.67* 10.3* 12.5* 15.0* 20.8* 28.6* 43.4* 54.4 88.6 104.0 Weights are given in pounds pet linear foot and are for pipe with plain ends except for sizes which are commercially available with threads and couplings for which both weights are listed. 'Weights marked with an asterisk in Schedules 30 and 40 are identical with weights for ttandard-weigkt pipe in former lists; these in Schedules 60 and 80 are identical with weights for extm-ttrong pipe in former lists. The Schedule Numbers indicate approximate values of the expression 1000 x P/S. per inch varies with the different pipe sizes. All threaded pipe should be made up with a thread paste suitable for the service under which the pipe is to be used. HANGERS Heating system piping requires careful and substantial support. Where changes in temperature of the line are not large, such simple methods of support may be utilized as hanging the line by means of rods or perforated strip from the building structure, or supporting it by brackets or on piers. When fluids are conveyed at temperatures of 150 F or above, however, hangers or supporting equipment must be fabricated and assembled to permit free expansion or contraction of the piping. This can be accom plished by the use of long rod hangers, spring hangers, chains, hangers or 585