Document pBBJkd71Zjz90DYX8jpzmbBJw

American Society o/ Heating and Ventilating Engineers Guide, 1928 be found from Table 2 by multiplying the capacities found therein by constants given in Table 7. Example.--What is the capacity of a 140 ft. 4 in. pipe with an initial pressure of 1 lb. and pressure drop of 2 oz. in the 140 ft. ? Solution.--From Table 2 jt is found that the capacity of a 100 f.t. 4 in. pipe with 1 lb. initial pressure and 2 oz. pressure drop, is 3475 sq. ft. Multiplying this value by 0.841 the constant for a 140 ft. length as given in Table 7 gives 2922 the capacity for the given conditions. Example.---What is the capacity of a 100 ft. 4 in. pipe with 2.1b. initial pressure and pressure drop of 1 oz.? Solution.--From Table 2, find 2457, the capacity of the 4 in. pipe with 1 lb. initial pressure and 1 oz. pressure drop. Multiplying 2457 by 1.03 the constant found in Column 2 of Table 7 for 2 lb. initial pressure gives Table 8. Pipe Sizes for One-Pipe, Gravity, Low-Pressure Steam ' Heating System, where Equivalent Length of Run from Boiler or Source of Supply to the Farthest Radiator does not exceed 200 ft. Capacity in Sq. Ft. of Equivalent Radiation Pipe Size. Inches Supply Main Dripped and Branches to Risers Dripped Steam and Condensate flowing in the same direction. AB j. 1 .. 56 Supply Risers Up-Feed C 25 45 Branches to Supply Risers and Radiators Not Dripped D* 20 Wet Return Main E 700 Drt Return Main F Radiator Valve Sizes AND Vertical Connections G 320. 20 m 122 98 55 1200 670 55 190 152 81 1900 1058 81 2 386 2)4 635 3 1163. 3)4 1737 288 464 799 1144 165 4000 2300 165 260 6700 3800 475 10,700 7000 745 -- 10,000 4 2457 1520 1110 -- -- ----- 5 4546 ---- L 2180 \ ---- -- -- 6 7462 -- -- -- ----- Copyright 1927 / American Society op Heating and Ventilating Engineers 1 Not to be Reprinted With- ^ ^' \ Beating and Piping Contractors National Association j out Special Permission Radiator branches more than 8 ft. in length should be one size larger than shown in Col. D. Note 1.--These tables apply where pipes are properly reamed. No allowances for defective material or workmanship have been made. (Also see Tables 18, 19 and 20). , .Note 8.--Capacities based on % lb. condensation per square foot equivalent radiation and actual diameter of standard pipe. Note 8.--Extra length to be added to straight run of pipe, for various fittings and valves to determine equivalent length. (See Table 6). ' Note 4-.--Where it is necessary to drip a steam main, branch to riser or riser, same should be dripped separately into wet return. Note 5.--Pitch of pipe should be not less than % in. in 10 ft.; on horizontal branches to radiators, at least in. in 10 ft. 98 Chapter III--Steam Heating Systems and Piping ,, the capacity of the 4 in. pipe with 2 lb. initial pressure and a pressure drop of 1 oz. per 100 ft.^ length. . T hie 8 is a pipe sizing table for small one-pipe gravity low-pressure am heating systems. This table was designed to meet the requirestea r tjlose laying out small systems where the equivalent length of mellfrom the boiler or pressure reducing valve to the farthest radiator is run eater than 200 ft. The capacities are based upon 1 oz. drop in "Assure per 100 ft., equivalent length of run excepting where the maxium allowable velocity limits the capacity below this value. The "anacities of supply mains as given in Column B are based upon a pressure d oo of 1 oz. per 100 ft. equivalent length. The capacities of up-feed Hsers as given in Column Care based upon the maximum velocity. The t I, q pIPE Sizes for Two-Pipe, Gravity, Low Pressure Steam, where i able . valent length of Run from Boiler or Source of Supply to v Farthest Radiator does not exceed 200 ft. Capacity in Sq. Ft. of Equivalent Radiation Pipe Sizes Inches A M i Wa 1)4 2 2)4 3 3)4 Supply Main Dripped and Branches to Risers Dripped Steam and Condensate Flowing in same Direction Supply Risers Up-Feed Branches to Supply Risers and Radiators Not Dripped Return Risers B C D* E 30 122 56 56 26 320 Wet Return Main F __ 7oo 122 122 190 190 58 670 .1200 95 1058 1900 386. 386 195 2300 4000 635 635 395 3800 6700 1163 1737 1129 1548 700 1150 7000 10,700 10,000 -- Dry Return Main Radiator Supply Valve ... G 320 670 1058 2300 3800 7000 10,000 B 30 56 122 190 386 ..... Radiator Return Valve */ 122 190 386 -- , _____ 4 2457 2042 1700 -- --... -- `---- -- 5 4546 -------- 3150 v------ : T--------- ..... 6 7462 -- -- ----- -- ~^ / American Societt of Heating and Ventilating Engineers Not to be Reprinted With copyngm:, vtj ^ BeotinQ and Piping Contractors National Association out Special Permission Radiator branches more 'than 8 ft. in length should be one size larger than shown in Col. Z>. Note 1.--These tables apply where pipes are properly reamed. No allowances for defective material or workmanship have been made. (Also see Tables 18, 19 and 20). + Note 8.--Capacities based on yi lb. condensation per square foot equivalent radiation and actual diameter of standard pipe. Note 3.--Extra length to be added to straight run of pipe for various fittings and valves to determine equivalent length. (See Table 6.) Note 4---Where it is necessary to drip a supply main, supply, riser or branch to a supply riser, same should be dripped separately into a wet return or through an adequate seal into a dry return. Never drip a supply pipe into a dry return except through an adequate seal. Note 6.--Pitch of pipe should not be less than ^ in. in 10 ft.; on horizontal branches to radiators, at least % in. in 10 ft. 99