Document MM0VRBqr60oEQzRJobXn68MJk

American Society of Heating and Ventilating Engineers Guide, 1930 Table 15. Pipe Sizes for Vacuum Pump Systems, where Equivalent Length of Run from Boiler or Source of Supply to Farthest Radiator Exceeds 200 Ft. Capacity in Sq. Ft. of Equivalent Radiation Based on 4 oz< Total Pressure Drop Pipe Rim Equivalent Length or Pipe from Boiler to Farthest Radiator, Including Main and Riser. (See Note 0.) Supply Main Dripped and Branches to Risen Dripped-- Steam and Condensate flowing in same direction. Maximum Capacities 100 Ft A Ve 1 m l lA 2 2^ 3 3M 4 5 6 8 10 12 B in 245 380 771 1270 2326 3474 4914 9092 14,924 31,066 56,689 90,985 200 Ft C 79 173 269 546 898 1645 2457 3475 6429 10,553 21,967 40,085 64,336 300 Ft. D 65 141 220 446 734 1342 2006 2828 5250 8618 17,935 32,730 52,530 400 Ft. E 500 Ft. F 56 122 190 386 635 1163 1737 2457 4546 7462 15,533 28,345 45,492 49 110 165 345 568 1040 1552 2196 4062 6669 , 13,880 25,334 40,660 600 Ft G Supply Risers Up-Feed Branches to' Supply Risers and Radiators Not Dripped H /* . 46 100 155 315 518 948 1419 2011 3712 6094 12,682 23,144 37,145 56 122 190 386 635 1129 * 1548 2042 -- 26 58 95 195 395 700 1150 1700 3150 ; -- -- Pipe Size Inches Return Mains and Risers Riser J Main K 100 Ft L % Hi 800 1400 lm mm 2400 3800 m2 8000 2 2J4 13,400 2H 3 21,400 3 3H 32,000 3M 4 44,000 200 Ft M 568 994 1704 2696 5680 9510 15,190 22,710 31,220 300 Ft N 462 ' 810 1387 2195 4622 7745 12,360 18,490 25,430 400 Ft 0 . 500 Ft. P 400 358 700 626 1200 , 1900 1073 1698 4000 6700 3575 5990 10,700 16,000 9565 14,300 22,000 19,660 600 Ft 0 326 570 , 976 1547 3256 5453 8710 13,020 17,910 Different makes o>f . supply and return valves, steam ' traps and other specialties vary as to capacity, therefore use size as recommended for any particular make. Vertical connection to be of same size as ';. valve and trap used. Return horizontal %runout to be no less than in. r.Aftvrtotit- iq'V7 J American Society or Heating and Ventilating Engineers 1 Not to be Reprinted With- pyr*B ' \ Heating and Piping Contractors National Association J out- Special Permission 356 Chapter 20--Piping for Steam Heating Systems INSTRUCTIONS FOR USING TABLE 15 I. Radiator branches more than 8 ft. in length should be one size larger than shown in Column 1. 2: It is not generally considered good practice to greatly exceed 1 oz. drop in pressure in each 100 ft. equivalent length of run nor to exceed 1 lb. total pressure drop in any system. 3. These tables apply where pipes are properly reamed. No allowance for defective material or workmanship have been made.. (Also see Tables 7 and 8). 4. Capacities based on J4 lb. condensation per square foot per hour equivalent radiation and actual diameter of standard pipe. 5. Extra length to be added to straight run of pipe, for various fittings and valves to determine equivalent length. (See Table 4). 6. Mains are to be proportioned according to the equivalent length of run from the boiler or source Of supply to the farthest radiators supplied by the main. Determine equivalent length of run then use figures in corresponding Columns (B to G) for sizing the entire run. For example: If the distance from boiler or source of supply to the farthest radiator on the longest main should be 300 ft., all mains are to be sized from Column D; if 400 ft.. Column E; if 600 ft., Column G. Supply risers are to be proportioned according to the equivalent length of run from the boiler or source of supply to the farthest radiator on each riser. Determine the distance to the farthest radiator then use figures in corresponding Columns (B to G) for sizing each riser; providing the amount of radiation for that riser does not exceed amounts shown in Column H. Where riser capacities are found to be in excess of amounts shown in Column H, step up to necessary size indicated in that column. For example: If the distance from the.boiler or source of supply to the farthest radiator on a supply riser is 300 ft., that riser is to be sized from Column D, providing the amount of radiation does not exceed the amount shown in Column H. If the amount exceeds that in Column H, use amounts shown in Column H for sizing that entire riser. If another riser taken from the same main as the one indicated is only 200 ft., this riser should be sized from Column C, providing the amount of radiation does not exceed that as shown in Column H. 7. The Guide Committee, 1930, after many check-tests, suggest that for practical purposes the pipe sizes on the usual heating system may be determined by using the pressure drop indicated by the longest main and riser on that system, neglecting the separate computations for each separate shorter run. 8. Return mains and risers are to be proportioned according to the equivalent distance in feet, from farthest radiator to the vacuum pump; using capacities in corresponding Columns (L to Q) for sizing entire return riser (Column J) and return main (Column K). The return pipe sizes are conservative and are subject to revision upon the completion of pending research investigations. 9. Where it is necessary to drip a supply main, supply riser or branch to a supply riser, same should be dripped separately through a steam trap into vacuum return. Never drip a supply riser into a vacuum return, except through a steam trap. 10. Lift fittings. (See page 362). II. Pitch of mains should be not less than )4 in. in 10 ft.; on horizontal branches to radiators and risers at least Vi in. in 10 ft. 357