Document Y9e6pZwMaYBaBma0GMyNe5bgV

American Society of Heating and Ventilating Engineers Guide, 1931 13Table . Pipe Sizes for Two-Pipe Vapor Heating Systems, where EquIVai Length op Run from Boiler or Source of Supply to Farthest - 81 Radiator Exceeds 200 Ft. Capacity in Sq. Ft. Equivalent Radiation Based on 2 oz. Total Pressure Drop EqtmMXBNT Length or Pipe prom Boiler to Farthest! Radiator, Including Main and Riser. (See Nat* 6.) Pcpfi Supply Maifi Dripped and Branches to Risers Dripped-- Size Steam and Condensate flowing in same direction. Inches Maximum Capacito 100 Ft 200 Ft toon. 400 Ft [Suj^IyRisen fp-Feed Brandies to Supply Risers and Radiators Not Dripped H 79 IK 173. 269 2 S46 IK 898 3 1645 3K 2457 6 8 lo~ 12 3475 6929 10,553 21,967 40,085 64,336 56 122 190 386 635 1163 1737 lisT 4546 7462 15,533 23,345 45,492 46 100 155 315 518 948 1419 loir 3712 6094 12,682 23.144 37.145 39 IT 134 273 449 30 56 lzf 190 l&T 635 822 1228 ~173i~ 3214 1129 1548 ~2042 5276 10,983 20,043 32,168 Different makes of supply and retm valves, steam traps and.other specials vary as to capacity, therefore use size recommended for any particular tnak Vertical connections to be of same si as valve and trap used. Return her zontal runout to be not less than % h Pipe Size Inches Dar Return Main Equivalent Lenoth op Run prom Boilee to PANTHEST RamatOB IN Fbbt Wet Rbtobn Main 100 200 300 too 1 IK IK 2 2K 3 ~3K 4 355 745 1173 2680 4300 7800 11,100 16,700 320 670 loss' 2300 285 595 943 2140 248 520 822 1880 3800 7000 3470 6250 3040 5480 10,000 15,000 8800 13,400 7880 11,700 __ ______________ :. ~ir 1000 1700 2700 5600 1900 4000 9400 15,000 6700 10,700 22,000 16,000 31,000 22,000 I(I 13,200 18,300 f^nvridht 1027 / AiOSIlICANSOCTETT Of HsATING AND VENTILATING ENGINEERS 1 Not tO be Reprinted Wit py ^ Heating and Piping Contractor* National Attodatum j out Special Pertnissl* ..vu.? Chapter 10--Piping for Steam Heating Systems F.jf A? ,_v INSTRUCTIONS FOR USING TABLE 13 '` , 1. Radiator oranuia more than 8 ft. in length should be one size larger than shown ii Column G. . . | js for systems which are open to atmosphere or operate under slight ". -2. -Th^rt^jrtial vacuum without use of vacuum pumps. vm nnr.lv where pipes are properly reamed. No allowances for defective " tetS^wor^ma"Bh`P have been made' ^Also see Tables 7 and 8). s' ''tjes t,ased on K lb. condensation per square foot per hour equivalent fr^jSnd actual diameter of standard pipe. ,'rr wvth to be added to straight run of pipe for various fittings and valves to I/ determ^uiSlent length. (See Table 4). j;; -v v{ains 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 (Bio E) fr supply mains; (/ to M) for dry-return mains; (N to Q) for wet-return mains 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. '' - Supply and return risers are to be proportioned according to the equivalent length ofirun from the boiler or source of supply to the farthest radiator on each riser. J por supply risers determine the distance from the boiler to the farthest radiator -served by that riser then use the figures in the corresponding Columns (B to E) tor " 'sizing each supply riser; providing the amount of radiation for that riser does not exceed V; amounts shown in Column F. Where supply riser capacities are found to be in excess ."of amounts shown in Column F, step up to necessary size indicated in that column. i -V- 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 F. If the amount V exceeds that in Column F, use amounts shown in Column F 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 k .that as shown in Column F. ..-i _ ' For return risers determine the equivalent length of run in feet from the top of each ~7,nser to the boiler, then use the figures in the corresponding Columns (J to M) for sizing I' ) each riser. >;7. For practical purposes the pipe sizes on the usual heating system may be determined by using the pressure drop indicated by the longest main riser on that system, neglecting the separate computations for each separate shorter run. ;,a ;8.- Where it is necessary to drip a supply main or a supply riser or a branch to a t. supply riser, same should drip separately into a wet return. The drip for a vapor or Vacuum system may be taken into a dry return through a steam trap. :C p- Pitch of mains should be not less than K in. in 10 ft.; on horizontal branches to - radiators and risers at least K in. in IQ ft. V liuL' 1" general it is desirable not to have a supply main smaller than 2 in. in diameter. 77 , suPPly main is larger than 2K in. at the beginning,' it is desirable that it snail not be smaller than 2K in. at the end. 168 169