Document 6RL5p045Lo5Gn0OD6Omv4J013

American Society of Heating and Ventilating Engineers Guide, 1929 .Table 5. Maximum Allowable Capacities of Up-Feed Risers for One-Pipe Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests Pzpb Sob A r iX" IX" V 2X" 3' 3X" 4' Velocitt Feet peb Second Pressure Drop Ounces per 100 Ft. . B 14.1 17.6 20.0 23.0 26.0 29.0 31.0 32.0 C 0.68 0.66 0.66 0.57 0.54 0.48 0.44 0.39 8q. Ft Radiation D 45 98 152 288 464 799 1144 1520 Capacitt B.La per Hour E 10,961 23,765. 36,860 69,840 112,520 193,600 277,000 368,000 Lb. Steam per Hour F 11.3 24.5 38.0 72.0 116.0 199.8 286.0 380.0 Note I.--Above capacities should never oe exceeaeu uu uus-^ -- Note -Capacities based on H lb. condensation per square foot equivalent radiation and actual diamNeotteerSo.--f sAtallndpaipred sphipoeu.ld be well reamed and free from constrictions. Fittings should be up to size. (See Tables 8 and 9.) Table 6. Maximum Allowable Capacities of Up-Feed Risers for Two-Pipe Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests Pxra Size Velocitt Feet peb Second Pressure Dbop Ounces peb 100 Ft. A X" l* IX" IX" 2" 2X' 3" 3X' 4" B 20 23 27 30 35 38 41 42 43. C __ 1.78 1.57 1.48 1.33 1.16 0.95 0.81 0.71 Sq. Ft. Radiation D 40 74 151 . 228 438 678 1129 1548 2042 Capacitt B.tu. per Hour E 9550 17,900 36,500 55,200 106,100 164,100 273,500 375,500 495,000 Lb. Steam pa Hoar F 10.0 18.45 37.65 57.0 109.5 169.4 282.2 387.0 510.5 Note 1.--Above capacities should never De exceeaea OU Itautf. Note 6.--Capacities based on K lb. condensation per square foot equivalent radiation and actual diameter of standard pipe. s Notes.--All pipe should be well reamed and free from constrictions. Fittings should be up to size. (See Tables 8 and 9.) 94 Chapter III--Steam Heating Systems and Piping of 1 oz. per 100 ft. where the greatest equivalent length of run from the boiler to the farthest heating unit does not exceed 200 ft. Table 12 is recommended for laying out small vapor systems on a basis of 1 oz. per 100 ft. where the greatest equivalent length of run from the boiler to the farthest heating unit does not exceed 200 ft. Tables 13 to 18 were compiled from the test .data of the Society's Research Laboratory and are for various types of balanced systems with different total pressure drops. These tables with their foot-notes may be used by any one with a knowledge of the profession to obtain satisfactory results. They cover the larger systems with total equivalent length of runs from 100 to 1200 ft. Tables 13 and 14 were designed for larger one and two-pipe low-pressure gravity steam heating systems, respectively. These tables are based upon a 4 oz. pressure drop from the boiler to the farthest heating unit and give capacities based upon such pressure drop for equivalent lengths ranging from 100 to .600 ft. These tables can be used for determining the size of pipe necessary to handle a given amount of heating surface, either in a main, branch to the riser, riser, or heating unit branch. Risers, or branches to risers or heating units, must not, however, be loaded above Table 7. Comparative Capacity of Steam Lines at Various Pitches* Pitch of Pipe in Inches per 10 Ft. Pitch op Pipe--in. X m. 1 IN. iX i. 2 IN. 3 IN. . 4 IN. 5 nr. 2Pipe Size Sq. Ft. Rad. Based on 240 B.tu. 2 a s Sq. Ft. Rad. Bused on 240 B.tu. 2 25 Sq. Ft. Rad. Baaed on 240 B.tu. Sq. Ft. Rad. Based a B. on 240 B.tu. 2 21 So. Ft Rad. Based on 240 B.tu. *>5> 3 Sq. Ft. Rad. Based on 240 B.tu. 2 21 8q. Ft Rad. Based on 240 B.tu. 2 21 Sg. Ft Rad. Baaed on 240 B.tu. 2 l H" r 25.0 12 v 30.3 14 37.3 18 40.4 19 42.5 20 46.1 21 47.5 22 49.3 23 45.8 12 52.6 15 63.0 17 70.0 20 75.2 22 83.0 23 87.9 25 90.2 26 w IX' r 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165.0, 28 172.6 29 .178.2 31 142.6 18 159.0 21 181.0 23 196.5 25 209.3 27 224.0 28 234.8 30 242.6 31 236.0 19 263.5 20 299.5 23 325.5 25 346.5 27 371.5 28 388.4 29 401.1 30 Table 8. Effect of Reaming Entrance to One-Pipe Risers* Maximum Capacity of Riser Reamed entrances............................... 24.7 lb. per hr. Rounded entrances............................. 23.9 lb. per hr. Squared entrances................................ 22.2 lb. per hr. Three wheel cutter.............................. 19.2 lb. per hr. Single wheel cutter.............................. 17.6 lb. per hr. Per Cent Decrease 0.0 3.2 10.1 22.2 28.7 Table 9. Per Cent Difference in Capacity Due to Variation of Pipe Size and Smoothness* Maximum Condensation, Lb. per Hr. Capacity of Pipe...................... ............... Minimum Per Cent Variation-- ........................... X" 14.00 15.20 8.6 1* 24.89 30.08 20.8 IX" 45.42 52.08 14.7 IX" 70.50 82.00 16.3 Data from American Society of Heating and Ventilating Engineers Research Laboratory. 95