Document b5y8x4LJk15xkzGGdZpvywEB0

HEATINC VENTILATING AIR CONDITIONING GUIDE 1944 Table 4. Comparative Capacity of Steam Lines at Various Pitches for Steam and Condensate Flowing in Opposite Directions3 Pitch of Pipe in Inches per 10 Ft Pitch of Pipe H IK. H IN. 1 m. iX at. 2 in. 3 IN. 4 IN. 5 IN. Pipe Size Inches Sq Ft Rad. Based on 240 Bta $ i s Sq Ft Rad. on 240 Bta T>S Ha s Sq Ft Rad. Based on 240 Bta M 3 Sq Ft Rad. Based on 240 Bta t M*9 3 Sq Ft Rad. on 240 Bta 2 He S Sq Ft Rad. Based on 240 Bta t? a a Sq Ft Rad. Based on 240 Bta > 1 SqFt Rad. Based on 240 Bta g H S t H 25.0 12 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 ix 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165.0 28 172.6 29 178.2 31 1M 142.6 18 159.0 21 181.0 23 196.5 25 209.3 27 224.0 28 234.8 30 242.6 31 2 236.0 19 263.5 20 299.5 23 325.5 25 346.3 27 371.5 28 388.4 29 401.1 30 .Data from American Society or Heating and Ventilating Engineers Research Laboratory. water in certain parts of the system until the steam flow is reduced sufficiently to permit the water to pass. The velocity at which such disturbances take place is a function of (1) the pipe size, whether the pipe runs horizontally or vertically, (2) the pitch of the pipe if it runs hori- Table 5. Length in Feet of Pipe to be Added to Actual Length of Run-- Owing to Fittings--to Obtain Equivalent Length Size of Pipe - Inches Length in Feet to be Added to Run Standard Elbow Side Outlet Tee Gate Valve* Globe Valve* Angle Valve H % lm nt 2 2H 3 3M 4 5 6 8 10 12 14 1.3 1.8 2.2 3.0 3.5 4.3 5.0 6.5 8 9 11 13 17 21 27 30 Valve in full open position. Example of length in feet of pipe to be added to actual length of run. 3 0.3 14 7 4 0.4 18 10 5 0.5 23 12 6 0.6 29 15 7 0.8 34 18 8 1.0 46 22 11 1.1 54 27 13 1.4 66 34 15 1.6 80 40 18 1.9 92 45 22 2.2 112 56 27 2.8 136 67 35 3.7 180 92 45 4.6 230 112 53 5.5 270 132 63 6.4 310 152 U--- tszkf- ^ Measured Length = 132.0 ft 4 in. Gate Valve * 1.9 ft 4--4 in. Elbows 36.0 ft i Equivalent Length - 169.9 ft i 1............. H 284 CHAPTER 15. PIPING FOR STEAM HEATING SYSTEMS Table 6. Steam Pipe Capacities Capacity Expressed in Square Feet of Equivalent Direct Radiation (Reference to this table will be by column letter A through L) This table is based on pipe size data developed through the research investiga tions of the American Society of Heating and Ventilating Engineers. Pipe 8i In. CAPACITIES OF STEAM MAINS AND RISERS Direction of Condensation Flow in Pipe Line With the Steam in One-Pipe and Two-Pipe Systems V lb x/a* lb Vi lb Mlb Mlb X lb M Os X Ot 1 Oz Drop Drop Drop 2 Oz Drop 4 Oz Drop 8 Oz Drop Against the Steam Two-Pipe Only Vertical Horizontal Special Capacities fob One-Pipe Systems Only Supply Risers UpFeed Radiator Valves and Radiator and Riser Connections Run outs AB C D E F G 1c K l lM m 2 2H 3 3% 4 5 6 8 10 12 16 30 39 46 56 79 87 100 122 173 134 155 190 269 273 315 386 546 449 518 635 898 822 948 1,163 1,645 1,228 1,419 1,737 2,457 1,738 2,011 2,457 3,475 3,214 3,712 4,546 6,429 5,276 6,094 7,462 10,553 10,983 12,682 15,533 21,967 20,043 23,144 28,345 40,085 32,168 37,145 45,492 64,336 60,506 69,671 84,849 121,012 30 in 157 56 245 346 122 380 538 190 771 1,091 386 1,270 1,797 635 2,326 3,289 1,129 3,474 4,913 1,548 4,914 6,950 2,042 9,092 12,858 14,924 21,105 . ... 31,066 43,934 56,689 80,171 90,985 128,672 169,698 242,024 -- 34 75 108 195 395 700 1,150 1,700 3,150 __ __ __ -- 25 45 98 152 288 464 799 1,144 1,520 ___ __ K I/S __ 28 28 62 62 93 93 169 169 260 .... 475 745 1,110 __ 2,180 __ __ __ __ __... __ __ __ --- - -- All Horizontal Mains and Down-Feed Risen UpFoed Risers Mains and Ondripped Run outs UpFeed Radiator Con- Run outs Risers nections Dripped Note.--All drops shown are in pounds per 100 ft of equivalent run--based on.pipe properly reamed, aDo not use Column H for drops of 1/24 or 1/32 lb; substitute Column C or Column B as required. bDo not use Column J for drop of 1/32 lb except on sizes 3 in. and over; below 3 in. substitute Column B. cQn radiator runouts over 8 ft long increase one pipe size over that shown in Table 6. zontally, (3) the quantity of condensate flowing against the steam, and (4) freedom of the piping from water pockets which under certain con ditions act as a restriction in pipe size. Reaming Important Three factors of uncertainty always exist in determining the capacity of any steam pipe. The first is variation, in manufacture, which appar ently cannot be avoided. The second is the care used in reaming the ends of the pipe after cutting. The effect of both of these factors increases as the pipe size decreases. According to A.S.H.V.E. Research Laboratory tests, either of these factors may affect the capacity of a 1-in. pipe as much as 20 per cent. The third factor is the uniformity in grading the pipe line. All of the capacity tables given in this chapter include a factor of safety. However, the factor of safety referred to does not cover abnormal defects or constrictions nor does it cover pipe not properly reamed. 285