Document 5LLRJe56kMvZanRD02MKv2Z7V

414 ' ____________ . ____________CHAPTER 23 . . .1946 Guide 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. - Equivalent Length of Run All tables for the flow of steam in pipes, based on pressure drop, must allow for the friction offered by the pipe as well as for the additional resistance of the fittings and valves. These resistances generally are stated in terms of straight pipe; in other words, a certain fitting will produce a drop in pressure equivalent to so.many feet of straight run of Table 3/ Length in Feet of Pipe to be Added to Actual Length of Ron-- 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* x i IX m 2 IX 3 3X 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. 3 4 5 6 7 8 11 13 15 18 22 27 35 45 - 53 63 Example of length in feet of pipe to be added to actual length of run. I*'" - 0.3 0.4 0.5 0.6 0.8 1.0 1.1 1.4. 1.6 1.9 2.2 2.8 3.7 4.6 5.5 6.4 14 18 . 23 ' 29 34 46 54 66 80 92 . . 112 136 180 230 270 310 7 10 12 15 18 22 27 34 40 45 56 67 92 112 132 152 Measured Length = 132.0 ft 4 in. Gate Valve = ` 1.9 ft 4--A in. Elbows = 36.0 ft v i Equivalent Length .= 169.9 ft --L........H the same size of pipe. Table'3 gives the number of feet of straight pipe usually allowed for the more common types of fittings and valves. In all pipe sizing tables in this chapter the length of run refers to the equivalent length of run as distinguished from the actual length of pipe in -feet. The length of fun is not usually known at the outset;" hence it may be necessary to assume some pipe size at the start. Such an assumption frequently is considerably in error and a more common and practical method is to assume the length of run and to check this assumption after the pipes are' sized. For this purpose the length of run usually is taken as double the actual' length qf pipe. TABLES FOR PIPE SIZING FOR LOW PRESSURE SYSTEMS2 Tables 4, 5, and 6 are based on the. actual inside diameters, of .the pipe . and .the condensation of lb (4 oz) of steam per square foot of equivalent direct radiation (abbreviated EDR) per hour. The drops indicated are Steam Heating Systems and Piping 415 Table 4. Steam Pipe Capacities for Low Pressure Systems (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. CAPACITIES OF STEAM MAINS AND .RISERS Direction op Condensation Flow in Pipe Line Special Capacities fob One-Pipe Systems Only With the Steam in One-Pipe and Two-Pipe Systems Against the Steam Radiator Two-Ripe Only Supply Valves Radiator In. . .. .. .. Risers and .or HOs Drop or HO* Drop 1 Os 20a Drop Drop 4 0s Drop . 8 0s Drop Vertical Hori zontal UpFeed Corn . nections Ronouts A B C DB F G /" Jb K Capacity Expressed in Square Feet E D R X 30 30 25 1 39 46 56 79 111 157 56 34 45 ix 87 100 122 173 245 346 122 75 98 m 134 155 190 269 2 273 315 386 546 380 ' 538 190 . 108 152 771 1,091 386 195. 288. 2X 449 518 635 898 1,270 1,800 635 395 464 3 822 948 1,160 1,650 2,330 3,290 1,130 700 800 1,230 1,420 1,740 -2,460 . 3,470 4,910 1,550 1,150 1,140 4 1,740 2,010 2,460 3,480 4,910 6,950 2,040 1,700 1,520 5 3,210 3,710 4,550 6,430 9,090 12,900 3,150 6 5,280 6,100 7,460 10,550 14,900 21,100 8 11,000 12,700 15,500 21;970 31,070 .43,900 10 20,000 23,100 28,300 40,100 56,700 80,200 12 32,000 37,100 45,500 64,300 91,000 129,000 16 61,000 69,700 84,800 121,000 i7o;ooo 242,000 .28 28 62 62 93 93 169 169 260 475 745 1,110 2,180 Capacity Expressed in Pounds per Hour X '8 1 10 12 14 ix m 2 2X '. 22 25 ; . 34 39 68 - 79 112 130 31 48 97 .159 3 : 206 237 291 3X 307 .355 _ 434 4 : 435 503 614 5 806 928 1,140 6 1,32C 1,520 1,87C 8 ' 2.75C 3,170 3,88C 10 5,01C 5,790 7.09C 12 8,040 9,290 11,400 16 15,100 17,400 21,200 20 43 67 137 225 411 614 869 1,610 2,640 5,490 10,000 16,100 30,300 -28 61 . -95 193 318 581 . 869 1,230 - 2,270 3,730 7,770 14,200 22,700 42,400 8 40 ` 14 . ,''87. . 31 135 48 - 273 97 449, 159 822 . 282 1,230 387 1,740 511 3,210 5,280 11,000 20,000 32,200 60,500 .9 19 27 49 99 175 -288 425 788 6 11 20 38 : 72 116 200 286 380 ___ 7 71 7 16 i6 23 . -23 42 42 65 . 119 186 -278. 545 - All Horizontal Mains and Down-Feed Risers Mains Up- and UnFeed dripped Risers, Run outs UpFeed Risen Radiator RunCon- nections Dripped Noie.--All drops shown are in psi per 100 ft of equivalent run--based on pipe properly reamed. "Do not use Column /? for drops of 1/24 ci; 1/32 psi; substitute Column C or Column B as required. . bDo not use Column J for drop of 1/32 psi except on sizes 3 in. and over; below 3 in. substitute Column B. "On radiator runouts over 8 ft long increase one pipe size over that shown in Table 4.