Document omKGDyRDrDvg0g9yxmXMZ9mo7

502 CHAPTER 21 1954 Guide Table 8. Steam Pipe Capacities for 30 Psig Steam Systems* Capacity Expressed in Pounds per Hour (Steam and Condensate Flowing in Same Direction) Pipe Size Inches Drop in Pressure--Pounds per 100 Ft in Length *4 *4 *4 1 2 *4 1 1*4 1*4 2 2*4 3 3*4 4 5 6 8 10 -12 15 31 69 107 217 358 651 979 1,390 2,560 4,210 8,750 16,300 25^600 22 46 100 154 313 516 940 1,410 2,000 3,640 6,030 12,600 23,500 36,900 31 63 141 219 444 730 1,330 2,000 2,830 5,230 8,590 17,900 33,200 52,300 38 77 172 267 543 924 1,630 2,450 3,460 6,400 10,400 21,900 40,600 64,000 45 89 199 309 1 627 1,030 1,880 - 2,830 4,000 7,390 12,100 25,300 46,900 74,000 63 125 281 437 886 1,460 2,660 4,000 5,660 10,500 17,200 35,100 66,400 104,500 Note: Steam at an average pressure of 30 psig is used as the basis for calculating the above table. sized from Column C; radiator runouts and undripped riser runouts from Column L; up-feed risers from Column J; the main riser on a down-feed system from Column C (it will be noted that if Column H is used the drop would exceed the limit of psi); the dry return from Column R; and the wet-return from Column Q. With a sVpsi drop the sizing would be the same as for Vr psi, except that the steam main and dripped runouts would be sized from Column B, the main riser on a down-feed system from Column B, the dry-return from Column O, and the wet-return from Column N. Notes on Gravity One-Pipe Air-Vent Systems 1. Pitch of mains should not be less than 1 in. in 10 ft. 2. Pitch of horizontal runouts to risers and radiators should not be less than i in. per foot. Where this pitch cannot be obtained, runouts over 8 ft in length should be one size larger than called for in the table. 3. In general, it is not desirable to have amain less than 2in. The diameter of the far end of the supply main should not be less than half its diameter at its largest part. Table 9. Steam Pipe Capacities for 150 Psig Steam Systems* Capacity Expressed in Pounds per Hour (Steam and Condensate Flowing in Same Direction) Drop in Pressure--Psi per 100 Ft in Length Pipe Size Inches *4 *4 *1 2 5 M 1*4 1*4 2 2*4 3 3*4 4 5 6 8 10 12 29 58 130 203 412 683 1,240 1,860 2,630 4,860 7,960 16,600 30,800 48,600 41 82 185 287 563 959 1,750 2,630 3,720 6,880 11,300 23,500 43,400 68,800 58 117 262 407 825 1,360 2,480 3,720 5,260 9,730 16,000 33,200 61,700 97,300 71 143 320 497 1,010 1,650 3,020 4,550 6,430 11,900 19,500 40.600 75.600 1 119.000 82 165 370 575 1,170 1.920 3,500 5,250 7,430 13,800 22,600 47,000 87,300 138,000 116 233 523 813 1,650 2,710 4,940 7,420 10.500 19.500 31,900 66,400 123,000 1 194.000 184 369 827 1.290 2,600 4.290 7,820 11,700 16,600 30,800 50,400 105.000 195.000 307,500 * Note: Steam at ah~average procure of 150 psig is used as the basis for calculating the above table. Steam Heating Systems Table 10. Return Pipe Capacities for 30 psig Steam Systems* Capacity Expressed in Pounds per Hour 503 Pipe Size % i mm .2 m 3 4 5 6 K 115 230 485 790 1,580 2,650 4,850 7,200 10,200 19.000 31.000 Drop in Pressure--Pounds per 100 Ft in Length H 170 340 710 1,160 2.360 3,900 7,100 10,600 15,000 27,800 . 45,500 M 245 4) 1,025 1,670 3,400 5,600 10.300 15.300 21,600 40.300 65,500 H 308 615 1,290 2,100 4,300 7,100 12,900 19,200 27.000 55,500 83.000 * Note: The above table is based on steam at pressurea of 0 to 4 psig. I 365 730 1,530 2,500 5,050 8,400 15.300 22,800 32.300 60,000 98,000 : _..rrvu nuuiV uwcooaijt 5. Where supply mains are decreased in size they should be dripped, or be provided with eccentric-couplings, flushon bottom. Example S: Size the one-pipe gravity steam system shown in Fig. 19 assuming that this is all there is to the system, or that the riser and main shown involve the longest run on the system. Solution: The total length of run actually shown is 215 ft. If the equivalent length of run is taken at double this, it will amount to 430 ft, and with a total drop of J psi the drop per 100 ft will be slightly less than A psi. It would be well in this case to use A psi, and this would result in the theoretical sizes indicated in Table 12. These theoretical sizes, however, should be modified by not using a wet-return less than 2 in., while the main supply, g-h, if from the uptake of a boiler, should be made the full size of the main, or 3 in. Also the portion of the main k-m should be made 2 in. if the wet-return is made 2 in. piluiu p'ljr'iiN c FOR UNE-PIPE VAPOR SYSTEMS Piping for one-pipe vapor systems is sized so as to permit only a few ounces pressure drop in the system. Otherwise, the method follows that outlined for sizing one-pipe gravity systems. Table 11. Return Pipe Capacities for 150 psig Steam Systems* Capacity Expressed in Pounds per Hour Pipe Size % 1 IX IX 2 2X 3 3X 4 5 6 H 156 313 650 1,070 2,160 3.600 6,500 9.600 13,700 25,600 42,000 Drop in Pressure--Psi pee 100 Ft in Length H 232 462 960 1,580 3,300 5.350 9,600 14,400 20.500 38,100 62.500 H 360 690 1,500 2,460 4,950 8,200 15.000 22,300 31;600 58,500 96.000 H 465 910 1,950 3,160 6,400 10.700 19.500 28.700 40.500 , 76,000 125,000 1 560 1,120 2,330 3,800 7,700 12,800 23,300 34.500 49,200 91.500 150,000 Note: The above table is based on steam at pressures of 1 to 20 psig 2 890 1,780 3,700 6,100 12,300 20,400 37,200 55,000 78,500 146.000 238.000