Document mnM6jxxLveYw7RbLjNeZmdJ0

530 CHAPTER 22 1955 Guide Table 2. Heat-Carrying Capacity of Standard Black Pipes with Temperature Drop op 20 Deg* Nominal Pipe Sizes % in. to 12 in., and Friction t to 800 milinches per foot (4 = Capacity, Mbh. B = Velocity, inches per second) (One milinch equals 0.001 in.) Milinch Fric- Nominal Pipe Size,, Inches Foot of Pipe H w 1H m 2 2H 3 3H 4 5 6 8 10 12 4 A 0.75 1.35 2.85 5.4 11.3 17.0 33.0 53.1 95 141 197 363 596 1250 2320 3730 B 1.5 1.7 2.1 2.4 2.9 3.2 3.8 4.3 5.0 6.5 0.0 . 7.0 , 7.9 9.6 11 12 6 A 0.9 1.7 3.6 6-75 14.0 21.2 41.3 66.4 119 176 248 456 748 1570 2920 4690 B 1.8 2.1 2.6 3.0 3.6 4.0 4.7 5.3 6.2 6.9 7.5 8.8 10 12 14 16 8 A 1.05 2.0 4.2 7.9 16.4 24.8 48.4 77.9 140 207 291 535 879 1850 3440 5520 B 2.1 2.5 3.0 3.5 4.2 47 5.6 6.3 7.3 8.0 8.8 10 12 14 17 19 10 A i.2 2.2 4.7 8.9 18.6 28.0 54.7 88.1 158 234 329 605 997 2100 3910 6270 B 2.4 2.8 3.4 4.0 4.8 5.3 6.3 7.1 8.2 9.1 9.9 12 13 16 19 27 12 A 1.35 2.45 5.2 9.8 20.5 31.0 60.4 97.4 175 259 364 671 1100 2320 4330 6950 B 2.7 3.1 3.7 4.4 5.3 5.9 6.9 7.8 9.1 10 11 13 15 18 21 24 m14 A 1.45 2.65 5.65 10.7 22.3 33.7 65.8 106 282 597 731 1200 .2530 4730 7590 B 2.9 3.4 4.1 4.8 5.7 6.4 7.6 8.5 9.9 11 12 14 16 20 23 26 16 A 1.55 2.85 6.05 11.5 24.0 36.3 70.8 114 205 303 428 787 1300 2730 5100 8190 B 3.1 3.6 4.4 5.1 6.2 6.9 8.1 9.7 11 12 13 15 17 21 25 28 20 A 1.75 3.25 6.85 13.0 27.1 41.0 80.0 129 232 344 484 892 1470 3100 5790 9300 B 3.5 4.1 4.9 5.8 7.0 7.7 9.2 10 12 13 15 17 20 24 28 3? 25 A 2.0 3.65 7.75 14.7 30.6 46.3 90.5 146 263 389 548 1010 1670 3510 6570 10560 B 4.0 4.6 5.6 6.5 7.9 8.8 10 12 14 15 17 19 22 27 32 36 30 A 2.2 4.0 8.55 16.2 33.8 51.2 100 162 290 430 607 1120 1850 3900 7280 11710 B 4.4 5.1 6.1 7.2 8.7 9.7 11 13 15 17 18 22 25 30 35 40 35 A 2.35 4.4 9.3 17.6 36.8 55.7 109 176 316 469 661 1220 2010 4250 7940 127S0 B 4.7 5.5 6.7 7.9 9.5 11 13 14 16 18 20 23 27 33 39 44 40 A 2.55 4.7 10.0 18.9 39.6 59.9 117 189 341 505 712 1320 2170 4580 8570 13780 B 5.1 5.9 7.2 8.4 10 11 13 15 18 20 22 25 29 35 42 60 A 2.85 5.3 11.3 21.4 44.7 67.7 133 214 386 572 807 1490 2460 5190 9720 15650 B 5.7 6.7 .8.1 9.5 12 13 15 17 20 22 24 29 33 40 47 54 60 A 3.15 5.85 12.4 23.6 49.4 74.9 147 238 427 633 893 1650 2730 5760 13780 17360 B 6.3 7.4 8.9 11 13 14 17 19 22 25 27 32 36 44 52 97370 A 3.45 6.35 13.5 25.7 53.8 81.4 160 258 465 690 1800 2970 6280 11760 18950 B 6.9 8.0 9.7 11 14 15 18 21 24 27 29 35 40 48 57 80 A 3.7 6.8 14.5 27.6 57.9 87.6 172 278 500 743 1050 1940 3200 6770 12690 20440 B .7.4 8.6 10 12 15 17 20 22 26 29 32 37 43 52 62 B100 A 4.15 7.7 16.4 31.1 65.4 99.0 194 314 566 840 1190 2200 3630 7680 14400 23200 8.3 9.7 12 14 17 19 22 25 30 33 36 42 48 59 70 150 A 5.2 9.6 20.4 38.8 81.6 124 243 393 709 1050 1490 2760 4560 9650 18120 29220 B 10 12 15 17 21 23 28 32 37 41 45 53 n 74 88 200 A 6.05 11.2 23.9 45.4 95.5 145 285 461 832 1240 1750 3240 53r0 11350 21320 34400 B 12 14 17 20 25 27 33 37 43 48 53 62 71 87 104 300 A 7.5 13.9 29.7 56.6 119 181 . 356 577 1040 1550 2190 4060 6730 14270 26830 43300 B 15 18 21 25 31 34 41 46 54 6(1 66 78 96 110 131 400 A 8.75 16.2 34.7 66.2 140 212 417 676 1220 1820 2570 4780 7910 16790 31580 51000 __B 18 21 26 30 36 40 48 54 64 71 78 92 105 129 154 500 A 9.85 18.3 39.2 74.8 158 239 471 765 1380 2060 2910 5410 8970 19040 35840 57580 B 20 23 29 33 41 45 54 62 72 80 88 104 119 147 600 A 10.9 20.2 43.2 82.5 174 264 521 846 1530 2280 3220 5990 9930 21100 39740 64210 B 22 26 32 37 45 50 60 68 80 89 97 115 132 162 800 A 12.7 23.6 50.5 96.5 204 310 610 992 1790 2670 3780 7030 11670 24820 46780 75620 B 25 30 37 43 52 59 70 80 94 104 114 135 155 191 * For other temperature drops the pipe capacities may be changed correspondingly. For example a temperature drop of 30 deg. the capacities shown in this table are to be multiplied by 1-5. Hot Water Heating Systems 531 alent number of elbows of the same pipe size which would have the same friction loss. An elbow is assumed to have the same'friction loss as a straight pipe having a length equal to 25 diameters (nominal) of the elbow. The resistance of various types of fittings expressed in equivalent elbow resistance is shown in Table 1. The friction loss in pipes and tubing may be determined from Fig. 2 and Table 2 for black iron pipes, and from Fig. 3 and Table 3 for type L copper tubing. The scale at bottom of Figs. 2 and 3 is the heat carrying capacity in thousands of Btu per hour based on a 20 deg temperature difference between flow and return risers. In order to use the scale for other than 20 deg difference, refer to footnote under Figs. 2 and 3. If the flow in a given pipe is calculated in 'pounds per hour, it may be FLOW OF WATER IN GALLONS PER MINUTE Fig. 3. Friction in Type L Copper Tubing of chart is based on 20 deg temperature difference between flow and return risers. ( ^ 20 1011 temperature drop is other than 20 deg, multiply, the actual heat conveyed by \actual temp, drop) ond read the corresponding friction. converted to corresponding gallons per minute by dividing the flow in pounds by 500, after which the friction may be found by entering Figs. - and 3 at the top scale reading which corresponds to the flow in gallons Per minute as determined. Orifices drilled in plates inserted in pipe unions are convenient means or introducing friction, where required to balance various circuits. The nction losses caused by various sizes of orifices are given in Table 4. CLASSIFICATION OF SYSTEMS Gravity ox forced systems of piping may be classified according to-piping r ,rat|gement and type of circulation as shown in Table 5. Flow . and anfl1? ma'n P'P'n8 (gravity systems) for one-pipe, two-pipe direct return, a wo-pipe reversed return systems are shown in Figs. 4, 5, and 6, re-