47
Table 14B: Maximum Capacity of Schedule 40 Black Pipe in CFH* (LP Gas) For Gas Pressures
of 0.5 psig or Less
Inlet Pressure 11.0 Inch W.C.; 0.3 Inch W.C. Pressure Drop
Nominal Pipe
Size, In.
Inside
Diameter, In.
Length of Pipe, Ft.
10 20 30 40 50 60 70 80 90 100
½ 0.622 88 60 48 41 37 33 31 29 27 25
¾ 0.824 184 126 101 87 77 70 64 60 56 53
1 1.049 346 238 191 163 145 131 121 112 105 100
1¼ 1.380 710 488 392 336 297 269 248 231 216 204
1½ 1.610 1064 732 588 503 446 404 371 346 324 306
2 2.067 2050 1409 1131 968 858 778 715 666 624 590
2½ 2.469 3267 2246 1803 1543 1368 1239 1140 1061 995 940
3 3.068 5776 3970 3188 2729 2418 2191 2016 1875 1760 1662
Inlet Pressure 11.0 Inch W.C.; 0.5 Inch W.C. Pressure Drop
Nominal Pipe
Size, In.
Inside
Diameter, In.
Length of Pipe, Ft.
10 20 30 40 50 60 70 80 90 100
½ 0.622 116 80 64 55 48 44 40 38 35 33
¾ 0.824 242 166 134 114 101 92 85 79 74 70
1 1.049 456 314 252 215 191 173 159 148 139 131
1¼ 1.380 937 644 517 442 392 355 327 304 285 269
1½ 1.610 1403 964 775 663 588 532 490 456 427 404
2 2.067 2703 1858 1492 1277 1131 1025 943 877 823 778
2½ 2.469 4308 2961 2377 2035 1803 1634 1503 1399 1312 1239
3 3.068 7615 5234 4203 3597 3188 2889 2658 2472 2320 2191
* 1 CFH of LP Gas is approximately equal to 2.5 MBH; contact your gas supplier for the actual heating value
of your gas.
Table 15: Equivalent Lengths of Standard Pipe Fittings & Valves
Nominal
Pipe Size,
Inc.
Inside
Diameter,
In.
Valves (Screwed) - Fully Open Screwed Fittings
Gate Globe Angle
Swing
Check
45°
Elbow
90°
Elbow
180 Close
Return
Bend
90 Tee
Flow Thru
Run
90 Tee,
Flow Thru
Branch
½ 0.622 0.4 17.3 8.7 4.3 0.7 1.6 3.5 1.6 3.1
¾ 0.824 0.5 22.9 11.4 5.7 1.0 2.1 4.6 2.1 4.1
1 1.049 0.6 29.1 14.6 7.3 1.2 2.6 5.8 2.6 5.2
1¼ 1.38 0.8 38.3 19.1 9.6 1.6 3.5 7.7 3.5 6.9
1½ 1.61 0.9 44.7 22.4 11.2 1.9 4.0 9.0 4.0 8.0
2 2.067 1.2 57.4 28.7 14.4 2.4 5.2 11.5 5.2 10.3
2½ 2.469 1.4 68.5 34.3 17.1 2.9 6.2 13.7 6.2 12.3
3 3.068 1.8 85.2 42.6 21.3 3.6 7.7 17.1 7.7 15.3