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RT-SVX063G-EN

Table 13. Sizing natural gas pipe mains and branches

Gas SupplyPipe Run (ft)

Gas Input (Cubic Feet/Hour)

1¼" Pipe 1½" Pipe 2" Pipe 2½" Pipe 3" Pipe 4" Pipe

1,060 1,580 3,050 4,860 8,580 17,500

20 726

1,090 2,090 3,340 5,900 12,000

30 583 873

1,680 2,680 4,740 9,660

40 499 747

1,440 2,290 4,050 8,270

50 442 662

1,280 2,030 3,590 7,330

60 400 600

1,160 1,840 3,260 6,640

70 368 552

1,060 1,690 3,000 6,110

80 343 514 989

1,580 2,790 5,680

90 322 482 928

1,480 2,610 5,330

100 304 455 877

1,400 2,470 5,040

125 269 403 777

1,240 2,190 4,460

150 244 366 704

1,120 1,980 4,050

175 224 336 648

1,030 1,820 3,720

200 209 313 602 960

1,700 3,460

Notes:

1. Table is based upon specific gravity of 0.60. Refer to the latest edition of the National Fuel Gas Code, Z223.1, unless superseded by local gas codes.

2. If more than one unit is served by the same main gas supply, consider the total gas input (cubic feet/hr.) and the total length when determining the appropriate gas

pipe size.

3. Obtain the Specific Gravity and BTU/Cu.Ft. from the gas company.

4. The following example demonstrates the considerations necessary when determining the actual pipe size:

Example: A 40' pipe run is needed to connect a unit with a 850 MBH furnace to a natural gas supply having a rating of 1,000 BTU/Cu.Ft. and a specific gravity of

0.60

Cu.Ft/Hour = Furnace MBH Input

Gas BTU/Cu.Ft. X Multiplier Table 14, p. 44

Cu.Ft/Hour = 850

The above table indicates that a 2" pipe is required.

Table 14. Specific gravity multipliers

Specific

Gravity Multiplier

0.50 1.10

0.55 1.04

0.60 1.00

0.65 0.96