Natural Gas Pipe Sizing

Ken Stansbury Natural Gas Generator Sales

Here's the pipe size chart we've used for years. This is for figuring pipe size for a dedicated line run from the fuel source with minimal number of bends (elbows) and a pressure of 11" water column (standard household gas pressure). Find the fuel requirement in cubic feet per hour at full load from the spec sheet for the generator you have selected. After measuring pipe length run, scan across chart until you pass required fuel flow. The top of the column gives required pipe size.

Length of Pipe (Feet) 1/2" 3/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 6" 8"
15 76 172 345 750 1220 2480 3850 6500 13880 38700 79000
30 52 120 241 535 850 1780 2750 4700 9700 27370 55850
45 43 99 199 435 700 1475 2300 3900 7900 23350 45600
60 38 86 173 380 610 1290 2000 3450 6800 19330 39500
75 ---- 77 155 345 545 1120 1750 3000 6000 17310 35300
90 ---- 70 141 310 490 1000 1560 2700 5500 15800 32250
105 ---- 65 131 285 450 920 1430 2450 5100 14620 29850
120 ---- ---- 120 270 420 860 1340 2300 4800 13680 27920
150 ---- ---- 109 242 380 780 1220 2090 4350 12240 25000
180 ---- ---- 100 225 350 720 1120 1950 4000 11160 22800
210 ---- ---- 92 205 320 660 1030 1780 3700 10330 21110
240 ---- ---- ---- 190 300 620 970 1680 3490 9600 19740
270 ---- ---- ---- 178 285 580 910 1580 3250 9000 18610
300 ---- ---- ---- 170 270 545 860 1490 3000 8500 17660
450 ---- ---- ---- 140 226 450 710 1230 2500 7000 14420
600 ---- ---- ---- 119 192 390 600 1030 2130 6000 12480