Maximum Recommended Air Flow (SCFM)
Through ANSI Standard Weight Schedule 40 Metal Pipe
The flow values in the table below are based on a pressure drop of 10% of the applied pressure per 100 feet of pipe for 1/8", 1/4", 3/8", and 1/2" pipe sizes; and a pressure drop of 5% of the applied pressure per 100 feet of pipe for 3/4", 1", 1-1/4", 2", 2-1/2", 3" pipe sizes.
The table gives recommended flows for pipe sizes at listed pressures and should be used to determine appropriate piping for air systems.
| Applied Pressure PSI | Nominal Standard Pipe Size | ||||||||||
| 1/8" | 1/4" | 3/8" | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | |
| 5 | 0.5 | 1.2 | 2.7 | 4.9 | 6.6 | 13 | 27 | 40 | 80 | 135 | 240 |
| 10 | 0.8 | 1.7 | 3.9 | 7.7 | 11.0 | 21 | 44 | 64 | 125 | 200 | 370 |
| 20 | 1.3 | 3.0 | 6.6 | 13.0 | 18.5 | 35 | 75 | 110 | 215 | 350 | 600 |
| 40 | 2.5 | 5.5 | 12.0 | 23.0 | 34.0 | 62 | 135 | 200 | 385 | 640 | 1100 |
| 60 | 3.5 | 8.0 | 18.0 | 34.0 | 50.0 | 93 | 195 | 290 | 560 | 900 | 1600 |
| 80 | 4.7 | 10.5 | 23.0 | 44.0 | 65.0 | 120 | 255 | 380 | 720 | 1200 | 2100 |
| 100 | 5.8 | 13.0 | 29.0 | 54.0 | 80.0 | 150 | 315 | 470 | 900 | 1450 | 2600 |
| 150 | 8.6 | 20.0 | 41.0 | 80.0 | 115.0 | 220 | 460 | 680 | 1350 | 2200 | 3900 |
| 200 | 11.5 | 26.0 | 58.0 | 108.0 | 155.0 | 290 | 620 | 910 | 1750 | 2800 | 5000 |
| 250 | 14.5 | 33.0 | 73.0 | 135.0 | 200.0 | 370 | 770 | 1150 | 2200 | 3500 | 6100 |