Experience has proved that the following are allowable velocities in pipes: air, 30 to 50 ft/s (9.1 to 15.2 m/s); compressed air, 25 to 40 ft/s (7.6 to 12.2 m/s); steam, 160 to 250 ft/s (46.8 to 76.2 m/s); water, 5 to 10 ft/s (1.5 to 3.0 m/s).