Do we have a maximum velocity for liquids in pipes,for preventing noise or errosion? Do we have a minimum velocity for liquids in pipes? In relation of which problem? Maximum velocity is a frequent topic on these forums. There must be some widely varying assumptions to get the range of numbers that I've seen here. For "dry gas" flow I use an actual velocity (as opposed to "velocity" calculated as SCF/FlowArea) of 100 ft/second or 15 psi/mile pressure drop as my upper design condition. Design capacity will be the lower of the SCF/day you get from 100 ft/sec or the SCF/day you get from 15 psi/mile pressure drop. That choice stays way below errosional velocities, won't slam a slug of water into plant-inlet pipeworks, and gives me a makeup compression Hp requirement I can live with. All of the vertical flow correlations show a critical velocity (for keeping water mobile) around 36 ft/sec. I figure that if it works in vertical flow, it should be quite conservative in horizontal flow. I've been using 36 ft/s as a minimum design condition for about 7 years now and see considerably less liquid accumulation in the piping I designed than I see in the piping I inherited.

MORE NEWS