As a few of you may know, my job is as a Chief Mechanic on seismic survey vessels. What we do is map geological formations for oil companies, to increase their probability of drilling in the right spot. Today I have been overhauling some 3 way high pressure ball valves, for our "shooting air" manifold. The pressure is normally 2000 or 2500 psi, so leaks are not very desirable. I don't remember the cfm of our 3 compressors, but the drive motors for them is close to 1000 hp each, so they are quite big. Normally we run just two of them when shooting.