spud gun/T-shirt gun valve

[fovea1959]

Originally Posted by D.Allred

Air is a compressible fluid. Water is not. Rapid expansion of compressed air when released will turn debris into shrapnel. Do not use any valve unless it is rated for compressed air.

David

ah. There's the answer. It's not that the valve is more likely to fail at 70PSI air than 70 PSI water, it's that *if* it fails, the damage is more catastrophic. makes sense.

ok, so I shouldn't use Schedule 40 PVC for the tank or anything "upstream" of the shooting valve, what *do* I use?