[BBray_T1296]

For our T-shirt Cannon: It is made entirely out of PVC. We use 3" pvc sewer pipe (rated to 300PSI) with an end cap at one end, reduced to 1"on the other end, through a (manual) ball valve, back up to 3" for the barrel.

The PVC storage tank (behind the ball valve) Has a weird fitting (I don't even know what to call it) but has a standard 3/8" threaded hole in it, where we connected first a FRC compressor via spare FRC pneumatic fittings, but was upgraded to interface with our 21 gallon shop compressor.

People distrust hand-built pvc as a pressure vessel, but we have successfully fired hundreds of T-shirts at 155 PSI (Firing nearly clear over our stadium [which is huge]), without incident. It was PVC cemented on the day we built it and has had zero maintenance in the 7 years we've had it.

If you wanted an electrically fired cannon (probably would fire a t-shirt further than with a manual ball valve), you could use a sprinkler system valve. They are designed to hold back a lot of water pressure, and hence, a lot of air pressure as well. They also actuate quickly and require maybe 12 volts.