2.5'' piston or dual 1'' metal sprinkler valves

[Erich The Scientist]

My pneumatic cannon I'm building is a 2.5'' piston valve air cannon. I was wondering if a 2.5'' piston valve would have more flow that dual 1'' sprinkler valves. The cannon is schedule 80 cpvc rated for 400 psi (my area can hit 110 degrees so it puts it down to about 300 psi max pressure). The cannon has an adapter on the barrel for changing barrels with a standard barrel for shooting or 3 to 5 feet. With my prototype, the cannon can work as low as 15 psi or as high as 370 psi on a good day. The simulations I did can not produce ideal simulations for sprinkler valves, so I was wondering if I should go for a larger bore.

[Ragnarok]

I was wondering if a 2.5'' piston valve would have more flow that dual 1'' sprinkler valves.

Massively so. Flow is proportional to area, not diameter, and a 2.5" valve has more than six times the area of a 1" valve. Even with two valves, the sprinkler aren't even close.

With my prototype, the cannon can work as low as 15 psi or as high as 370 psi on a good day.

I strongly advise against using PVC pipe at anything like 370 psi. Even if the pipe is nominally rated to that, a single crack in the pipe or a sudden jolt could compromise it, and PVC has horrific failure characteristics (it shatters into a lot of very sharp pieces) - you don't even want to risk it having that much energy contained.