valve leakage

[subterranean]

im currently building my first pneumatic and im going to be using a sprinkler valve. my chamber is going to be 3"x6' ive heard that these valves have a slow leak in them and im wondering if it will take so much time to fill the chamber that the leaking would move the potato down the barrel


p.s. is a pneumatic cannon with 1.5"x8' barrel with a 3"x(6' or 10')chamber going to be a very good cannon or is the ratio pretty messed up?

[)DEMON(]

Once sprinkler valves get to a few Psi they seal so you really don't need to worry about this. You chamber and barrel should be fine. As long as you use lots of teflon tape, make sure there is nothing on the threads or in the way and tighten your fittings then nothing should leak.

[jrrdw]

My sprinkler valve acts exactly that way, i have no problem when useing my air compressor to pump it up, but i don't know how other air supplies will work. Thats something to think about.

[subterranean]

so the barrel chmaber ratio is ok, because i havent seen my cannons were the chmaber is longer than the barrel

[Billy Bob]

Where do you buy the sprinkler valves ?
Where I live there are no usefull valvues only ball valve and shit slow magnetic valves.

My Buddy gives me an "Asco" 1" membran valve. I rebuild that like all your do that in your pictures i seen. I think about build me an bigger pneumatic gun with two valves but one 1" valve should be cost 165 €.
I say shi*. The sprinkler valves look brilliant.

[ProfessorAmadeus]

Well dumping that much air through a sprinkler valve is going to be useless. maybe try a 3 inch barrel sealer. They arnt' very hard to make and will make you cannon worth you while. With a 10 ft chamber and a 8 ft barrel you going to use some of the air while shooting and the rest will be wasted and will just take longer to fill.

[subterranean]

so how long do you think i should make the chamber? so that all of the air is used?

[squeaks]

Play around with the GGDT, it'll tell you what you want to know.