Leaking

[Mooglebass]

I recently build a Pneumatic cannon. 1.5" x 3ft barrel and a 1.5" x 2 foot chamber. Im using a 1" sprinkler vavle that I recently bought from BCram. Everything is together and ready to go but one thing.

I fill it out and i can hear a slow hisssing sound coming from the barrel. I took the barrel off and could feel the air slowly passing throught the vavle and out. I took the valve apart and cleaned the rubber and put it back in. Still does it. What could be the problem with my cannon? Im not sure on the psi i put in but the compresser had 50 psi and it stopped filling the cannon so i think it equaled out.

Any ideas on this?

[pvcmaster]

I had the same problem when I first used a sprinkler valve. It turned out that mine was backwards, the small solenoid hole should be on the barrel side, and a flow arrow should be printed on the side of the valve. I don't know if this is your problem, but it was mine. If this does not work, your valve may just have trouble building up pilot pressure. Try putting a ball valve in front of the sprinkler valve, close it, fill your chamber, then open the ball valve, and your sprinkler should be sealed.

Hope this helps. I would also suggest getting a larger chamber, the chamber pipe is almost always larger than the barrel size in pneumatics.

[Mooglebass]

I checked the valve and the arrows are poiting toward the barrel. If i turn it around it makes this werid farting sound lol. Ill try the valve idea monday when i can get a valve from work to use. I did try to fire a potato though but it pushed the spud to the end of the barrel. I may try again in a bit. I cleand any junk off the rubber but maybe there is some more in there.

I know ill up the size fo the chamber later, and use this one for another gun in the future.

[mopherman]

try tightening you soleniod. it could be leaking pilot pressure

[Mooglebass]

Do you mean whats on the inside of the gun? The white piece in the of the rubber with the screw on the bottom?

[iPaintball]

Why is your chamber so small?

[Mooglebass]

Just used the 10ft stick of 1.5" i had. Ill be changing it soon enough.

[frankrede]

apply grease to your diaphragm, not too much but get it well lubricated.

[jimmy101]

Another thing to try is to flush water through the valve to insure there isn't junk in it. If you have the proper fittings you can just hook the inlet side of the valve up to a gardern hose (IIRC hoses are 3/4"). Cycle the valve a few times then see if it will hold the 30~60 PSI that a typical house water supply provides.

The valve is designed for water so it won't hurt it.

[Mishkan]

Put a little soap and water around all the seams on the gun. Pressurize it slowly and you'll see if there's a leak in your joints. Old trick..

[frankrede]

but that has nothing to do with the sprinkler valve, read the topic before you post