2 Inch Barrel Sealing Piston Valve Cannon

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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BeaverRat
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Well... Here it is

Specs:

-1.5 inch barrel - 5 ft. long

-2 inch chamber - roughly 33 inches long (can't remmember exactly, but the C:B ratio is 1:1)

-2 inch tee with 1-1/4th inch coupling piston

-Hubb design piston with built in check valve

-Spring bumper + neoprene rubber cushin (spring helps seal because I am using a hand pump, it works flawlessly yet has very light pressure as to not degrade performance)

-Behind 2 inch tee is a 2 inch female adapter, a 2 inch mail adapter, a 2"x1" slip to femail thread adapter, a small nipple made out of 2 1" male adapters with a threaded shrader valve so the valve has 2 PVC layers to thread into, and finally a 1 inch modified sprinkler valve

-In front of the tee is a 2"x1.5" modified slip adapter

-SS hose clamp with molded wooden barrel support

-I may get some piston pics if I ever have to take it apart.

[youtube][/youtube]
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Crna Legija
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looks very clean, some paint would finish it off.

what pressure was that video at?
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deathbyDWV
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Looks good. Great job... Why is there a threaded adaptor on the chamber? I was guessing so the chamber can be switched for a different one (maybe longer or shorter?) or is there a different reason?
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BeaverRat
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I wanted to be able to experiment with chamber size because I will be hand pumping it... I think 1:1 is a do-able ratio.
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BeaverRat
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Ok, I have a quick question... I pumped it up to 60 PSI, and in noticed there is a slight leak on the PVC connection between the 2 inch 90 degree elbow and the 2 inch female adapter that the chamber screws into. I plugged it with some epoxy, and the leak stopped, but is the fact that there was a leak (it's a very small leak, but you can definetly hear it) putting the chamber at risk of flying off or exploding?
Thanks
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Technician1002
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It indicates that there is a space that is not glued. It is not a tiny space like a bubble, but a large space so the inside and outside air meet. If you properly glued this with the primer, glue, and assembled with a 1/4 twist, it should not leak. If you pushed it together and had a burr on the cut edge of the pipe, that may have cut a trench in the glue softened pipe and made a narrow leak path. With a narrow leak path, it is unlikely to blow apart. If it is a large glue void, it may stress and come apart. Only you know how you glued it together.
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BeaverRat
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Ok, it is a very small leak... One strange thing is that it was not leaking yesterday at 60 PSI. It just started leaking today. Is that dangerous that it developed a leak versus having one from the start?
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Gun Freak
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How long did you wait before pressurizing? Sounds like you made a bubble before it was fully cured. As long as it is sealed now it should be fine.
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BeaverRat
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I waited a full 24 hours... I might just re-do it - all I need to fix it is 2 2 inch female adapters, 1 2 inch tee, a 2x1.5 inch adapter, and a 2 inch 90 degree elbow.
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Gun Freak
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You don't have to redo it as long as the leak is gone...
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BeaverRat
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Well, the leak came back because the epoxy seal broke... I have decided to just re-do the housing part... It will only cost about 5 dollars and 30 minuntes of work - so I'm not to upset.
jsparr
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nice barrel sealer what kinda piston??
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BeaverRat
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It is the Hubb piston as detailed in the first post... Basically, it is a 1-1/4th PVC Coupling with plugs on either side. It has a built in check valve and an o-ring seal.
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