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Why is the ball valve of my potato gun releasing the pressure? Answered

The ball valve of my air cannon releases the pressure once it climbs above 5 psi. Is there any way to fix this? Or am I stuck with a $30 door stop
I'd buy a new one but it just started to leak air, it was working, plus it's glued to my U joint, and really don't wanna rebuild it.



Best Answer 7 years ago

Butterflys are delicate versions of Ball valves for strength use the slow Gate valve.
The pvc plug is still a best answer..... A

o and my ball valve works again.. I realized that lubing it with WD40 wasn't the smartest move because it allowed the air to force it open lol

FYI for all curious I do have a sprinkler valve swap able trigger, it's just so unearthly loud that my neighbors complain
15 psi and you can hear the thing from out side of my house when shot in the basement.... dam tiny diaphragm valve

i would recomend using a butterfly valve instead


7 years ago

i would say that your ball valve is worn and you need to replace it.

So you think so too


7 years ago

When you fire the cannon the pressure gets much higher the 5 PSI.
A ball valve is a low cost, sensitive machine that may be able to do 200 PSI.
You may have damaged the ball seat or split a radial pipe connection.
We used schedule 80 pipe and a hand screw seal instead of a Gate valve which is better then a ball valve.

Did you verify exactly where your leak exits gas ?


it just goes through the ball valve joint
I used some fog machine smoke (the water vapor kind) to see where it was coming from and it was just pouring out from the ball valve opening
I can't see where exactly due to the fact that it is connected to a U joint
So I guess I'll have to replace it, at least I have tons of time now that schools over

Good discovery technique.
I still recommend a hand screw type cover it is stronger than a ball valve,
but alas slower.


I may just get a new igniter for my combustion cannon, but it only shoots with Lysol
I swear I've tried every thing from gas to starter fluid, but Lysol is the only thing it shoots

Seems to atomize well and you have the mix of air and Lysol just right !