SpudFiles

This is my first piston valve gun. It has two 5 ft long air tanks, 3 in. diameter. The piston housing is 3 in. with a 2 in. barrel. Soon to come: golf ball barrel! I'll see if I can get some videos later.

The only issue I have with it is that sometimes my pilot release valve doesn't bring the piston back. I believe it's because it's either too small or too tight. I really don't know enough about them to tell. I've messed around with wrapping layers of tape around the back of the piston (ghetto, I know) for a tighter fit but it's too hard to tell exactly what the problem is. Maybe somebody could help?

Note: The broken cinder block is from me trying to pick it up. I made about one and a half steps until it basically crumbled. Luckily, none smashed my foot I know the video of the prior shot looks unimpressive, but one more psi and the thing wouldve been shattered

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Nice first effort a ghetto piston like that needs a good pilot though, what are you using? A sprinkler valve would be an adequate solution.

yeah i'm using a sprinkler but for some reason it doesnt seem like it's opeing all the way. If i can get this darn video uploaded, maybe you could see. It almost whistles for a second or two before firing

There i posted the video

The yellow coiled line is screwing you over by dramatically increasing the sprinkler pilot volume. You need to mount the sprinkler pilot on the valve itself.

alright, ill give it a try!

Nice gun too much pilot volume.... I would also try using a we've for a pilot..

A we've?

I'm uploading another video to youtube now of a better shot.

QEV autocorrect?

I personally wouldn't use this gun because of all the dwv on it, it's going to explode sooner or later. Nice job besides that just make sure to use NSF-pw fittings next time.

All the parts are pressure rated. I made sure. I bought and glued dwv elbows that weren't pressure rated so I had to throw them away. I double checked all parts after that. They're safe, I promise. I wouldn't use it otherwise.

Thank u jack!!! Listen to 8ton.. I wouldnt bring that thing past 40 or 50 psi or your going to get a piece of pvc embedded into you for sure due to the drain waste vent fittings..

None of them are dwv. My uncle's friend works in a lab that has access to pressure rated fittings that usually aren't. I'd show you pictures but my primer got all over where it says. The lowest rated part is the blowgun with a max of 90 psi

The sockets look quite deep so I suspect acs2997 is correct and he is just using the DWV-style pressure rated fittings.

If it has NSF-PW on the fittings, they'll be pressure rated.

Trust me, I wouldn't be using it if my life was at risk.