My first Piston Valve.

[spudgunnerwryyyyy]

This is my first piston valve, it is in a 2" tee with 1.5" porting. The piston is comprised of 1.5" pipe, 2 cast epoxy segments, foam bumper, rubber sealing face and a bolt to hold it all together.

Comments and criticisms would be apprecitated.

Hoping to hear from jackssmirkingrevenge, and McCrowley because they helped a bunch.

EDIT: This piston has been replaced by this one herehttp://www.spudfiles.com/forums/viewtop ... tml#129239
check it out it has o-rings

[MrCrowley]

Looks good, did you manage to fix the problem with all the air going out the pilot?

[spudgunnerwryyyyy]

Thanks, well it isn't finished yet, I need a 2" female adpater and 2" threaded plug to fit over the 2" pipe sticking out. But with my breath (3psi I checked lol) blowing from the chamber side the piston slides back 3/4" so your longer piston bigger bumper idea is working great. Any comments on if the pilot space is to large or is there any other problem.

[MrCrowley]

Is there much area on the face of the piston that is not covered by the seat(barrel) when it is sealing?

If there is not enough area the air pressure may not have enough area on the piston to push it back and fire the gun.

[spud yeti]

That looks like a pretty decent piston valve you've got. Is it serviceable? Nice work though.

[jackssmirkingrevenge]

looks like it should work well assuming the piston is a reasonably tight fit. 3/4" of travel is about right for that configuration, though like MrCrowley pointed out above the difference in areas between barrel and chamber isn't so great which might be a factor. Only one way to find out tho, good luck with finishing it

[MrCrowley]

What's with the holes in the tee?

Just letting you know, while i've been here in America I decided to buy some fittings to do something similar with what you are doing with the female adapter and end cap, my old way of sticking a end cap on leaks a bit and I hate using JB Weld because it looks like sh|t on guns.

[spudgunnerwryyyyy]

Well I did do the screws to service but then I figured out the female adaptor is way easier. The piston's epoxy cast parts have enough surface area to open. I'm going to Adams Hardware today to get the parts to finish.

Edit: the piston fits perfectly and slides easy with lithium grease.

[spudgunnerwryyyyy]

Ok I got it working. It breaks ping pong balls at 35psi with a 2"x24" chamber and a 1.5"x48" barrel. I will be posting it in the pneumatic section when I get my 3"x24" chamber hooked up. I had to use crazy amounts of white lithium grease to get it to work but now its just amazing.

Thanks again to McCrowley and jsr for all their help with getting this to work.

[mark.f]

Cool. Just one other question though, what is the sealing face made out out?

Like your avatar, by the way.

[jackssmirkingrevenge]

Congrats for getting it to work

I had to use crazy amounts of white lithium grease to get it to work but now its just amazing.

Is this because the piston very tight in the chamber?

[spudgunnerwryyyyy]

Yah the piston was pretty tight but now its just great. When I fill the pilot its loose enough to also fill the chamber but when I open the pilot the valve actuates its such a nice concept.

[spudgunnerwryyyyy]

Ok, next part of build now accomplished. I put a modded 3/4" sprinkler valve to pilot because it has such a large pilot space. HUGE difference. Valve actuates with zero delay and now i can fire it much easier because its way easier to press a blow valve than to twist a 1/2" ball valve.

[spudgunnerwryyyyy]

now has a piston with o-rings shown here
http://www.spudfiles.com/forums/viewtop ... tml#129239