SpudFiles

I recently purchased a qev and slide check valve for use on a semi-auto. The qev works fine, but the slide check valve leaks when under pressure in either position. I tried lubricating it and inspecting the o-rings, but I can't figure out what's not working with it. I bought it new, and it looks exactly like this one:
I can provide pics if it would be helpful.

Have you tried submerging it in water to see exactly where it's leaking from?

Yeah that was the first thing I did. It leaks out where the slide meets the inner cylinder on both ends, past the o rings.

Does it leak above a certain pressure or at any pressure? Are you sure the o-rings aren't torn?

It leaks at any pressure, even 1 atm. I didn't see any tears in the o-rings, but it did seem to slide really easily. Also, the o-rings weren't the typical black rubber, but seemed more like a tan latex material.

I took the valve apart again, and there is a tear in one o-ring. Any ideas where I could get replacements?

Nitrile.

Measure the size then eBay is your friend.

Have a look at the porting, the holes probably have sharp edges from poor finishing. A light filing would solve this.

Thanks for your help, I'll post pictures of the finished cannon when I'm done.

In the meantime this chart is a useful reference: http://www.simritna.com/news/PDF/Simrit ... _FINAL.pdf