qev question

[madmarcs]

Hello spudfiles i just have a quick question about a valve that I bought. My understanding of qevs is that they have a small spring inside them to push the piston back into place after the air reservoir has been released. so it came as a surprise when i could not find a spring in the valve and could push the piston back with my finger without it returning back to it's original place. i was wondering if this is okay or if i should see about getting another valve. The valve i bought is a simple 3 way qev that i have seen on several other projects.

-Madmarcs

[PaperNinja]

While I'm sure QEVs with springs exist, I think they more typically work like this:
In any case, you should just test it. If it works? Great! If not... less great.

[Goats spudz]

Most QEVs don't have springs inside them, You only need one if you plan on semi auto, However there are much more efficient ways of accomplishing that.

[PaperNinja]

Mine has semi auto and no spring...

[madmarcs]

thanks for the info and the speedy replies. The cannon i am building will be bolt action and will dump the reservoir for each shot bet will be hooked up to a co2 regulator and bottle so refilling the reservoir will be a snap.

[Goats spudz]

Mine has semi auto and no spring...

"However there are much more efficient ways of accomplishing that."

[PaperNinja]

More efficient semi auto than QEV with a spring, without a spring or both?

[jackssmirkingrevenge]

If you're pressurising the system from the pilot side, there is no need for a spring. If on the other hand you're filling from the chamber side, you need to add a spring and make some sort of equalisation hole.