how does a qev valve work?

[Tijn_416cs]

I'm making a semi auto airsoft gun, and I heard alot about quick exhaust valves.
I want to use 12gram co2 cartridges and I thought about having a set up like 12G co2->Qev->schradervalve or blowpistol
would that work? Thanks

[Hurricane Air Arms]

12 gram Co2 cartridges won't get you remarkably far on a QEV. And you should search the forum and the internet, especially youtube, for diagrams and workings of a QEV...

They're backpressure piston valves. Air inside a T-Piece is dumped out of a trigger behind the piston to create a pressur imbalance on the barrels side, the piston is shoved back by force and the rest of the air in the T is briefly dumped down the other exit - the barrel.