Thursday, May 22, 2014


Recently I have been thinking about the subject of pneumatic launchers again. That led me to go rummage through the pneumatic parts bins at the surplus dealer again...

And I bagged this for a couple bucks.

This is a Humphrey Products QE-3 quick exhaust valve. If you have never heard of QEVs, they are industrial hardware, used mainly in pneumatic automation, but they are functionally equivalent to piloted firing valves used in some types of airguns and quite useful for this purpose. You may know variants of this family as piston valves, diaphragm valves, modded sprinkler valves, or "backpressure valves" (a NICism).

QEVs are a useful bit of kit, being compact, ready-made and higher-spec than most hobbyist DIY valves and stuff gutted from nerf airguns, which is just the direction I was thinking of going in experimentation. Strange that I randomly find one now.

There is just one problem.

That doesn't look right...

Yeah, that's not right. I bought a gutless valve. Apparently, someone used this valve body as a pipe elbow at some point in the past, then surplused it.

Well, the castings are good and it's not Chinese junk. About 8 bucks to rebuild with new parts and then it will be solid. Gonna do that later.


  1. Making it fire Mega darts would be an interesting twist.

    1. Mega airguns I know are fun and I want to try it sometime, but this won't be one. At least not a dedicated one.

      I have bigger plans for this valve right now. Without going too much into detail, I plan to do for the stefan side of things what the last 4 years of Nerf products and modding have done for stock class.

    2. The campus I play on just opened up the doors for homemades as long as you wouldn't mind getting shot in the face by it (that is the actual rule). I want to bring mine to one once.