2 Inch QEV Cannon

[farcticox1]

He only went and split Bamby in half, IN HALF

[Jamzearljones]

So... because I can’t leave well enough alone...

My only problem is; as it is plumbed now, it fills through the pilot valve. I have since discovered that my QEV does not allow me to fill it through the pilot valve. So basically I have a closed chamber with no way to fill it. I was thinking about tapping a fill plug and ball valve into it somewhere... I’m just not sure if the PVC will hold up to that... also... is that safe? Otherwise I’m going to end up taking the back end apart to include a Tee in somewhere.

[jackssmirkingrevenge]

He only went and split Bamby in half, IN HALF

I'm guessing it was a modular archery target like this one.

I’m just not sure if the PVC will hold up to that... also... is that safe? Otherwise I’m going to end up taking the back end apart to include a Tee in somewhere.

For a small diameter in thick PVC it's not usually a problem, something like a 1/4" threaded schrader valve should do the job depending on what you are using to fill.

[farcticox1]

I do that, try and get in to a join so you get double thickness, I usually epoxy them in as well, just to be sure

[Jamzearljones]

I'm guessing it was a modular archery target like this one.

Yes it was a modular archery deer, but the shot went clear through and split the union between the two halves to pieces. The deer is broken... but still usable. Needs more golf balls.

And now... MK-IV

I went scientific and tension tested a ¼ and a ⅜ NPT tap in PVC and decided to go with the ⅜. The fitting in the PVC was stronger by about 200 lbs when tested and it is still small enough to treat a 2” coupling like a flat surface. I did tap into a joint that used both the coupling and a SPGT fitting making it even thicker than just a normal PVC pipe in a coupling. It ended up working great, though the space was a little cramped for a ball valve and a fill plug. I included a short piece of hose to get around the confined space. The ball valve is now well protected and filling is easy. The hose also puts less leverage and stress on the ⅜ tapped hole than if I had been able to put the fill plug directly on the ball valve.

The last bit is the 1-½” matching QEV that just made its way into my hands. I’m thinking about reviving MK-III with it unless anyone has any other ideas for me? Also found a 2” sprinkler valve that I’m working on converting from electric to pneumatic.

Now for pictures!!!

[mrfoo]

Bloody hell.

[farcticox1]

what he said

[jackssmirkingrevenge]

The deer is broken... but still usable.

me_irl

I really have to commend you on the rapidity of your progress, excellent work!

[Jamzearljones]

I took this from another post because what I’m asking applies here. And now that you mention this it is going to bug me that I’m not using the valve correctly.

If this is done and no pressure goes to the trigger during fill up, my fear is that the gun may fire when the safety valve is switched and the pressure from the valve rushes to the trigger simulating/causing enough of a depressurization of the QEV.

If it's a commercial QEV, it would not seal if filled from the chamber side anyway.

Please elaborate? If you are referencing the 2” QEV I use, I did/do have this problem. My solution was to use a spring behind the main diaphragm that fits into a circular indent in the back of the case when the diaphragm is slammed open. I would prefer to use the valve as intended if there is a better/more correct way.?
I attempted to fill through the pilot valve on MK-IV which is what lead to the fill plug tapping issue, so I don’t know how this could be intended to operate... because it evidently was successfuly used in service without the spring in place right up to a plant shutdown (which is how it came to me).

[jackssmirkingrevenge]

Typically, the piston of a commercial QEV is a cup seal that does not allow gas to flow to the pilot chamber, the logic being that you want to separate pilot vent and main vent. Without being able to see the internal configuration of your valve it's hard to tell if this is the case, do you have a part number on it?

[Jamzearljones]

Without being able to see the internal configuration of your valve it's hard to tell if this is the case, do you have a part number on it?

Hows this? I couldn’t figure out what I was looking for when I looked it up.

This is the back of the smaller one that I haven’t used yet.

Heres the rest of today’s work. I finished the sdr21 sleeve by grinding out and inverting a 1-½” to 2”male threaded fitting on the end of the sleeve. The breech of the barrel fits snug through the union on the QEV. With the golfball barrel ready. I decided to split some solid 2” beech slabs

[farcticox1]

They make stuff in Australia

[jackssmirkingrevenge]

Smaller one is a Goyen RCAC25FS



Larger one is a Goyen RCAC45FS



The schematics I found aren't very clear but neither of them appear to allow air to go to the pilot area from the chamber.

They make stuff in Australia

Well they aren't there to fuçk spiders...

[Jamzearljones]

More importantly to me, each of the diaphragms have a return spring so I was not wrong to fit one in. The missing springs might be how/why I got them I just imagine these valves back in the plant refusing to seal up and dumping air for an eternity and a half :bounce:

[Jamzearljones]

YouTube vision!!!

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[youtube][/youtube]