Why did I fail?

[spudnutbutthut]

Wel, some of you may remember my propane powered pneumatic canon thread.

Well, I attempted it.


propane bottle connected to a camp stove burner adjuster knob, that goes through a hose to a hose barb that is mounted in the chamber. The chamber is 2in and is supposed to pressurize. Then I have a modfied sprinkler valve that goes to a 2 inch barrel. When I put in the propane tank, turn on the burner etc. the chamber doesn pressurize or leak.... I have a pressure gauge. When I press the sprinkler valve trigger (blowgun) the propane comes out of the bottom of the blowgun and the diaphram doesnt open. What am i doing wrong, why is there NO pressure but gas still flows.

[jor2daje]

I'm pretty sure camp stoves have built in regulators to keep the pressure low, how did you connect the camp propane adapter to you gun, you should modify a cheap pencil torch.

[D_Hall]

I'm pretty sure camp stoves have built in regulators to keep the pressure low, how did you connect the camp propane adapter to you gun, you should modify a cheap pencil torch.

What he said. Camp stoves generally operate at only a few psi.

[spudnutbutthut]

Ok i switched to a pencil torch, it pressurizes but when i pull the trigger the propane comes out of the bottow of the blowgun and the membrane dosent open... there is also some leaking from the sprinkler valve...WTF?!

[jrrdw]

Is the arrow on the sprinkler valve pointed towards the barrel or chamber?

[spudnutbutthut]

the barrel it says "FLOW -> " toward the barrel.

[jrrdw]

Are you getting to 30psi and above quickly?

[spudnutbutthut]

around 25 + yes, not QUICKLY but pretty ok speed why? it was at 20 i think...

[jrrdw]

Sometimes sprinkler valves diaphrams won't seal until you reach around 30psi, the quicker the better. Take it apart and see if there is any debree causing it to not seal correctly.

[spudnutbutthut]

should the bottom of the sprinkler valve be epoxied shut?

[jrrdw]

The only reason to epoxy would be if the solonoid was removed and the hole would need filled.

[spudnutbutthut]

okay, it pressurizes quickly to 60 psi, then when i press the sprinkler valve it lets the gas out the bottom of it.... WHY>!

[jor2daje]

What sort of sprinkler valve are you using?

[jrrdw]

What kind of blow gun are you venting the sprinkler valve with? Try loosening the blow gun enough so you can take it off as fast as you can, pressurize the chamber the yank the blow gun off and see if it releases the stored air out the barrel.

[MrCrowley]

What kind of blow gun are you venting the sprinkler valve with? Try loosening the blow gun enough so you can take it off as fast as you can, pressurize the chamber the yank the blow gun off and see if it releases the stored air out the barrel.

Wouldn't it leak out the blowgun where it's threaded in to the sprinkler valve or damage the threads if you yank it out?

Is your blowgun up the right way? Do you have a hose between the valve and blowgun or is the blowgun directly connected to the valve? How big is your chamber?