3 Way Valve N.O. and N.C.

[DinerKid]

I have been looking at 3 way valves for a cannon i am planning out however i can not seem to figure out if i want a normally open or normally closed valve. I did some Google searches and came up with nothing helpful so i figured i would ask the experts. I was hoping to have it set up so that when the circuit is disconnected the valve will go to a position as to allow the tank to be filled and when i push a push button switch the valve will pilot the qev.

What i don't want is the opposite. So i would have to hold the button and power the solenoid in order to fill the tanks and then release to pilot the qev as i plan to use a battery for power so i don't want to have to power the solenoid for too long.

I believe the situation that i want would call for a normally open 3 way valve but i just want to be sure before i buy anything.

Thanks
~DK

[PVC Arsenal 17]

You need a normally open valve. When the trigger is NOT being pushed, pressure is supplied to the gun. When the trigger IS pushed, the supply pressure is cut off and the pilot volume behind the QEV will be exhausted.

[DinerKid]

That is what i thought thanks.

What do you think of this one. It is 1/4 inch so it should be fine for piloting a 1/2" QEV.
http://cgi.ebay.com/3-2-Way-Solenoid-Ai ... 705wt_1083

~DK

[PVC Arsenal 17]

That's an electronic valve, though it does apparently have manual override. Personally I think it would be overkill. You would be fine with a smaller QEV to pilot the 1/2" QEV, and then a compact, manually actuated N.O. valve to pilot the smaller QEV. That's called a cascading setup.

I would recommend the Clippard MJVO-3.

Here is one of mine setup with an 1/8" QEV and a thumb paddle actuator.

[DinerKid]

I was thinking about using the MJVO-3 but for the design i am working on it would be in a horrible place as far as comfort goes so i was thinking if i used an electric 3 way i could then place the trigger switch anywhere really so it would be more comfortable. I am still a little bit on the fence. Just to make sure if i used a manual 3 way it would also have to be N.O. correct?

Where did you get the finger lever for it? i looked for one with the lever attached but i couldn't find one.

~DK

[PVC Arsenal 17]

Correct. I don't know exactly what your design looks like, but if your configurations are really limited you may indeed have to use an electronic valve. They just seem bulky to me and the incorporation of electronics complicates things. (not much, though)

Have you thought of a sleeve valve? http://www.mcmaster.com/#4622k57/=7goycj

The "trigger" is a Pneumadyne product.

[DinerKid]

Yeah i have looked into them but they are even worse for this situation. I have to finish the CAD first before i eliminate any ideas. Thanks so much you have been really helpful.

~DK

[PVC Arsenal 17]

My knowledge of DCV's doesn't go very far beyond the handful of 3-way valves I've worked with so I don't know what else to suggest that might help you in your situation. I'm sure POLAND_SPUD will find your thread shortly and offer some of his input.

[Technician1002]

A manual 3 way will also need to be NO so the air hose is connected to the chamber until you pull the trigger.

[POLAND_SPUD]

yes, you can use a solenoid valve (also NO). Just remember that it requires batteries

you can also use bike brake cable to actuate the valve from a distance...


I've never build such a system but if you think of it it isn't very complicated