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Valve options
Posted: Sun Nov 18, 2007 5:30 pm
by carl2.0
Yeh Im looking for some alternative valve options(besides a ball valve) that i can use instead of the sprinkler valve for my pneumatic cannon
Posted: Sun Nov 18, 2007 5:32 pm
by ShowNoMercy
Burst disk? Butterfly valve?
Posted: Sun Nov 18, 2007 5:34 pm
by psycix
Build a piston valve
Among those are the most powerful valves there exist and you can make them as complicated or just as easy as you like.
Just build a simple barrel sealing piston and be amazed of the power it gives.
Posted: Sun Nov 18, 2007 5:35 pm
by potatoflinger
Or a QEV.
Posted: Sun Nov 18, 2007 5:38 pm
by ShowNoMercy
Why no sprinkler valve though?
Posted: Sun Nov 18, 2007 7:03 pm
by SpudUke5
Posted: Sun Nov 18, 2007 7:25 pm
by DYI
I've built a triggered burst disk and a piston valve, but I would have to say that when I finally got the burst disk valve working, I was far happier than when I finished the piston valve. Likely because sealing a union in an application that it wasn't designed for at 3 times its rated pressure isn't half as easy as it may sound. The sound of 90 ci of gas at 400 psi venting out of a 2" opening 12' above my head at over the speed of sound has never sounded so good as it did today. (actually, today was the first time I've ever heard it)
But yeah, build a piston valve. QEVs are generally small and expensive, butterfly valves are slow and expensive, and burst disks are big, fast, cheap, and loud as hell, but a real b*tch to work with.
If you have an 8" bore barrel 50 feet long though, a butterfly valve begins to look like an incredibly good option though.
Posted: Sun Nov 18, 2007 7:34 pm
by Ragnarok
DYI wrote:The sound of 90 ci of gas at 400 psi venting out of a 2" opening 12' above my head at over the speed of sound has never sounded so good as it did today.
That must have left your ears ringing...
Piston valves are far easier than people may at first think, and are probably the best all round valve type, fast to open, very good flow, and easy to use.
If you spend your time on it, you can make a very nice example, even if you're completely new to it.
Posted: Sun Nov 18, 2007 7:46 pm
by Zen///
Muhahahah
I used a piece of clear tape as a burst disk with my ballvalve copper gun...
It's alot louder and puts battery's through my 200page art book!!

Posted: Sun Nov 18, 2007 7:46 pm
by DYI
That must have left your ears ringing...
Surprisingly enough, it didn't. I think I damaged my hearing when that 138ci Oxy-MAPP hybrid exploded two feet from my face.
I wonder how loud this would be with no barrel at 450 psi. The Krakatoa explosion comes to mind...
Posted: Sun Nov 18, 2007 7:52 pm
by windshrike
DYI wrote:That must have left your ears ringing...
Surprisingly enough, it didn't. I think I damaged my hearing when that 138ci Oxy-MAPP hybrid exploded two feet from my face.
I wonder how loud this would be with no barrel at 450 psi. The Krakatoa explosion comes to mind...
Do it. Do it
NOW.
Well, If you do take my advice, please don't be within 100 yards of this thing.
Posted: Sun Nov 18, 2007 8:20 pm
by DYI
Do it. Do it NOW.
Well, If you do take my advice, please don't be within 100 yards of this thing.
This just brought to mind an idea for the most evil practical joke ever.
Posted: Sun Nov 18, 2007 8:24 pm
by octane89
I dry fired a paintball gun without a barrel and scared my friend enough to make him piss a little. If you know PB guns, it was a Ego, which are loud with a barrel. Im sure you had something like that in mind...
Posted: Sun Nov 18, 2007 10:25 pm
by EGOed
When a 8" 200psi carbate burst disc blows on a pressure vessel at the chemical plant that I work .....Sounds like a "real " cannon fireing....Probably even louder.......My EGO isnt loud at all compared to most paintball guns.