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Butterfly Valve
Posted: Fri Jun 23, 2006 10:56 pm
by MrCrowley
i was wondering can you use a butterfly valve on a pneumatic spudgun like they did on mythbusters with the chicken gun it worked for them and was air tight.
im a newbie here but i have built several combustion and i thought i wuld try a golf ball pneumatic with the simplicity of a butterfly valve it looks like it can release air fast enough
Posted: Fri Jun 23, 2006 10:57 pm
by Shrimphead
Ya you can, but a sprinkler valve is not really more complicated if you don't mod it and it will give better performance.
Posted: Fri Jun 23, 2006 10:59 pm
by MrCrowley
yeah but its hard to find and if you do find one theyre really expensive in new zealand and can go for about $100NZD
Posted: Fri Jun 23, 2006 11:03 pm
by Shrimphead
Really!?!?!? That sucks. I got mine here for about $13USD. Yeah if I were you I would go with a butterfly or ball valve for a first gun, then a piston or diaphragm later. Or you could go combustion.
Posted: Fri Jun 23, 2006 11:10 pm
by Atlantis
I don't think he means American Dollars. He means New Zealand Dollars.
I just googled New Zealand Moeny and this came up on google itself
1 New Zealand dollar = 0.6217 U.S. dollars
That means $62.17 American, am I right?
Posted: Fri Jun 23, 2006 11:11 pm
by MrCrowley
yeah it sucks pipe u wuld pay $5 for wuld cost me $60 ive gone combustion several times and pneumatic is more powerful evn with a butterfly valve so it would b tht or a ball valve but i think butterfly valves let more air through quicker
sounds right to me $62USD our economy isnt doing too good latley so tht sounds right
wot do u reccomend butterfly or ball valve
Posted: Fri Jun 23, 2006 11:14 pm
by Atlantis
A butterfly valve would probably be easier to open, ball valves are just easy to attach to pipe.
Posted: Fri Jun 23, 2006 11:20 pm
by MrCrowley
yeah thanks for that and butterflys are cheaper here then ball valves and i like them better for some reason
Posted: Fri Jun 23, 2006 11:33 pm
by Shrimphead
I knew that he meant NZD, but I figured 100 of them would still be a lot of money, especially considering the context.
Posted: Fri Jun 23, 2006 11:41 pm
by carlbelcher
A butterfly valve would defiantly let more air though faster because they let air though on both sides of the plate as they open.
As seen in this pic.

Posted: Sat Jun 24, 2006 12:46 am
by MrCrowley
yeah and i like the handles as well i feel they are more safe like its not as easy to pull as a modded sprinkler valve and i dnt have to mod nething
edit:a guy in new zealand has offered me 45mm inside dia pipe for the barrel which is perfect for a GB but im not sure if its pressure rated. would the barrel have to be if its infront of the valve so its NOT holding any compressed air?
Posted: Sat Jun 24, 2006 2:02 am
by carlbelcher
You’ll want your barrel to be pressure rated because as the projectile is being fired at least part of the barrel is subjected to the full pressure of the chamber.

If your barrel is not pressure rated it may explode upon firing.

Posted: Sat Jun 24, 2006 2:30 am
by MrCrowley
yeah i mite sleeve it with some extra 2" pipe left over from a combsution spudugn. this guy in new zealand lives down the road from me by coincedence and he is giving me 1.4m of 45mm pipe for FREE!!!!! im not sure what type of pipe but ill sleeve it unless it says Class D which is pressure rated to 175psi
Posted: Sat Jun 24, 2006 2:34 am
by carlbelcher
If it’s rated for 175psi you should be fine. What psi are you thinking of using anyway?
Posted: Sat Jun 24, 2006 3:13 am
by MrCrowley
everyone seems to be using 100psi but the max i would go to be safe would be 120psi is that safe?