Butterfly valve?

Build a homemade water gun or water balloon launcher and tell us about it.
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Hunt_and_Annoy
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Joined: Sat Feb 12, 2005 1:00 pm

Butterfly valve?

Post by Hunt_and_Annoy » Thu May 15, 2008 12:36 am

I searched it and nothing came up, but i recall seeing it somewhere before. Has anyone used a butterfly valve in a water gun?

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Silence
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Re: Butterfly valve?

Post by Silence » Thu May 15, 2008 12:41 am

A butterfly valve is basically a ball valve, but instead of a ball with a hole through it, there is a flat disc that rotates about an axle crossing the barrel. The flow will not be very laminar, simply because when the valve is open, that disc is in the middle of the pipe (although it would lie parallel to the flow, it still creates turbulence). Note the disc doesn't rotate like a circle; it would rotate if you used a side view, not a top view.

Butterfly valves tend to be common in very large sizes - inches or even feet in diameter. They're probably what's used in Pumpkin Chunkin' contests. I saw one in one of the MythBuster's chicken gun. Their really slow opening times mean you need a rather long barrel to compensate by giving the projectile more time to accelerate.

aEx155
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Re: Butterfly valve?

Post by aEx155 » Thu May 15, 2008 3:21 am

The Mytherbusters did use it in their chicken cannon. The used a really long torque are with weights at the end so that it would open faster.

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