Pneumatic Burst Disc

[cannon freak]

I am about to build a fairly large pneumatic cannon, and I want the valve to be 4in but I can not find any 4in ones around where I live. So I thought that maybe if I was to take some malleable plastic and a wire, then epoxy the two pieces of plastic together over the wire which will be in a circle shape. when it is hooked up to a battery it should melt the plastic away and therefore be a very effective burst disc. The wire that I will use will be 22 gage magnet wire since I have a lot of it laying around, and the plastic is from on of those easy set pools with the inflatable ring around the top, we are throwing it out so there is quite a bit of material left for me to use, and a 12 volt car battery.

[beebs111]

sounds like a good idea, but i would think that pool toy plastic would have a low pressure burst, maybe its just me though

[cannon freak]

Its one of those large pools about 15 feet diamiter and the ring stuff is pretty thin but the walls and the bottem are quite thick, but ya I should start doing some testing just to make shure.

[beebs111]

good luck, it sounds like a good idea

[sgort87]

The best burst discs I've found for this are made from those thin disposable plastic plates sold in packs of like 100. Ideas for triggering this have been tossed around from the method of just letting the presure build up and pop the plastic out to the design of actually having something puncture the plastic causing an airsteam that ruptures the rest of the disc out allowing a very large flow.