Need some part suggestions for pneumatic

natey14 · Mon Dec 12, 2005 9:30 am

Well I'm going to build my next pneumatic cannon and I need to know some good pressure rated pieces. I want to have a safe launch of around 100 psi. Now, I am planning on using 2 feet long of 4 inch SCH40 piping. And 4 feet long of 1.5" sch40 piping. The pressure max for 4 inch is 220 and for 1.5" is 330.

Now I am planning on putting an end cap on the 4 inch pipe which is pressure rated. So the pieces that I need help with are some kind of reducer that goes from 4" to 1.5" that is pressure rated. And a good valve that is pressure rated and preferrably not a ball valve. I'm thinking something electric.

Also I would like to know, where on this should I put my pressure gauge and my schrader valve. And it isn't going to have any curves. Just tank, reducer, valve and barrel. Thanks for help in advance!

boilingleadbath · Mon Dec 12, 2005 5:30 pm

As to pressure rated reducing bushings, check mcmaster - you should be able to get all the fittings you require (4" coupling, 4" endcap, 4"-1.5" reducing bushing) for roundabouts 18$. Smaller fittings are cheaper, and you arn't gaining too much preformance from the chamber being a large diameter; download the GGDT and check it out.

And for a valve, you are basicaly limmeted to a sprinkler valve, or to constructing your own valve - unless you want to spring for a supah (100$ from spudtech).
A bit a browsing on the wiki should net you the answear to any questions you have.

natey14 · Mon Dec 12, 2005 9:49 pm

Ok how about a 4 foot long 1.5" barrel with a 2 foot long 2" tank. Can you recommend a sprinkler valve and explain how I would use it?

Also what is the difference between SCH40 and SCH80?

boilingleadbath · Tue Dec 13, 2005 6:06 pm

First question: Can't you use the GGDT?
Second question: Do some of your own research you little leach.
Third question: Sch 80 is thicker, harder to get, and more expensive. It is generaly not needed in a pneumatic.

natey14 · Tue Dec 13, 2005 8:57 pm

I'm not trying to be a leach I just came here hoping for someone to answer my questions seeing as this is the spud cannon questions part of the forum.