SpudFiles

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!

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.

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?

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.

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.