cannon idea need some help

[[insert name]]

so me and one of my friends are building our second pneumatic potato cannon, so we have a little experience. This time around we are going to run the cannon off of compressed air from a bottle, like the kind on paintball guns.

how would we get the air into the air chamber. we were planning on using steel pipe because that seems to be really strong.

also what kind of valve could we use because a sprinkler valve doesnt hold back the pressure were after. [/img]

[starman]

The standard quick release systemfor air tools works great. How much air were you planning to put in there?

[SpudFarm]

so me and one of my friends are building our second pneumatic potato cannon, so we have a little experience. This time around we are going to run the cannon off of compressed air from a bottle, like the kind on paintball guns.

how would we get the air into the air chamber. we were planning on using steel pipe because that seems to be really strong.

also what kind of valve could we use because a sprinkler valve doesnt hold back the pressure were after. [/img]

you should use a 2" steel chamber out of sch 40 and a 1.5" steel barrel aswell as a 1.5" steel union, then you put in a burst disk and crank it up to 500psi

[Hubb]

Spring loaded ball valve? Homemade piston valve?

[[insert name]]

i was planning on using around 200 psi but the max i would use is 900 is that over kill? also would steel pipe hold that much pressure?

[SpudFarm]

2" steel would have an absolute max of 500psi on constant pressure.

that is my opinion.

[DYI]

If the steel is SCH 40 seamless or higher, 900psi is fine. With SCH 40 welded, it should hold, but I wouldn't want to be standing beside it.

[SpudFarm]

don't listen to DYI he is insane

[[insert name]]

okay so steel pipe is fine for high pressure as long as it is sch 40?

Also will 900 psi be over kill i wouldn't think so but i would like to know?

[DYI]

okay so steel pipe is fine for high pressure as long as it is sch 40?

Also will 900 psi be over kill i wouldn't think so but i would like to know?

SCH 40 is fine as long as it is seamless. Otherwise, it's a risk. SCH 80 or higher is nice if you can get it, because SCH 40 seamless is very uncommon. Anything less than SCH 40 welded is stupid and extremely dangerous at 900 psi.

And a general rule about overkill in launchers: it doesn't exist.

[SpudFarm]

http://www.sorinc.com/usefulInfo_pipeSize.stm

[[insert name]]

one more question how would we get the air from the air tank to teh ari chamber we were planning on running the air tank to a reg and then into the air chamber on the canon. ho would we get the air into the chamber with no leaks at around 500 +- psi

[frankrede]

one more question how would we get the air from the air tank to teh ari chamber we were planning on running the air tank to a reg and then into the air chamber on the canon. ho would we get the air into the chamber with no leaks at around 500 +- psi

MAGIC!
I think you should spend sometime browsing the site and look at some pneumatic cannons for some inspiration