Barrel sealing piston valve seal

[Kobl]

I'm constructing a new pneumatic gun and was wondering, should the piston valve seal up when blowing into it?

EDIT: on McMaster part #4596K422 it says not to use with compressed gases nor does it give a pressure rating, but is schedule 80, is still safe to use up about 80 or 90 psi?

-Butt

[squeaks]

sch 40 is safe around 100-150 psi. sch 40 is rated to 200ish psi but it isn't recomended to take it that high. I'd forget the sch 80 'cause it's way too expensive most times. Pistons usually won't seal when you blow into them, but once you hook it up to a compressor or if you're vigorous with a bike pump it'll seal instantly.

P.S. they put that "not rated for compressed gases" thing on because they know that there are crazy people like us that get the idea to make some kind of particle accelerator out of it. They just don't want to be sued if it breaks because when it bursts from water it just cracks. When it bursts from a compressed gas it explodes sending shrapnel everywhere.

[Kobl]

Thanks squeaks. Hopefully I'll actually be able to document this canon.

-Butt

[Brian the brain]

Mine seals by blowing on it..and I AM talking about a valve here people!

[Kobl]

Really? What kind of rubber and what thickness are you using?

Breaking news, this new piston gun will a clear barrel, yay111!!11

-Butt

[Brian the brain]

Neoprene , 8mm.....