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PVC tank bursting?

Posted: Sun Feb 20, 2005 11:47 pm
by Bufftigerx
I'm making my first spud gun. I'm making a simple design with a sprinkler valve. How can i make sure that the PVC tank does not explode? Has anyone experienced a tank blow up on them? if so, what pressure did it explode at? Should i be concerned about this hazard?

Also, what is the best way to install a pressure gauge on a length of pvc pipe?

Posted: Mon Feb 21, 2005 1:03 pm
by PCGUY
The best way to install a pressure guage would be somewhere where your pipe and a fitting overlap, so it has twice as thick plastic to hold onto.

Then just drill out the hole, tap it, and screw in your pressure guage with plenty of teflon tape to make sure it doesn't leak. After that some people use some type of epoxy to seal around the base of the guage, but that isn't required.

I've heard of cannons blowing up, but everytime it was from a hybrid or a cannon in VERY thin wall drain pipe. A hybrid creates hundreds of PSI. For safety, only use SCH 40 pressure rated PVC (not cellular core that has no pressure rating).

Posted: Mon Feb 21, 2005 1:09 pm
by spudshot
the same goes for fittings, never use any non pressure rated fittings, the pressure fittings will say NSF-PW on them, also make sure to solvent weld the fittings together, you WILL need solvent, also called primer, and pvc cement. ABS cement can NOT be substituted, go here for how to solvent weld http://www.burntlatke.com/weld.html

Posted: Mon Feb 21, 2005 11:28 pm
by Bufftigerx
Thanks a lot for those answers, very good info.

another question, what is the highest psi / optimum psi you would recommend for firing the cannon?

Posted: Mon Feb 21, 2005 11:48 pm
by PCGUY
Weird... I could have swore I posted about PSI...
But anyways I woulden't go over 100psi or 125psi.

Posted: Tue Feb 22, 2005 6:51 pm
by BC Pneumatics
I like to stay 10% under the max rating of my weakest part. If I have a valve stamped 100psi, I dont go over 90.

Posted: Tue Mar 01, 2005 7:22 pm
by iamthewalrus
what is the highest psi any of you have heard of in a pneumatic cannon :?: that was successful, because i shoot my gun at 160 or 180 on average and its been working fine. will psi levels this high effect my gun in the long run??

Posted: Tue Mar 01, 2005 8:05 pm
by spudshot
well, you'll most likely blow yourself up eventually using pressures that high, just because it holds it now doesnt mean it'll always hold, i try to keep around 100 PSI, anything above that is REALLY pushing the envelope i think

Posted: Tue Mar 01, 2005 8:10 pm
by iamthewalrus
k, thanks for the tip, prolly saved me a lot of trouble :)

Posted: Tue Mar 01, 2005 8:43 pm
by BC Pneumatics
There are HPA rilfes that use 3000+psi.

Posted: Tue Mar 01, 2005 8:54 pm
by spudshot
bc i think he means just in pneumatic potato cannons made of PVC

Posted: Mon Mar 07, 2005 10:03 pm
by jdp204
i usually run mine at abou 80 and it still shoots aout of sight, but that could be because of my slim barrell and beefy chamber

Posted: Tue Mar 08, 2005 12:43 am
by BC Pneumatics
spudshot wrote:bc i think he means just in pneumatic potato cannons made of PVC
I thought he meant just high pressure guns in general. I've tanken a pvc launcher up to 800psi. (Small pipe=big rating) But dont ever try this.

Posted: Tue Mar 08, 2005 1:30 pm
by iamthewalrus
what did u shoot at 800psi? and how far did it fly??

Posted: Tue Mar 08, 2005 6:27 pm
by BC Pneumatics
iamthewalrus wrote:what did u shoot at 800psi? and how far did it fly??
It was a .45cal slug witha FMJ. (No charge, just the slug) It only went a few feet, then it hit a 4x4. Did some good damage too :)