"Burst Disc" safety device?

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
User avatar
boyntonstu
Sergeant
Sergeant
Posts: 1039
Joined: Sun Jun 28, 2009 8:59 am

Wed Mar 17, 2010 11:09 am

You build a steel pipe cannon and pressurize it to 1500 psi.

You mount a copper cap/burst disk in a position that blows away from you if it bursts.

IOW A copper circuit breaker for air pressure.

I imagine that splitting copper is a lot better than shattering steel.

Has anyone photos or videos of bursting steel and/or copper?
nosnik
Private 4
Private 4
Posts: 68
Joined: Wed Dec 30, 2009 2:30 am

Wed Mar 17, 2010 11:24 am

1500 psi??? :O your scary :shock: (im afraid of 120psi already ) :cry:
metalmeltr
Specialist 4
Specialist 4
Posts: 426
Joined: Thu Dec 18, 2008 3:42 pm
Location: united states

Wed Mar 17, 2010 11:25 am

This is an interesting idea, however i think that the copper bursting could send hazardous shrapnel out if it bursts. I know that C02 tanks use a burst disc to prevent overpressurization, but I don't know what material they use. Is there not a commercially available pressure relief valve that will work in your operating range?
joepage2008x2
Private 3
Private 3
Posts: 57
Joined: Thu Jul 02, 2009 2:12 pm

Wed Mar 17, 2010 11:37 am

What is 1200psi for?
I know that brass is a very common material for burst disks - I think thats what is used with the little CO2 cartridges.
Pressure release valve is probably the safest option but I imagine them to be an expensive part if bought commercially because they are uncommon.
User avatar
Gippeto
First Sergeant 3
First Sergeant 3
Venezuela
Posts: 2504
Joined: Sat Jan 19, 2008 10:14 am
Location: Soon to be socialist shit hole.
Has thanked: 2 times
Been thanked: 17 times

Donating Members

Wed Mar 17, 2010 11:48 am

I believe the burst discs on "paintball" type tanks are copper.

You can get a relief valve (poppet style) for 1200psi...I've one in front of me set at 1500psi. :twisted: (needed model #)

http://www.swagelok.com/search/product_ ... S-4R3A5-BU

Not cheap though...I think when I last priced one out it was ~$150cdn buying it through the business.

A phone call would be in order.
"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
boyntonstu
Sergeant
Sergeant
Posts: 1039
Joined: Sun Jun 28, 2009 8:59 am

Wed Mar 17, 2010 12:41 pm

Gippeto wrote:I believe the burst discs on "paintball" type tanks are copper.

You can get a relief valve (poppet style) for 1200psi...I've one in front of me set at 1500psi. :twisted: (needed model #)

http://www.swagelok.com/search/product_ ... S-4R3A5-BU

Not cheap though...I think when I last priced one out it was ~$150cdn buying it through the business.

A phone call would be in order.
My thinking is to make everything homemade if possible.

If a copper cap fitted to a short length of copper tubing would burst before the steel cannon to which it is attached, wouldn't that be sufficient?


BTW What do you use to pump high pressures?
metalmeltr
Specialist 4
Specialist 4
Posts: 426
Joined: Thu Dec 18, 2008 3:42 pm
Location: united states

Wed Mar 17, 2010 12:44 pm

Most peple use a shock pump or comressor from a refigerator for high pressure. I personally feel that your idea of a piece of copper pipe with a cap is far too dangerous to serve as a safety device.
User avatar
boyntonstu
Sergeant
Sergeant
Posts: 1039
Joined: Sun Jun 28, 2009 8:59 am

Wed Mar 17, 2010 1:06 pm

metalmeltr wrote:Most peple use a shock pump or comressor from a refigerator for high pressure. I personally feel that your idea of a piece of copper pipe with a cap is far too dangerous to serve as a safety device.
????

"I believe the burst discs on "paintball" type tanks are copper. "

What is the difference?
metalmeltr
Specialist 4
Specialist 4
Posts: 426
Joined: Thu Dec 18, 2008 3:42 pm
Location: united states

Wed Mar 17, 2010 1:26 pm

Maybe I am misunderstanding how the copper would behave when it bursts, but i see shrapnel everywhere.
User avatar
Gippeto
First Sergeant 3
First Sergeant 3
Venezuela
Posts: 2504
Joined: Sat Jan 19, 2008 10:14 am
Location: Soon to be socialist shit hole.
Has thanked: 2 times
Been thanked: 17 times

Donating Members

Wed Mar 17, 2010 1:36 pm

Stu, you can buy a burst disc at Walmart for a couple bucks. The difference is the thickness and diameter of the copper disc....and the fact that they are a KNOWN quantity.

To use them, you would need to drill and tap appropriately, as they do not use a tapered pipe thread, but seal on the lower edge....metal to metal.

If you decided to make one, the best idea I can suggest at the moment, is a pipe union (1/8"npt) fitted with foil discs. You'll need to experiment with it to determine how many disks you'll need, and I would suggest placing a pipe plug in the downstream end of the union to protect the disks from accidental damage.

Hydrostatic testing is to be preferred.

You will of course have to drill a small (1/8") hole through the pipe plug to allow any gas to vent.

Be very careful (should go without saying...but others read these posts too :roll: ) with the direction of venting as well.
"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
turner
Specialist
Specialist
Posts: 113
Joined: Fri Aug 07, 2009 11:48 pm

Wed Mar 17, 2010 7:29 pm

http://paintballgateway.com/burstdiscs.html
they should be 1/8 npt. the fill nipple and gauges are 1/8 npt. i dont see how they seal any other way besides Teflon tape because the paintball regs are rounded
User avatar
twizi
Corporal
Corporal
Posts: 511
Joined: Thu Nov 27, 2008 9:04 pm
Location: up yours

Wed Mar 17, 2010 7:40 pm

paintball burst disk for a 3000hpa tank or 4500 usally burst at 5000psi
they are made from brass and believe me u dont want to be near a 4500psi carbon fiber tank when it burst or when it explodes because some dumbass puts triflow in the fill nipple
dont play with airsofter with 1000$ gun and play with a 5 dollar pair of glasses
Post Reply