Can I Pressurize a Cornelius Keg with Air?

[stuffandthings]

Firstly, I'm not using a corny keg to brew beer.
I'm using it as a pressure vessel for a scientific purpose.
Could I pressurize a keg with air?
I know the CO2 tanks come empty; would they and the keg handle regular air?

Thanks.

 

[processhead]

Air is fine to use. The pressure used is the only limiting factor.

 

[hnycrk]

The only concern I could see is not using a clean air source. Many compressors have oil residues in the line, and could possible contaminate your keg. Just something to think about.

edit... just re-read post. Your not using for beer. So you're good to go.

 

[stuffandthings]

Air is fine to use. The pressure used is the only limiting factor.

Would the pressure be different for air compared to CO2?

 

[pickles]

No pressure is the same. I think he's referring to using an air compressor that would be capable of delivering 100+ psi.

 

[jrgtr42]

No problem. I used a bike tire pump to test my kegs when I got them.
attached it with a barbed disconnect, it held plenty of pressure for testing.

 

[stuffandthings]

Could I use something like a gas station pump to directly get the kegs to 102 psi? 87 psi?
The keg will be brand new.
Or would I need a co2 tank and regulator?

 

[snccoulter]

No no no no. don't go that high. I could not tell you what the pressure relief valve will pop at but the Kegs are not designed to go to high pressures. They are low pressure vessels.

Edit: Wiki says they can go to 130 but when was the last time it was pressure tested.

 

[dryboroughbrewing]

I think corny's have a max working pressure of 130 PSI, though they should be clearly labeled on the outside. You can get there however you like, there should also be a prv in the lid too that should pop when you exceed its tolerance as well.

 

[dryboroughbrewing]

I think corny's have a max working pressure of 130 PSI, though they should be clearly labeled on the outside. You can get there however you like, there should also be a prv in the lid too that should pop when you exceed its tolerance as well.

Should also note the PRVs generally pop much lower than that.

 

[stuffandthings]

I've heard used ones pop early, but people have said a brand new one would go to at least 90.
In any case, the pressure would just release through the valve right? (Would it be a safety hazard?)

 

[JJFlash]

I use air compressor to pressure test my corny kegs every 2 years for leaks. Only run up to 40psi, keg itself is stamped 130psi max.

 

[stuffandthings]

I'm thinking to just use CO2, as it seems to be more easy to fill.
Is there any way to use CO2 in the tank without building up any pressure?

 

[Cottonmouth]

Just two words - safety glasses. Possibly a full face shield if you are going to pressurize a corny keg anywhere close to the upper end of it's limits.

 

[stuffandthings]

Ok.
I'm beginning to realize taking a Cornelius keg to 90 psi isn't a safe idea.
So instead, I'll get an actual pressure vessel.
Is the filling method the same as filling a Corny keg? I know this isn't the best place to ask this question, but still.

 

[Domantori]

Ok. I'm beginning to realize taking a Cornelius keg to 90 psi isn't a safe idea. So instead, I'll get an actual pressure vessel. Is the filling method the same as filling a Corny keg? I know this isn't the best place to ask this question, but still.

Maybe I'm over thinking, but wouldn't it be safer to use a inert gas like nitrogen to pressure test? I've had the misfortune of blowing a rupture disc on a 5000 gallon reactor at work (chemical plant) and it's not a pretty sight. Luckily, the disc worked as designed and the entire vessel didn't blow up. One thing we always worry about though is build up under the disc and the disc not working due to this. I don't know if this is likely in your case but just things to think about if this is a used Cornelius. You can never be too safe.

 

[snccoulter]

you know there is tanks at Harbor Freight and other stores designed to carry pressurized air around and they fill the same as a tire. http://www.harborfreight.com/11-gallon-portable-air-tank-65595.html

 

[baulz]

No problem. I used a bike tire pump to test my kegs when I got them.
attached it with a barbed disconnect, it held plenty of pressure for testing.

For cleaning lines I fill a keg with PBW and use a bike pump to pressurize it and pump through the lines. Sometimes it's a lot of work if the lid isn't sealing well!

 

[stuffandthings]

you know there is tanks at Harbor Freight and other stores designed to carry pressurized air around and they fill the same as a tire. http://www.harborfreight.com/11-gallon-portable-air-tank-65595.html

Can you actually open these things?
I need to place a solid object inside a pressurized container.

 

[snccoulter]

Sorry, it is just a cylinder with a port to fill.

 

[pickles]

Can you actually open these things? I need to place a solid object inside a pressurized container.

I've got to know, what are you making??

 

[stuffandthings]

I've got to know, what are you making??

It's a science project on the effect of air pressure on the efficiency of a Stirling engine. A Stirling engine is an external combustion engine in which a difference in temperature causes the contraction and expansion of air inside the engine to move a piston. I'm increasing the pressure of the engine by placing the engine in a Cornelius keg.

 

[brewguyver]

It's a science project on the effect of air pressure on the efficiency of a Stirling engine. A Stirling engine is an external combustion engine in which a difference in temperature causes the contraction and expansion of air inside the engine to move a piston. I'm increasing the pressure of the engine by placing the engine in a Cornelius keg.

Seems like you could use a corney initially at lower pressure while you try to find something that will work for a more advanced set of tests. It also gives you time to build the bunker to hide in when the vessel explodes!

 

[dyqik]

Seems like you could use a corney initially at lower pressure while you try to find something that will work for a more advanced set of tests. It also gives you time to build the bunker to hide in when the vessel explodes!

Yeah, a factor of two or three over atmospheric is probably enough to get good data for a test like this. (I am an experimental physicist, working with cryogenic systems, including Gifford-McMahon and pulse tube coolers and occasionally Stirling cycle coolers, which are Stirling engines run in reverse). 15 and 30 psi is enough for initial tests, before you decide if it's worth going to higher pressures.

I assume that you won't be running a combustion source inside the pressure vessel - firstly air under pressure will greatly increase the rate of combustion, possible nullifying your experiment, and secondly, at higher partial pressures of oxygen (this includes pressurized air) there's a greater risk of other components of the system igniting. This also applies to a lesser extent to electrical components if there's a risk of sparks.

If you are doing a university type research project, then testing under moderate vacuum would also be good to do, and somewhat safer than high pressure. You should also investigate the local safety regulations about pressure vessels - I don't know about the US, but in the UK, a vessel intended to operate at over 5 bar (75psi) has to be certified, and any modifications have to be certified separately. Cornies don't usually have to, as the design operating pressure is below 5 bar, although they are tested higher.

 

[stuffandthings]

Yeah, a factor of two or three over atmospheric is probably enough to get good data for a test like this. (I am an experimental physicist, working with cryogenic systems, including Gifford-McMahon and pulse tube coolers and occasionally Stirling cycle coolers, which are Stirling engines run in reverse). 15 and 30 psi is enough for initial tests, before you decide if it's worth going to higher pressures.

I assume that you won't be running a combustion source inside the pressure vessel - firstly air under pressure will greatly increase the rate of combustion, possible nullifying your experiment, and secondly, at higher partial pressures of oxygen (this includes pressurized air) there's a greater risk of other components of the system igniting. This also applies to a lesser extent to electrical components if there's a risk of sparks.

If you are doing a university type research project, then testing under moderate vacuum would also be good to do, and somewhat safer than high pressure. You should also investigate the local safety regulations about pressure vessels - I don't know about the US, but in the UK, a vessel intended to operate at over 5 bar (75psi) has to be certified, and any modifications have to be certified separately. Cornies don't usually have to, as the design operating pressure is below 5 bar, although they are tested higher.

I'm using an LTD Stirling engine that can run on hot water.
California counts anything that has a pressure above 15 psi as a "tank."
I don't know why nothing applies on Corny kegs.
I want to see a logarithmic curve, and I need at least five bar to show that.

By the way, are Corny kegs ASME rated? I read in one post that they are, in which case they should be fine until 130 psi.
I would buy a pressure vessel if I could find one.