anyway to identify which gas is in this cylinder?

[disney]

Greetings all. I was given this cylinder from a retired gentleman (who has no idea what gas it was), and honestly thought it was empty, but after freeing up the cylinder/valve protective cap (took a while as it was rusted..), if I crack the valve, I get what i believe is the sound of gas still under high pressure. is there an easy /cheap way to tell what gas it is, or would there be a marking stamped somewhere? Even just having a bottle to trade would be great, but I would hate to turn it in, if I could still use the gas in it.

thank you for any help you are able to provide

 

[flyerdan]

Put a regulator on it and fill a balloon to test for density. Unregulated, tip on side and blast some out so you have ice, put it in water and see if it carbonates. That will confirm / exclude helium and CO2

 

[Too many Kubotas]

Smell it, and try lighting it. Should narrow it down some.

 

[zzvyb6]

Place to start. But: a few things to consider. Is the tank too old to recertify? If its other than the color suggests, is it worth trying to use? Would it make a better wind chime that a welding surprize ? If the top end is corroded and the valve breaks off, the tank will try to go flying, perhaps going thru whatever it wants, including you.

 

[D&D]

Greetings all. I was given this cylinder from a retired gentleman (who has no idea what gas it was), and honestly thought it was empty, but after freeing up the cylinder/valve protective cap (took a while as it was rusted..), if I crack the valve, I get what i believe is the sound of gas still under high pressure. is there an easy /cheap way to tell what gas it is, or would there be a marking stamped somewhere? Even just having a bottle to trade would be great, but I would hate to turn it in, if I could still use the gas in it.

thank you for any help you are able to provide

what size tank is it?

 

[alexpops]

^^ What ZZ said. be careful lighting. & check the test date to see if it can be traded in or you'll need to get it re-tested before anyone will fill. the top around the valve looks sketchy, like it sat outside for a while & the cap trapped water against the valve threads. I would make sure both ends are pointed in safe directions before messing with it too much. You can buy a new tank online or at your local weld gas supplier for relatively cheap & the safety factor isn't a question.

 

[WranglerX]

Look at valve body closely and see if it has a "CGA XXX" designation.... Certain valve body types have different configuration for different gasses..... Its a first clue to what type of gas may be in cylinder....

CGA Fitting Reference | CONCOA

A CGA fitting is the standardized system for the attachment of a compressed gas cylinder to the required regulator or transfer line. Examples of CGA fittings would be CGA-580 for Non-flamable, Non-oxidizing gases such as Nitrogen, Argon, or Helium. CGA-590 is used for compressed air and CGA-326...

www.concoa.com

 

[alexpops]

Looks like CGA 580 on the valve so either argon or argon co2 mix? Unless this gentleman retired from AC business in which case maybe nitrogen.

 

[etpm]

Argon has no smell. Pure CO2 can have an acidic sensation for some people, which can be perceived as kind of an odor. C25, which is 75% argon and 25% CO2 has no odor. It's not acetylene, which has a strong odor, because the cylinder and valve are wrong for acetylene. The valve threads don't look like a CO2 valve and the cylinder doesn't look like a CO2 cylinder. CO2 is relatively low pressure. C25 is high pressure because of the argon. It could be a gas that will harm you pretty fast if you smell it. Unlikely, but you never know. All high pressure cylinders that contain flammable or toxic gasses or mixtures that contain toxic gasses will have left hand threads. So check if it has left hand threads. If it does then maybe it is best to trade it in, don't smell it. I sure wouldn't. If you have a regulator for oxygen then see if it threads in. Set the pressure on the regulator to zero and hold a lit match or similar near the output of the regulator and slowly increase the pressure on the reg. As the gas starts to flow out if it is oxygen the match will start to burn really fast. If it just goes out then the cylinder is filled with an inert gas. If inert gas fill a balloon with the inert gas and see if it rises. If it does then you have helium. If it sinks then either argon or C25 or nitrogen is most likely.
Eric

 

[WranglerX]

Looks like CGA 580 on the valve so either argon or argon co2 mix? Unless this gentleman retired from AC business in which case maybe nitrogen.

Could be...