Evaluating a "Free" O2 tank?

[claycookiemonster]

A friend is a retired paramedic and mentioned that he has an old Aluminum O2 tank lying around. My ears perked up. He dropped it off the other day. He described it as a "liter flow" tank. Just over 4 inches in diameter and about 17 inches tall to the top of the tank itself. With regulator it weights 8 lbs. The gauge indicates it's empty.

While clearly not new, it appears pretty reasonable. It has a regulator, though whether it would be useful in aviation is the real question. How would I evaluate it to determine it's value as an O2 tank for flying? What safety checks would be necessary? How do I interpret the numbers cast into the neck of the bottle?

 

[MacCool]

Start by getting it hydrostatically tested either at a SCUBA dive shop or welding shop. Then make sure it has the valve you need for the regulator you plan to use. Most aviation valves are CGA540 and most medical valves are CGA870 - important because if you get a tank with a 870 valve, you might not be able to get it filled at your airport). Most tanks need to pass hydrostatic testing every 5 years. The date of the most recent test will be stamped on the shoulder of the tank. I have a "donated" tank too...I bought all the stuff I need off Amazon.


Here's a pretty good thread on putting together an oxygen system. https://www.pilotsofamerica.com/community/threads/doc-bruce-diy-oxygen-system.3399/

 

[walkman]

likely the scuba shop at least is farming it out, try asking the local firehouse.

There's likely a cheaper local option than the scuba shop

you'll need VIP, bomb test, and have it oxygen cleaned.

 

[RVDan]

Around my neck of the woods, the only option is the Scuba shops. Both in my area do the hydrostatic tests in house.

 

[BobTurner]

Around my neck of the woods, the only option is the Scuba shops. Both in my area do the hydrostatic tests in house.

Another place for the hydro test is commercial fire extinguisher companies. Ours charges $40 to hydro test my O2 tank. And yes, for aluminum tanks, the test is ‘good’ for 5 years.

 

[roadrunner20]

Your local welding gas suppliers usually process medical cylinders too.

 

[RVDan]

Your local welding gas suppliers usually process medical cylinders too.

A lot of times the gas suppliers just do a cylinder exchange. You get one with a current hydrostatic test date, but not necessarily a new date with 5 yrs left.

 

[MacCool]

Your local welding gas suppliers usually process medical cylinders too.

Yes...if not, adapter harnesses are readily available. Failing that, replacing the existing valve with a different tank valve is a pretty simple matter.

 

[mbauer]

Your local welding gas suppliers usually process medical cylinders too.

If they do, they have a Pharmacology License that only allows them to sell to medical doctors.

Best option is to talk to your doctor and get a prescription due to "Hypoxic Events". Must have this designator to get from local home medical supply stores.

I fill mine off of a welding Oxygen tank, using adapters readily available on line. The tank you want to use has the CGA (Compressed Gas Association) valve number on it, just look up adapters to hook up to the Oxygen tank.

All Oxygen comes from the same tank. Further testing meets specs for the Medical/Aviator requirements.

For instance Medical has moisture in it, to keep from drying out the the throat; most patients use 24/7. Aviator has no moisture, it can freeze at altitude. Learned this from Military flight school, part of the class just before going into the altitude chamber. Hypoxia is a real danger, altitude chamber will clearly show you why.

Mike

 

[RV7A Flyer]

All Oxygen comes from the same tank. Further testing meets specs for the Medical/Aviator requirements.

For instance Medical has moisture in it, to keep from drying out the the throat; most patients use 24/7. Aviator has no moisture, it can freeze at altitude. Learned this from Military flight school, part of the class just before going into the altitude chamber. Hypoxia is a real danger, altitude chamber will clearly show you why.

Mike

While true that all O2 comes from the same tank, there's no further testing required. Only lab-grade O2 is different, and you wouldn't be getting that.

And "medical grade O2" is the same as "aviator's" or "welder's" O2...they all come from the same place. Medical O2 supplies add moisture *at the patient's bedside*, it's not in the O2 tanks in the O2 farm at the hospital.

 

[Bdflies]

Oh, if we could all sit down with a beer and discuss this! While it’s kinda true that "all Oxygen comes from the same place.", not exactly. Most any air separation facility produces ‘industrial' or ‘commercial' Oxygen and Medical Oxygen. It surprises most folks that the requirement for Medical Oxygen is that it meets minimum purity of 99.0% and industrial Oxygen requires 99.5% purity. Yeah, that’s not a typo. Aviators Breathing Oxygen, however, is required to meet requirements of maximum Total Hydrocarbon content, among other measures. I’m in the Deep South. I always questioned why the ABO was so damned expensive. Turns out that the Oxygen produced in the liquefaction facilities near us (lots of them!) didn’t meet the requirements for ABO. So, while there were several Oxygen producers near our Louisiana facility, the ABO that we sold, came from Pennsylvania. Not saying that all the ABO comes from there, but ours did. I still have the CGA books, if anyone wants to know all the specifics of the various grades. "Zero Grade, UHP, Grade 4, Grade 5, etc.. All different specs for applications with specific sensitivity.
All that being said, a very good friend fills his "ABO" cylinder from his welding cylinder and I’ve used it.
40+ years in a family owned Welding / industrial gas supplier. Lots of useless knowledge!

Bill

 

[RV7A Flyer]

I'm willing to bet that it's not the capabilities of the plants or any differences in the purity of the O2, but a matter of the certifications and approved procedures and licenses to sell it as USP-approved O2. From what I can glean, not being an expert of course, all the manufacturers switched to producing a single-grade (for aviation, industrial and medical...NOT research grade, a different animal) decades ago. Cheaper to have a single process that meets all 3 specs, instead of 3 separate processes.

And another area of expense (for medical) is the FDA requirements on storage, handling and filling of tanks, etc.

But I maintain that these days, and for quite a long time now, the actual O2 that's produced is the same stuff for all 3 categories.

 

[RV7A Flyer]

I'm willing to bet that it's not the capabilities of the plants or any differences in the purity of the O2, but a matter of the certifications and approved procedures and licenses to sell it as USP-approved O2. From what I can glean, not being an expert of course, all the manufacturers switched to producing a single-grade (for aviation, industrial and medical...NOT research grade, a different animal) decades ago. Cheaper to have a single process that meets all 3 specs, instead of 3 separate processes.

And another area of expense (for medical) is the FDA requirements on storage, handling and filling of tanks, etc.

But I maintain that these days, and for quite a long time now, the actual O2 that's produced is the same stuff for all 3 categories.

BTW

So, while there were several Oxygen producers near our Louisiana facility, the ABO that we sold, came from Pennsylvania. Not saying that all the ABO comes from there, but ours did.

How much more did they charge you for this special ABO, and how much more did you charge your customers, above the price of so-called industrial grade? Tidy profits to be made?

 

[Bdflies]

"Tidy profits"?

Sheesh. Forget it. It’s all the same stuff.

Bill

 

[rsr3]

From memory… Not sure about the States, but across the pond I believe our aluminium cylinders have a life whereas steel cylinders do not. I also believe it’s not good to let a cylinder go completely empty otherwise it can become “contaminated” with air!

 

[BobTurner]

From memory… Not sure about the States, but across the pond I believe our aluminium cylinders have a life whereas steel cylinders do not. I also believe it’s not good to let a cylinder go completely empty otherwise it can become “contaminated” with air!

Here in the US there is no life limit on Al cylinders, but they must be hydro-tested every 5 years. So every 5 years they get exposed to both air and water.