Question Where do you get oxygen cylinders filled?

[coolfilmaker]

I’m investigating different system types and I’m trying to figure out if getting large oxygen cylinders filled with medical grade oxygen is something that isn’t that hard to do or if it’s actually a big pain. It seems like it can’t be that hard because a lot of the nitrox systems I see have them.

 

[The Chairman]

Medical O2 has moisture in it. Aviators has no moisture in it.

It may all come from the same source but the aviators O2 is dry, or at least drier. You don't want to put moist gas in your scuba system for obvious reasons, but you do want moist gas in a medical O2, again for obvious reasons.

Citation?

 

[Capt Jim Wyatt]

It was one of our employees that had been hooked in the hand.

Citation

20+ years of knowing it.

Moisture in an airplane at 20,000 feet freezes O2 lines.

No moisture in hospital O2 irritates lungs.

Common sense.

 

[TravisD]

If there is any moisture content difference, it's not going to matter if you're continuous blending thru a stick. The ambient air will already be a lot wetter, and your moisture separators will deal with it.

 

[Capt Jim Wyatt]

If there is any moisture content difference, it's not going to matter if you're continuous blending thru a stick. The ambient air will already be a lot wetter, and your moisture separators will deal with it.

Extra moisture in the desiccant shortens the filter life.

If sending O2 directly to tanks as in boosting or PP blending, aviators is the wise choice.

 

[Still Kicking]

I drove by a metal recycler's yard the other day and saw that someone had left a T bottle on the curb. Needless to say, that bottle didn't go into the waste stream. Airgas swapped for a full one without blinking an eye.

As for pricing, that's another shell game. In the good old days when I need He and I could afford it, Airgas would quote me a price. I would tell them, "Praxair sells to me for $50 less." "Sure, we can do that." Lol

Re: welding/breathing O2..... there can be a lot of contaminents in breathing gas (water vapor, inert gases etc) and it will sustain life as long as there is sufficient O2. But contaminents in welding gas can really ruin a weld.

 

[flymolo]

Extra moisture in the desiccant shortens the filter life.

If sending O2 directly to tanks as in boosting or PP blending, aviators is the wise choice.

I’m not certain I’m convinced of this. I’ve been using medical grade oxygen to fill steel and aluminum tanks for a few years now. When I open them up they’re as clean as they were the previous year when I put the valves back on.

 

[Capt Jim Wyatt]

I’m not certain I’m convinced of this.

Opinions vary.

 

[The Chairman]

Quick search:

No, aviation oxygen, also known as Aviator's Breathing Oxygen (ABO), is designed to be drier than medical oxygen, with a moisture content of less than 0.01%, while medical oxygen can contain up to 67 ppm of moisture.​

Jim is right.

Google Search

 

[macado]

Medical O2 has moisture in it. Aviators has no moisture in it.

It may all come from the same source but the aviators O2 is dry, or at least drier. You don't want to put moist gas in your scuba system for obvious reasons, but you do want moist gas in a medical O2, again for obvious reasons.

Not to be pedantic but while aviator's grade oxygen is, at least, on-paper certified to be "drier" than medical grade I do not believe in reality it is actually any drier than medical or industrial O2 grade. It all comes from the same source and tanks are typically filled using the same process. Industrial cylinders might only be vacuumed once or no vacuum at all before filling but they are all filled from the same bulk (liquid) oxygen source at the gas supplier.

It is literally just what oxygen standard the gas is actually tested and held to and the paper trail that follows the bottle. I'm sure there are exceptions here and I don't want to speak in absolutes but this is my understanding of the process. I'm perfectly happy to be corrected here so don't take my word as gospel.

Industrial / Medical / Aviator's oxygen is typically produced through distillation and distributed as a liquid, which naturally results in a very low moisture content. All the oxygen produced is essentially the same purity. They are not purposely introducing any moisture into medical oxygen cylinder however in some cases moisture is added to medical-grade oxygen using a humidifier bottle when given to patients.

Again, I'm happy to be corrected here if I'm misunderstood anything that has been explained to me in the past.

 

[The Chairman]

I do not believe in reality it is actually any drier than medical or industrial O2 grade.

This is what I believe to be true. I was told by an Airgas employee that they fill them from the same source. The 67ppm is the max, not a target. Hospitals utilize humidifiers to increase moisture where needed.