Aviators vs. Medical vs. Welding O2

[IronPenguin]

I saved a medical O2 tank from the garbage, and took it to my local gas supply co. They said they Will Not fill it with Welding grade O2, and I don't have a prescription for Medical grade, but they told me that they Will fill it with Aviator's grade. Some research later I discovered that they all come from the same O2 concentration machines.. I read that Av. is dryer than Med., and Weld. is purer than either.
So, would Av. O2 work just as good as Med. or Weld. O2?
What diffusion stone would work best with it?

 

[SilverZero]

Well I can't comment on purity other than to say people use welding CO2 all the time and never worry about it, so at the relatively tiny levels we use O2 I can't imagine anything is going to affect the beer. But I do know that it's best to use a 0.5 micron diffusion stone for pure oxygen.

EDIT: Was just reading on a SCUBA forum about this as well. It's basically all about insurance and liability. The gas is the same. Welding purity might be higher but the tolerance and the difference might make it a moot point (both are over 99.5% I think). Medical is less dry because it gets humidified at the hospital bed delivery system. This is just at-a-glance info so don't cite me in your research or anything.

I wouldn't think twice about filling with whatever gas you can get.

 

[Horseflesh]

If that cylinder was in the trash it might have been there for a good reason.

 

[DurtyChemist]

If that cylinder was in the trash it might have been there for a good reason.

Agreed. It may just be out of hydro date or it may have an actual problem with the valve and it's cheaper for them to throw it out. I wouldn't expect any medical facility to throw out a bottle just because it's out of date and I'd expect a welding shop to check dates on any bottle they fill.

 

[SilverZero]

If that cylinder was in the trash it might have been there for a good reason.

Ha, wow, I didn't even read that part. Yeah, probably put it back in the trash.

 

[Ike]

My recollections of the medical vs. aviator's O2 are similar to someone upstream but just a bit different: I'd heard that they're essentially the same, but the aviator's O2 was actively dehumidified prior to compression, so it's "dryer." The reasoning I was given was that when operating at high (thus colder) altitudes, any water that finds its way into the pilot's regulator can lead to frost that jams the regulator. Usually, when a regulator fails it fails by going into bypass, so the pilot doesn't stop getting O2 but the tank empties very quickly (like a SCUBA tank on bypass).

 

[IronPenguin]

If that cylinder was in the trash it might have been there for a good reason.

It wasn't IN the trash lol. I snagged it when the new owners decided to throw everything out.. I also got an O2 concentrator too but it hasn't been serviced in a few years..
Aside that, Thanks for the O2 input everyone!
Also, do you think that I can use a .2 micron diffusion stone with that pure of O2 then?

 

[mcgimpkins]

deleted

 

[mikescooling]

All O2 is the same, some of it gets tested more than others. It comes from the same place. The hospital used to add some humidity to some types of masks, but now they use O2 generators. Get it filled or swapped and use it if you can.