Oxygen question

James Appel

I have a question (never having dived a rebreather outside the USA).

How do you know your getting medical grade oxygen when getting fills, as it seems that in some placed only industrial grade maybe available.

What is the difference between industrial grade and medical grade (besides medical grade is analyzed and industrial is not).

Joe

The difference is in the quality control. It all comes out of the same banks - at least in the US and I'm sure in other places where you are dealing with a major company.

The risk is in someone filling a contaminated bottle but I would expect that to be minimal with O2. It is far greater with inert gas bottles since they often switch them around - ie - repaint an Ar bottle to make it He & fail to properly vacuum it.

jradomski

I have never had a problem getting good oxygen anywhere.. if in 3rd world countries.. I usually find out what types of valves are in use and have my own adapters incase the LDS doesnt do oxygen.. I have gotten my fills at hospitals more than once..

Also be aware that medical grade doesnt guarantee 100% oxygen, Many medical facilites around the world use Oxygen derived from PSA systems.. This oxygen ,must meet the standard 93 +/- 3%.. if they are going for the best purity its 95.4.%, but they usually taget the standard at 93% because this generates significantly greater volumes of gas..


for 95.4% the remainder is argon 4.5%, trace gases .1% (mostly co2)

at 93% there is 2.5% n2 in the gas

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.