welding oxy vs medical

[casseopeia]

I ran across something in the course of researching. There is a website, publication or ad suggesting that the oxygen sold for welding, medical and aviation use all come from the same bulk batch. That there is no difference and suggests that private pilots recharge their O2 bottles with welding oxygen to save money.

I always thought they were different and believed the warnings about trying to 'breathe' welding oxygen.

I was actually trying to find out if there is a problem using abandoned medical oxygen for welding. I suspect there is, but the usual warnings about "not knowing the source" isn't going anywhere.

 

[aviat]

The main reason you are not suppose to use medical oxygen in aviation use, is that medical oxygen contains moisture and can freeze at altitude, whereas aviation breathing oxygen contains no moisture. Other than that I don't know if there is a difference.

 

[casseopeia]

thanks aviat,

Perhaps the reason is similar for welding.

 

[chicopee]

Also oxygen used by aviator is graded for breathable purposes-not so for oxygen use for gas welding.