Go to your local welding supplier. *The oxygen is just the same as you
get from an FBO and a fraction of the price.

Andy

I don't believe that it can be welders oxygen. It can't even be
medical oxygen. It must be "Gaseous aviator’s breathing" (AVB)
oxygen. I read it has to do with the moisture content to prevent
freezing. True?

It there an FAA regulation on this? I can't find it.

Some info here http://www.faa.gov/pilots/safety/pil..._Equipment.pdf.