On Nov 14, 3:52 pm, "Maxwell" wrote:
"Dallas" wrote in message

...

On Wed, 14 Nov 2007 19:46:39 GMT, Viperdoc wrote:

You could get a prescription and then use a medical bottle

I distinctly remember reading that medical O2 was not acceptable (legal?)
for aviation.

Something about the humidity being too high and freezing in the valve.

--

That's always been my take on it to Dallas, per our suppliers. Medical and
industrial are filled from the same source. Aviation is essentially the
same, but has to be dryer to avoid freezing in extremely low temps.

Precautions taken to avoid impurities in the filling process might differ.
But I bet there are some industrial OX users that are pretty picky about
getting clean pure OX as well. Not everyone just uses it simply for welding
and cutting.

According to the gas company I spoke with, all 3 grades of O2 come
from the same source. Medical O2 adds the moisture after the O2 comes
from the bottle (to avoid drying people out). The difference
(according to the gas company) is the certification. When they fill an
aviation bottle they must test it for use in aviation. That test
results in a certification of the O2 in the bottle. I'm not sure if
the FBO's do that or if they are somehow able to certify their main
bottles.

-Robert