On Mon, 27 Feb 2017 19:41:31 -0800, pyotr filipivich
wrote:


I'm still curious as to how one can have compounds in a 100% or
even 99.9% Oxy environment.

Because commercially pure (medical or welding) gas simply isn't that
pure. In all but the smallest plants, oxygen, nitrogen and argon
tanks are filled by boiling that component of liquid air, separated by
a fractionation tower. Oxygen contains a little nitrogen and all the
compressed gases contain traces of helium.

Research grade (so called "5 9s") gas is made by refining the
commercial grade gas through filters, catalysts and absorbers. That
gas is quite expensive (I pay $1/liter in 200 liter cylinders for neon
for my sign making) and has little commercial use.

John



When medical OX is made, the pump is in a nylon pump and it squeezes the
oxygen by squeezing a hose from a series of filters into the tank.

Except for very small operations such as a hospital refilling their
own "E" tanks, oxygen is NOT compressed. Much more efficient to boil
the liquid.

Even when an oxygen compressor is used, it contains no nylon. The
nylon would diesel on the compression stroke. My experience with
breathing air and oxygen compressors is that they use a mica-graphite
compound for seals and piston rings.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address