If you pump air into the medical OX with a cast iron pump with oil
in the rings - you send all sorts of crap from the pump. It also
picks up anything from the air it sucks in. Gas / Diesel / pollen .....
and pumps it into the tank. Lots of junk from the air. Guy painting
the building or out-gas paint...

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.

It is like a scuba tank - can't just suck in the CO the pump puts out
into the tank.

When I get an OX tank from a company - it comes from a welding supply
in a welding tank.

When I get an OX tank from a company - and it is for life/death it is
from the medical OX supplier.

Water is sucked into the pump and into the tank / hose in real time.
It is kept out of OX for life.

OX is generated in chemical reactions in canisters for airplanes. Now
and then one catches fire and causes news on the TV.

N2 tanks are 'dry' tanks also. No water. Many plasma machines use N2
not air. Plasma creates instant steam and it blasts the beam wide and
cools it as well giving a poor and sloppy cut edge.

Martin

On 2/13/2017 11:14 AM, pyotr filipivich wrote:
Martin Eastburn on Sun, 12 Feb 2017
21:20:21 -0600 typed in rec.crafts.metalworking the following:
The impurity is 'natural' from pumps and valves. In medical oxygen that
might feed through machines that are very expensive or feed a person
with 20% of their lung left, the air is FILTERED heavily.

At 10 or 20,000 feet with flights up to 80,000 one does not want
moisture in the air line. Simple as that.

I'm still confused.

What sort of 'impurities" can be in an oxygen environment? Okay,
water / humidity I can understand - it is "inert". But how did it get
in their in the first place? One would think that distilling Oxygen
out of the atmosphere would first remove the water.
Part of my confusion come from having dealt with the specs for
manufacturing medical equipment which would be part of the oxygen
system. "Not oil at all." Not before, not after, not during "Thou
shallt have no oil in the presence of the metal. Neither shall it be
on the tools thou useth. On the finished part is straight off."



Just like your plasma - water kills.

Think of a vacuum cleaner / shop vacuum - and then one with a Hepa
filter on it. What air do you breathe while you clean up with it ?

Martin


On 2/12/2017 8:39 PM, pyotr filipivich wrote:
on Sat, 11 Feb 2017 20:01:33 -0800 (PST) typed in
rec.crafts.metalworking the following:
So I got a cylinder from a friend, that is a Avox System 9700 series, 11.0 CU FT 1800 PSI. Which I really really like, but I am confuse about if I have to refill it which O2 should I use, what if I just can not get aviators oxygen?

Actually I just don't know much about this.

Can someone help me?

Oxygen is oxygen. And unless someone can explain why they are
adding an impurity to the tank, the rest is hand waving.

Adding "Aviation" or "Medical" (like "all natural" or "marine") to
the label merely means it is going to cost you more.

--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."