Posted by Ueli (195.162.170.2) on October 03, 2000 at 07:48:29:
In Reply to: Let me get this straight ... posted by Q on October 03, 2000 at 01:57:58:
Let me tell you about an impressive experiment in one of the first chemistry lessons:
The teacher let stream some oxygen through a piece of metal tubing, and nothing happened. Then he pulled a greasy wad through the tube and repeated the oxygen through the tube, result this time: a nice loud explosive bang.
Conclusion: Oxygen and oils don't go together.
To separate oxygen from air, many stages of compression and cooling are needed to reach liquefied air at a temperature below about 123 °K (-150 °C, -238 °F). On the way to this all contaminants in the original air have long frozen out and what's left are Nitrogen (N2), Oxygen (O2) and the noble gases Argon (A) and Helium (He). Of course, the compressors cannot be lubricated with organic oil, so there is no danger from that corner.
The same machinery is used to produce oxygen for medical, aviation and industrial use, and the retailer usually fills the small tanks from the same large storage tank (ask about that).
But it's probably a good idea, as jonny says, to buy a new tank.
But do not lubricate the valve should it be a bit hard to turn :-)
PFNAD's
Ueli