At 09:30 AM 6/17/98 +0000, you wrote:
>
>> At 03:37 PM 6/16/98 -0500, Gano, Ken wrote:
>> >A word of caution. The oxy-acetylene tanks are probably the property of the
>> >welding supply company. I worked for one years ago, and the USUAL practice
>> >is to sell a lease or take a deposit, but not to sell the cylinders
>> >themselves..
>>
>> Maybe so, but some companies *will* sell the tanks. I bought
>> a set of tanks years ago, because I planned on keeping them
>> and didn't feel like paying rental charges forever.
>
>Buying the cylinders is fine if you still get them refilled at the same
>supplier, but watch out if you try to get them refilled at a different
>place. There are all sorts of safety regulations aimed at protecting
>their employees from the hazard of "unknown source" cylinders that may
>not be sound.
Well as far as I understand, the saftey precautions should be taken care of
by current/valid testing (which I think is DOT approval). A cylinder that
is personally owned needs to be retested every 5 years but one that is owned
by a gas company only needs certification every 10 years (why I don't know).
This is what my gas supplier told me. If you look at a cylinder it should
be date coded for the last time it's been tested (it's cool to check out and
see how old the cylinders are, one I just check was first certified in 43,
it's as old as my dad. It was then certified every five years until the
sixties, when it was certified every 9 or 10 years. My supplier says he has
one from the early 1900's, it has a square bottom, next time I'm around I
want to check it out). If I remember how the testing goes, the cylinder is
places in an protective tank, which is then filled with water. The cylinder
is then pressurized (over pressurized?), the tank expands some amount, and
the amount of water that is displaced is measured. Then the pressure is
released and the amount that the tank contracts (the amount of water that
returns) is measured. I can't remember which is the elastic measure and
what the term for the other measure is. The tanks have to meet some set
number for expansion. There are also different ratings for the tank
depending upon how much the tank expands contracts, this is why some
cylinders of the same size are rated to hold more gas than others.
This is just what I remember from a conversation I had with my supplier some
time ago, I'm not sure I have every thing correct.
Also as far as tank ownership, there are normally several marks on the tanks
(like cattle brands) that mark the owner. Some people try to remove these
and claim the tank as their own, but normally don't get them all removed and
are spotted (by someone who knows/cares). This info also came from my
supplier and from the personal experience of some stupid college kids at my
school (who were arrested right after they picked up some CO2 tanks from the
local gas supplier. Seems that the same supplier also supplies the school
with tanks/extinguishers and noticed that these particular tanks actually
belonged to the school. Bright kids.)
So while some companies don't want to fill other tanks for whatever reason,
if the tanks is certified and the valve is good then it should be safe.
If anyone wants more info let me know and I can ask my gasman.
Matt Wehland mwehland@webtripper.com http://www.webtripper.com
95 Mustang GT Crystal White 5spd Best 14.601, in street trim
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