"Jim Stewart" wrote in message
...
Grant Erwin wrote:

It isn't so much the stampings as the fitting. Does your acetylene
regulator
thread into it? If so, it is very likely an acetylene tank, since the
only other tanks I know of with that fitting are propane. - GWE

not always, if the tank is a "B" cylinder, most acetylene regulators wont
fit without an adaptor like this:
http://www.arizonatools.com/catalog/detail/16006/
The "B" cylinder holds 40 cu. ft. They look like this.
http://store.weldingdepot.com/cgi/we...ml?id=3D6nV5uX

good luck,
walt