Not sure exactly where to go, but most welding supply/oxygen places have it. That's where I get mine! And I know Richmond should have what you need, considering that Richmond was where my guys had to send my old tank to get a new hydro test.
Anyway, [ame="http://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q=richmond+virginia+welding+supplyhttp://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q=richmond+virginia+welding+supply"]looky here[/ame], see what you can see.