|High pressure cylinder.|
This cylinder contains 20 cubic feet of argon under about 2000psi of pressure. Or at least it did when I first got it: I use it to purge sample bottles of air-sensitive element samples before re-closing them, so it's slowly getting used up. When it's empty I'll get it refilled: Argon costs about fifty cents a cubic foot, once you've paid for the cylinder and regulator needed to handle it. Those cost a good bit more, but can be reused indefinitely.
Gases like argon, helium, nitrogen, oxygen, carbon dioxide, and of course acetylene are easily available at any welding supply store. They are all set up to re-fill such cylinders on a routine basis (in fact, it's their main business). Larger cylinders are typically leased to you, but small ones like this you buy outright.
Source: Claudin Welding Supply
Contributor: Theodore Gray
Acquired: 18 February, 2003