Helium is abundant in the Sun's atmosphere but is found at trace level in the Earth's atmosphere. However, it may also be found in fossil form in natural gas pockets in some oil fields, where it is extracted by drilling deep into the subsoil of certain regions in the U.S.A., Algeria and Qatar.
Helium is an extremely light gas (its density is 0.169 kg/m3) and is therefore very volatile. It is colorless, odorless, non-flammable and completely inert. This noble gas is essential to many industrial applications thanks to its characteristics: very low boiling point allowing electrical superconductivity, very low density, high thermal conductivity, very low solubility.
Helium is a chemically inert gas and plays a critical role in a wide array of industries and applications.
For example, helium is utilized both as a pure gas and in mixtures with argon for TIG or MIG welding. In some applications, helium has an advantage over argon in gas-shielded arc welding because it provides greater arc heat for the same welding currents and arc length. This results in deeper penetration, which is preferable for welding heavier materials that require greater welding speed or when metals of high thermal conductivity are to be welded.
Below you will find some of the main applications using helium.