Cryogenics – the science of materials at extremely low temperatures – has become more and more important to industry. One important aspect of this field is the liquefaction of normally gaseous elements, including the following, which are widely used throughout industry:

Oxygen – Used extensively in BOF furnaces in the steel industry, for metal cutting, as a rocket fuel and in medicine.

Acetylene – Widely used in welding.

Nitrogen – Used in refrigeration systems, for metal degassing, in aerosol packaging and in cryogenic surgery.

Hydrogen – Used as a rocket propellant and in the production of several metals.

Argon – Widely used in incandescent lamps and fluorescent tubes.

Helium – Used for arc welding, in the manufacture of electron tubes and in cryogenic research.

Carbon Dioxide – Used in refrigeration, to make aerosol tanks and in fire fighting.

Other cryogenic fluids include liquefied natural gas, fluorine, krypton, neon, methane and ethane.