In commerce, liquid Oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid Oxygen is obtained from the Oxygen found naturally in air by fractional distillation in a cryogenic air separation plant.


  • Widely used with a fuel gas for cutting, welding, brazing and soldering. The use of Oxygen gives higher flame temperatures than if air is used.
  • In oxy-cutting, an oxy-fuel flame preheats the steel to its ignition temperature. A jet of gaseous Oxygen flows onto the red-hot steel, generating more heat and melting the steel. The steel in contact with the Oxygen jet is oxidised, creating metallic slag which is blown from the cut, allowing more steel to react with the Oxygen.
  • In plasma and laser-cutting steel, an arc or laser beam is used to heat the steel to its ignition temperature. Oxygen is then used in the same way as with Oxygen-cutting to create an exothermic reaction and to blow away any metal oxide or slag.
  • Thermal lancing Oxygen is used in conjunction with the steel lance to create a high-temperature melting process capable of drilling or cutting through materials such as concrete, brick, stone and most metals.
  • High-purity Oxygen is used in the laboratories, process-control operations, metal analysis instruments and in semi-conductor production.
  • Used as an assist gas in lasers for cutting mild steel.

Commercial Oxygen

Purity:- 99.995%

1 H2O 3
2 N2 15
3 Ar 10
4 H2 0.2
5 CO+CO2 0.2
6 CnHm 0.5

Oxygen Grade 1

Purity:- 99.999%

1 H2O 2
2 N2 5
3 Ar 5
4 H2 0.2
5 CO+CO2 0.2
6 CnHm 0.2

Oxygen Special Grade

Purity:- 99.9995%

1 H2O 1
2 N2 1
3 Ar 1
4 H2 0.1
5 CO 0.1
5 CO2 0.1
6 CnHm 0.2