In the gas welding process, the welding heat is obtained from the combustion of fuel gases in the presence of a supporter in combustion. And, in most of the gas welding process oxygen is use as a supporter for combustion. And the various fuel gases are hydrogen, coal gas, liquid petroleum gas (LPG), and acetylene etc. Oxygen. Oxygen is found nearly everywhere in nature, either in free state or in a combination with other elements. It is one of the chief constituents of atmosphere i.e.21% Oxygen and 78% Nitrogen. It is a supporter of combustion. Its chemical symbol is O2….