(1)The compressed gases shall be free from impurities, which are likely to corrode the metal of the cylinder or form an explosive substance with it or cause the gases to decompose or explode.(2)The gases shall be as dry as possible and in no instance shall the aqueous phase separate when a liquefied gas is cooled to 0° C.(3)Before filling any cylinder with gases like carbon monoxide, coal gas, hydrogen or methane, the gas shall be free from hydrogen sulphide and other sulphurous impurities as far as practicable and the moisture shall be less than 0.02 g/m3 of gas at normal temperature and pressure.(4)The purity of gas shall conform to the relevant Indian Standard accepted by Chief Controller.
