.-Valves fitted to the cylinder shall be clearly and durably marked in accordance with the following provisions by stamping, engraving or similar processes:-(i)the specification of the valves;(ii)year and month or quarter of manufacture;(iii)manufacturer's symbol;(iv)working pressure;(v)the name or chemical symbol of the gas for which the valve is to be used;(vi)the type of screw threads on the outlet, in case of left handed as (L.H.);(vii)Inspector's stamp;(viii)where dip tubes are provided, special indications shall be given by a clear and durable marking on the valve or on a badge fixed between the valve and the cylinder and the total length in millimetre of the tube shall also be indicated.
