- The valve fitted to the cylinder shall be clearly and durably marked in accordance with the following provisions by stamping, engraving or similar processes, namely:-i. the specification of the valve;ii. year and month or quarter of manufactureiii. 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 millimeter of the tube shall also be indicated.
