Section 18(2)(vii) in The Static And Mobile Pressure Vessels (Unfired) Rules, 1981
(vii)each safety relief valve shall be plainly and permanently marked with the pressure in kg/cm2 at which it is set to discharge, with the actual rate of discharge of the device in cubic metres per minute of the gas at 150C and at atmospheric pressure, and with the manufacturer's name. The rated discharge capacity of the device shall be determined at a pressure of 120 per cent. of the design pressure of the vessel;