Section 65(5)(b) in Maharashtra Factories Rules, 1963
(b)(i)The minimum thickness of the shell of a sizing cylinder shall be actually measured once in a period of two years.(ii)If during its working life, the shell of a sizing cylinder is at any time punctured requiring repairs to the cylinder to close the punctured portion, the thickness of the sheet of the shell near such puncture or opening shall be measured by a competent person.