Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 146, § 23

If upon inspection the district engineering inspector finds the boiler to be in safe working order with the fittings necessary to safely and properly set up the boiler and its appurtenances conform to the rules of the board, the department shall issue to the owner or user thereof a certificate of inspection stating the maximum pressure at which the boiler may be operated, as ascertained by the rules of the board, and thereupon such owner or user may operate the boiler mentioned in the certificate. If the district engineering inspector finds otherwise, the department shall withhold the certificate until the boiler and its fittings are put in a condition to ensure safety of operation and to ensure that the boiler and its appurtenances conform to the rules of the board and the owner or user shall not operate such boiler, or cause it to be operated, until such certificate has been granted.