The master or person in charge and the engineer in charge shall ensure that-
(a) Steam pressure does not exceed that allowed by the certificate of inspection; and(b) The safety valves, once set, are not tampered with or made inoperative.
46 C.F.R. §109.555
CGD 73-251, 43 FR 56828, Dec. 4, 1978, as amended by CGD 95-028, 62 FR 51208, Sept. 30, 1997