Maryland Code, PUBLIC SAFETY 12-911
(b) Except as provided in § 12-909(d)(3) of this subtitle, the certificate is valid for the period that corresponds to the interval between certificate inspections as established by regulation under § 12-909 of this subtitle.
(c) If the certificate inspection interval for a boiler or pressure vessel is extended under § 12-909(d)(5) of this subtitle, the Chief Boiler Inspector shall promptly issue a certificate to the owner of the boiler or pressure vessel that bears the new expiration date.
(d) (1) The certificate shall be posted under glass in the room that contains the boiler or pressure vessel that was inspected.
(2) If the boiler or pressure vessel is not located in a building, the certificate shall be posted in a location convenient to the boiler or pressure vessel that was inspected or in any place where the certificate will be accessible to interested parties.
(e) (1) The Chief Boiler Inspector or an authorized deputy boiler inspector may suspend a certificate at any time when, in the opinion of the inspector, the boiler or pressure vessel for which the certificate was issued:
(i) cannot be operated without danger to public safety; or
(ii) is found not to comply with regulations adopted under this subtitle.
(2) The suspension of a certificate continues until:
(i) the boiler or pressure vessel is made to conform to the regulations adopted under this subtitle; and
(ii) the certificate is reinstated.
(f) If a boiler or pressure vessel for which a certificate was issued based on the report of a special inspector ceases to be insured by an authorized insurer, the certificate is invalid.