Mich. Comp. Laws § 339.5946

Sec. 946. (1) A person shall not operate under pressure a boiler that is subject to the inspection requirements provided in this article without a valid inspection certificate. (2) A person shall not cause a boiler that is subject to the inspection requirements provided in this article to be operated at a pressure that exceeds the maximum operating pressure specified on the boiler's inspection certificate. (3) In addition to any penalties or remedies under article 6, a person that violates this section is guilty of a misdemeanor punishable by a fine of not more than $500.00, or imprisonment for not more than 60 days, or both. Each day a boiler is operated in violation of this section is a separate offense.