Okla. Stat. tit. 40, § 40-141.15: Certificate of operation required - Violations

After twelve (12) months for power boilers, twenty-four (24)

months for low pressure steam heating, hot water heating and hot

water supply boilers, and thirty-six (36) months for pressure

vessels following the date on which this act becomes effective, it

shall be unlawful for any person, firm, partnership or corporation

to operate in this state a boiler or pressure vessel covered by this

act, including boilers and pressure vessels covered by owner-user

inspection service provided for in Section 14, without a valid

certificate of operation. The operation of a boiler or pressure

vessel without such certificate of operation, or at a pressure

exceeding that specified in such certificate of operation or in

violation of this act or the rules and regulations promulgated under

it, shall constitute a misdemeanor on the part of the owner, user or

operator thereof. Each day of such unlawful operation shall be

deemed a separate offense.