Ohio Rev. Code Ann. § 4104.10

All unfired pressure vessels, except unfired pressure vessels exempt under section 4104.04 of the Revised Code, shall be thoroughly inspected during fabrication and upon completion and shall not be operated until a copy of the manufacturers' data report, properly executed and signed by the inspector is filed in the office of the superintendent of industrial compliance. All unfired pressure vessels shall conform in every detail with applicable rules adopted by the board of building standards pursuant to section 4104.02 of the Revised Code.