Michigan Compiled Laws, Chapter 339. Occupational Code § 339.5901

(a) “Antique steam boiler” means a boiler that is no longer used in production applications and is used to demonstrate the historical significance of steam boilers in American history.

(b) “Approved apprenticeship program” means a training program for boiler operators or stationary engineers that is certified by or meets the standards of the Office of Apprenticeship in the United States Department of Labor and is approved by the board.

(c) “Associated auxiliaries” means equipment that is required in the operation of a boiler that includes, but is not limited to, pumps, regulators, feedwater heaters, superheaters, de-superheaters, economizers, air preheaters, draft fans, combustion and pollution control equipment, and prime movers.

(d) “Board” means the board of boiler rules described in section 905.  1

(e) “Boiler” means a closed vessel in which water is heated, steam is generated, or steam is superheated, or a combination of those actions occurs, under pressure or vacuum by the application of heat from combustible fuels, electricity, or nuclear energy.  Boiler does not include facilities of an integral part of a continuous processing unit but does include a fired unit for heating or vaporizing liquids other than water, if the unit is separate from a processing system and is complete within itself.

(f) “Boiler for agricultural purposes” means a portable boiler used in a field or similar open area for the sole purpose of operating farm equipment or farm machinery.

(g) “Boiler operator” or “stationary engineer” means an individual who is engaged in the operation of boilers and associated auxiliaries.

(h) “Certificate inspection” means an inspection that is conducted for purposes of preparing a report described in section 945.  2  The certificate inspection shall be an internal inspection if construction allows;  otherwise the certificate inspection shall be as complete an inspection as possible.

(i) “External inspection” means an inspection that does not involve examination of the internal surfaces of the pressure parts of the boiler.

(j) “Heating surface” means the heating surface determined by the boiler manufacturer and recorded in the manufacturer's data report or by rules established by the board for a boiler if the manufacturer's data report is not available or the boiler is not stamped with its heating surface.

(k) “High pressure, high temperature water boiler” means a water heating boiler operating at pressure that exceeds 160 p.s.i.g. or temperatures that exceed 250 degrees Fahrenheit.