For the purposes of this chapter, the following definitions apply:

(1) "Boiler classification" means for the purpose of determining the appropriate class of boiler operating engineer's license required:

(a) a determination of the conditions under which the boiler is actually being operated, with respect to:

(i) the operating pressure;

(ii) the operating temperature; and

(iii) the BTUs per hour or horsepower per hour produced; but

(b) is not based upon the maximum allowable working pressure (MAWP) rating limit(s) established on the boiler's manufacturer's data plate.

(i) The department may require the boiler owner to provide appropriate verification from the power supplier, which establishes the BTU per hour or horsepower per hour rate at which the boiler is being fired, as applicable.

(2) "Department" means the Department of Labor and Industry.

(3) "Hot water supply boiler" means a boiler, completely filled with water, intended for operation at pressures not exceeding 160 psig and/or temperatures exceeding 250 degrees F., measured at or near the boiler outlet, that furnishes hot water to be used external to itself.

(4) "Monitoring" the operation of a boiler means appropriate periodic maintenance and observation of the functioning of a hot water heating boiler or hot water supply boiler, which contains all failsafe features necessary to operate fully unattended. Failsafe features include control circuitry that stops the flow of fuel and/or control feed water to the boiler.

(5) "Operating" a power boiler or steam engine means the manual operating and monitoring of an automatically fired power boiler or steam engine, which requires the operator to be present while the boiler is fired.

(6) "Power boiler" means a boiler in which steam or other vapor is generated at a pressure of more than 15 pounds per square inch gauge pressure (psig).

(7) The department incorporates by reference the definitions related to boiler operators in building code rules at ARM 24.301.711, which include the following terms:

(a) boiler;

(b) high temperature water boiler;

(c) hot water heating boiler;

(d) standard boiler;

(e) state special boiler;

(f) steam heating boiler;

(g) temporary boiler;

(h) traction engine;

(i) water heater; and

(j) water heating system.