50-74-303. Engineer's license classifications. (1) Engineers entrusted with the operation, care, and management of steam or water boilers and steam machinery, as specified in 50-74-302, are divided into six classes, including first-class engineers, second-class engineers, third-class engineers, agricultural-class engineers, low-pressure engineers, and limited low-pressure engineers.

(2) Licenses for the operation of steam or water boilers and steam machinery are divided into six classifications in accordance with the following schedule:

(a) First-class engineers are licensed to operate all classes, pressures, and temperatures of steam and water boilers and steam-driven machinery with the exception of traction and hoisting engines.

(b) Second-class engineers are licensed to operate steam boilers operating not in excess of 250 pounds per square inch gauge saturated steam pressure, water boilers operating not in excess of 375 pounds per square inch gauge pressure and 450 degrees F temperature, and steam-driven machinery not to exceed 100 horsepower per unit, with the exception of traction and hoisting engines.

(c) Third-class engineers are licensed to operate steam boilers operating not in excess of 150 pounds per square inch gauge saturated steam pressure or not in excess of 150 horsepower per hour and water boilers operating not in excess of 160 pounds per square inch gauge pressure and 350 degrees F temperature.

(d) Agricultural-class engineers are licensed to operate steam boilers that operate not in excess of 150 pounds per square inch saturated steam pressure and that:

(i) are not operated for more than 6 months of the year; and

(ii) are not operated for purposes other than the harvesting or processing of agricultural products.

(e) Low-pressure engineers are licensed to operate steam boilers operating not in excess of 15 pounds per square inch gauge pressure and water boilers operating not in excess of 50 pounds per square inch gauge pressure and 250 degrees F temperature.

(f) Limited low-pressure engineers are licensed to operate hot water heating boilers not in excess of 30 pounds per square inch gauge pressure and 210 degrees F temperature and hot water supply boilers not in excess of 160 pounds per square inch gauge pressure and 210 degrees F temperature.