81-5,172.

Boilers and vessels to which act does not apply.

The Boiler Inspection Act shall not apply to:

(1) Boilers of railway locomotives subject to federal inspection;

(2) Boilers operated and regularly inspected by railway companies operating in interstate commerce;

(3) Boilers under the jurisdiction and subject to regular periodic inspection by the United States Government;

(4) Boilers used exclusively for agricultural purposes;

(5) Steam heating boilers in single-family residences and apartment houses with four or less units having a safety valve set no higher than fifteen pounds pressure per square inch;

(6) Heating boilers using water in single-family residences and apartment houses with four or less units having a safety valve set no higher than thirty pounds pressure per square inch;

(7) Fire engine boilers brought into the state for temporary use in times of emergency;

(8) Boilers of a miniature model locomotive or boat or tractor or stationary engine constructed and maintained as a hobby and not for commercial use and having a diameter of less than ten inches inside diameter and a grate area not in excess of one and one-half square feet and that are properly equipped with a safety valve;

(9) Boilers or fired pressure vessels not exceeding two hundred thousand British thermal units of input;

(10) Unfired pressure vessels not exceeding (a) five cubic feet in volume or (b) a pressure of two hundred fifty pounds per square inch;

(11) Unfired pressure vessels owned and maintained by a district or corporation organized under the provisions of Chapter 70, article 6; and

(12) Unfired pressure vessels (a) not exceeding a maximum allowable working pressure of five hundred pounds per square inch, (b) that contain carbon dioxide, helium, oxygen, nitrogen, argon, hydrofluorocarbon refrigerant, or any other nonflammable gas determined by the State Fire Marshal not to be a risk to the public, (c) that are manufactured and repaired in accordance with applicable American Society of Mechanical Engineers standards, and (d) that are installed in accordance with the manufacturer's specifications.