Minnesota Administrative Rules

4645.3100 PIPING.

Subpart 1.

Pipe used in heating system.

Pipe used in heating and steam systems shall not be smaller in size than that prescribed in that portion of chapter 21 of the publication, issued in 1954, entitled Heating, Ventilating, Air Conditioning Guide, by the American Society of Heating and Ventilating Engineers, 51 Madison Avenue, New York, New York, starting with "Sizing Piping for Steam Heating Systems" on page 491 and continuing through "Sizing Piping for Indirect Heating Units" on page 506, which portion of chapter 21 of said guide is hereby adopted by the commissioner of health with the same force and effect as if the same were fully set forth in and written as part of this subpart. The ends of all steam mains and low points in steam mains shall be dripped.

Subp. 2.

Valves.

Steam return and heating mains shall be controlled separately by a valve at boiler or header. Each steam and return main shall be valved. Each piece of equipment supplied with steam shall be valved on the supply and return ends.

Subp. 3.

Thermostatic control.

The heating system shall be thermostatically controlled using one or more zones.

Subp. 4.

Coverings.

Boilers and smoke breeching shall be insulated with covering having a thermal resistance (1/c) value of not less than 1.96 and one-half inch plastic asbestos finish covered with four ounce canvas. All high-pressure steam and return piping shall be insulated with covering not less than the equivalent of one inch four-ply asbestos covering. Heating supply mains in the boiler room, in unheated spaces, unexcavated spaces, and where concealed, shall be insulated with a covering of asbestos air cell having a thickness of not less than one inch.

Statutory Authority:

MS s 144.55; 144.56

History:

L 1977 c 305 s 39

Published Electronically:

January 21, 2000