PDFWAC 296-52-70080
Magazine heating system requirements.
Magazine heating system requirements and the following apply:
(1) Heat sources. Magazines requiring heat must be heated by either:
(a) Hot water radiant heating; or
(b) Air directed into the magazine building by hot water or low pressure steam (15 psig) coils located outside the magazine building.
(2) Heating systems. Magazine heating systems must meet the following requirements:
(a) The radiant heating coils in the building must be installed where explosive materials or their containers cannot touch the coils and air is free to circulate between the coils and the explosive material containers.
(b) The heating ducts must be installed where the hot air released from a duct is not directed toward the explosive material or containers.
(c) The heating device used in connection with a magazine must have controls, to prevent the building temperature from exceeding 130°F.
(d) The electric fan or pump used in the heating system for a magazine must be:
(i) Mounted outside;
(ii) Separate from the wall of the magazine;
(iii) Grounded.
(e) Electric motor, device controls, and electric switch gear.
(i) The electric fan motor and the controls for electrical heating devices used in heating water or steam must have overloads and disconnects which comply with the National Electrical Code, (NFPA Number 70-1992).
(ii) All electrical switch gear must be located a minimum distance of twenty-five feet from the magazine.
(f) Water or steam heating source.
(i) A heating source for water or steam must be separated from a magazine by a distance of at least:
(A) Twenty-five feet when the heating source is electrical;
(B) Fifty feet when the heating source is fuel fired.
(ii) The area between a heating unit and a magazine cannot contain combustible materials.
(g) The storage of explosive material containers in the magazine must allow for uniform air circulation, so temperature uniformity can be maintained throughout the explosive materials.