Section 45.71. Kiln design and layout

(a) Grades. Grades within the kiln that permit loaded cars to attain a momentum of 150 feet per minute is prohibited. In no case shall the grade exceed 15 inches per 100 horizontal feet.

(b) Door fastenings. All doors shall be provided with a method of keeping them open while the kiln is being loaded. Counterweighted vertical-lifting doors shall be prohibited, unless all counterweight cables are fire-resistant and the counterweights are boxed or guided.

(c) Operating pits. Where operating pits are provided, they shall be ventilated, drained, and lighted. They shall not be less than 6 feet in depth and 3 feet in width. All valves, dampers, damper rods, traps and other operating devices shall be located in the operating pit. The roof of this pit, including ventilating openings and manholes, shall be constructed so as to prevent injury to the operator; it shall be provided with gratings, doors, and guards. It shall not be necessary to enter the kiln proper for any operating regulation.

(d) Steam line insulation. All steam mains, located in or adjacent to this operating pit, shall be covered with asbestos or other heat-insulating material.

(e) Ventilation. When the kiln doors are protected by a roof or a building used for loading, unloading, or storage, suitable ventilating windows or other openings, shall be provided directly above the doors to allow escape of steam and moisture.