R 408.14553 Furnaces.

Rule 4553. (1) Cold or damp metal ingots shall be preheated and dried before being added to molten metal. (2) A furnace which needs to be tilted for discharge shall have operating controls located outside any splash area or the operator shall be protected by a splash shield. (3) A furnace tender shall be not less than 2 feet from the furnace when tapping or plugging, or the tender shall be protected by a splash shield. (4) A gas or oil fired melting furnace installed or modified after the effective date of this part shall be equipped with a control system which shall: (a) Prohibit ignition and combustion until completion of a purge cycle which will provide a minimum of 4 complete volume air changes in the ignition and combustion chamber. (b) Positively and immediately shut off the fuel supply in case of a pilot light or combustion failure, or flame failure where direct ignition to the burner is used. (5) A holding furnace installed or modified after the effective date of this part shall be equipped as prescribed in subrule (4)(b). (6) The requirements of subrules (4) and (5) do not apply to a gas or oil melting or holding furnace that employs explosion resistant immersion tubes and where the products of combustion do not discharge into a closed equipment work chamber or into a confined space.