This chapter shall govern the design, installation, operation and maintenance of industrial furnaces used for commercial and industrial processing of materials.
Industrial furnaces shall be designed, installed, operated and maintained in accordance with this chapter, NFPA 86, and the construction codes, including the Fuel Gas Code and the Mechanical Code.
Enclosed rooms, basements or other areas below grade containing industrial furnaces shall be provided with combustion air in accordance with the construction codes, including the Mechanical Code and the Fuel Gas Code, and with ventilation in accordance with the Mechanical Code.
Industrial furnaces shall be located so as not to pose an ignition hazard to flammable vapors or mists or combustible dusts that may be present as a result of a manufacturing operation or other lawful use and occupancy of the building.
Roofs and floors of furnaces shall be insulated and ventilated to prevent temperatures at combustible ceilings and floors from exceeding 160°F (71°C).
Fuel-gas piping serving industrial furnaces shall be designed and installed in accordance with the Fuel Gas Code. Piping for other fuel sources shall comply with the requirements of this section.
Each industrial furnace shall be provided with an approved manual fuel shutoff valve in accordance with the construction codes, including the Mechanical Code and the Fuel Gas Code.
Valves for fuel supply lines shall be located within 6 feet (1829 mm) of the appliance served.
Exception: When approved and the valve is located in the same general area as the appliance served.
The design of manual fuel shutoff valves shall incorporate a permanent feature that visually indicates the open or closed position of the valve. Manual fuel shutoff valves shall not be equipped with removable handles or wrenches unless the handle or wrench can only be installed parallel with the fuel line when the valve is in the open position.
Interlocks shall be provided for Class A furnaces so that conveyors or sources of flammable or combustible materials shall shut down if either the exhaust or recirculation air supply fails.
Class A and B furnaces that contain, or are utilized for the processing of, combustible materials shall be protected throughout by a fire extinguishing system complying with the requirements of FC Chapter 9.
A fixed fire extinguishing system shall be provided for Class C or D furnaces to protect against such hazards as overheating, spillage of molten salts or metals, quench tanks, ignition of hydraulic oil and escape of fuel.
The following data for Class A furnaces shall be furnished on the manufacturer's nameplate:
- The solvent used.
- The number of gallons (liters) used per batch or per hour of solvent entering the furnace.
- The required purge time.
- The oven operating temperature.
- The exhaust blower rating for the number of gallons (liters) of solvent per hour or batch at the maximum operating temperature, or with regard to low-oxygen furnaces, the maximum allowable oxygen concentration.
Equipment shall be maintained in accordance with the manufacturer's instructions.