L&L Special Furnace Co. Inc. delivered a floor-standing, dual-chamber box furnace to an aircraft maintenance repair and overhaul station in Oklahoma. The top chamber, which has working dimensions of 16 inches wide x 15 inches high x 32 inches deep, is used for heat treatment of various steels and alloys up to 2200°F. The bottom tempering chamber, which has working dimensions of 14 inches wide x 12 inches high x 32 inches deep, can be used to temper various steels. It can also be used for aluminum thermal processing. The furnace is equipped with a specially designed control/pyrometry package to allow it to conform to AMS 2750E standards for class-2 equipment.

Two-zone SCR control with digital biasing for temperature gradient adjustment for the top chamber is included, along with thermocouple reference ports for both chambers. There is a single-zone SCR for the tempering chamber. The furnace also features 0.25-inch NPT thermocouple ports located in the best possible position representative of each corner of the furnace for both chambers. The tempering furnace is equipped with an air-cooled fan to promote excellent uniformity at low temperatures.