Surface Combustion, Maumee, Ohio, received a patent (U.S. patent #6,283,749) for the MetaLined(tm) VacuDrawR series of inside/out (I/O) construction furnaces.

Surface Combustion, Maumee, Ohio, received a patent (U.S. patent #6,283,749) for the MetaLined(tm) VacuDrawR series of inside/out (I/O) furnaces. The MetaLined series is designed to handle processing problems where interaction between the work processed and the furnace insulation cannot be tolerated. The metallic furnace lining, also known as an inside-out construction, is now available for vacuum and atmosphere backfill processing. The VacuDraw batch controlled vacuum/atmosphere furnace is available in gas-fired radiant tube or canned electric heating element designs and is designed to use a nitrogen or nitrogen/hydrogen gas blend. One charge of atmosphere gas is introduced after an initial vacuum evacuation of the furnace chamber. Potential uses of the furnace design include clean tempering of ferrous parts, clean annealing of copper/brass parts, tempering of powdered metals (P/M) parts after oil quench and cleaning of P/M parts.