Solar Atmospheres placed two orders with Vacuum Furnace Systems (VFS), Souderton, Pa., for redesigned Blowhard Model II type vacuum furnaces with advanced rapid quenching. The design improvements center on the use of helium gas with an overspeed turbine fan wheel driven by a 100 hp motor that operates at full motor current with the use of an ABB variable frequency drive. Engineers at VFS made an effort to minimize pressure losses in the internal heat exchanger and the gas flow path. This modification ensures maximum helium gas velocities to the hot zone quench nozzles operating at 10-bar overpressure.