Abstract: An electrically heated vacuum furnace is provided with special lead-through devices for transmitting current to the heating elements. In order to recognize gas discharges which can occur between a lead-through and a tank wall, the insulation of the lead-through is surrounded by an auxiliary electrode. A thermocouple can also be used instead of an auxiliary electrode. A signal derived from the auxiliary electrode can be used to shut off the furnace power to avoid damage thereto.

Abstract: In an installation for the vacuum heat treatment and subsequent hot isostatic redensification of materials comprising a work space inside a container, heating unit, work-space insulation and an outer chamber with a vacuum connection and a pressure-gas connection, insulation is also provided at the interior of the chamber wall. The chamber is water-cooled.

Abstract: A vacuum-tight closure assembly includes a valve seat; a spreadable valve plate movable into a closed position for assuming a spreaded state in which it sealingly engages the valve seat; and a guide arrangement for a centered guiding of the valve plate during its motion into the closed position. The guide arrangement includes guide faces located in the vicinity of and stationarily with respect to the valve seat and counterguide faces located on and movable with the valve plate. The guide faces cooperate with the counterguide faces during the motion of the valve plate towards the closed position.