Overpressure protector for insulating gas filled chamber of electrical equipment - has release burst disc consisting of thin metal foil preventing leakage loss and layer of brittle material e.g. graphite

摘要

The safety valve for a gas-filled electrical device has a round hole in the wall of the device covered with a disc of graphite (4), this being the bursting element in the event of over-pressure. The graphite disc is held by a retaining ring (10) with several bolts (12) screwed around its circumference. There is a rubber ring (13) between disc and retaining ring and also a sealing ring (7) on the underside of the disc. A foil of rolled aluminium or stainless steel (6) prevents seeping of the gas through the porous graphite, and a thin metal plate (16) on the retaining ring protects the graphite disc from external damage. ADVANTAGE - Simple to manufacture. No leakages yet immediate rupture when safety pressure reached.