SEAL Russian patent published in 2002 - IPC

FIELD: seals designed for linearly movable locking members switched from closed to open positions and vice versa to shut off medium flow. SUBSTANCE: seal consists of metal members confining pressure cavity which may be loaded from outside to attain sealing. Use of only metal members, makes it possible to use seal within wide range of temperatures and under conditions of extremely high wear causes, either by frequent operation of locking member, or by working medium action. Sealing system has locking member whose seal is provided by movable seat tightly connected to tube length, which in its turn is connected to flange. Entire structural unit is connected by means of flange to seal body which are statically tightened with the help of sealing member relative to each other. Membranes together with supporting plate form a pressure cavity loaded through hole and connecting branch pipe with pressure Ps which acts in pressure cavity, and pressure Pg acts in other pressure cavity. Formed inside tube length with the help of metal sealed to tube length is pressure channel between holes and connecting branch pipe. Membrane has wear-resistant coating along line of contact with locking member. Supporting plate fulfils double function. First, it is radial guide of membrane for prevention of plastic deformation caused by action of friction forces in operation of valves. Secondly, it confines axial stroke in change of pressure direction with closed locking member. In this case, membrane rests on entire circular surface of supporting plate. As surface pressing down of membrane decreases, no residual deformation may occur due to less preliminary stress in assembled state without pressure effect. EFFECT: higher efficiency due to improved design. 36, 11 dwg