Patent ID: 8051876

Claim:
A pressure limiting valve device for protecting hydraulic pressure packs against an overload and hydraulic props against falling rocks in underground mining and tunnel construction comprising a valve housing, a consumer connection coupled to the valve housing, a pressurized fluid outlet in the consumer connection for allowing flow of pressurized fluid, a movable closure in the valve housing for ensuring separation of the pressurized fluid outlet and the consumer connection, a flow gap between the movable closure and the pressurized fluid outlet, a valve spring in the valve housing for exerting force such that the movable closure is movable against the force exerted, a seal on the movable closure for securing the flow gap, the valve housing and the consumer connection remaining connected when the overload occurs for discharging the pressurized fluid, wherein the seal comprises a groove and a non pre-tensioned seal ring with limited flexibility disposed in the groove without pre-stressing, the seal ring having a first side facing the consumer connection, a second side opposite the first side away from the consumer connection, top and bottom opposite sides between the first side and the second side, the groove having a shape for allowing partial or total flow of the pressurized fluid into the groove and around the seal ring, and wherein the seal ring is displaceable towards the consumer connection due to flow of the pressurized fluid on sides of the seal ring including the second side away from the consumer connection; the device further comprising a system pressure fluid, and wherein the groove and the seal ring are disposed in the movable closure such that the system pressure fluid acts on the seal ring when the valve is in a closed position, the device further comprising a blind hole in the consumer connection and connection bores connecting the blind hole and the flow gap, wherein the groove and the seal ring partially extend into opening cross-sections of the connection bores when the device is in a fully closed position.