A capacity control valve includes a valve housing discharge, port, a suction port, and control ports, and a valve element to be brought into contact with and separated from a valve seat by a driving force of a solenoid to open and close a communication between the control and discharge ports or communication between the control port and the suction port. A sliding region is formed by an inner peripheral surface of the valve housing and an outer peripheral surface of the valve element, a groove extending in a circumferential direction is formed in at least one of the housing inner peripheral surface of the valve housing and the outer peripheral surface of the valve element, and the sliding region has a structure in which a swirling current is generated in the groove by fluid flowing from a high-pressure side to a low-pressure side in a clearance between the inner peripheral surface and the outer peripheral surface of the valve element.

A fluid pressure reducing valve apparatus includes a pressure reducing valve. The valve has: a body containing a fluid-flow chamber, a liquid supply orifice into the chamber, a liquid outlet from the chamber, a regulation plate opposed to the orifice, a spring acting to urge the plate towards the orifice, and a diaphragm between the plate and the body to close the chamber between them. A controllable motor drive acts between the body and an end of the spring remote from the plate. A flow meter is positioned downstream of the outlet. A controller is arranged to receive flow data from the flow meter and to control the motor drive for withdrawal of the remote end of the spring in accordance with flow rate measured by the flow meter. For an increase in demand flow, the plate is partially withdrawn to maintain downstream pressure on such increase and vice versa.

A retarding control assembly for a brake valve may include a bleed line configured for arrangement between a spring chamber of a brake command assembly and a tank line. The bleed line may include a check valve configured to allow fluid flow from the spring chamber to the tank and a check valve bypass configured to allow fluid flow from the tank line to the spring chamber passed the check valve and defining a restricted pathway.

A retarding control assembly for a brake valve may include a bleed line configured for arrangement between a spring chamber of a brake command assembly and a tank line. The bleed line may include a check valve configured to allow fluid flow from the spring chamber to the tank and a check valve bypass configured to allow fluid flow from the tank line to the spring chamber passed the check valve and defining a restricted pathway.

A spring-operated relief valve can include a biasing assembly, a valve inlet, a valve seat, and a disc assembly that is biased toward the valve seat by the biasing assembly. A fluid guide, such as a groove or chamber, can be formed at the interface between the valve seat and the disc assembly. The fluid guide can be configured to direct fluid that flows across the valve seat to provide an upward force on the disc assembly during a relief event.

A spring-operated relief valve can include a biasing assembly, a valve inlet, a valve seat, and a disc assembly that is biased toward the valve seat by the biasing assembly. A fluid guide, such as a groove or chamber, can be formed at the interface between the valve seat and the disc assembly. The fluid guide can be configured to direct fluid that flows across the valve seat to provide an upward force on the disc assembly during a relief event.

A driving tool includes a chamber to store compressed air and a relief valve in communication with the chamber. The relief valve includes an inflow channel communicating with the chamber and an outflow channel with a larger diameter formed at a downstream side of the inflow channel. A valve stem moves along the inflow channel. An O-ring to seal the inflow channel is attached in an annular groove of the valve stem. Air release channels are defined in the valve stem. Each air release channel includes an inlet that opens to an inner circumferential chamber and an outlet that opens to the outflow channel to allow the compressed air to be discharged from the inner circumferential chamber to the outflow channel when the O-ring moves toward the outflow channel and moves beyond the inflow channel due to the internal pressure of the chamber.

A driving tool includes a chamber to store compressed air and a relief valve in communication with the chamber. The relief valve includes an inflow channel communicating with the chamber and an outflow channel with a larger diameter formed at a downstream side of the inflow channel. A valve stem moves along the inflow channel. An O-ring to seal the inflow channel is attached in an annular groove of the valve stem. Air release channels are defined in the valve stem. Each air release channel includes an inlet that opens to an inner circumferential chamber and an outlet that opens to the outflow channel to allow the compressed air to be discharged from the inner circumferential chamber to the outflow channel when the O-ring moves toward the outflow channel and moves beyond the inflow channel due to the internal pressure of the chamber.

A valve spring seat sleeve, a valve assembly, and a plunger pump are disclosed. The valve spring seat sleeve includes a cylindrical hollow structure, a first fluid hole, a first notch and a second notch; the cylindrical hollow structure includes a plunger passage; the first fluid hole passes through a sidewall of the cylindrical hollow structure and communicated with the plunger passage; the first notch and the second notch are located on a side of the cylindrical hollow structure opposite to the first fluid hole; the cylindrical hollow structure includes a first end portion, a second end portion and an intermediate portion, a center of the first fluid hole is located at the intermediate portion, the cylindrical hollow structure further includes a spring mounting portion located between the first notch and the second notch.

The invention relates to a pressure-controlled shut-off valve (1) for temporarily interrupting the air supply to a fuel cell stack in a fuel cell system, comprising a valve piston (3) which can be moved back and forth in a cylindrical housing bore (2) and which is biased in the direction of a seal seat (5) by the spring force of a spring (4), wherein a connection between an air inlet channel (6) and an air outlet channel (7) is produced or interrupted depending on the axial position of the valve piston (3). According to the invention, the valve piston (3) delimits a spring chamber (8), which receives the spring (4) and to which ambient pressure is applied, on one side and a control chamber (9), which is connected to the air inlet channel (7), on the other side within the housing bore (2). The invention additionally relates to a fuel cell system comprising a shut-off valve (1) according to the invention.