A valve device includes: a poppet that is formed in a hollow shaft shape except for a leading end, has a tapered closure part at the leading end and a side hole passing through a wall of the hollow shaft-shaped part, and rotates around a shaft center thereof during opening and closing actions; and a valve seat having a sloped seat surface with which the closure part of the poppet comes into contact when closing the valve device. The closure part of the poppet or the seat surface of the valve seat, whichever has a higher hardness, has a cut mark of the opposite direction from a direction of rotation of the poppet around the shaft center that occurs during the valve closing action.

An embodiment provides a check valve including a valve case, a positive pressure valve having a resin ring sealing member, and a resin negative pressure valve. The positive pressure valve and the negative pressure valve are disposed in the valve case. The positive pressure valve includes a first mount surface and a second mount surface disposed on an inner diameter side of the first mount surface. In the valve case, a presser cap is mounted on the positive pressure valve so as to sandwich the ring sealing member and the negative pressure valve with the first mount surface and the second mount surface of the positive pressure valve.

An exercisable check valve having a fluid delivery test channel and piston closure is disclosed herein. A valve closure member stops flow through the valve in the presence of backwards pressure or when engaged by the piston. The valve may be tested by applying a pressure source to the fluid delivery test channel to cause the piston to engage the valve closure member and stop flow through the valve. A test rod may then be inserted into a test rod port to ensure the valve closure member is in the proper closed position. The check valve may also include a biasing element to bias the valve closure member to an open position and a drainage channel. The check valve may be used in any piping or valve system.

Provided is a check valve element enabling efficient supply of fluid while suppressing the occurrence of chattering. The check valve element is provided to be displaceable upstream and downstream in a downstream flow path extending downstream from a valve seat having an opening for introducing a fluid and is pressed against the valve seat by a pre-closing urging force applied thereto toward an upstream side. The check valve element has an arresting portion provided on an outer peripheral surface thereof, a sliding resistance imparting member support portion supporting a sliding resistance imparting member such that the sliding resistance imparting member slides along the wall of the downstream flow path when the check valve element is displaced upstream and downstream, and an urging member support portion supporting an urging member urged upstream so that the urging member urges the sliding resistance imparting member upstream, thereby causing the sliding resistance imparting member to increase in outer diameter while being arrested by the arresting portion.

There is provided a check valve capable of effectively suppressing the generation of chattering. The check valve includes: a housing including an inlet channel, a valve chest, and an outlet channel; a seat member provided around the inlet channel, the seat member including a seat portion; a valve element pressed against the seat portion to close the inlet channel; a biasing member configured to push the valve element toward a valve seat; a guide portion provided at the housing and configured to guide the valve element when the valve element moves in an axial direction; and a damper chamber communicating with the valve chest through a space between the valve element and the guide portion, the damper chamber being configured to attenuate axial moving force of the valve element. The biasing member is arranged in the valve chest.

A check valve comprises a housing, a fluid passage, a seat, a valve member and a stop. The fluid passage extends through the housing. The seat is disposed in the fluid passage. The valve member is positioned in the passage to engage the seat. The stop extends through the housing to engage the valve member. The stop is accessible from outside the housing to adjust a distance the valve member can travel from the seat. In one embodiment, the stop includes a variable stop feature, such as an offset pin or a cam. In another embodiment, the stop includes a pump control valve. In yet another embodiment, the housing includes markings to indicate a position of the stop. The valve member comprises a ball or a poppet in different embodiments.

An apparatus and a system for application of pressure to a fluid, as well as a corresponding use. The apparatus includes an introduction port for introducing the fluid into the apparatus; a cooling apparatus port and an outlet port; a controllable first valve device having an adjustable first opening pressure value; a second valve device having a second opening pressure value; a controllable third valve device having an adjustable third opening pressure value; the first valve device and the third valve device being automatically controllable for simultaneous application to the fluid of the first predefinable pressure value for output at the outlet port and of the second predefinable pressure value for output at the cooling apparatus port.

A method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit. The method includes providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof, and providing an uncoupling pressure prevailing in the supply conduit for the purpose of activating shut-off valves in the supply conduit and on the cylinder, and activating a release which uncouples the coupling. A coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly including a pump, a cylinder, a supply conduit between the pump and the cylinder, and such a coupling.

A dynamic seal assembly is disclosed for use in a valve having an upstream pressure side and a downstream pressure side, the dynamic seal assembly including an annular seal member having a generally C-shaped cross-section and including opposed upstream and downstream legs defining an internal cavity with an opening facing toward the upstream pressure side of the valve, wherein the upstream leg has a radial length that is greater than a radial length of the downstream leg and includes a retaining foot that extends angularly away from the upstream leg in an upstream direction at an angle of between about 0° and 90°, and a metallic spring is disposed within the internal cavity of the seal member for providing a constant sealing force to the seal member.

A filtering device includes a tubular outer body with an intermediate chamber containing a pair of cup-shaped valve elements mounted floating and slidable coaxially with opposing cavities in which an axially compressed spring is housed. The first cup-shaped valve element is arranged coaxially outside the second cup-shaped valve element and has a base with a central through opening and a tubular portion with a series of ribs. The second cup-shaped valve element has a perforated base abutting against a perforated plug fixed to one side of the cavity passing towards the master cylinder. The perforated plug forms a through seat that slidably houses an appendage of the second cup-shaped valve element. Passages are formed around the plug that establish fluid communication between the intermediate chamber and a passage to the master cylinder.