A pressure reducing valve includes: a body, a valve seat, and a valve element opening and closing the valve seat according to a difference between a pressure on the inlet side and a pressure on the outlet side. A pressure chamber, which is a space part between the valve element and the valve seat, is provided on the inlet side of the valve element. The valve element includes a plurality of horizontal holes each opening to the pressure chamber, and a vertical hole bringing the horizontal holes and the outlet side of the valve element into communication with each other. The horizontal holes and the vertical hole are provided in such a manner that a value of a ratio of a flow channel area of the vertical hole to a total area that is a total of flow channel areas of the horizontal holes exceeds 1.16.

In an embodiment, a system comprises a valve disc configured in an overpressure protection device. The system can also include a valve gasket configured to rest on the valve disc. The system also includes a valve seat configured above the valve gasket, wherein the valve gasket is sealed in between the valve seat and the valve disc. The system further includes a supporting structure configured above the valve seat. The supporting structure is configured to enable the valve gasket to remain in position between the valve disc and the valve seat in response to an increase in pressure.

A coupling for a break-away valve assembly includes a coupling and an adapter, the coupling including: a valve arranged in an annular body, the annular body having a valve seat including a first portion and a second portion, adjacent to the first portion, of greater internal diameter relative to the first portion, the valve being biased in a first direction to seal against the valve seat on disconnection of the coupling from the adapter, wherein the valve is biased in a second direction, and the valve is adapted to extend past the first portion into the second portion of the valve seat to release a volume of fluid if the pressure acting on the valve exceeds a predetermined surge pressure threshold.

A device and method for shutting off fluid-flow in a pipe. The device includes a moveable sealing member inside a pipeline, a longitudinal spring configured to bias against the sealing member in a first direction, and a lateral spring at an angle to the longitudinal spring wherein the lateral spring is configured to bias against the sealing member in a second direction. The device includes a housing with a passage configured to be positioned inline with a pipeline, and a sealing seat. A locking element is biased against the sealing member using the lateral spring to maintain an open position with the sealing member off of the sealing seat. The locking element is configured to move from the sealing member upon a fluid overpressure in the passage, whereby the sealing member extends into the seal seat to close off the pipeline upon the overpressure.

A check valve assembly for use with a liquid jet cutting system can include a check valve body a high-pressure fluid inlet on one end and a high-pressure fluid outlet on the other end along a central axis of the check valve body. The check valve body can have a first metallic seal surface on an outer surface of the check valve shaped to engage an endcap of the liquid jet cutting system to form a first seal. The assembly can include an annular low-pressure fluid chamber surrounding a portion of the check valve body and defined at least in part by an annular gasket, the check valve body, the first seal, and the endcap. The check valve body can include a low-pressure fluid channel, and a check valve positioned between the low-pressure fluid channel and a high-pressure fluid chamber.

A pressure-reducing valve 1 includes a tubular valve body 3 movably accommodated in a housing 2, a valve seat 4 fixed inside the housing 2, and an urging member 5 that urges the valve body 3 in a direction separating from the valve seat 4. The valve seat 4 includes an annular elastic member (O-ring 42) capable of abutting against the valve body 3, an annular portion (inner ring portion 41b) that covers an outer periphery of the elastic member, an inner peripheral portion 43b disposed on an inner periphery of the elastic member, a connecting portion (closing plate portion 43a) that connects the annular portion and the inner peripheral portion 43b, and a detachment prevention portion provided in at least one of the inner peripheral portion 43b and the annular portion on a valve body side to prevent the elastic member from detaching from the annular portion.

An embodiment of a valve, such as a water valve, includes a body, a sleeve, and a rod. The body includes a body cavity, and the sleeve is removably disposable within the body cavity and includes a sleeve cavity. And the rod is movably disposable within the sleeve cavity and is configured to form a fluid-tight seal between the body cavity and the sleeve cavity while the rod is in a closed position and is configured to allow a fluid to flow from the body cavity to the sleeve cavity while the rod is in an open position. Furthermore, one or more components of the valve each can be made partially or fully from one or more polymers.

A pressure relief valve includes a valve body including a monitored pressure inlet leading to a monitored pressure region, a piston having a shear seal bore and a surface facing the monitored pressure region, a vent passage and a the shear seal assembly comprising a seal plate having a sealing surface thereon, and the shear seal assembly includes a sealing surface facing the seal plate and having a first annular area, and a first surface having an annular surface area at least twice as large as the first area of the sealing surface, the first surface facing away from the first area, and a biasing seal in contact with the first surface.

A traveling relief valve for down-hole use in a well. In one embodiment, the traveling relief valve comprises a seat, a screw, a seal, a carrier, a spring, and a ported tube, where the traveling relief valve is configured to include a first flow interface between the seat and the carrier for flow when the well is producing, and a second flow interface between the seal and the carrier for back-flow in the well.

A flow control device includes a valve body defining an inlet, an outlet, and a flow path. A valve seat assembly includes a fitting coupled to the valve body, a seat ring coupled to the fitting and defining a valve seat. The seat ring includes an inner groove formed on an interior surface of the seat ring. A control element is movable relative to the valve body between a closed position, in which the control element engages the valve seat, and an open position, in which the control element is spaced away from the valve seat. The seat ring is coupled to the fitting by snap-fit connection such that a portion of the fitting is disposed in the inner groove of the seat ring.