A check valve unit 1 includes: a container body 2 including a valve body housing portion 21, a valve seat 22, and a protruding portion 23, the valve body housing portion 21 having a cylindrical shape, the valve seat 22 being formed at one end portion of the valve body housing portion 21 and protruding from an inner peripheral surface of the valve body housing portion 21, the protruding portion 23 being formed at the other end portion of the valve body housing portion 21 and protruding from the inner peripheral surface of the valve body housing portion 21; and a valve body 3 including a valve portion 31 and a guide portion 32 and disposed in the container body 2, the valve portion 31 coming into contact with the valve seat 22 at a time of preventing backflow of refrigerant, the guide portion 32 including a plurality of blades.

The present invention relates to an air admittance valve (AAV) that operates automatically at low pressures to selectively open and close an air passageway between an inlet and an outlet. The AAV comprises a valve body having a centrally disposed, internal valve chamber in communication with the ambient environment, and having a valve seat. The AAV includes a sealing member having a flexible diaphragm that is fastened to a support ring, the ring defining one or more lugs on an outer periphery thereof. The AAV further includes a cap member within which the sealing member may be disposed, such that the one or more lugs may interact with an interior surface of the cap. The sealing member may selectively seal or unseal from the valve seat in response to pressure differentials between the inlet and the outlet.

Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly to allow or stop a flow for use with enclosed environment includes a housing having, an inlet disposed at a first end of the housing fluidly coupled to environment surrounding housing, an outlet disposed at a second end of housing fluidly coupled to enclosed environment, and an interior volume divided into a first zone, a second zone, and a third zone, a first valve having a first valve seat and a first sealing member urged by an existing force between a closed or open position; and a second valve having a second valve seat and a second sealing member urged by an existing force between a closed or open position.

A valve 10, for relieving ground water pressure on a swimming pool for containing pool water. A body 30 defines a flow path. An element 20 is mounted to be moved in a direction from a position, in which at least one feature 22 of the element co-operates with at least one feature 33 of the body to form a sealing arrangement to block the flow path to retain the pool water, to a position in which the flow path is open to allow ground water into the swimming pool. The sealing arrangement defines an effective area over which the ground water pressure acts to drive the element in the direction, and an effective area over which pool water pressure acts to drive the element opposite the direction. The co-operable features are configured such that a ratio, of the effective area over which the ground water pressure acts to the effective area over which pool water pressure acts, has a value of at least 0.9.

The invention relates to a shut-off body (1) for a valve which comprises a support ring (2) and an elastic valve membrane (3) which is arranged inside the support ring and which closes the inside of the support ring, which valve membrane is essentially flat.

Valve and related assemblies, systems, and methods may include a self-cleaning feature that may be configured to at least partially displace material from a portion of the valve. Such valves may be utilized in a pressure exchanger.

A downhole flow control device includes a housing, an inlet port, an outlet port and a valve seat surface surrounding the inlet port. A valve plate is mounted within the housing to move between an open position in which the valve plate is separated from the valve seat surface to define a separation flow path therebetween to permit flow in a forward direction from the fluid inlet to the fluid outlet, and a closed position in which the valve plate is engaged with the valve seat surface to close the separation flow path to restrict flow in a reverse direction from the fluid outlet to the fluid inlet. At least one of the valve seat and valve plate defines a geometry to encourage an increase in static pressure of fluid flow in the separation flow path when the valve plate is in the open position.

A check valve including a clevis, a hinge pin, a hinge configured to be rotatably coupled to the clevis by the hinge pin, and a disc configured to be detachably coupled to the hinge. The hinge includes a first hinge member having a male interlocking feature and a second hinge member defining a female interlocking feature corresponding to the male interlocking feature. The second hinge member is configured to be detachably coupled to the first hinge member. When the first hinge member is coupled to the second hinge member, the male interlocking feature of the first hinge member is received in the female interlocking feature defined in the second hinge member to prevent angular separation of the first and second hinge members about the hinge pin. The first and second hinge members may define a non-circular opening configured to prevent rotation of the disc relative to the hinge.

Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly to allow or stop a flow for use with enclosed environment includes a housing having, an inlet disposed at a first end of the housing fluidly coupled to environment surrounding housing, an outlet disposed at a second end of housing fluidly coupled to enclosed environment, and an interior volume divided into a first zone, a second zone, and a third zone; a first valve having a first valve seat and a first sealing member urged by an existing force between a closed or open position; and a second valve having a second valve seat and a second sealing member urged by an existing force between a closed or open position.

A valve assembly for a compressor includes a flow passage defining an inlet, an outlet, and a valve seat located proximate the inlet. The valve assembly also has a valve member that includes a head portion engageable with the valve seat. The head portion has a front face, a rear face located closer to the outlet than the front face, and a side face extending between the front and rear faces. The head portion further has a first convex curvature formed between the front face and the side face. The valve member also includes a collar portion extending toward the outlet from the rear face of the head portion.