Provided is a muffler valve 1 which is attached to a separator partitioning the inside of a muffler and opens and closes an exhaust passage according to the pressure of an exhaust gas of an engine. A valve body is swingably supported by a support shaft with respect to a valve seat. The valve body is urged in a closing direction by a spring member externally inserted to the support shaft. A valve seat substrate of the valve seat arranged along the separator is formed in a substantially flat-plate ring shape having an opening in the center. A valve body substrate of the valve body is formed in a flat dish shape having a flat rim. The muffler valve provides excellent handleability during attachment and can reduce the manufacturing cost of the muffler, improve manufacturing efficiency, and maintain high durability of the muffler.

A system for gas extraction is provided with a flap valve coupled to a bore with a pivot axis offset from an axis of the bore. The valve includes a higher mass on a shorter side of the pivot axis. A valve surface on the shorter side is inclined above a horizontal plane when the valve closes. The valve opens during liquid and gas flow to extract gas from the flow. As liquid flows over the valve, the valve is forced to close. The center of gravity of the valve relative to the offset pivot point ensures that the valve remains closed during liquid flow. As gas flows over the valve, closing forces are reduced and under internal vacuum, the mass distribution about the offset pivot axis allows the flap of the valve to tilt; opening the valve and allowing gas to enter the bore.

A drainage device includes a conduit extending from a bottom end toward a top end and a valve coupled to the conduit. The valve includes a first stop having an opening and an obstruction within the conduit. The obstruction, in a first configuration, may be spaced apart from the opening, enabling fluid to flow through the first stop and through the conduit. The obstruction, in a second configuration, may block the opening to prevent fluid flow through the first stop and through the conduit. The obstruction may move from the first configuration to the second configuration in response to (1) fluid pressure acting in a direction from the bottom end toward the top end of the conduit, or (2) when a fluid having a higher density than the obstruction is disposed within the valve.

A subsurface safety valve assembly that includes a valve housing comprising a valve seat with a circumference and a seat seal surface. The valve assembly also includes a flapper rotatably connected to the valve housing and comprising a flapper seal surface. The flapper is rotatable into sealing engagement with the seat seal surface in a closed position to form a circumferential surface-to-surface seal. The valve assembly also includes a dovetail groove cut into the seat seal surface or the flapper seal surface and a seal ring held within the dovetail groove and positioned to form a seal against the seal ring when the flapper is in the closed position. The seat seal surface, the flapper seal surface, the dovetail groove, and the seal ring are shaped such that the load on the seal ring is uniform around the seal ring when the flapper is in the closed position.

The present invention relates to a variable-flow-path air valve for water hammer prevention and a design method. The variable-flow-path air valve includes a valve body with a top provided with an air intake-exhaust port. A ball valve seat and a floating ball are arranged below the air intake-exhaust port. The valve body is provided with at least one swing check valve configured to be opened inward. The swing check valve includes: a swing valve disc connected to a valve body hinge, a variable-flow-path air inlet controlled by the swing valve disc to open and close, a device for limiting the opening degree of the swing valve disc, and a sealing device. In the present invention, the air valve takes in air through the air intake-exhaust port and the variable flow path, and discharges air only through the air intake-exhaust port.

A valve assembly includes a valve body that defines an internal flow passageway between an inlet and an outlet, and a valve seat disposed in the valve body with a sealing surface perpendicular to the flow passageway. The valve assembly further includes a clapper pivotally correlated to the valve seat having a closed configuration extending across the valve seat configured to substantially close off the flow passageway, and an open configuration configured to substantially allow fluid flow in the flow passageway from the inlet to the outlet through the valve body. An annular valve seat seal is disposed within an annular groove formed in a surface of the valve seat, where the annular valve seat seal is disposed at an interface between the valve seat and the clapper when the clapper is in the closed configuration.

A valve assembly includes a valve body that defines an internal flow passageway between an inlet and an outlet, and a valve seat disposed in the valve body with a sealing surface perpendicular to the flow passageway. The valve assembly further includes a clapper pivotally correlated to the valve seat having a closed configuration extending across the valve seat configured to substantially close off the flow passageway, and an open configuration configured to substantially allow fluid flow in the flow passageway from the inlet to the outlet through the valve body. An annular valve seat seal is disposed within an annular groove formed in a surface of the valve seat, where the annular valve seat seal is disposed at an interface between the valve seat and the clapper when the clapper is in the closed configuration.

One or more techniques and/or systems are disclosed for a flap valve in a diaphragm pump. The flap valve includes a body and a self-centering hinge portion. A front portion of the body includes a front surface having a raised portion and a recessed portion. The front surface is configured to form a seal with a surface of the pump when the body is in a closed position, the surface of the pump being at an inlet or an outlet of a pumping chamber. The body is configured to allow a downstream flow of a fluid when the flap valve is in an open position. The self-centering hinge portion is operably connected to the body. The self-centering hinge portion has a dynamically changing longitudinal axis. The body is configured to simultaneously translate and rotate about the dynamically changing longitudinal axis to form the seal.

A subsurface safety valve assembly that includes a valve housing comprising a valve seat with a circumference and a seat seal surface. The valve assembly also includes a flapper rotatably connected to the valve housing and comprising a flapper seal surface. The flapper is rotatable into sealing engagement with the seat seal surface in a closed position to form a circumferential surface-to-surface seal. The valve assembly also includes a dovetail groove cut into the seat seal surface or the flapper seal surface and a seal ring held within the dovetail groove and positioned to form a seal against the seal ring when the flapper is in the closed position. The seat seal surface, the flapper seal surface, the dovetail groove, and the seal ring are shaped such that the load on the seal ring is uniform around the seal ring when the flapper is in the closed position.

A check valve (1) which comprises an obturator (2) and a biasing mechanism, the biasing mechanism arranged to urge the obturator towards a closed condition, and the check valve further comprising an actuator assembly (5, 7a, 7b) which is arranged to be selectively activated to cause the obturator to be in an open condition, and the check valve comprising a controller which has a control signal input to cause the controller to selectively activate the actuator assembly.