A valve assembly for an exhaust system of a vehicle. The valve assembly includes a housing, a valve flap and a mass damper. The housing defines an inlet, an outlet, and a longitudinally extending exhaust gas passageway in fluid communication with the inlet and the outlet. The valve flap is disposed in the housing and is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is less restricted. The mass damper is disposed within the exhaust gas passageway. The mass damper is attached to the valve flap and comprise of a material having a high density. The mass damper is shielded from the exhaust gas flowing through the exhaust gas passageway when the valve flap is in the second position.

A check valve includes a valve seat defining an aperture and a seating surface. A flapper is a single homogeneous component having a contact surface and a filler portion. The flapper is pivotally movable relative to the valve seat between a valve closed position in which the contact surface is sealably engaged to the seating surface thereby occluding flow through the aperture, and a valve open position in which the contact surface is a distance from the seating surface. The filler portion has a plurality of voids such that a density of the flapper is lower than if the voids were not present. A method is also disclosed.

A check valve comprises a valve housing defining a valve opening; and a flapper element. The flapper element has a proximal end, and is pivotally mounted to the valve housing adjacent the periphery of the valve opening at its proximal end for pivotal movement between a closed position, in which it blocks the flow of fluid through the valve opening and a fully open position in which it permits the flow of fluid through the valve opening. At least one spring damping element is located between the flapper element and the valve housing for providing a damping force resisting the pivotal movement of the flapper element towards its open position. The at least one spring damping element being operable to produce a damping force only over a final range of the pivotal movement of the flapper element as it approaches its fully open position.

Valve assemblies include a valve body having a fluid passage through the valve body and a valve member disposed in a chamber of the valve body. The valve assembly further includes a first seat and a second seat, where both seats are configured to contact and provide a seal between the valve body and the valve member to at least partially inhibit fluid flow through the fluid passage. Methods of providing a seal in a valve include forcing a primary seat into a seat portion of a valve body to provide a seal between a valve member and the valve body with the primary seat and deflecting at least one arm of a secondary seat to provide another seal between the valve member and the valve body with the secondary seat.

A check valve comprises a valve housing defining a valve opening and a pair of flapper elements pivotably mounted to the valve housing for rotation relative to the housing between an open position in which they permit fluid flow through the valve opening and a closed position in which they prevent fluid flow through the valve opening. Each flapper element comprises at least one bumper element arranged to engage a stop when in the open position, the bumper element comprising an elastically deformable tongue extending from an upper surface of the flapper element.

A clapper comprises a first valve body piece, a second valve body piece, wherein the second valve body piece is separate from the first valve body piece, and a seal. The first valve body piece has a seal groove. The second valve body piece has an angled edge. The seal is disposed in the seal groove of the first valve body piece. When the first and second valve body pieces are coupled together, radial compression of the seal between the seal groove and the angled edge causes the seal to be retained within the clapper.

A link couples a support body and a valve body in a first arrangement where a first link-forming member is rotationally movably supported by the support body and in which a second link-forming member is rotationally movably supported by the valve body. The link includes: a link length that is a length of the first link-forming member, as measured between a rotation axis with respect to the support body and a rotation axis with respect to the second link-forming member; and a link length that is a length of the second link-forming member, as measured between a rotation axis with respect to the valve body and a rotation axis with respect to the first link-forming member. The link lengths differ from each other. The link is also configured to enable coupling between the support body and the valve body in a second arrangement inverted with respect to the first arrangement.

A check valve comprises a valve housing defining an opening and a plurality of flapper elements each having a proximal end and a distal end. The flapper elements are pivotally mounted to the valve housing at their proximal ends for pivotal movement between a closed position, in which they block the flow of fluid through the opening and an open position in which they permit the flow of fluid through the opening. Each flapper element is generally triangular or trapezoidal in shape such that the flapper elements together create a generally conical or frustoconical surface when the valve is in the closed position. A resilient band extending around a circumference of the conical or frustoconical surface defined by the plurality of flapper elements in the closed position for biasing the flapper elements towards the closed position.

A check valve assembly for a compressor or a vacuum pump includes a valve body adapted to receive a valve plate pivoting between a first open position and a second closed position. The valve body is connected to a discharge port of a compressor unit or to the intake port of a vacuum pump. A second fluid conduit is attachable to the valve body and is connected to an external network. The assembly includes a shaft and at least one bearing for connecting the valve plate to the valve body. The valve plate includes an elongated area having a hollow tube through which the shaft is inserted for rotatably mounting the valve plate. At least one bearing is positioned on the shaft within the hollow tube.

A backflow prevention device includes a main pipe body extending along a first center longitudinal axis, at least one check valve disposed within the main pipe body, an inlet pipe connected to an inlet side of the main pipe body, and an outlet pipe connected to an outlet side of the main pipe body. The inlet pipe and the outlet pipe extend along a second center longitudinal axis. The first center longitudinal axis is offset with respect to the second center longitudinal axis in a direction perpendicular to the first and second center longitudinal axes. A center of the valve seat of the at least one check valve is offset with respect to the second center longitudinal axis in the direction perpendicular to the first and second longitudinal axes.