A valve device for a fuel cell arrangement in a motor vehicle includes: a housing; a flow duct extending in the housing; a shaft mounted rotatably in the housing; a flap configured to influence the flow cross section of the flow duct, wherein the flap is arranged on the shaft, and coupled to an electric motor and a gear mechanism; a valve seat arranged in the flow duct; and a seal arranged on a radially encircling edge of the flap such that the seal is in contact with the valve seat when the flap is in a closed position, and such that the shaft penetrates the flap at an angle. The shaft with the flap arranged thereon is movable by the electric motor only via the gear mechanism and movement of the flap is blocked in all other cases due to a frictional force generated by the seal.

A centric butterfly valve (1) in which top and bottom boss surfaces (19, 29) are formed to be spherical, an outer peripheral end of the blade portion of the valve disk (24) is formed to be an M-shaped section part (29) with round-shaped apex parts (27) and a round-shaped valley part (28) smoothly linked, and the centric butterfly valve has a valve disk (3) having an extended part (41) obtained by successively and slightly extending the spherical surface of each of the top and bottom boss surfaces (19, 20) to a blade portion (40) side.

A butterfly valve includes a valve element that turns with a shaft to control open/closed states of a passage or adjust an opening degree of the passage. The valve element includes a plate and an elastic member provided along an outer circumference of the plate. The elastic member has seal parts that touch and leave an inner surface of the passage to close and open the passage. The plate has specific shapes on both sides with respect to an axis of the shaft, the specific shapes narrowing gaps between the plate and the inner surface on lower-pressure sides of seal centers of the seal parts in a valve closed state.

A control damper for a housing of an air-handling unit includes a rigid main body rotatable about a first rotational axis. A sealing element extends radially outwardly from a first side of the rigid main body. The sealing element is formed of a resilient material. The sealing element further includes a resilient lip extending outwardly from a distal end thereof. The lip has a first series of undulations formed in an outer edge thereof, wherein the undulations form a wave-shaped profile in the outer edge of the lip.

A valve for an exhaust gas line of an internal combustion engine in which a closure body is arranged in a duct and is positioned in a recess of a shaft, the closure body being pivotable about a rotation axis of the shaft. The closure body has two sides and a circumferential surface arranged between the two sides. The circumferential surface has sections with different external dimensions. A first external dimension of the circumferential surface of the closure body in a first section is smaller than the smallest internal dimension between end regions of the recess of the shaft in which the closure body sits. A second external dimension of the circumferential surface in a second section is greater than the smallest internal dimension of the recess of the shaft. The circumferential surface contacts the shaft in each of the two end regions of the recess.

A centric butterfly valve (1) in which top and bottom boss surfaces (19, 29) are formed to be spherical, an outer peripheral end of the blade portion of the valve disk (24) is formed to be an M-shaped section part (29) with round-shaped apex parts (27) and a round-shaped valley part (28) smoothly linked, and the centric butterfly valve has a valve disk (3) having an extended part (41) obtained by successively and slightly extending the spherical surface of each of the top and bottom boss surfaces (19, 20) to a blade portion (40) side.

Valve assembly (10) comprises two valve portions, an upper and lower valve portion (12,24), each having a valve housing indicated generally at (16,18) which are generally annular and a valve closure member (20,20′) which is pivotally mounted within the housing. The valve closure member (20,20′) is in the form of an annular disc and is provided with spindles (22,22′) by means of which the valve closure member is pivotally mounted within the housing. The valve closure member (20,20′) and the spindles (22,22′) are machined from a single piece of metal.

A butterfly valve includes a valve body with an internal flow passage extending in a direction of a flow passage axis, a disk-shaped valve member supported in the internal flow passage rotatably about a rotation axis perpendicular to the flow passage axis and having a spherical valve seat surface in an outer peripheral portion, an annular recessed portion surrounding the internal flow passage on the side surface of the valve body in a direction of the flow passage axis, and a seat ring attached to the annular recessed portion such that a valve seat portion provided in an inner peripheral edge portion thereof projects into the inner flow passage. The valve seat portion has a triangular cross section and is formed such that a bisector of a vertex angle in the triangular cross section of valve seat portion is perpendicular to a tangential line to the valve seat surface.

Flap valves include a valve housing and a flap disc in a flow channel of the valve housing. The flap disc can be pivoted between an open position and a closed position. The flow channel on its outer circumference includes a sealing lip arrangement, which has two elastic sealing lips arranged at a distance from each other in the direction of flow. With the valve disc in the closed position, the sealing lips bear under elastic prestress against the sealing surface of the valve disc to form a seal and thereby form an annular cavity surrounding the sealing surface of the valve disc. Further, with the flap disc in the closed position, the passage of fluid from the high-pressure side in the flow channel to the low-pressure side of the flow channel prevented due to the cross-sectional areas of the two sealing lips of the sealing lip arrangement being inclined or bent towards the inside of the annular cavity.

The disclosure relates to a butterfly valve having a valve opening defined through the valve body and including a seat retainer fastened to the valve body; a disc with an optimized profile rotatably mounted within the valve opening; an interstice between the disc and valve body; a valve seat cavity defined in the seat retainer and the valve body; a fluid port defined in the valve body, wherein the fluid port is connected to the valve seat cavity and the interstice.