A valve housing for a check valve comprises a housing body for mounting a pair of flapper elements and a pair of valve openings extending through said valve body. The valve openings are separated by a web which extends from one side of the valve body to an opposed side of the valve body. The valve body and web define sealing surfaces around the valve openings on one face of the valve housing. The web comprises a slot extending into the web from a face thereof on said one face of said valve housing and extending along a length of the web.

A valve assembly and a method of additively manufacturing the same are provided. The valve assembly includes a valve housing defining first and second mounting features, such as recessed dimples or protruding bumps, positioned on opposite sides of a substantially cylindrical channel to define a hinge axis. One or more valve flaps are positioned within the cylindrical channel, each valve flap including a hinge member extending along the hinge axis and defining two or more complementary features or coupling members for engaging either the mounting features of the valve housing or an adjacent hinge member.

The valve comprises a fluid inlet and/or outlet duct (8) comprising a flowrate regulator element (9) and a seating (10) for said fluid inlet and/or outlet duct (8), said seating (10) including a surface (10b) adapted to be attached to a portion of an internal bag (4) made of flexible material in the container (1), and is characterised in that it comprises a cover (11) to protect said seating (10) and comprising a hole for access to said fluid inlet and/or outlet duct (8); said cover (11) comprising means (13, 14) for securing a protective wrapping (5) enveloping the internal bag (4) on said seating (10). The container is characterised in that it includes at least one valve (3a, 3b) for the injection and/or extraction of fluid, and in that a portion of said internal bag (4) made of flexible material is attached to the seating (10) of the inlet duct (8) of said valve (3a, 3b) and that a portion of the protective wrapping (5) for said internal bag (4) is held against said seating (10) by the cover (11).

According to the present disclosure, there is provided a check valve comprising a valve housing defining a pair of valve openings. A pair of flapper elements are pivotably mounted to at least one hinge pin for rotation relative to the housing between an open position in which they permit fluid flow through the respective valve openings and a closed position in which they prevent fluid flow through the valve openings. The check valve also includes at least one hinge pin receiving post that extends upwardly from the valve housing, wherein the at least one hinge pin receiving post comprises a first, lower end portion having an opening for receiving said at least one hinge pin, a second, upper end portion and a flexible, serpentine portion intermediate said end portions.

A check valve comprises a valve housing defining a pair of valve openings, a pair of mounting posts arranged on opposed sides of the valve housing, a hinge pin mounted between said mounting posts, a pair of flapper elements pivotably mounted to the one or more hinge pins for rotation relative to the housing between an open position in which they permit fluid flow through the respective valve openings and a closed position in which they prevent fluid flow through the valve openings. A pair of elastically deformable leaf spring stop elements, each of which comprise respective end portions that are mounted to, and extend upwardly from, said mounting posts and a stop portion arching upwardly from, and extending between said end portions, such that each flapper element will engage a respective surface of said stop portion when in the open position.

A flapper element for a check valve comprises at least one mounting lug configured to receive a shaft for rotation relative thereto and having a row of teeth for engaging complementary teeth on a mounting lug of a similar flapper element. The complementary teeth tie the rotation of the two flapper elements.

A flapper assembly for an aspirator system includes a flapper plate and a valve assembly. The flapper plate defines a first plurality of apertures. The valve assembly includes a first valve plate disposed over the first plurality of apertures and a first pressure relief assembly arranged to move the first valve plate relative to the flapper plate.

A hose coupling for a hydrant has a ventilation device. The ventilation device has a non-return valve that is received in a receptacle incorporated into an outer flange of the hose coupling.

Provided is a duct damper comprising: a hollow housing provided inside the duct so as to enable ventilation; a blocking plate provided in the housing and opening and closing the hollow; a fastener detachably fixing the blocking plate to the housing; and shape maintaining members respectively provided on the sides of the blocking plate so as to respectively maintain half of the shape formed by the blocking plate. According to the present invention, even if both sides of the blocking plate are bent with a center bar as an axis, since the shape maintaining members half and half support the both sides of the blocking plate, respectively, so as to maintain the shape, vibrations are not generated at either side of the blocking plate, thereby preventing noise.

A stop pin for a check valve includes a first end and a second end and extending from the first end to the second end in a longitudinal direction along a longitudinal axis. The stop pin also includes at least one slot therein extending in said longitudinal direction, said at least one slot defining a respective at least one flexible, cantilevered tongue having a free end and a connected end connected to said stop pin.