A malodor reflux blocking unit using the cardiac valve principle, includes a space providing portion inserted into the drain pipe through the drain hole and configured to provide a drain space for the drainage, blocking portions which are, in a non-draining state, disposed to face each other and configured to block communication between the drain pipe and the drain space due to a water film phenomenon which occurs due to drainage water being present between the blocking portions, and intermediate portions configured to mediate connection between the blocking portions and the space providing portion.

A check valve (10) for controlling a flow of fluid by fluid pressure, comprising a housing (11) and a resilient flexible valve element (12) inside the housing (11), wherein the valve element (12) is formed as a hollow and longitudinally tapered body (16) with an open wide end (18) and a closed narrow end (19), and wherein the wide end (18) of the valve element (12), in a default configuration, engages an inner surface of the housing (11) to close the check valve (10) and is deformable by a predetermined fluid pressure from the inlet (13) to open the check valve (10). The tapered body (16) comprises a radially outwardly projecting flange (17) at the wide end (18), which flange comprises a curved outer surface portion (20) having a degree of curvature of 85 to 95 degrees, wherein the housing (11) is formed with a protrusion (29) having a curved surface (30) for engaging the curved outer surface portion (20) of the flange (17).

A check valve (10) for controlling a flow of fluid by fluid pressure, comprising a housing (11) and a resilient flexible valve element (12) inside the housing (11), wherein the valve element (12) is formed as a hollow and longitudinally tapered body (16) with an open wide end (18) and a closed narrow end (19), and wherein the wide end (18) of the valve element (12), in a default configuration, engages an inner surface of the housing (11) to close the check valve (10) and is deformable by a predetermined fluid pressure from the inlet (13) to open the check valve (10). The tapered body (16) comprises a radially outwardly projecting flange (17) at the wide end (18), which flange comprises a curved outer surface portion (20) having a degree of curvature of 85 to 95 degrees, wherein the housing (11) is formed with a protrusion (29) having a curved surface (30) for engaging the curved outer surface portion (20) of the flange (17).

A valve device includes: a hollow member having a through-hole with an axis, an internal surface delimiting the through-hole, a peripheral surface delimiting the hollow member's transverse extent with respect to the axis, and at least one deformation zone deformable to reduce the transverse extent when compression forces act on the peripheral surface, the deformation of the deformation zone moving the hollow member from a rest to a use state, and at least one closure portion extending radially from the hollow member inside the through-hole up to a respective free edge, in contact with the internal surface of the hollow member and/or with at least one free edge of another closure portion occluding the through-hole when in use. The at least one closure portion includes a flexible membrane, foldable when subjected to a fluid and/or solid pressure which moves in the through-hole along the axis, thereby defining a passage.

A valve device includes: a hollow member having a through-hole with an axis, an internal surface delimiting the through-hole, a peripheral surface delimiting the hollow member's transverse extent with respect to the axis, and at least one deformation zone deformable to reduce the transverse extent when compression forces act on the peripheral surface, the deformation of the deformation zone moving the hollow member from a rest to a use state, and at least one closure portion extending radially from the hollow member inside the through-hole up to a respective free edge, in contact with the internal surface of the hollow member and/or with at least one free edge of another closure portion occluding the through-hole when in use. The at least one closure portion includes a flexible membrane, foldable when subjected to a fluid and/or solid pressure which moves in the through-hole along the axis, thereby defining a passage.

A check valve includes a plate-shaped valve seat member provided with a fluid discharge port, a plate-shaped valve member provided on a downstream side of the valve seat member and configured to open/close the discharge port, a coil spring provided on a downstream side of the valve member and configured to bias the valve member toward the discharge port, a spring receiving member provided for the coil spring on a downstream side thereof, and a plurality of guide rods provided at the periphery of the valve member and formed to extend in an upstream-to-downstream flow direction, each having a downstream end portion attached to the spring receiving member, and configured to guide the valve member in the upstream-to-downstream flow direction.

The present invention provides a one-way drain valve comprising a fitting and a duckbill valve, wherein the fitting comprises one or more formations that prevent inward folding of the duckbill membrane upon reverse flow conditions without constituting an obstruction to the normal drain flow where entrained solids could forth a plug and thus, prevent adequate drainage. The formations extend parallel to or ergent from a fitting longitudinal axis. The fitting may comprise a recess or other suitable feature adapted to facilitate engagement with the duckbill valve.

The present invention provides a one-way drain valve comprising a fitting and a duckbill valve, wherein the fitting comprises one or more formations that prevent inward folding of the duckbill membrane upon reverse flow conditions without constituting an obstruction to the normal drain flow where entrained solids could forth a plug and thus, prevent adequate drainage. The formations extend parallel to or ergent from a fitting longitudinal axis. The fitting may comprise a recess or other suitable feature adapted to facilitate engagement with the duckbill valve.

Disclosed herein is a trap assembly for draining waste water toward sewer pipes while blocking back flow of odors. In a preferred embodiment the trap assembly comprises of a housing having a hollow interior, open, upper and lower ends. The housing is connected to a drain pipe at the lower end and extending outwardly therefrom into a substantially vertical orientation, a valve member formed of buoyant material; a retainer assembly connected to said housing in an at least partially supporting relation to a valve member. Further the valve member disposable into and out of sealing engagement with the valve seat dependent on direction of liquid flow along a flow path.

Disclosed herein is a trap assembly for draining waste water toward sewer pipes while blocking back flow of odors. In a preferred embodiment the trap assembly comprises of a housing having a hollow interior, open, upper and lower ends. The housing is connected to a drain pipe at the lower end and extending outwardly therefrom into a substantially vertical orientation, a valve member formed of buoyant material; a retainer assembly connected to said housing in an at least partially supporting relation to a valve member. Further the valve member disposable into and out of sealing engagement with the valve seat dependent on direction of liquid flow along a flow path.