The present invention relates to a check valve and, more particularly, to a check valve comprising a main disk and a separate auxiliary disk, the main disk making a rapid closing operation, and the auxiliary disk, which has an area smaller than that of the main disk, making a slow closing operation, thereby reducing the velocity of a reverse flow inside a conduit, right before the disks are finally closed, and preventing a slam (a characteristic phenomenon wherein, when the disks are closed with a bang, an instantaneous increase in pressure wave raises the possibility of piping fracture and causes noise and vibration) of the disks and water hammer.

A check cover assembly for a backflow prevention (BFP) assembly including a dome-shaped base with an upstanding shroud, wherein the shroud forms an inner area configured to receive a test cock to support and protect the test cock. The shroud forms a gap for accessing the test cock to selectively open and close the test cock while installed in the inner area. The base forms a passageway from the inner area into the BFP assembly configured so that when the test cock is open, a pressure reading of a pressure zone in the BFP assembly can be taken via the test cock. A retention fork is in a slit formed in the shroud so that the test cock is captured in the inner area but the test cock can be removed from and inserted into the inner area without rotation when the retention fork is removed from the slit.

A combination water outlet device and a toilet are provided. The combination water outlet device comprises a housing, and a spray pipe. The housing is disposed with an inlet and an outlet. The outlet surrounds the spray pipe, the spray pipe comprises a pipe body, a nozzle, and a valve port. At least two water passages are disposed in the pipe body. The nozzle is disposed on a first end of the spray pipe configured to extend out of the housing, and the valve port is disposed on a second end of the spray pipe. The valve port comprises at least two first water inlet holes and at least two valve flaps. The at least two valve flaps are respectively configured to close the at least two first water inlet holes. The inlet comprises at least two water inlet passages and at least two check valves.

A respirator directional valve (10) includes a valve housing (12), a plurality of valve flaps (16-18), which can be moved by a gas stream or by a flowing medium and are arranged at the edge, and a number of support surfaces (20-22) as a valve seat. A number of support surfaces (20-22) corresponds to a number of valve flaps (16-18). Each valve flap (16-18) is adapted to a surface of a respective support surface (20-22). The support surfaces (20-22) are sloped in relation to a cross-sectional surface through the valve housing (12). The support surfaces (20-22) together form a tip pointing in the flow direction of the respirator directional valve (10). A method for manufacturing such a respirator directional valve (10) is provided including method features relating to the use of such a respirator directional valve (10).

The invention relates to a blade-type check valve for gaseous and liquid media, to be used in medical technologies as well as in waste water technology with at least three triangular blades, grouped in round configuration at the edges of a polygonal bore of a valve ring or housing, with the number of blades corresponding to the number of faces of the bore. At least at one of the three sides, the valve blades feature an integrated joint, which may also consist of fabric, whereas the two other sides of the valve blades form an articulated lock. The valve can be installed in any position and closes automatically, actuated by the backflow respectively return flow of the medium, without external energy.

Disclosed herein are embodiments of a value assembly, methods of manufacturing the same, and methods of using the same. In one embodiment, a sensor assembly comprises a housing having a through-bore, a first flap coupled to a first shaft and a second flap coupled to a second shaft, wherein the first shaft and the second shaft are coupled within the housing; and one or more gear assemblies coupled to the first shaft and the second shaft, wherein the gear assemblies are configured to rotate the first flap and the second flap from a first position to a second position to prevent a flow from traversing through the through-bore, and from the second position to the first position to allow the flow to traverse through the through-bore.

An apparatus to allow or stop an air flow into an enclosed environment or piping system comprises (a) a housing, (b) a first valve seat, (c) a first sealing member, (d) a second valve seat, (e) a second sealing member, (f) at least one locking mechanism configured to limit a movement of the first sealing member and/or the second sealing member; wherein the first sealing member moves away from the first valve seat when the second pressure is greater than the first pressure in a predetermined pressure difference; wherein the second sealing member moves away from the first valve seat when the third pressure is greater than the second pressure in a predetermined pressure difference; wherein the first pressure communicates with a system pressure in the piping system; and wherein the third pressure communicates with an ambient air pressure.

The invention relates to a blade-type check valve for gaseous and liquid media, to be used in medical technology as well as in waste water technology with at least three triangular blades, grouped in round configuration at the edges of a polygonal bore of a valve ring, with the number of blades corresponding to the number of faces of the bore, At least at one of the three sides, the valve blades feature an integrated joint, which may also consist of fabric, whereas the two other sides of the valve blades form an articulated lock, The valve can be installed in any position and closes automatically, actuated by the backflow respectively return flow of the medium, with-out external energy.

A check cover assembly for a backflow prevention (BFP) assembly including a dome-shaped base with an upstanding shroud, wherein the shroud forms an inner area configured to receive a test cock to support and protect the test cock. The shroud forms a gap for accessing the test cock to selectively open and close the test cock while installed in the inner area. The base forms a passageway from the inner area into the BFP assembly configured so that when the test cock is open, a pressure reading of a pressure zone in the BFP assembly can be taken via the test cock. A retention fork is in a slit formed in the shroud so that the test cock is captured in the inner area but the test cock can be removed from and inserted into the inner area without rotation when the retention fork is removed from the slit.

Described is a multi-stage pump having at least two stages. The multi-stage pump includes a first pump stage and a second pump stage each having a chamber of different diameter and volume. The multi-stage pump also includes a plunger having first and second plunger sections. The first plunger section has a first plunger diameter, a first end configured for coupling to a drive mechanism, and a second end opposite to the first end. The second plunger section has a second plunger diameter that is less than the first plunger diameter, a third end in contact with the second end of the first plunger, and a fourth end opposite the third end. Movement of the plunger produces a displacement volume for the first chamber that is different than a displacement volume produced for the second chamber. The multi-stage pump can be configured in different operational modes to provide different flow rates.