A pressure relief valve is disclosed with a first stage valve that is in series with a second stage valve, with an enclosed cavity between the first stage valve and the second stage valve. The first stage valve relieves pressure from an enclosure into the enclosed cavity between the stages, when the pressure is above a cracking pressure of the first stage valve. The second stage relieves pressure from the enclosed cavity when the pressure is above the cracking pressure of the second stage valve.

A damping valve having a damping valve body with at least one flow channel for damping medium. A valve rod is arranged in the flow channel. The valve rod cooperates with a valve disk and a valve seat surface. The valve rod carries a further valve disk that cooperates with a second valve seat surface. The first valve disk together with the first valve seat surface forms a first partial valve having a first permanently open pilot orifice cross section, and the second valve disk together with the second valve seat surface forms a second partial valve having a second pilot orifice cross section, and a shuttle valve is formed which opens one partial valve and closes the other partial valve depending on the flow direction.

A valve for a positive displacement pump, a valve seat, a valve body for use therewith, and a pump comprising such a valve are described. The valve comprises a valve body and a valve seat each having engagement surfaces which are configured, in use, to at least partially engage with one another when the valve is in a closed position to thereby mitigate fluid flow therethrough. The valve body is movable, in use, relative to the valve seat along a linear path of motion from the closed position to an open position, wherein at least a peripheral portion of the engagement surface of the valve body extends at an obtuse angle relative to the linear path of motion in the direction of motion from the closed position to the open position and wherein the length of the peripheral portion is at least 13% of the length of the engagement surface.

A valve for a positive displacement pump, a valve seat, a valve body for use therewith, and a pump comprising such a valve are described. The valve comprises a valve body and a valve seat each having engagement surfaces which are configured, in use, to at least partially engage with one another when the valve is in a closed position to thereby mitigate fluid flow therethrough. The valve body is movable, in use, relative to the valve seat along a linear path of motion from the closed position to an open position, wherein at least a peripheral portion of the engagement surface of the valve body extends at an obtuse angle relative to the linear path of motion in the direction of motion from the closed position to the open position and wherein the length of the peripheral portion is at least 13% of the length of the engagement surface.

A damping valve having a damping valve body with at least one flow channel for damping medium. A valve rod is arranged in the flow channel. The valve rod cooperates with a valve disk and a valve seat surface. The valve rod carries a further valve disk that cooperates with a second valve seat surface. The first valve disk together with the first valve seat surface forms a first partial valve having a first permanently open pilot orifice cross section, and the second valve disk together with the second valve seat surface forms a second partial valve having a second pilot orifice cross section, and a shuttle valve is formed which opens one partial valve and closes the other partial valve depending on the flow direction.

A system and method for controlling a flow is disclosed. The system includes an inlet channel (100, 310) and an outlet channel (200, 320). The inlet channel has an inlet port at a first end configured to be connected to a patient, and a second end with an at least part-annularly shaped aperture (314). The outlet channel has an outlet port at a first end, and an aperture (313) at a second end. The system further comprises a flow channel arranged concentrically outside the at least part-annularly shaped aperture. The flow channel is in fluid connection with the outlet channel. The at least part-annularly shaped aperture of the inlet channel and the aperture of the outlet channel are separated by a seating means (312). The at least part-annularly shaped aperture of the inlet channel and the flow channel are separated by the seating means.

A waterless trap for use in a drain assembly includes flow enhancing features to promote the vortex water flow of water received in the trap, an improved sealing arrangement to enhance the seal between a seal member and the housing to inhibit sewer gas leaks from an attached drain pipe by maintaining an evaporation barrier that assists in retaining water in a corresponding p-trap, and a plurality of air passages can allow the trap seal to open with ease when the drain pipe is pressurized. These features may be used in combination with one another or may be independently employed.

A valve assembly and system, method, and apparatus thereof can comprise a valve body having a side surface and a valve body contact surface; a ring surrounding the valve body such that an inner surface of the ring is slidably engaged with the side surface of the valve body; and a retainer at an upper surface of the ring and movable with the ring relative to the valve body such that the retainer moves with the ring as the ring slides along the side surface of the valve body.

A valve assembly and system, method, and apparatus thereof can comprise a valve body having a side surface and a valve body contact surface; a ring surrounding the valve body such that an inner surface of the ring is slidably engaged with the side surface of the valve body; and a retainer at an upper surface of the ring and movable with the ring relative to the valve body such that the retainer moves with the ring as the ring slides along the side surface of the valve body.

A check seat assembly includes a check valve seat with a by-pass passage in parallel with a check valve passage of the check seat assembly to meter flow and maintain stability of a hydraulic system, such as a hydraulic cylinder. The check valve may include an o-ring seated in a V-shaped groove. The check seat assembly may allow flow from a pump to a hydraulic cylinder to freely pass through the check valve to pressurize one side of a piston of the hydraulic cylinder, such as a front side of the piston to retract a corresponding rod connected to the piston.