A gate valve includes a valve body, a transmission base disposed in the valve body, and two gate plates disposed at two sides of the transmission base. The gate plates are connected together through an elastic member disposed in the transmission base. When the transmission base is located at a first position, the gate plates are received in a chamber and moved towards each other by the elastic member to open valve openings. When the transmission base is located at a second position, the valve openings are sealed by the gate plates, and an elastic positioning portion of the elastic member is abutted against a positioning plate of the valve body for providing a buffer positioning effect to the gate plates. Therefore, the gate valve of the present invention is opened and closed by using the elastic member, and has advantages of smooth movement, simple structure, and good adaptability.

A device for controlling a flow rate and expanding a fluid in a fluid circuit. The device is formed with an enclosure and a valve element arranged inside the enclosure. The valve element which is arranged movably in a linear movement in the direction of a longitudinal axis relative to the enclosure has a sealing surface and a control area formed at a first end face of the valve element and arranged adjacent to the sealing surface in the axial direction. The sealing surface is formed as a lateral surface of a straight circular cylinder with a constant outer diameter. An outer diameter of a surface of the control area corresponds to the outer diameter of the sealing surface. The control area has throughflow apertures and at least one control aperture. The valve element in the control area is formed with a substantially hollow circular cylindrical-shaped wall.

A device for controlling a flow rate and expanding a fluid in a fluid circuit. The device is formed with an enclosure and a valve element arranged inside the enclosure. The valve element which is arranged movably in a linear movement in the direction of a longitudinal axis relative to the enclosure has a sealing surface and a control area formed at a first end face of the valve element and arranged adjacent to the sealing surface in the axial direction. The sealing surface is formed as a lateral surface of a straight circular cylinder with a constant outer diameter. An outer diameter of a surface of the control area corresponds to the outer diameter of the sealing surface. The control area has throughflow apertures and at least one control aperture. The valve element in the control area is formed with a substantially hollow circular cylindrical-shaped wall.

A pipe stopper includes an expandable stopper body defining a stopper cavity and configurable in an expanded configuration and a contracted configuration; a pressure assembly comprising a pressure housing and a piston, the piston slidably engaged with a housing cavity of the pressure housing, the piston operatively connected to the expandable stopper body; and a valve stem define a stem fluid pathway, the valve stem movable between an open position and a closed position; wherein, in the open position, the stem fluid pathway is in fluid communication with the housing cavity and the expandable stopper body is movable to the expanded configuration, and in the closed configuration, the stem fluid pathway is not in fluid communication with the housing cavity and the expandable stopper body is movable to the contracted configuration.

A pipe stopper includes an expandable stopper body defining a stopper cavity and configurable in an expanded configuration and a contracted configuration; a pressure assembly comprising a pressure housing and a piston, the piston slidably engaged with a housing cavity of the pressure housing, the piston operatively connected to the expandable stopper body; and a valve stem define a stem fluid pathway, the valve stem movable between an open position and a closed position; wherein, in the open position, the stem fluid pathway is in fluid communication with the housing cavity and the expandable stopper body is movable to the expanded configuration, and in the closed configuration, the stem fluid pathway is not in fluid communication with the housing cavity and the expandable stopper body is movable to the contracted configuration.

A sealing ring made of an elastomer material is fitted on the front side of an essentially rectangular valve plate for sealing a vacuum valve opening. On the rear side, the valve plate has a recess with an undercut boundary wall which forms a sloping surface which, for fastening the valve plate on a carrier, is braced with a sloping surface of the carrier. The valve plate has a lug which protrudes beyond the rear side thereof and has a through-passage bore through which a clamping screw is screwable into a threaded bore of the carrier, for bracing the valve plate sloping surface with the carrier sloping surface. In a side view of the valve plate, seen parallel to the longitudinal sides, the straight-line extension of the longitudinal center axis of the through-passage bore runs past the sloping surface at a distance from the rear side of the valve plate.

A sealing ring made of an elastomer material is fitted on the front side of an essentially rectangular valve plate for sealing a vacuum valve opening. On the rear side, the valve plate has a recess with an undercut boundary wall which forms a sloping surface which, for fastening the valve plate on a carrier, is braced with a sloping surface of the carrier. The valve plate has a lug which protrudes beyond the rear side thereof and has a through-passage bore through which a clamping screw is screwable into a threaded bore of the carrier, for bracing the valve plate sloping surface with the carrier sloping surface. In a side view of the valve plate, seen parallel to the longitudinal sides, the straight-line extension of the longitudinal center axis of the through-passage bore runs past the sloping surface at a distance from the rear side of the valve plate.

A proportioning valve for a reverse osmosis system that controls the production of product water by the differential pressure across the purification membrane. By sensing increasing tank pressure to actuate the proportioning valve, the flow of waste water is restricted. Placement of seals within the cavity of the valve, as well as placement of waste water inlet and outlet ports, protects tension components that provide reverse tank pressure from waste water exposure. A needle valve assembly responsive to an actuating assembly that senses tank pressure removes the need for an inlet tank water port while restricting water flow.

A proportioning valve for a reverse osmosis system that controls the production of product water by the differential pressure across the purification membrane. By sensing increasing tank pressure to actuate the proportioning valve, the flow of waste water is restricted. Placement of seals within the cavity of the valve, as well as placement of waste water inlet and outlet ports, protects tension components that provide reverse tank pressure from waste water exposure. A needle valve assembly responsive to an actuating assembly that senses tank pressure removes the need for an inlet tank water port while restricting water flow.

In embodiments, a gate valve includes a valve body including a flow passage from a first opening to a second opening, and a gate channel having a first end intersecting the flow passage and a second end delineated by a third opening. A valve cover fits over the third opening. A cap fits over a valve cover opening. In embodiments, a valve cover includes a body with a second sealing surface protruding from a first sealing surface, both around an opening of the body. A cap has a third sealing surface to mate with the first sealing surface, and a fourth sealing surface congruent to the second sealing surface. In embodiments, a valve cover cap includes a body with a first sealing surface on an end of a wall. Pin flanges each have a pin hole having a pin hole axis oriented perpendicular to a center axis of the wall.