A ball valve positioned between a first line and a second line includes a housing and a ball disposed a ball disposed within the housing. The ball includes a bore and is configured to rotate between an open position and a closed position. The ball valve also includes an annular seat disposed between the housing and the ball. The annular seat includes a first annular sealing ring extending circumferentially about a radially-outer surface of the annular seat and an axially-extending passageway extending through the annular seat to enable fluid flow from a valve cavity to an annular space between the annular seat and the housing. The first annular sealing ring, the axially-extending passageway, and the annular space facilitate movement of the annular seat away from the ball as the ball rotates from the closed position toward the open position.

A valve apparatus, such as a downhole valve apparatus, includes a housing having a flow path therein and a valve member mounted within the housing and being operable between closed and open configurations to control flow along the flow path. An actuator assembly is moveable from a first position to a second position to sequentially perform first and second actuation functions, the first actuation function being associated with the operation of an auxiliary system, and the second actuation function opening the valve member from its closed configuration.

A valve apparatus, such as a downhole valve apparatus, includes a housing having a flow path therein and a valve member mounted within the housing and being operable between closed and open configurations to control flow along the flow path. An actuator assembly is moveable from a first position to a second position to sequentially perform first and second actuation functions, the first actuation function being associated with the operation of an auxiliary system, and the second actuation function opening the valve member from its closed configuration.

The present disclosure discloses a valve, comprising: a housing; at least one valve body disposed in the housing, and the at least one valve body being rotatable in the housing; and at least one sealing element provided between the housing and the at least one valve body, wherein the at least one sealing element is formed by integral molding. According to the present disclosure, the sealing element is molded on the valve body or the housing, thereby reducing the production cost while ensuring the leakproofness of the sealing elements.

The present disclosure discloses a valve, comprising: a housing; at least one valve body disposed in the housing, and the at least one valve body being rotatable in the housing; and at least one sealing element provided between the housing and the at least one valve body, wherein the at least one sealing element is formed by integral molding. According to the present disclosure, the sealing element is molded on the valve body or the housing, thereby reducing the production cost while ensuring the leakproofness of the sealing elements.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tube member. A seal ring, which receives a liquid pressure inside the valve housing and comes into tight contact with the joint member and the sealing tube member, is provided between the joint member and the sealing tube member. The sealing tube member has a biasing pressure receiving surface receiving the liquid pressure inside the valve housing in a direction along a direction of the valve body. The seal ring is disposed at a position where the sealing tube member is not pressurized in the direction of the valve body. An area of a valve sliding contact surface is set to be larger than an area of the biasing pressure receiving surface.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tube member. The sealing tube member has a biasing pressure receiving surface that receives a pressure of a liquid inside the valve housing and biases the sealing tube member to the valve body side. An area S1 of the biasing pressure receiving surface and an area S2 of a valve sliding contact surface of the sealing tube member are set to satisfy Expressions (1) and (2),

S1<S2S1/k (1)

k<1 (2) where k is a pressure reduction constant of a liquid flowing through a minute gap between the valve sliding contact surface and the valve body, and is a lower limit value for the pressure reduction constant determined based on physical properties of a liquid.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tube member. The sealing tube member has a biasing pressure receiving surface that receives a pressure of a liquid inside the valve housing and biases the sealing tube member to the valve body side. An area S1 of the biasing pressure receiving surface and an area S2 of a valve sliding contact surface of the sealing tube member are set to satisfy Expressions (1) and (2),

S1<S2S1/k (1)

k<1 (2) where k is a pressure reduction constant of a liquid flowing through a minute gap between the valve sliding contact surface and the valve body, and is a lower limit value for the pressure reduction constant determined based on physical properties of a liquid.

A plug valve for controlling flow through high-pressure fluid flow lines has a valve chamber and a rotatable valve body. The chamber has an undercut. First and second valve seat inserts are mounted in the chamber undercut. The valve body has a midsection, a flow port extending through the midsection, a passage extending between an upper surface and a lower surface of the midsection, an upper valve stem extending from the midsection upper surface, and a lower valve stem extending from the midsection lower surface. The upper surfaces of the valve body exposed to internal fluid pressure and lower surfaces of the valve body exposed to internal fluid pressure have substantially equal surface areas. First and second plug seal rings having substantially equal diameters are mounted, respectively around the upper valve stem and the lower valve stem.

The invention relates to a valve having an inlet and an outlet, and a closure member. The closure member comprises an inlet area with a plurality of inlet openings and an outlet area. Main flow channels extend from initial openings in the inlet area through the closure member to openings in the outlet area, said initial openings are located in an initial flow inlet area of the inlet area which is first subjected to fluid from the inlet of the valve when the closure member is rotated from a fully closed position towards an initially open position.