A rotary valve comprising a housing with a valve chamber, wherein the valve chamber has at least one inlet and at least one outlet, wherein the inlet and/or the outlet are at least partially closable, as required, by a valve body which is rotatable about an axis and is arranged in the valve chamber, wherein, on that side of the housing facing the valve body, the inlet and/or the outlet is enclosed by a sliding seal, and wherein the sliding seal bears sealingly, under elastic preload, against that surface of the valve body facing the housing.

Provided is a three-way valve for flow rate control capable of suppressing an increase in driving torque for a valve body, which is caused due to contact between the valve body and a valve port forming member. The three-way valve for flow rate control includes: a valve main body (6) including a valve seat (8), the valve seat (8) having a columnar space and having a first valve port (9), which allows outflow of a fluid and has a rectangular cross section, and a second valve port (18), which allows outflow of a fluid and has a rectangular cross section; first and second valve port forming members (70) (80), which are fitted to the valve main body (6) and form the first valve port (9) and the second valve port (18), respectively; a valve body (34) being provided in a freely rotatable manner in the valve seat (8) of the valve main body (6) so as to simultaneously switch the first valve port (9) from a closed state to an opened state and switch the second valve port (18) from an opened state to a closed state, the valve body (34) having a cylindrical shape and having an opening; a pressure applying portion (94) (96) configured to apply pressures of the fluid leaking through a gap between the valve body (34) and the valve seat (8) to the first and second valve port forming members (70) (80) so as to suppress shift of a position of the valve body (34) when the valve body (34) opens and closes the first valve port (9) and the second valve port (18); and drive means (3) for driving the valve body (34) to rotate.

A control valve includes a casing that has a port in which an outflow opening is formed, a joint that is joined to an opening end surface of an outflow opening in the port, a rotor that is rotatably accommodated inside the casing, a slide ring that has a slide surface for sliding on an outer circumferential surface of the rotor, a sealing ring that is interposed between an inner circumferential surface of the port and an outer circumferential surface of the slide ring, and a holder that is disposed between the inner circumferential surface of the port and the outer circumferential surface of the slide ring and holds the sealing ring from an outer side in a port axial direction with respect to the sealing ring. The holder is disposed to be separated from at least any of the joint and the port.

A control valve includes a casing, a valve body, and a seal cylindrical member. The casing includes an inlet and an outlet. The valve body is rotatably disposed inside the casing and includes a circumferential wall portion in which a valve hole that allows the inside and outside to communicate is formed. The seal cylindrical member includes one end portion which communicates with a downstream side of an outlet and the other end portion on which a valve sliding contact surface is provided. In the other end portion of the seal cylindrical member, a protrusion height changes continuously in a circumferential direction along a shape of an outer circumferential surface of the circumferential wall portion. A thick portion which is thicker compared to other portions is provided in a region of the other end portion of the seal cylindrical member at which the protrusion height is high.

Apparatus and method contemplating a high pressure fluid end assembly having a body defining a body bore and defining a recess in the body intersecting the body bore. A closure is joined to the body and forms a sealing surface. A seal is mounted to the body in the recess and configured to extend from the recess beyond the body bore to seal against the sealing surface formed by the closure.

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.

Apparatus and method contemplating a high pressure fluid end assembly having a body defining a body bore and defining a recess in the body intersecting the body bore. A closure is joined to the body and forms a sealing surface. A seal is mounted to the body in the recess and configured to extend from the recess beyond the body bore to seal against the sealing surface formed by the closure.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tubular member. The joint member and the sealing tubular member are provided with first facing portions that face each other in an axial direction of the sealing tubular member and second facing portions that face each other in the axial direction while being disposed inward of the first facing portions in a radial direction of the sealing tubular member. The second facing portions are provided with an urging spring that is interposed between the joint member and the sealing tubular member and that urges the sealing tubular member toward the valve body.

An apparatus for controlling flow through a flow body comprising an intake opening and an output opening in the flow body, a cavity with a first cross-sectional shape and an opening, a diaphragm or a bellows, wherein the diaphragm or the bellows seals the opening of the cavity and the diaphragm or the bellows includes a hole, a plunger with the cross-sectional shape corresponding to the cavity, wherein the plunger is longitudinally movable within the cavity and a plunger portion forms an orifice with cavity portion, and a rod coupled with the plunger for facilitating the longitudinal movement of the plunger, wherein the rod comprises a rod cross section that corresponds to the hole in the diaphragm or the bellows.

A valve for use in oil and gas production or similar applications includes a plug or other flow barrier disposed in a cavity of a hollow valve body with a metal-to-metal sealing surface that is not reliant on any rubberized or elastomeric material to effect a seal.