Abstract: A gate valve includes a valve plate located in a movable manner within a holder, a sealing for sealing off of the valve plate relative to the holder, and a wedge arrangement with several first wedge elements located on the valve plate in its direction of movement at a distance from one another, and second wedge elements belonging to the first wedge elements, by means of which the valve plate is pressed transverse to the direction of movement of the valve plate against the sealing with a movement into a closing position. In order to facilitate a low-friction actuation with a reduced actuation force, also in a compact and space-saving manner, the second wedge elements are supported on the holder, so that they can move relative to the holder.

Abstract: A vacuum valve with a valve housing with a valve opening, a closing element, and at least one peripherally closed seal on the closing element with first and second seal main sections and first and second seal connecting sections allocated to corresponding seat main sections and connecting sections. The seal extends in a groove defined by two side walls and a base wall. The first seal main section is arranged on a front end face of the closing element and has a middle part where the seal extends in a straight line. The seal is clamped by a clamping bar at least across part of the middle part, with the clamping bar fixed on the closing element and forming one of the side walls. Through at least one second sub-region of the longitudinal extent of the seal, the two side walls and base wall are formed by the closing element.

Abstract: A valve seat (10) for use in a valve incorporating a valve gate is disclosed, the valve seat comprising a valve seat body (12) and a biasing device (14) such as a spring (14), the biasing device being integral with the valve seat body. The biasing device and valve seat body may be welded together or may be formed in a single metal workpiece by a machining, casting or forging process. The valve gate and valve seat cooperate to form a metal-to-metal seal within the valve. At least a portion (15) of the valve seat is typically welded to at least a portion of the valve. A pipeline including at least one valve is also disclosed, as is a method of fitting a valve seat to a valve.

Abstract: The present invention provides more efficient, cost effective coke drum valve devices and system as well as more efficient, cost effective methods for isolating the flow of matter in a delayed coker unit operation. Specifically, embodiments of the invention relate to various seat systems used in valves for delayed coking operations.

Abstract: A gate valve capable of shearing through any downhole tooling and maintaining its seal capability after the shearing operation is complete. The gate valve has a body with a flow passage therein and a gate being linearly movable between a closed position blocking flow through the flow passage and an open position. First and second valve seats are mounted on opposite sides of the gate and have sealing surfaces that engage the gate when the gate is in the closed position. Shear elements are connected to and carried by each of the valve seats and are capable of axial movement relative to the valve seats in response to movement of the gate from the open position to the closed position.

Abstract: A parallel movement mechanism including guide grooves and guide rollers and a vertical movement mechanism including cam grooves and cam rollers are interposed between a drive rod and a valve shaft of an air cylinder, and a valve seal of a valve plate is moved vertically toward and away from a valve seat surface to open and close the opening by moving the valve shaft in parallel to the valve seat surface by the parallel movement mechanism and moving the same vertically with respect to the valve seat surface by the vertical movement mechanism.

Abstract: A three-way dual seat valve having a valve body including mutually spaced apart annular first and second valve seats. Reciprocally mounted with respect to the valve body is a valve stem which carries within the valve body an annular, dual-faced valve stem gate. Each gate face thereof is sealingly engageable with a respective valve seat in response to reciprocal movement of the valve stem.

Abstract: A three-way dual seat valve having a valve body including mutually spaced apart annular first and second valve seats. Reciprocally mounted with respect to the valve body is a dual-faced valve stem gate, wherein each gate face thereof is sealingly engageable with a respective valve seat in response to reciprocal movement of the valve stem gate effected via a leadscrew drive system.

Abstract: A gate valve has support members that are attached to a main body structure of the gate valve adjacent to the valve gate opening. These support members are affixed on both sides of the valve gate opening radially around a gate sleeve.

Abstract: A gate valve seat has structure formed on it to provide a sealing edge or lip which flexes when loaded. The lip forms a dual seal against portions of the gate valve body when the seat is placed under load.

Abstract: A backseat assembly includes: a housing that includes a bonnet and a tubular portion and forms a void and a passageway therein; a gate/segment assembly that includes a gate and a segment; a stem that moves upward or downward along with the gate while being connected to the gate; an elastic stopper that is provided in the bonnet so as to be located at a position facing the front end of the segment; a sealing surface that is formed on the bonnet; and a sealing surface that is formed on the stem and engages with the sealing surface formed on the bonnet, wherein when the gate valve is in the fully open position, a metal sheet is formed between the sealing surfaces respectively formed on the bonnet and the stem, and the segment is biased downward relative to the gate by the stopper.

Abstract: A vacuum valve including a valve opening, a valve seat surrounding the valve opening, and a valve plate. During closing starting from the open position, the valve plate is moved over a main section of the closing path in a main closing direction parallel to the valve plate and the plane of the sealing surface, and then over a final section running at an angle to the sealing surface plane for guiding the valve plate onto the valve seat. A guide element on the wall that guides the valve plate over the end section of the closing path interacts with a guide element on the valve plate. The valve plate is guided over the final section of the closing path by guide surfaces that are angled relative to the sealing surface, and at least one guide surface is arranged on a guide element of the valve plate or the wall.

Abstract: A gate valve for controlling the flow of pressurized fluid having a dynamically-energized seal between a seat ring and a valve body. The dynamically-energized seal may be located in an annular groove defined in a flange sealing face of the seat ring to seal against an annular shoulder sealing face of the valve body. A plurality of fasteners may bring the flange sealing face of the seat ring to a mechanical stop against the shoulder sealing face of the valve body and dynamically energize the dynamically-energized seal. An obturator may engage and disengage the seat ring to control flow through the gate valve.

Abstract: A gate valve has a body, the body having a cavity and a flow passage intersecting the cavity. A seat is mounted to the body at the intersection of the flow passage and the cavity. A gate is installed at the cavity and has an engaging face that slidingly engages the seat while the gate is being moved between open and closed positions. The end faces between a seat pocket and the seat are hard-coated and smooth-finished to provide sealing when mated. The hardcoated pocket and seat sealing surfaces extend the life of the valve by eliminating the need for an elastomeric seal of limited life.

Abstract: This invention relates to a novel control valve with a new gating mechanism, new flow throttling mechanisms and metal seal rings, more particularly to a trunnion control gate valve with those novel features used for on-off and flow fluid throttling under multiple extreme conditions or in sever serve; such as the engine fuel control system with highly oxidative fluid under extreme temperature, the integrated gasification combined cycle (IGCC) under high temperature and pressure, Fluid Catalytic Cracking Unit (FCCU) under high temperature over 1200 F with diamond like catalytic particles, shale fracking process under high pressure and velocity fluid with sand and corrosive additives, other critical applications for products life lasting 5 to 30 years like deepsea flow control systems and nuclear power plants or for highly critical rocket engine applications of million cycles without failure.

Abstract: Disclosed is an expanding gate valve that expands the gate assembly by engagement of symmetrical opposing inclined cam surfaces with corresponding symmetrical opposing wedges, where at least one of the wedges is driven by the stem that moves the gate assembly, and where the gate assembly is urged back toward the retracted position by at least one lateral-force-inducing member at least when the gate assembly is not in the closed position. Example compact and full body gate valve designs are disclosed. Lateral-force-inducing members may comprise one or more springs, such as a snap-ring, or may comprise cam followers running against surfaces defining the gate members' movement profile. A sealed sleeve is also disclosed that seals the interior of the valve body from pressure in the pipeline when the valve is open, while allowing the gate assembly to expand and retract laterally.

Abstract: A gate valve seat for a gate valve includes a seat having a stepped outer wall surface, with a spring, spacer ring, front facing lip seal, and a rear facing lip seal disposed about the stepped outer surface of the seat. The spring may be releasably locked into a compressed configuration for installation of the gate of the gate valve.

Abstract: A door for sealing an opening (2) in a wall (3) of a vacuum chamber (4) relative to the atmosphere includes a sealing element (1), which is attached to at least one rod (9, 9?, 9?) and which can be moved between an open position, in which the sealing element releases the opening (2), an intermediate position, in which the sealing element covers the opening (2) but is raised from a seat (7) surrounding the opening (2), and a closed position, in which the sealing element is pressed against the seat (7), a door body (10), which carries the at least one rod (9, 9?, 9?) and the sealing element (1) and which can be tilted about a tilt axis (20) relative to the wall (3) in order to move the sealing element (1) between the intermediate position and the closed position, and at least one tilting actuator (25, 25?, 26, 26?), which has an inner cavity (27) into which a compressed gas can be introduced in order to tilt the door element (10) about the tilt axis (20).

Abstract: A gate valve including a valve body having a bore there-through, a gate moveable through the bore for blocking and unblocking flow through the bore, a moveable stem coupled to the gate for moving the gate between a first position blocking flow through the bore and a second position not blocking flow through the bore, and a scraper for scraping at least a portion of an outer surface of the stem when the stem is moving for moving the gate.

Abstract: A system includes a split gate valve with first and second gate sections coupled together and configured to move together within a cavity of the split gate valve between an open position and a closed position. The split gate valve includes a rolling actuator to reduce friction and to convert a rotational input into a linear motion to move the first and second gate sections between the open and closed positions. The split gate valve also includes at least one expansion bar configured to bias the first and second gate sections from one another to seal against opposite seats of the split gate valve, wherein each expansion bar includes a spring mechanism configured to compress upon moving the first and second gate sections into and beyond the closed position to prevent buckling of the expansion bar.

Abstract: A gate valve has a body, the body having a cavity and a flow passage intersecting the cavity. A seat fabricated from a ceramic and/or hardfacing alloy matrix composite substrate is mounted to the body at the intersection of the flow passage and the cavity. A gate fabricated from a ceramic and/or hardfacing alloy matrix composite substrate is installed at the cavity and has an engaging face that slidingly engages the seat while the gate is being moved between open and closed positions. The engaging faces of the gate and seats are coated with a low-friction material to facilitate sliding. The ceramic and/or hardfacing alloy matrix composite substrate construction of the gate and seats with low friction engaging surfaces enhances the gate valve's bearing stress capacity.

Abstract: A gate valve includes a floating gate valve seat that effects a seal between a gate of a gate valve and a gate valve body using a metal seal. The gate valve includes a floating gate valve seat interposed between a gate and a gate valve body. The gate valve seat has a spring member with a cylindrical portion secured to the gave valve seat. The spring member has a leg that exerts a spring force against the gate valve body to maintain a seal between the floating gate valve seat and the gate. A metal-to-metal seal seals between the cylindrical portion of the spring member and a cylindrical portion of the gate valve seat.

Abstract: The present invention provides more efficient, cost effective coke drum isolation valve devices and system as well as more efficient, cost effective methods for isolating the flow of matter from location to another in the delayed coker unit operation where the valve comprises a first seat; a second seat aligned with said first seat; a blind; a main body having an orifice dimensioned to align with an orifice in said line; wherein said main body is coupled to said line; an upper and lower bonnet coupled to said main body, wherein said bonnets may be removed in order to replace valve parts without separating the main body from the line; and a plate located inside a bonnet, wherein the plate comprises a planar surface that contacts a surface of the blind.

Abstract: A gate valve assembly having metallic valve seats that are axially resilient and maintain a static sealing interface between the valve seat and a body pocket and a sliding dynamic sealing interface between the valve seat and a gate in the valve assembly. The valve seats are annular members having slots formed radially through the valve seats from the inner and outer circumferences. Sleeves may be provided that are coaxial to the valve seats; the sleeves may be on the inner surface of the valve seats, outer surface of the valve seats, or both. Shims may optionally be set in the slots.

Abstract: A valve assembly preferably including a housing having a recess and a flange face and a valve sleeve disposed within the recess. The sleeve preferably includes an annulus having an outer surface and an inner surface that defines a passageway about a central axis, the outer and inner surfaces being radially spaced from one another to define a wall. The wall has a first end portion and a second end portion axially spaced from the first end portion, and homogenous material properties from the first end portion to the second end portion. Preferably, the first end portion defines a lip for supporting the annulus in the recess and further defines a first chamber that encases at least a portion of a first support member. The second end portion preferably defines a flange portion along the outer surface for engaging the flange and further defines a second chamber that encases at least a portion of a second support member.

Abstract: A gate valve has a body, the body having a cavity and a flow passage intersecting the cavity. A seat ring is mounted to the body at the intersection of the flow passage and the cavity, the seat ring having an engaging face. A gate in the cavity has an engaging face that slidingly engages the face of the seat ring while being moved between open and closed positions. A friction-resistant coating is on at least one of the faces.

Abstract: A gate valve has a body, the body having a cavity and a flow passage intersecting the cavity. A seat ring is mounted to the body at the intersection of the flow passage and the cavity, the seat ring having an engaging face. A gate in the cavity has an engaging face that slidingly engages the face of the seat ring while being moved between open and closed positions. A seat sealing element is located in a cavity between seat rings and a counterbore formed in the flow passage and body of the valve. The sealing element blocks flow from the flow path to the interior of the valve. The sealing element also prevents debris from entering the counterbore-to-seat interface to improve sealing integrity. The sealing element has an axial spring property that enhances contact between the seat and gate and accounts for thermal expansion of the valve internals.

Abstract: A valve for use in connection with oil production and gas production comprising a valve housing (1) which is connected to at least one inlet (2) and an outlet (3), which together define a flow channel (16) through the valve, a valve body (9), which is set up to selectively open and close for fluid flow in the flow channel (16). A valve seat (6,7), is fitted with at least one seal against the valve housing (1), the valve seat (6) is fitted with an undercut (31) on the side of the valve seat that faces the valve body (9). The undercut (31) is in direct fluid communication with the flow channel (16).

Abstract: A gate valve for vacuum capable of preventing a seal member from being cracked or particles from being produced due to a stress concentration even if the seal member is repeatedly compressed in the state that the adhesive agent is separated from the open side of a seal member mounting groove and capable of suppressing particles from being produced due to the rub of the seal top part with the seal surface.

Abstract: A gate valve includes a plate-shaped valve element which is rectangular-shaped to suit the shape of an opening of a processing chamber and has a size larger than the opening. A hermetically sealing member to perform hermetic sealing by abutting on and being pressed against an outer side of the processing chamber is provided in the valve element. A microwave reflecting mechanism which is formed in a groove shape so as to surround a periphery of the hermetically sealing member is provided at an outer peripheral portion of the hermetically sealing member.

Abstract: A sealing microsawtooth ring joint, made between a toothed seating surface and a full plain seated surface by a microsawtooth ring with its tooth crest on the seating surface being a cutting edge whose corner or whose crest angle is about 90°˜120°, with its tooth height Zt being about 10˜20 times the roughness Ra of the seated surface, and with the ratio of its tooth pitch Xs to its tooth height Zt being 20˜500 to ensure that the tight joint has a microcosmic line contact followed by a surface contact or to ensure that the tight joint has both such a line contact as to be able to provide a necessary seating stress locally and such a surface contact as to be able to protect the line contact from being excessively pressed to get blunt or disappeared, can be used either as a pressure-tight joint or as a self-energizing tight joint of any two surfaces such as flats to flats, cones to cones or spheres, spheres to spheres or cones etc.

Abstract: The present disclosure provides a valve for controlling the flow of abrasive particles along a predetermined path from the outlet of a hopper to a conveying line in a particle collection or transportation system. The design of the valve reduces the occurrence of erosive wear resulting from contact with the flow of abrasive particles. A method of making the valve that enhances the hardness of localized areas in the valve that are subject to high wear conditions is also disclosed.

Abstract: A valve for use in the control of pressurised air from a pressure tank, the pressure tank including a wall in which an outlet port is formed, the wall having an inner surface and an outer surface. The valve comprises a valve body of generally cylindrical configuration having an inner end which in use is located inside the pressure tank and an outer end which in use is located outside of the tank. A flow passage extends through the valve body, the flow passage having an inlet at or adjacent the inner end of the body and an outlet at or adjacent the outer end of the body. A valve seat surrounds the flow passage and a valve closure member is moveable towards and away from the valve seat to close and open the valve respectively. An operating means is provided for moving the valve closure member in order to operate the valve.

Abstract: The sluice gate valve includes at least one binding reduction mechanism to reduce binding during actuation of the sluice gate. In one embodiment the mechanism includes a the guide elements and the tracks, the guide elements and the tracks being arranged such that a predetermined amount of rotational motion of the gate around the stem is permitted during actuation of the valve to reduce valve binding. In another embodiment the mechanism includes a stuffing box assembly including a stuffing box, a bushing, and a collar, where a convex curved surface of the collar slides on a concave curved surface of the bushing such that a predetermined amount of pivoting of the stem up to a predetermined cone angle is allowed. In a preferred embodiment the sluice gate valve includes both mechanisms.

Abstract: A valve assembly preferably including a housing having a recess and a flange face and a valve sleeve disposed within the recess. The sleeve preferably includes an annulus having an outer surface and an inner surface that defines a passageway about a central axis, the outer and inner surfaces being radially spaced from one another to define a wall. The wall has a first end portion and a second end portion axially spaced from the first end portion, and homogenous material properties from the first end portion to the second end portion. Preferably, the first end portion defines a lip for supporting the annulus in the recess and further defines a first chamber that encases at least a portion of a first support member. The second end portion preferably defines a flange portion along the outer surface for engaging the flange and further defines a second chamber that encases at least a portion of a second support member.

Abstract: The disclosure provides an efficient design for a pressure rated oil field gate valve that meets the challenges of providing a quality product with minimal increase in price due to the design. It minimizes weight increase in the valve body over valves not meeting strict pressure specifications, due to strengthening ribs at strategic places without having to increase the overall body size as in commonplace in the industry. It provides redundancy of seals with minimal costs and no change in seat pockets over valves not capable of meeting the higher standards. It provides multiple shear points along a valve stem that can still allow a user to operate the valve from external to the valve bonnet. It further provides for additional sealing of the valve bonnet to the valve body by using elasticity in metal over long lengths to maintain a compression seal between the bonnet and the body.

Abstract: The present invention generally comprises a floating slit valve for interfacing with a chamber. A floating slit valve moves or “floats” relative to another object such as a chamber. The slit valve may be coupled between two chambers. When a chamber coupled with the slit valve is heated, the slit valve may also be heated by conduction. As the slit valve is heated, it may thermally expand. When a vacuum is drawn in a chamber, the slit valve may deform due to vacuum deflection. By disposing a low friction material spacer between the chamber and the slit valve, the slit valve may not rub against the chamber during thermal expansion/contraction and/or vacuum deflection and thus, may not generate undesirable particle contaminants. Additionally, slots drilled through the chamber for coupling the slit valve to the chamber may be sized to accommodate thermal expansion/contraction and vacuum deflection of the slit valve.

Abstract: A shut-off instrument for a flow medium, in particular a slide valve instrument designed for pressurization on both sides with an instrument housing forming a flow channel and a slide valve chamber and with a soft-sealing shut-off element closing off the flow channel and with a slide valve stem which penetrates a seal arrangement and/or bearing arrangement in a housing neck extension delimiting the slide valve chamber and which is rotationally connected to a stem nut coupled to the shut-off element by a screw contact. The shut-off element is designed to include more than one part and at least one external dimension of the main body is slightly smaller than a nominal width of the flow channel and seal elements are arranged on opposite support surfaces of the main body via an engaged connection projecting over the external dimension with a peripheral edge collar.

Abstract: A gate valve seat for a gate valve includes a seat having a stepped outer wall surface, with a spring, spacer ring, front facing lip seal, and a rear facing lip seal disposed about the stepped outer surface of the seat. The spring may be releasably locked into a compressed configuration for installation of the gate of the gate valve.

Abstract: A method and apparatus for non-interruptible change out of a gas meter utilizing the meter set assembly swivel connections to create a bypass of the meter. The apparatus is machined to conform to the swivel and the threads of the meter inlet and outlet. A clamping mechanism maintains the meter and the apparatus in place while internal mechanisms create a gap between the swivel and the inlet or outlet of the meter. A sliding mechanism disengages the swivel gasket normally disposed between the meter inlet or outlet and the swivel for replacement during the meter exchange. Once the gap is created, a second apparatus similar to the first apparatus is attached to the other of the meter inlet or outlet. A hose providing fluid communication between the two apparatuses acts as the bypass during change out of the meter.

Abstract: A slide valve apparatus includes a first member having a first fluid channel for allowing a fluid to flow therethrough, a second member sliding along the first member and having a second fluid channel formed in a manner to communicate with the first fluid channel, and a first elastic membrane formed in the sliding surface along which the second member and the first member slide relative to each other and having a first communicating hole communicating with the first fluid channel. In manufacturing the slide valve apparatus, a gas is spurted from the open edge of the first fluid channel in at least a stage between the start up of the step of forming the elastic membrane and the end of the step of baking the elastic membrane so as to form in the elastic membrane the communicating hole communicating with the first fluid channel.

Abstract: A gate valve is disclosed for mounting in a pipeline, the gate valve comprising a valve body and a gate mounted in the valve body so as to be movable between an open position, and a closed position where a valve opening formed in the valve body is closed by the gate. The gate comprises two opposed faces spaced from the transverse plane of the gate, at least one face being provided with at least two seals that each extend around the face one seal being located within the periphery of the other such that both seals, when the gate is in the closed position, seal against a seat of the valve body to seal against the pressure of fluid acting on the gate in use. A gate is disclosed having four seals in total, two on the upstream gate face and two on the downstream gate face.

Abstract: An outfeed gate includes a fixed plate and a sliding plate, wherein bearing strips protect the fixed and sliding plates from excessive wear as they slide over each other. The outfeed gate safely accepts material from a high temperature and pressure environment to an ambient environment, and deposits the material in a material exit apparatus.

Abstract: A valve assembly preferably including a housing having a recess and a flange face and a valve sleeve disposed within the recess. The sleeve preferably includes an annulus having an outer surface and an inner surface that defines a passageway about a central axis, the outer and inner surfaces being radially spaced from one another to define a wall. The wall has a first end portion and a second end portion axially spaced from the first end portion, and homogenous material properties from the first end portion to the second end portion. Preferably, the first end portion defines a lip for supporting the annulus in the recess and further defines a first chamber that encases at least a portion of a first support member. The second end portion preferably defines a flange portion along the outer surface for engaging the flange and further defines a second chamber that encases at least a portion of a second support member.

Abstract: A knife gate valve includes a reinforced valve seat which prevents displacement of the valve seat when the valve is opened and closed. The valve includes a valve body defined by a first and second body halves. The valve halves are assembled to define a flow path, a knife gate channel and a seat channel. A knife gate is disposed between the body halves and is adapted to traverse the gate channel. The knife gate is configured to be in an open position to allow process flow through the valve and a closed position to prevent process flow through the valve. A seat assembly is positioned within the channel guide and is defined by a horizontal segment, a pair of vertical segments and a lower segment. The seat assembly is compressed between the first and second valve body halves. At least one reinforcing plate is disposed within a portion of the horizontal segment, such that the horizontal segment maintains its rigidity when the knife gate traverses the seat assembly.

Abstract: Embodiments of a valve assembly for a process chamber having improved seal performance are provided herein. In some embodiments, a valve assembly for a process chamber includes a housing having an opening disposed in a wall thereof and through which a substrate may be transferred; a door movably coupled to the housing in a plane substantially parallel to the wall of the housing for selectively sealing the opening; a compressible sealing member disposed at least partly between an upper surface of the door and a corresponding surface of the housing for forming a seal therebetween by compression of the compressible sealing member in a direction substantially perpendicular to the wall when the door is in a closed position; and a mechanism for restricting the exposure of the compressible sealing member to an environment on a process chamber side of the housing.

Abstract: A valve for use in connection with oil production and gas production comprising a valve housing (1) which is connected to at least one inlet (2) and an outlet (3), which together define a flow channel (16) through the valve, a valve body (9), which is set up to selectively open and close for fluid flow in the flow channel (16). A valve seat (6,7), is fitted with at least one seal against the valve housing (1), the valve seat (6) is fitted with an undercut (31) on the side of the valve seat that faces the valve body (9). The undercut (31) is in direct fluid communication with the flow channel (16).

Abstract: The disclosure provides a non-ported expanding gate valve and method of use, including an expanding gate assembly and a slotted guide, fixedly positioned on the valve body and slidably coupled with a gate assembly. The guide has slots of varying widths that are used with a pivoting rocker arm coupled with the gate assembly to adjust the thickness of the gate assembly at the proper timing. The guides perform multiple functions, including: centralizing a rocker arm during opening between seats; collapsing the gate assembly when opening; allowing and controlling expansion when closing; guiding lateral movement during operation of the gate assembly between opposing guides on the sides of a flow passageway; guiding axial movement during operation of the gate assembly between opposing guide side flanges; retaining seats in position when the valve is open; and/or stiffening the guide in a lateral direction to control movement of the gate assembly.

Abstract: A valve for pressurized or liquefied gas comprises a valve body (12) with a gas flow channel (16) and in this channel a sealing seat (30) for an open/close element (32) having a free end (60) where a shoulder (62) is provided. An annular seal (64) is mounted on the free end (60) of the open/close element (32), the annular seal (64) having a front end face (66) facing the sealing seat (30) and a rear end face (68) resting on the shoulder (62) of the open/close body. A holding ring (70) surrounds the annular seal (64) circumferentially and comprises a radial lip (72) that bears on the outer edge of the front end face (66) of said annular seal (64). The annular seal (64) includes an outer annular shoulder (74) on the edge of its front end face and the radial lip (72) with the holding ring (70) has an annular bead (76) facing this outer annular shoulder (74) of the annular seal (64).

Abstract: Pump, in particular a servo steering pump for motor vehicles, having a flow control valve and a valve sleeve which has inflow openings to the flow control valve and a pressure connection to a hydraulic load.