Abstract: The present invention provides a method for replacing seals in recreational vehicles gate valves without removing valve housing from plumbing. The method for replacing blade seals in a gate valve features coupling a valve housing of the gate valve to suitable plumbing, the valve housing having a removable blade seal cartridge slidably arranged and latched therein in order to receive a movable blade of a drive unit of the valve gate to control the flow of the medium through the valve gate and to prevent the medium from entering the drive unit; and unlatching the removable blade seal cartridge from the valve housing so as to enable replacement of the blade seal cartridge without having to remove the valve housing from the suitable plumbing.

Abstract: A double-disk slide valve (10), the shut-off plates (16, 17) of which are displaceable by means of an actuator rod (21) and which is provided with a bridging pipe (22) having two sealing rings (23, 24) that are in operative engagement with corresponding housing sealing seats (14, 15) of the slide valve housing (11) when the slide valve is in the open position. At least one of the two housing sealing seats (14, 15) rests, by the action of a resilient element (25), under predetermined pressure against the sealing ring(s) (23, 24) associated with the bridging pipe (22) when the slide valve is in the open position and against the peripheral edge of the shut-off plate(s) (16, 17) when the slide valve is in the closed position.

Abstract: The present invention provides a gate valve for controlling the flow of a medium through suitable plumbing, featuring a valve housing for coupling the gate valve to the suitable plumbing; a detachable drive unit having a movable blade arranged therein; detachable blade seals for slidably arranging in the valve housing in order to receive the movable blade to control the flow of the medium through the gate valve and to prevent the medium from entering the drive unit; and a latching mechanism for detachably coupling both the drive unit and blade seals to and from the valve housing so as to replace either the drive unit, the blade seals, or both, without having to remove the gate valve from the suitable plumbing.

Abstract: A valve assembly comprising a valve body defining a fluid passage with a seat member positioned adjacent the fluid passage. A gate, having a leading edge, is supported in the valve body and is moveable relative to the fluid passage along a given axis between an open position and a closed positioned wherein the gate sealingly engages the seat member. The seat member includes a portion whose tangent is perpendicular to the given axis. At least a portion of the gate leading edge that is laterally aligned with the portion of the seat member whose tangent is perpendicular to the given axis may extend at an obtuse angle relative to the given axis. The gate leading edge may be configured such that any portion of the leading edge contacting a respective portion of the seat member is non-parallel to a tangent of that portion of the seat member.

Abstract: A valve comprises a housing, an annular housing seat, and a gate. The housing comprises a fluid inlet and a fluid outlet. The housing seat is fixed in position relative to the housing via epoxy. The gate comprises a gate seat and a fluid passageway that extends through the gate. The gate is movable relative to the housing between an open position and a closed position. The gate is also configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, and configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position.

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: A gate valve comprising a first part (10), a second part (12), and inlet/outlet parts (14), wherein the first and second parts define a cavity in the body and where a wedge (18) is movable in said body. The gate valve comprises guiding objects (22; 22?) on generally opposite sides of the wedge for guiding said wedge movement, where a major part of each guiding object is accommodated in the first part, and a portion of the guiding object extends into a region of the cavity defined by the second part, thus essentially overlapping an area of said part. The guiding objects may be releasably mounted or be integral with the valve housing upper part.

Abstract: A Pendulum Valve having Independently and Rapidly Controllable Theta- and Z-axis Motion. The valve actuator used in the present invention provides the benefit of wide open unrestricted flow of a pendulum valve coupled with the high-resolution and wide dynamic range flow throttling of a ball or butterfly valve. The actuator mechanism will include motor drives and associated control system so that the drives are closely coupled to give highly controlled motion. The drive assembly introduces a concentric shaft arrangement that, when coupled with the highly controllable motor drives, exploits a cam-follower arrangement to make the relative rotation between the two concentric shafts result in highly controlled theta and z-axis motion. Finally, the plate to seal spacing afforded is greater than previously possible with prior valve actuator mechanisms, thereby substantially reducing flow turbulence through the valve as the valve plate eclipses the valve ports.

Abstract: The present invention relates to an improved vacuum gate valve for a corrosion prevention. The corrosion prevention vacuum gate valve comprises a second actuator which includes a hollow first body which has a second compression air inlet for moving up the corrosion prevention sealing member and a hollow second body which has a third compression air inlet moving down the corrosion prevention sealing member and at least one flow control groove which is provided at the upper side for moving the fluid from the chamber to the vacuum pump.

Abstract: The present invention provides a thin film spacer for maintaining a gap between a slit valve door and a sealing surface of a slit valve, such as a metallic insert. The film spacer can extend the life of a seal by limiting the line of sight exposure of the seal to corrosive gases within a wafer processing chamber, for example, and by controlling the compression percentage of the seal. The spacer may be located on an outer ambient side of the slit valve away from any corrosive gasses that may exist in the chamber.

Abstract: Methods and apparatus to align a seat ring in a valve are described. An example fluid valve includes a valve body having a curved internal surface to receive a seat ring and a seat ring having a sealing surface to receive a movable control member and a curved surface opposite the sealing surface to engage the curved internal surface of the valve body.

Abstract: A fail-safe shutter (13) for a “cross-stack” monitor, comprises a body member (14) having an aperture (1) through which, in use, an associated monitoring instrument is adapted to sight. A gate (3) is movable between a retracted, open position in which the aperture (1) is exposed, and a closed position in which the aperture (1) is closed-off by a portion of the gate (3), and means are provided to bias the gate (3) towards its closed position.

Abstract: An improved method and apparatus for a valve assembly features a valve body, a first seat ring mounted in the valve body, a second seat ring mounted in the valve body, and a retractable blade gate slideable in between the first seat ring and the second seat ring. The gate is moveable between open and closed position. A first elastomeric ring is disposed in between the valve body and the first seal ring and projecting towards the gate blade. A second elastomeric ring is disposed in between the second seat ring and the valve body and projecting towards the gate blade.

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-of 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 vacuum chamber having a gate valve including a chamber housing defining an internal vacuum region and first and second openings through the chamber housing and a gate valve secured to the chamber housing. The gate valve includes a sealing door located in the processing region and configured to seal the first opening in the chamber housing; a vertical actuator located outside the chamber housing; a one-sided horizontal actuator located within the processing region and connected to the sealing door; and a valve shaft extending through the second opening in the chamber housing and connecting the vertical actuator to the one-sided horizontal actuator.

Abstract: A knife gate valve comprising a two-piece valve body, a knife gate, an elastomeric transverse seal, an elastomeric perimeter seal, and a pair of elastomer liners. Each elastomer liner is positioned between the knife gate and one of the mating valve body halves and defines a chamber for receiving the perimeter seal. Each liner has a port that corresponds to the flow channel, a sealing portion that extends into a sealing chamber to cooperate with the transverse seal, and an orifice liner extension that lines the orifice of the corresponding valve body half. O-rings, preferably of a softer material than the elastomer liner, may be positioned on the outer rim of the orifice liner extensions for creating a seal among the elastomer liner, the corresponding valve body half, and a corresponding mating flange of a fluid handling system.

Abstract: A valve seat has an outer surface, a rearward end, a face and a forward end. A passage extends from the rearward end to the face. A valve element slidingly contacts the face. Stress relief flanges are located on the face in areas of high bearing stress. Each flange has a thickness that allows it to deflect slightly to reduce bearing stresses.

Abstract: A gate valve for controlling fluid flow, in which a valve body forms a cylindrical flowbore and includes a gate cavity intersecting the flowbore to provide opposed openings into the flowbore. Seat pockets are formed in the opposed openings, each with a radial base and a side wall, and may optionally include metal carrier ring sealed in the seat pockets. The gate is slidably movable within the valve body between open and closed positions. Annular seat elements are mounted in each seat pocket for limited axial movement on opposite sides of the gate, with a first seal surface for sealing against the seat pocket or optional carrier ring, and a second seal surface for sealing against the gate. A non-metallic bridging seal formed as a face seal is provided between the first seal surface of the annular seat element and the seat pocket (or optional carrier ring).

Abstract: A valve assembly for insertion in a pipe containing fluid under pressure includes a valve body adapted to be assembled over the pipe and a valve-stopping mechanism that mounts on the valve body. The hollow valve body interior and an access opening in the valve body are sufficiently large to receive a hole saw element no smaller than the outside diameter of the pipe as installers advance the hole saw element radially through the access opening to form a gap in the pipe. The valve-stopping mechanism includes a gate with a cross sectional area greater than the pipe that mates with the valve body interior so that the gate can be advanced radially through the gap in the pipe into direct fluid-tight contact of the valve body in order to thereby stop the flow of fluid through the pipe.

Abstract: A gate valve having a polymeric monolithic liner, the liner having cylindrical flange portions projecting from either side to form a fluid passageway through the liner, first and second housing portions forming a liner cavity, the liner being disposed in the liner cavity, a first face ring having a first cylindrical tubular portion and a first radially outwardly projecting, annularly extending face ring flange, the first tubular portion being received in the first annular flange portion of the liner, a second face ring having a second cylindrical tubular portion and a second radially outwardly projecting, annularly extending face ring flange, the second tubular portion being received in the second annular flange portion and a gate valve element slidably received in a valve element cavity formed in the liner.

Abstract: A gate seal for a knife gate valve comprising a sealing surface lining the gate channel and an integral gasket for compression between valve body halves, a chest seal for a knife gate valve comprising a body having an expandable sealing surface and one or more injection chambers adapted to receive an injectable packing, each chamber having a cross-sectional area that is completely surrounded by the body member, and/or a knife gate valve comprising one or both such seals. The chest seal body may comprise a knife gate slot that is peripherally surrounded by the body. The gate seal and the chest seal may comprise a single integral elastomeric member or separate components.

Abstract: A vacuum valve comprises a valve housing with a valve opening having a longitudinal axis and a valve seat, a valve plate which is displaceable in a straight line in a displacement direction between an open position in which it releases the valve opening and a closed position in which its contacts the valve seat of the valve housing and closes and seals the valve opening, this valve plate being arranged on at least one valve rod which is displaceable axial to the displacement of the valve plate, a flexible sealing ring which is arranged at a front side of the valve plate or at the valve seat of the valve housing, a sealing surface which is arranged at the valve seat of the valve housing or at the front side of the valve plate and which is contacted by the sealing ring in the closed position of the valve plate, wherein the sealing surface and the sealing ring are arranged in parallel planes which are inclined relative to the displacement direction of the valve plate around an axis extending at right angles to t

Abstract: A shutoff device for shutting off liquids or gases comprises a device housing (10) and a device (13) movable in said housing (10), the device (13) being provided with an opening (14). For sealing purposes, annular sealing bodies (28) are provided which are supported in annular fluid cylinders (27). The contact surfaces (34) are coated with a hard-material layer (37,39) which is subjected to microfinishing. The sealing bodies (28) are yieldingly supported such that they are capable of following any deformation or displacement of the device (13). The sealing is particularly suitable for aggressive and abrasive media and solids-carrying media.

Abstract: A gate valve has seat rings pressed into counterbores to form seals. Each counterbore is located at an intersection of a flow passage with a central cavity of a body of the gate valve. The counterbore has a cylindrical constant diameter sidewall. The seat ring has an outer end that forms a pilot section and is of smaller outer diameter than the inner diameter of the counterbore. The seat ring also has an outer portion that is of equal or larger diameter than the inner portion, defining an interference section. The interference section creates an interference fit with the counterbore, forming a seal.

Abstract: A gate valve comprises a valve body, a stem bore which extends through the valve body, a stem which is disposed in the stem bore and which includes a first stem portion that is sealed to the stem bore, a second, smaller diameter stem portion that is sealed to the stem bore, and a gate pocket that is located between the first and second stem portions, and gate which is disposed within the gate pocket between the first and second seats.

Abstract: A gate valve assembly includes a valve seat and a valve. The valve seat includes a passage opening and a contacting region surrounding the passage opening. The valve includes a groove located on a marginal region of the valve, and a sealing body positioned in the groove. The passage opening is closed by covering the valve over the valve seat, and an upper surface of the sealing body is tightly contacted with the contacting region. Therefore, the valve is prevented from rubbing against the valve seat and producing particles.

Abstract: A sealing member includes a gland packing pressed into a wide, flat, ring-shaped seal housing to seal a sliding portion of a gate plate. The seal housing has a bamboo shoot-like shape or a bevel-like shape structure in front and cross sectional view and includes wide ring-shaped or oval shaped steps and a rear step. An inner wall of the seal housing has an included face that abruptly rises to be oriented almost perpendicular to the axis of the gate plate, in the sliding direction, a ring-shaped face that is extended from the included face to be oriented almost parallel to the axis, the step that is extended from the ring-shaped face, a ring-shaped face that is similar to the ring-shaped face and is extended from the step, the step that is extended from the ring-shaped face, a ring-shaped face that is similar to the ring-shaped face and is extended from the step, and an opening end that is extended from the ring-shaped face.

Abstract: A knife gate valve is provided, comprising: a unitary valve body having a flow channel extending there through, a guide segment and a stuffing box. A knife gate is located in the guide segment, the stuffing box and the flow channel and is slideable between an open and closed position. Lateral seals are provided in the stuffing box and can be replaced while the valve body is connected in its associated fluid system. These seals include an injectable sealing material contained in the stuffing box. A knife gate seat is provided in the valve body for sealing the knife gate and it can be replaced without completely removing the valve body from its associated fluid system.

Abstract: A valve assembly for insertion in a line formed by an existing pipe of predetermined outside diameter containing fluid under pressure includes a valve body with a bonnet-supporting flange that defines an access way into the valve body through which an installer can cut and remove a section of the existing pipe. A bonnet with a moveable gate having a width no less than the predetermined outside diameter of the pipe, includes a flange-mating portion that fits into the access way in a fluid-tight fit while defining a gate opening through which the gate moves into the valve body to a closed position in which the gate extends through the gate-receiving gap in the pipe and into fluid-tight engagement of the valve body.

Abstract: A valve seal structure enabling the replacement of a metal seal ring, comprising a main body, a metal seat ring prepared separately from the main body to seal a flow channel of the main body, a set ring assembling the metal ring seat to the main body at the periphery of the flow channel in a detachable manner, a first elastomeric ring sheet to seal the boundary between the metal seal ring and the main body and a second ring sheet to seal the boundary between the metal seat ring and the set ring.

Abstract: Flexible, plastic, solids-containing liners or panels are disposed in the chamber of the valve body for contacting, interfacing engagement with the gate. Accordingly, the panels and gate substantially fully occupy the chamber, and prevent an entry of slurry solids thereinto. The panels are rubber-backed to insure that the panels are pressed, sealingly, against the flat faces of the gate, and are arranged in parallel with the chamber walls.

Abstract: A gas meter installation including gas supply plumbing and point of use plumbing will have a gas meter therebetween. A valve can be installed with the gas meter for shutting off the flow of gas to the point of use. This valve is preferably a gate valve mounted with the a gas meter, and can be retrofitted into existing installations, or installed with the new plumbing installation. The valve can be shut off by remote activation for example due to a seismic sensor causing a controller to send a signal to activate the valve. The control can also interact with electricity shut off apparatus, automatic meter reading apparatus and point of use security systems.

Abstract: A vacuum valve comprises a valve body with a valve opening having an axis a closing member which is displaceable between an open position of the valve and a closed position of the valve in a closing direction extending at an angle to the axis of the valve opening, a sealing surface which surrounds the valve opening and which has at least two main portions which are arranged so as to be offset relative to one another in the direction of the axis of the valve opening, are connected with one another by connection portions, and whose imaginary generating lines have at least a portion or a tangent extending substantially vertical to the closing direction, a circumferentially closed seal which is arranged at the closing member and which has two main portions corresponding to the main portions of the sealing surface and connection portions which connect the two main portions, which seal can be placed against the sealing surface by of a displacement of the closing member in the closed position of the valve, wherein a

Abstract: A valve arrangement includes a valve housing that defines a product passageway and a valve seat within the product passageway. A valve wedge is disposed within the housing passageway, and moves along a direction of operation between a closed position and an open position. A pair of opposed wings are carried on the valve wedge, adjacent a guide track. Rollers are carried on the wings for rolling engagement with the tracks and scraper blades are carried on the wings adjacent the rollers to scrape contamination from tracks.

Abstract: A vacuum valve comprises a wall with a valve opening and a valve seat, a valve plate which is pressed against the valve seat in the closed state, an elastic sealing ring which is arranged at the valve plate or at the valve seat and, in the closed state of the valve, is pressed by a pressing force against a sealing surface arranged at the valve seat or at the valve plate and seals the valve opening, and a supporting ring which is made of plastic and which is arranged at the valve plate or at the valve seat and, at least in the closed state of the vacuum valve, lies closer to the valve opening than the sealing ring, viewed from the sealing ring, and limits the pressing force acting on the sealing ring in the closed state of the vacuum valve.

Abstract: The present invention is directed to a compact and modular gate valve comprising an elongated body which comprises first and second ends, a hole which extends longitudinally between the first and second ends, a first opening which communicates with the hole proximate the first end, a second opening which communicates with the hole proximate the second end, and a bore which extends transversely through the body and intersects the hole; a first seat which is mounted in a first intersection of the bore with the hole and a second seat which is mounted in a second intersection of the bore with the hole, the first and second seats each including a passageway that aligns with the bore; a valve stem which is slidably positioned in the hole and which includes first and second piston portions that are separated by a gate portion, the stem being movable between an open position in which a hole in the gate portion is aligned with the passageways and a closed position in which the hole is offset from the passageways; and

Abstract: A vacuum valve comprises a valve body (1) with a valve opening (3) having an axis (4); a closing member (2) which is displaceable between an open position of the valve and a closed position of the valve in a closing direction (5) extending at an angle to the axis of the valve opening (3); a sealing surface (7) which surrounds the valve opening (3) and which has at least two main portions (8) which are arranged so as to be offset relative to one another in direction of the axis (4) of the valve opening (3), are connected with one another by connection portions (9), and whose imaginary generating lines (10) have at least a portion or a tangent (22) extending substantially vertical to the closing direction (5); a circumferentially closed seal (12) which is arranged at the closing member (5) and which has two main portions (13) corresponding to the main portions (8) of the sealing surface (7) and connection portions (14) which connect these two main portions (13), which seal (12) can be placed against the sealing

Abstract: A sealing member 9 includes a gland packing 92 pressed into a wide, flat, ring-shaped seal housing 91 to seal a sliding portion of a gate plate 2. The seal housing 91 has a bamboo shoot-like shape or a bevel-like shape structure in front and cross sectional view and includes wide ring-shaped (oval shaped) steps 90 (90a and 90b) and a rear step 93a. An inner wall of the seal housing 91 has an inclined face 95 that abruptly rises to be oriented almost perpendicular to the axis of the gate plate 2 (the sliding direction), a ring-shaped face 96 that is extended from the inclined face 95 to be oriented almost parallel to the axis, the step 90a that is extended from the ring-shaped face 96, a ring-shaped face 97 that is similar to the ring-shaped face 96 and is extended from the step 90a, the step 90b that is extended from the ring-shaped face 97, a ring-shaped face 98 that is similar to the ring-shaped face 97 and is extended from the step 90b, and an opening end that is extended from the ring-shaped face 98.

Abstract: The invention is directed to a gate valve assembly which comprises an elongated body having a longitudinal bore extending therethrough; a plurality of gates slidably disposed in the longitudinal bore across respective flow passages which each extend laterally through the body between corresponding inlet and outlet ports; each gate being movable between an open position wherein an opening in the gate is aligned with its respective flow passage and a closed position wherein the opening is offset from its respective flow passage; and an actuator for moving the gates simultaneously between a first position, wherein at least one of the gates is in its open position, and a second position, wherein the at least one gate is in its closed position.

Abstract: A packing system for a gate valve is disclosed which includes a sealing member structured to be positioned between a compression member and packing material housed in a cavity formed in the upper edge of a valve housing to provide even and consistent pressure of the packing material against the gate of the valve, thereby preventing leakage from about the gate of the valve. The packing may also include a gasket between the compression member and sealing member to provide additional sealing assurance.

Abstract: A gate valve unit is provided for controlling the flow of a fluid through a conduit. The gate valve unit includes a valve body including a conduit connector member or flange. A valve face block affixed to the valve body includes first and second backwardly sloped surfaces. A pair of movable gate leaves are disposed on the first and second surfaces of the face block and are movable away from and toward a central passage through the unit for controlling fluid flow through the unit. A face seal provides a seal between the surfaces of the face block and the gate leaves. A visor seal is attached to the valve body which is movable between an operative position in which the visor seal provides sealing between the gate leaves, and an inoperable position away from the gate leaves so as to not interfere with the operation of the gate leaves.

Abstract: A hermetic-seal valve for a thermal-regeneration plant for depuration of emissions, where the valve is set in a duct (13) which connects an inlet pipe (28) for entry of an emission that is to be treated or an outlet pipe (29) for exit of an emission that has been treated, and a treatment chamber (22), said valve comprising an obturator seating (14), an obturator (16) having the shape of a truncated cone for opening and closing the seating (14), and means (18) for actuating the obturator (16) via an interposed stem (20), in the said valve the seating (14) consisting of a ring (30), one internal top end of which has a circumferential undercut (50) shaped like a truncated cone and provided with a series of radial holes (54) connected to an external fan or to the outside environment (56, 57), the undercut (50) being provided with a first edge (52), which has a diameter equal to the diameter of the obturator seating (14) and a second edge (53), located above the first edge and of larger diameter, where both edges

Abstract: The invention relates to an existing pipe cut-off method and slitting method, by which an existing pipe made of cast iron and steel can be cut off. With a cut-off method according to the invention, first, a part of an existing pipe 1 is enclosed and sealed up by a seal-up housing 2 in an airtight state, a cutting tool 30 having a plurality of blades 30c is accommodated in the corresponding seal-up housing in a state the cutting tool is attached to the abovementioned seal-up housing 2. Next, the cutting tool 30 is fed toward the center of the abovementioned existing pipe 1 while slitting the existing pipe 1 by rotating the cutting tool 30 by power of a prime mover, and the abovementioned existing pipe 1 is cut off by the cutting tool 30 by turning the abovementioned seal-up housing 2 in the circumferential direction R of the existing pipe 1.

Abstract: A knife gate valve having modular ends for attachment to pipe ends is disclosed. A knife gate is movable transversely to a fluid flow path and constrained by guide plates positioned along opposite edges of the gate. Pairs of spacer rings each supporting a respective valve seat are positioned on opposite sides of the guide plates, the seats sealingly interfacing with the knife gate and the guide plates. Modular ends formed from tubes with flanged ends extend outwardly from the valve in opposite directions for connection to the pipe ends. The flanged ends of the tubes interface with the seats. End plates are attached on opposite sides of the guide plates. The end plates have openings which receive the tubes and surfaces around the openings which engage the flanged ends of the tubes and capture the modular ends, seats and spacer rings against the knife gate and the guide plates.

Abstract: A dual pendulum valve assembly for connecting a process chamber and a vacuum pump of a semiconductor manufacturing system. The valve assembly includes an isolation valve for sealing an opening to the pump during cleaning of the system and an annular cover for protecting a valve seat of the opening to the pump during use of the system. In particular, the valve assembly includes a housing having an interior space and a pair of openings through which fluid can enter and exit the interior space. A process valve is movable within the interior space between an opened position allowing fluid to pass through a first of the openings from the process chamber and a closed position sealing the first opening. The isolation valve is movable within the interior space between an opened position allowing fluid to pass through a second of the openings into the vacuum pump and a closed position sealing the second opening.

Abstract: A valve substantially made of plastic material having a housing which is connected to a conduit for a flowing medium, which housing contains a slide which is capable of movement transversely to the direction of flow of said medium between a closed position, in which the flow can be shut off, and an open position, in which said flow can be released, wherein the housing has a lower housing, for the connection, and an upper housing for the slide, which is detachably connected therewith.

Abstract: A plate valve which includes two sliding plates and which carries seal portions with an elongated slot. A valve body of the plate valve includes a second elongated slot with further seal portions extending from a valve aperture. A cable of different diameters can be accommodated and sealed by the cooperating resilient seal portions.

Abstract: A closure is movably mounted on the tank top of a pneumatic tank truck. The closure is movable between open and closed positions relative to an opening in the tank top by a pneumatically operated piston. An inflatable seal seals the closure to the tank top when the closure is in open position. Air jets are employed to clean dirt and debris from a guide supporting the closure. All operations can be performed without the driver climbing to the tank top.

Abstract: A gate valve is disclosed having a telescopingly interfitted seat assembly that fits into a recess in a gate chamber between the gate valve body and the gate. A sealing cavity is formed between two seat elements that form the telescopic connection. A preferably unidirectional seal is disposed therein having two lip seals. The unidirectional seal is preferably oriented to allow leakage for a pressure differential wherein the gate chamber has a higher pressure than the pressure on the opposite side of the seal from the gate chamber. The seal is preferably made of non-permeable material and the material is preferably flexible but non-elastic with little or no memory. Additional such seals may be used for sealing with the gate valve body. In one embodiment, an expansion member is provided for extending into an open end of the seal to expand the two lip seals.

Abstract: A seat assembly including preferably telescoping seating elements for use between a gate and a pocket in a gate valve body are disclosed. A seal is provided between the telescoping seating elements that is axially moveable and acts to seal with one or more sloping surfaces disposed on the seating elements. A spring acts to bias the seal towards the sloping surfaces so as to provide an initial seal. The sloping surfaces prevent movement of the seal in one axial direction. As line pressure increases the seal will move against the sloping surfaces with increased force to maintain the seal between the line or valve bore and the bonnet of the valve. A reverse pressure differential across the seal that is greater than the biasing force will cause the seal element to move in the opposite axial direction and bleed off the pressure across it.