| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 251306000 | Head and/or seat packing | 49 |
| 20090014675 | RESILIENT SEATED BUTTERFLY VALVE WITH INTERCHANGEABLE OFF-CENTER AND ON-CENTER DISCS - The resilient seated butterfly valve has a common spherical center for receiving either an on-center or off-center disc, both of which are rotatably mounted in the body. A seal has a seat spherical surface. The seal is affixed to the circumference of the valve chamber. It has an on-center seal region for engagement with the on-center spherical sealing edge of the on-center disc. The seal has an off-center seal region for engagement with the off-center spherical sealing edge of the off-center disc. The seal may include an outlet flange, an outlet ramp, an inlet ramp, and an inlet flange. The front face of the seal for the off-center disc extends beyond the position of the front face of the seal for the on-center disc. | 01-15-2009 |
| 20090032759 | Shut-off organ with anchored ceiling element - A shut-off organ for a fluid line, particularly for the turbine feed line of a hydroelectric power plant, has a housing and a clack valve in the housing that can be pivoted between an open position and a shut position. The clack valve has at least one swallowtail-shaped groove, into which an elastic sealing element having an essentially wedge-shaped cross-section that narrows towards the outside is laid. The sealing element rests against a conical sealing seat of the housing with its narrowed outer edge, forming a seal, in the shut position, thereby shutting off the shut-off organ. The possibility of the sealing element being sucked out is precluded even if the clack valve is opened while it stands under high hydraulic pressure, due to a rigid pin that extends through the sealing element essentially crosswise to the longitudinal expanse of the groove. | 02-05-2009 |
| 20090039305 | Butterfly Valve - A butterfly valve, in which fluid leakage inside a valve disc and from a shaft seal part between through holes of a seat ring and a stem is prevented, when the valve disc is displaced under fluid pressure with the valve closed. Without increasing the operation torque of the stem, the fluid leakage is prevented even after continuous on/off (open/close) operations over a long period of time. The butterfly valve includes the seat ring fitted to the inner peripheral surface of the hollow cylindrical valve body, the stem supported on the valve body via the through holes of the seat ring, and the discal valve disc with the stem mounted and supported in the valve shaft hole. The annular protrusion having the tapered surface with the outer periphery thereof inclined with respect to the valve axis is formed radially inward of the peripheral edge of the through holes on the inner periphery of the seat ring. The bowl-shaped annular depression engaged with the tapered surface is formed on the inner periphery at the opening end of the valve shaft hole of the valve disc. | 02-12-2009 |
| 20100019184 | VALVE SEAL WITH INTEGRAL FLEXURE JOINTS - A valve seal for use with a valve having a valve element including a plurality of radiused corners. The valve element is rotatably mounted within a frame disposed in a flowbody. The valve seal including a plurality of curved portions in cooperative alignment with the radiused corners of the valve element. The valve seal being partially disposed within a mounting groove formed in an edge surface about a substantial portion of the valve element. A plurality of flexure joints are formed in the seal member and in spaced relation from the curved portions. The plurality of flexure joints providing spring loading of the seal relative to the frame when the valve element is in a closed position. | 01-28-2010 |
| 20100148107 | VALVE ARRANGEMENT - A valve arrangement has an annular housing with valve seat and a two-part valve plate that is rotatable about an axis. The seat is in the form of a disk including two adjacent openings with a web between and the axis is parallel to the web. The two parts of the valve plate are next to each other with their planes parallel and offset in a perpendicular direction. They are connected to each other through one of the openings by a connection piece extending through the one opening. In a closed position for the valve, the valve plate part are respectively positioned on opposite sides of the valve seat and cover and seal the respective openings due to a seal that is between the valve plate parts and the valve seat. | 06-17-2010 |
| 20100301249 | BUTTERFLY VALVE PLATE SEALING ASSEMBLY - Butterfly valve plate sealing assemblies are provided that include a sealing ring and a retention spacer disposed at least partially within a sealing ring groove formed about a periphery of a butterfly valve plate. The sealing ring includes a first portion, a second portion configured substantially perpendicular to the first portion, and a substantially L-shaped cross-section. The sealing ring is positioned at least partially within a groove opening and a groove body defining the sealing ring groove. The retention spacer is positioned at least partially within the groove opening and adjacent the first portion of the sealing ring. The retention spacer is configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow. The second portion of the sealing ring may be configured to optimize stiffness for a desired sealing ring tension. | 12-02-2010 |
| 20100308248 | BUTTERFLY VALVE WITH A RIGID SEAL - A valve is disclosed and can include a valve body having a central bore for passage of fluid there through and a longitudinal axis. The valve can also include a seal installed within the valve body along the central bore. The seal can include a first seal member having an annular ring portion and a hub portion extending from the annular ring portion. The seal can also include a second seal member including an annular ring configured to engage a distal end of the hub portion and create a sealing engagement between the hub portion and the annular ring when a compressive force is applied to the first and the second seal members. | 12-09-2010 |
| 20110024660 | Angle-seating butterfly vane and method for producing the same - The invention relates to vanes used in butterfly valves utilized in fluid control systems requiring special relationships between passing fluid and vane rotation and furthermore can provided leak proof shut-off when in the closed valve position. My invention furthermore features a shape that greatly reduces the customary high dynamic torque created by fluid suction effects on a vane when in the open position. | 02-03-2011 |
| 20110024661 | BUTTERFLY VALVE, PREFERABLY FOR A BLOW OFF CIRCUIT OF A GAS TURBINE PLANT - A butterfly valve, preferably for a blow off circuit of a gas turbine plant. In one aspect, the invention can be a butterfly valve for a blow off circuit of a gas turbine plant comprising: a supporting ring having an inner perimeter edge defining a fluid flow section and an annular seat arranged along the inner perimeter edge; a disc, which is pivoted to the supporting ring and is mobile between a valve closing position, wherein the disc obstructs the fluid flow section, and a valve opening position, wherein the disc does not obstruct the fluid passage section; a sealing ring partially housed in the annular seat and adapted to abut against a peripheral edge of the disc when the disc is in the valve closing position; the sealing ring comprising an inner annular portion, which is contained in the annular seat, and a projecting annular portion, which projects radially from the annular seat and is hollow. | 02-03-2011 |
| 20110095221 | EXHAUST BRAKE VALVE ASSEMBLY - An exhaust gas flow control valve assembly comprises a valve casing forming an exhaust gas passage defining a cylindrical inner peripheral surface and a butterfly-type exhaust gas flow control valve disposed within the exhaust gas passage and movable between an open position and a closed position. The flow control valve includes a single-piece valve disc member having a circumferential groove formed in an outer peripheral surface thereof, and a flat, resilient stainless steel sealing ring disposed in the groove with a clearance for radial displacement of the sealing ring relative to the groove. The sealing ring includes a cylindrical outer peripheral surface provided with rounded corners. The outer peripheral surface of the sealing ring is in firm contact with the inner peripheral surface of the valve casing solely by an elastic force of the sealing ring when the exhaust gas flow control valve is in the closed position. | 04-28-2011 |
| 20110114863 | Butterfly Valve, Valve Seat and Valve Seat Retainer - Butterfly valves comprise a valve seat comprising a generally S-shaped cross-section and a valve seat retainer configured with appropriately shaped cooperating surfaces. Fluid control systems comprising such a butterfly valve are also disclosed. | 05-19-2011 |
| 20120025118 | BUTTERFLY VALVE PLATE SEALING ASSEMBLIES - A sealing assembly for use in a valve plate assembly includes a sealing ring and a retention spacer. The sealing ring has a radial ring section and an axial ring section, the axial ring section extends axially from the radial section and includes an outer diameter surface and a contact face, the contact face includes a contact surface and an annular slot, and the contact surface is located radially outward relative to the annular slot. The retention spacer is configured to be positioned adjacent the sealing ring | 02-02-2012 |
| 20120168659 | BUTTERFLY VALVE - In a butterfly valve having: a seat ring that is mounted on the inner circumferential face of a valve body; a valve stem that passes through a through hole in the seat ring, and is supported by the valve body; and a discoid valve element that is supported by way of fixing the valve stem in a valve stem hole, and which is opened and closed as a result of the valve element turning together with the valve stem turning, a hollow cylindrical bush is inserted into the through hole in the seat ring, and is mounted in a sealed manner in a valve stem fitting hole provided in the valve element, without projecting beyond the outer circumferential face of the seat ring. | 07-05-2012 |
| 20120181469 | THRUST PLATE FOR BUTTERFLY VALVE - A thrust plate for a butterfly valve includes a thrust plate body that defines a recess. The recess extends between a bottom thrust surface, side walls and an open top. A wear-resistant coating is located on the bottom thrust surface. | 07-19-2012 |
| 20120267557 | Butterfly Valve - A butterfly valve having a valve body is provided. The butterfly valve includes a valve disk assembly rotationally coupled to the valve body. The valve disk assembly has a disk member with a first surface disposed about a periphery having a first diameter and a second surface offset from the first surface. A seal ring is arranged adjacent the first surface, the seal ring having a first outer surface with a second diameter, wherein the second diameter is larger than the first diameter. A retainer is coupled to the second surface adjacent the seal ring opposite the first surface. The retainer has inner surface arranged to radially constraining the seal ring on the disk member. | 10-25-2012 |
| 20120273708 | BUTTERFLY VALVE HAVING FUNCTION OF MAINTAINING SEALING PERFORMANCE UNDER LOW AND HIGH TEMPERATURES - Disclosed is a butterfly valve capable of controlling a flow of a fluid according to a rotation of a disk. The butterfly valve includes a body provided with an inner space having two open ends; a disk unit having a disk rotatably installed at the inner space, and configured to selectively open and close the inner space according to a rotation of the disk; a first seat portion protruding from an outer circumferential surface of the disk; a second seat portion protruding from an inner circumferential surface of the body, and arranged to face the first seat portion; and a sealing unit mounted to the body, and formed to contact the first and second seat portions such that a gap between the outer circumferential surface of the disk and the inner circumferential surface of the body is sealed. Under this configuration, the butterfly valve may have an enhanced reliability under low and high temperatures and a high pressure. | 11-01-2012 |
| 20120319022 | FLEXIBLE SEALS FOR PROCESS CONTROL VALVES - Flexible seals for process control valves are disclosed. An example disclosed seal includes a seal for use with a butterfly valve. The example seal includes a substantially flexible ring-shaped carrier configured to be moveably fixed within the butterfly valve and to surround a flow control aperture therein. The example seal includes a seal stiffener adjacent the substantially flexible ring-shaped carrier to increase the stiffness of the substantially flexible ring-shaped carrier in a first flow direction. The example seal includes a substantially rigid seal ring to engage an opposing surface. | 12-20-2012 |
| 20130032744 | VALVE HAVING AN ELASTOMER/CERAMIC SEALING RING - The invention relates to an annular, endless sealing ring having a part ( | 02-07-2013 |
| 20130161552 | BUTTERFLY VALVE - A butterfly valve ( | 06-27-2013 |
| 20130168589 | HIGH TEMPERATURE BUTTERFLY VALVE - A high-temperature butterfly valve ( | 07-04-2013 |
| 20130168590 | BUTTERFLY VALVE - A butterfly valve ( | 07-04-2013 |
| 20130284963 | Butterfly Valve and Stem Sealing Assembly - A butterfly valve capable of preventing leakage under demanding environmental and operating conditions. The valve includes two stem seal assemblies. The stem seal assemblies include a first pusher, a first energizer, a second pusher, a second energizer, and a force transmitting member. The force transmitting member is configured to transfer an axial load to the second pusher, which causes the first and second energizer to expand radially to create a secondary and tertiary seals between the stem seal assembly and valve stem. In addition, the force transmitting member is configured to transfer an axial load to the first pusher which creates a primary seal. | 10-31-2013 |
| 20130299728 | BUTTERFLY VALVE - A thickness of a valve is set smaller than a distance (inter-seat distance) in a valve thickness direction from a first seat part to a second seat part, and hence a gap between the valve and the first seat part and a gap between the valve and the second seat part are reduced to suppress seat leakage with all a variation of dimension thereof. | 11-14-2013 |
| 20130341548 | CONTAMINATION RESISTANT BUTTERFLY VALVE - A butterfly valve assembly for use in a fluid flow containing particles of debris is provided including a valve element. The valve element has a seal groove that extends about a periphery and defines an upstream side and a downstream side of the valve element. A seal is disposed within the seal groove. A clearance exists between the seal and an edge of the seal groove. Also, a relief is formed in either the valve element or the seal. The particles of debris accumulate in the relief and not the clearance. | 12-26-2013 |
| 20140027660 | LOW LEAKAGE FLUE DAMPER - A flue damper comprises a damper gate having first and second sides, and first and second seal stops. In one embodiment, a first seal is mounted to the first side of the damper gate and has a free end in sealing engagement with the first seal stop under pressure conditions, while a second seal is mounted to the second side of the damper gate and has a free end in sealing engagement with the second seal stop under the pressure conditions. In an alternative embodiment, the first seal is mounted to the first seal stop and has a free end in sealing engagement with the first side of the damper gate under pressure conditions, while the second seal is mounted to the second seal stop and has a free end in sealing engagement with the second side of the damper gate under the pressure conditions. | 01-30-2014 |
| 20140117267 | VALVE DEVICE FOR CONTROLLING AN EXHAUST GAS FLOW OF AN INTERNAL COMBUSTION ENGINE - A valve device for controlling an exhaust gas flow of an internal combustion engine includes a housing comprising a channel which has the exhaust gas flow therethrough. A shaft is disposed in the housing. The shaft is rotatably mounted about a shaft axis. A flap is connected to the shaft. The flap controls a flow cross section of the channel. The flap comprises two flexurally rigid support plates. The support plates each comprise an outer periphery. An elastic flap body is arranged between the support plates. The elastic flap body comprises an outer periphery which is larger on all sides than the outer periphery of the support plates. A distance between the outer periphery of the elastic flap body and the outer periphery of the support plates is largest in an area of the shaft axis, and smallest at an angle of 90° relative to the shaft axis. | 05-01-2014 |
| 20140151592 | BUTTERFLY VALVE AND METHOD OF CHECKING FOR LEAKS IN THE SAME - A butterfly valve is disclosed. In one aspect, the butterfly valve includes a pipe-shaped housing, a valve disk rotatably arranged within the pipe-shaped housing, a space forming member formed along an outer circumference of the valve disk, and a leak check port provided in the housing and configured to be connected to a space between the space forming member and the housing. | 06-05-2014 |
| 20140175316 | MANUAL BALANCING VALVE - Disclosed is a manual balancing valve having an upstream end and a downstream end, and a first equalizing ring ( | 06-26-2014 |
| 20140203201 | BUTTERFLY VALVES HAVING MULTIPLE SEALS - Butterfly valves having multiple seals are described herein. An example butterfly valve includes a body defining a passageway between an inlet and an outlet. The example butterfly valve includes a first flexible seal coupled to a first surface of the body adjacent the inlet to engage a first portion of a disk. The example butterfly valve also includes a second flexible seal coupled to a second surface of the body adjacent to the outlet to engage a second portion of the disk different than the first portion. | 07-24-2014 |
| 20140231688 | VALVE ASSEMBLY - A valve assembly ( | 08-21-2014 |
| 20140231689 | VALVE ASSEMBLY INTENDED FOR USE TOGETHER WITH A PALLET CONTAINER AND A LINER - A valve assembly ( | 08-21-2014 |
| 20140239214 | Butterfly Valve - A butterfly valve is described which comprises a valve disc located within a flow passage provided in a housing and engageable with a seat provided within the housing, the valve disc and housing cooperating with one another, when the valve disc occupies a closed position, to define an annular void extending around the periphery of the valve disc at a position spaced from and independent of the main valve seat, an inlet port and an outlet port communicating with the void to allow the supply of sealant to the void to form a seal between the valve disc and the housing. | 08-28-2014 |
| 20140312258 | AIRTIGHTNESS MAINTAINING STRUCTURE FOR BUTTERFLY VALVE - An airtightness maintaining structure for a butterfly valve includes a valve element having a rotating shaft and a valve body, a rotation supporting portion having a pivotably supporting member that fits onto the rotating shaft and pivotably supports the rotating shaft, and a rotating shaft seal arranged to contact in a fitting state both an end surface of a member on an outer radial and a surface of a member on an inner side either the rotation shaft or the pivotably supporting member and has an annular portion. In a closed valve state of the valve element, the rotating shaft seal moves radially due to a pressure difference between a high fluid pressure acting on one side of the valve element and a low fluid pressure acting on the other side and contacts both the valve element and the rotation supporting portion on the high fluid pressure side. | 10-23-2014 |
| 20140374639 | BUTTERFLY VALVE WITH A RIGID SEAL - A valve is disclosed and can include a valve body having a central bore for passage of fluid there through and a longitudinal axis. The valve can also include a seal installed within the valve body along the central bore. The seal can include a first seal member having an annular ring portion and a hub portion extending from the annular ring portion. The seal can also include a second seal member including an annular ring configured to engage a distal end of the hub portion and create a sealing engagement between the hub portion and the annular ring when a compressive force is applied to the first and the second seal members. | 12-25-2014 |
| 20150021507 | CYLINDRICAL VALVE ASSEMBLY - A cylindrical valve assembly, including: a housing defining a fluid flow channel there through; a cylindrical core disposed within the housing and defining a fluid flow channel there through; and at least one cylindrical valve door disposed between the housing and the cylindrical core; wherein, when the at least one cylindrical valve door is actuated, the fluid flow channels through the housing and the cylindrical core are one of opened and closed; and wherein the at least one cylindrical valve door does not protrude into any portion of the interior of the cylindrical core when actuated. Preferably, the at least one cylindrical valve door includes a pair of cylindrical valve doors. | 01-22-2015 |
| 20150028242 | FLUID VALVE APPARATUS HAVING ENCLOSED SEALS - Fluid valve apparatus having enclosed seals are disclosed. An example fluid valve includes a movable flow control member positioned between an inlet and an outlet of a fluid flow passageway of the fluid valve. A retainer is removably coupled to the flow control member such that the retainer and the flow control member define a sealing cavity when the retainer is coupled to the flow control member. A seal is positioned within the sealing cavity to define a sealing surface of the flow control member. The seal has an inner core composed of a first material, where the core is substantially encased with a sheath composed of a second material different than the first material. The retainer clamps the seal to the flow control member. | 01-29-2015 |
| 20150041699 | INTAKE SYSTEM - The intake system has a valve seat, a plate valve, and an elastic sealing member. A path is provided to pass through the valve seat and to communicate with an intake passage of an internal combustion engine. The plate valve fits to or separates from the valve seat to close or open the path. The plate valve is provided with through holes passing through the plate valve in the thickness direction at a valve periphery part. The through holes are arranged linearly one after another in a peripheral direction of the plate valve to be offset to each other in the direction perpendicular to the peripheral direction. The elastic sealing member includes an elastic covering part that covers a first surface and a second surface of the plate valve and elastic coupling parts that are disposed in the through holes and are coupled with the elastic covering part at the first surface and the second surface. | 02-12-2015 |
| 20150053880 | HIGH TEMPERATURE SEALS FOR USE IN ROTARY VALVES - High temperature seals for use in rotary valves are described herein. An example seal for use with a rotary valve includes a primary seal to engage a flow control member when the primary seal is in a first condition and a secondary seal at least partially disposed within the primary seal. The primary seal is to prevent the secondary seal from engaging the flow control member when the primary seal is in the first condition and the secondary seal is to engage the flow control member when the primary seal is in a second condition. | 02-26-2015 |
| 20150083955 | BI-DIRECTIONAL ROTARY VALVE - A bi-directional cryogenic rotary valve having a housing defining a fluid passageway, a control member rotatably disposed within the fluid passageway, and a seal assembly positioned along an inner surface of the housing to provide a bubble tight seal between the housing and the control member. The rotary valve adapted to operate at or near cryogenic temperatures (i.e., at −160° C.) while maintaining an affective seal in both the forward and reverse directions. The rotary valve being capable of retrofitting against wear and operational stress sustained from repeated use and operation. | 03-26-2015 |
| 20150102250 | FLOW CONTROLLER - A flow controller is provided. The controller includes a shell body, a first supporting member, a driving shaft and an elliptical valve. The shell body has a passage passed therethrough. The first supporting member is assembled to the shell body. The driving shaft is assembled to the first supporting member. The elliptical valve is pivotally assembled in the passage and is connected with the driving shaft. The elliptical valve is rotated by the driving shaft for opening or closing the passage. When the passage is closed by the elliptical valve, the elliptical valve tightly abuts against an inner circular wall of the shell body for completely closing the passage, so that the controller is suitable in a high temperature and high pressure environment. | 04-16-2015 |
| 20150115190 | WEAR-RESISTANT VALVE ASSEMBLY - A wear-resistant valve assembly includes a valve body; a stem penetrating through the valve body; a valve disk installed in the chamber of the valve body and contacting an inner wall of the valve body; a valve body wear-resistant layer formed at an inner annular area of the valve body, which is also at a position contacting the valve disk; and a valve disk wear-resistant layer formed on an outer annular area of the valve disk at a position contacting the valve body; and wherein the valve body wear-resistant layer and the valve disk wear-resistant layer are made of materials selected from carbon alloys and satellite alloys. Furthermore, the valve disk is a triple-eccentric structure; and a drain-proof-ring wear-resistant layer and a valve seat wear-resistant layer are further formed. | 04-30-2015 |
| 20150359180 | GRAIN BIN VACUUM TUBE EXTENSION SYSTEM FOR EVACUATING GRAIN FROM A GRAIN BIN - A grain bin vacuum tube extension system with (i) an extension tube comprising a bottom surface and a plurality of slots on the bottom surface of the extension tube, (ii) a sealing strip that is slidably secured to the bottom surface of the extension tube and that comprises a plurality of slots, and (iii) a butterfly valve that is configured to close when the slots on the bottom surface of the extension tube are aligned with the slots in the sealing strip and to open when the slots on the bottom surface of the extension tube are not aligned with the slots in the sealing strip. The sealing strip is slidably secured to the bottom surface of the extension tube such that the slots on the bottom surface of the extension cube align with the slots in the sealing strip when the sealing strip is slid to an open position. The sealing strip creates and airtight seal against the bottom surface of the extension tube when the butterfly valve is in an open position. | 12-17-2015 |
| 20160061333 | VALVE FOR AN EXHAUST GAS LINE OF AN INTERNAL COMBUSTION ENGINE - An exhaust line valve for an internal combustion engine. A closure body is arranged in a duct of the valve and is fastened to a shaft. The closure body when closed separates upstream and downstream duct sections. Two projections extend into the duct, each having a valve seat pointing in an opposite direction of the duct. By pivoting the closure body from its closed position, the sealing surfaces of the closure body are raised from their respective valve seats. A polymer seal is arranged on the valve seats and in the closed position the polymer seal sealingly contacts the associated sealing surface of the closure body. A circumferential surface of the shaft or the closure body is located in an edge region of the closure body. The polymer seal contacts in a sealing manner at least a region of the circumferential surface facing the upstream section of the duct. | 03-03-2016 |
| 20160069459 | ORBITAL SEAT IN A BUTTERFLY VALVE - A sealing member is described including a surface contacting a valve body that is at least a portion of a sphere. | 03-10-2016 |
| 20160138719 | Butterfly Valve Seal Retaining Arrangement - A butterfly valve seal arrangement in a butterfly valve having a cylindrical flow channel with a wall includes a seal flange, an elastomeric seal, a seal channel, and an annular seal retaining ring. The seal flange extends into the cylindrical flow channel from the wall of the cylindrical flow channel. The seal channel is recessed into the wall of the cylindrical flow channel adjacent to the seal flange. And the annular seal retaining ring includes tabs extending into the seal channel which hold the annular seal retaining ring in the cylindrical flow channel. An elastomeric seal is held in compression in the seal channel and against the seal flange by the annular seal retaining ring, and extends into the cylindrical flow channel forming a seal surface held in compression against a vane seat of a vane in a position perpendicular to a direction of flow. | 05-19-2016 |
| 20160201808 | SELF-SEALING BUTTERFLY VALVE | 07-14-2016 |
| 20170234436 | BUTTERFLY VALVE SEAT WITH SEAT COVER | 08-17-2017 |
| 20170234437 | VACUUM PRESSURE CONTROL APPARATUS | 08-17-2017 |
| 251307000 | Adjustable | 1 |
| 20080272324 | ELLIPTICAL SEALING SURFACE FOR BUTTERFLY VALVE - A reduced component wear valve is comprised of a valve body having a passage therethrough and a disc attached to a rotatable shaft. The disc is utilized with a seal forming a gap between the disc and the seal proximate to the rotational axis of the disc. When the disc is in the open position, the seal major axis is greater then the disc diameter and they do not touch. As the disc rotates to near closure, the disc perimeter engages the minor axis of the seal (which is smaller than the disc diameter), and the disc stretches the seal in the minor axis direction thus decreasing the major axis such that the gap is closed. The seal can be pre-formed in an elliptical shape or it can be formed into an elliptical shape by a retaining mechanism. The seal may be a single-piece or a multi-piece assembly press-fit into the valve body. Zero or light disc to seal contact during the majority of the valve disc rotation minimizes valve seal wear and rotational friction. | 11-06-2008 |
