Valve seats, valve assemblies, and related methods

Valve seats may include an insert and an outer housing. The insert may comprise a first material and the outer housing may comprise a second material. The second material of the outer housing may exhibit a hardness that is greater than a hardness of the first material of the insert. Valve assemblies and related method may include valve seats.

TECHNICAL FIELD

The present disclosure relates generally to valve seats, and, more particularly, to valve seats including multiple materials, valve assemblies including valve seats including multiple materials and related methods.

BACKGROUND

Many valve types have been employed for stopping and controlling the flow of fluids in a pipe or other flow path. Each of these valves offers certain advantages while suffering from other disadvantages. Some valve types include plug valves, ball valves, stop or globe valves, angle valves, butterfly valves, and gate valves.

Ball valves comprise a rotatable ball having a bore therethrough corresponding to the fluid flow path together with one or more seats for sealing with the ball surface. Typical ball valves have a valve body and a valve member (e.g., a ball) operatively connected to the valve body by an upstream and a downstream seal. The valve body defines a flow passage having an upstream flow-through end (e.g., leading end), a downstream flow-through end (e.g., trailing end), and a valve receiving chamber located between the upstream and downstream flow-through ends of the flow passage. The valve member is located within the valve receiving chamber, and includes a throughbore that allows passage of fluid through the valve member. The seals or seats, in conjunction with the valve member and the valve receiving chamber, define a cavity around the valve member. To prevent leakage of the valve, the seals or seats are pressed against the valve member with a given or fixed sealing pressure based, at least in part, on the maximum pressure environment in which the valve may be installed.

The valve member is coupled to an actuator via a valve stem, which is selectively rotatable to rotate the valve member within the valve receiving chamber, between a fully open position and a fully closed position. Generally, in a two way valve, the fully open position occurs when the throughbore is aligned with the flow passage at zero degrees of rotation from a centerline of the flow passage and the fully closed position occurs at ninety degrees of rotation of the valve member from the centerline.

The valve member ball is contained within the valve body between two valve seats with physical compression applied to the seats during assembly, such that the seats bear into the ball with force. In such designs, the valve seats act as a seal at the point at which they bear onto the ball, and as a seal at points at which they bear against the valve body. The valve seats also act as a spring to maintain the sealing force during operation of the valve. The “off” position usually corresponds to a position of the ball wherein the conduit is at right angles to the valve body passageway. However, lesser angular displacements may result in an “off” or partially “off” condition, depending upon the geometry of the valve components. The full “on” position is typified by the ball conduit being coaxially aligned with the fluid passageway of the valve body. A conventional ball valve provides varying degrees of flow restriction based upon the degree of alignment of the ball conduit with the valve body passageway. Thus, for a given pressure, flow is controlled by varying the degree of alignment of the ball conduit with the valve body passageway.

During the life of the ball valve, switching the ball between the “on” and “off” positions subjects the valve seats to thermal cycling, which can damage the valve seats and cause the seats to experience “creep,” which degrades the seal and causes leakage within the ball valve assembly. Valve seats made of softer, more elastic materials require less compressive force to seal the ball; however, such softer, more elastic materials are more susceptible to creep, which may occur rapidly at elevated temperatures. To compensate, valve seats are often configured to provide a maximum physical compression against the ball, wherein the sealing force may be maintained even if some thermal degradation or creep occurs. However, such compressive forces require more torque to operate the ball valve.

BRIEF SUMMARY

Various embodiments of the present disclosure comprise a valve seat including an insert and an outer housing. The insert may comprise a first polymer material. The insert may be configured to be positioned proximate a valve member and to contact the valve member. The insert may define a portion of a seal between the valve member and a valve body in which the valve member is positioned. The outer housing may comprise a second polymer material. At least a portion of the insert may be positioned within the outer housing. The outer housing may be configured to be positioned between the insert and the valve body to define another portion of the seal between the valve member and the valve body. The second polymer material of the outer housing may exhibit a hardness that is greater than a hardness of the first polymer material of the insert.

Another embodiment of the present disclosure may comprise a valve assembly including a valve body, a valve member, and at least one valve seat. The valve body may include at least one port. The valve member may be positioned within the valve body. The valve member may be configured to selectively enable fluid to pass through the at least one port in the valve body. The at least one valve seat may include a seat member and a support member. The seat member may comprise a polymer material. The seat member may be positioned adjacent to the valve member and be configured to seal against the valve member. The support member may comprise another polymer material. The support member may be positioned between the seat member and the valve body and configured to seal against the valve body.

Another embodiment of the present disclosure may include a method of providing a seal in a ball valve. The method may include positioning a first section of a seat comprising a first polymer material adjacent to a movable ball of the ball valve. The method may also include positioning a second section of the seat comprising a second polymer material adjacent to a body of the ball valve. The movable ball may be forced into the seat to form a seal between the movable ball and the valve body with the seat.

DETAILED DESCRIPTION

The illustrations presented herein are not meant to be actual views of any particular fluid exchanger or component thereof, but are merely idealized representations employed to describe illustrative embodiments. The drawings are not necessarily to scale. Elements common between figures may retain the same numerical designation.

As used herein, relational terms, such as “first,” “second,” “top,” “bottom,” etc., are generally used for clarity and convenience in understanding the disclosure and accompanying drawings and do not connote or depend on any specific preference, orientation, or order, except where the context clearly indicates otherwise.

As used herein, the term “and/or” means and includes any and all combinations of one or more of the associated listed items.

As used herein, the term “substantially” or “about” in reference to a given parameter means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially met may be at least 90% met, at least 95% met, at least 99% met, or even 100% met.

As used herein, the term “fluid” may mean and include fluids of any type and composition. Fluids may take a liquid form, a gaseous form, or combinations thereof, and, in some instances, may include some solid material.

Embodiments of the present disclosure may be utilized to control fluid flow in a system operated at normal environmental conditions and/or in high pressure and/or high temperature systems. In some embodiments, such systems may include industrial applications (e.g., power plants, processing systems, mineral extraction, etc.), vehicles (e.g., ships, tankers, submarines, locomotives, etc.), or control systems (e.g., hydraulic systems, pneumatic systems, etc.).

Valve assemblies may include a valve member, such as a ball, contained in a valve body between two valve seats with physical compression applied to the seats during assembly such that the seats bear into the ball with force. In such designs, the valve seats act as a seal at the point at which they bear onto the ball. The valve seats also act as a seal at points at which they bear against the valve body. The valve seats also act as a biasing force or spring to maintain the sealing force during operation of the valve. This design may be problematic in that softer, more elastic materials, which require less compressive force to form a seal against the ball, are less resilient to thermal stressing over the life of the valve. Moreover, softer, more elastic materials are susceptible to deformation, such as higher rates of creep, at any given temperature, and are prone to rapid rates of creep at elevated temperatures. An example of a common material used for valve seats that is susceptible to such problems is polytetrafluoroethylene (PTFE). Thermal stressing and creep can degrade the seal against the ball valve, and result in leakage, particularly when the ball is switched between the open and closed positions.

Further, valves may be utilized to control fluid flow in high pressure and/or high temperature systems may be exposed to relatively large forces associated both with the pressure and impact from fluid flow (e.g., changes in fluid flow) that are absorbed by the valve seats when the valve is closed, opened, or moving between the open and closed positions.

In order to avoid some of the problems with relatively softer seats, seats may be formed from higher strength materials that can withstand higher loads resulting from high pressure or shock and generally higher operating temperatures. Such higher strength seats may present the disadvantage of requiring a higher sealing force combined with their higher frictional coefficient, in comparison to relatively softer seat materials, resulting in a significantly higher torque being required to operate the valve. For example, such high strength materials may create higher friction between the valve seats and the valve member than the relatively lower strength valve seat materials. The increased friction may require increased amounts of torque to operate the valve. High pressure systems may also increase the amount of torque required to operate the valve. The combined effect of the increased friction and the increased pressure may result in large amounts of required torque. Large amounts of torque may require larger, cumbersome, and/or more expensive actuation devices (e.g., electronic or manually operated actuators).

Embodiments of the present disclosure may provide a valve seat (e.g., a compound valve seat) that comprises multiple materials in multiple regions. For example, such valve seats may include a relatively lower strength material (e.g., a material exhibiting a lower hardness) that is positioned adjacent a valve member (e.g., a ball element) and a relatively higher strength material (e.g., a material exhibiting a relatively higher hardness) that supports the lower strength material (e.g., under a higher loading scenario) and that may be positioned between the lower strength material and a body of the valve. In some embodiments, the valve seat may comprise one or more sections (e.g., two separable, distinct pieces or elements) that each comprise one of the higher or lower strength materials and that are utilized in unison to define the valve seat. In additional embodiments, the valve seat may be formed as a single section with multiple material regions or may include more than two separate, distinct pieces or elements.

FIG. 1illustrates a cross-sectional view of a valve100(e.g., a ball valve) including one or more valve seats112in the closed position. The ball valve100may include a valve member (e.g., ball102, obstructor, etc.) movably positioned (e.g., floating or mounted) in a valve body104(e.g., including a central housing with two end caps) to control fluid flow through the valve100. The valve body104may define a conduit106(e.g., path, passage, port, etc.) through the valve body104. The ball102may include a port108(e.g., hole, path, passage, etc.) through the ball102. A stem110may extend through the valve body104and be operatively coupled to the ball102. The ball102may be configured to selectively inhibit (e.g., obstruct, at least partially inhibit, substantially stop, substantially prevent, etc.) fluid flow through the ball valve100when the ball102is in a closed position (e.g., positioned such that the port108is not aligned with the conduit106), as illustrated inFIG. 1. The stem110may cause the ball to rotate between the closed position and an open position (e.g., wherein the ball102is positioned such that the port108is aligned with the conduit106, as shown inFIG. 2).

The seats112(e.g., seal, annular ring, etc.) may be positioned within the valve body104where the ball102and the conduit106meet. Each valve seat112forms a substantially fluid-tight seal through engagement with portions of the valve100, for example, with the valve member or ball102and the valve body104. The seats112may at least partially or substantially entirely inhibit flow of fluid around the ball valve100when the ball102is in a closed position and/or an open position by defining one or more seals between the ball102and the valve body104.

The ball102may rest adjacent to and/or against the seats112. The seats112may be annular (e.g., ring-shaped, substantially circular, etc.). The seats112may be configured to form a seal between the ball102and the valve body104. In some embodiments, the seats112may have a complementary shape to the ball102. For example, the seats112may exhibit a conical shape (e.g., frustoconical) with an angled inner surface. In some embodiments, the seats112may have a complex shape (e.g., an at least partially arcuate shaped cross section) such as a hemispherical slice configured to complement a spherical shape of the ball102(e.g., having substantially the same radius).

As depicted, one or more of the seats112may be formed in at least two regions or sections. A first region114may be at least partially formed from a first material (e.g., substantially all or an entirety of the first region114may comprise the first material) and a second region116may be at least partially formed from a second material (e.g., substantially all or an entirety of the second region116may comprise the second material). In some embodiments, the first material and the second material may be different materials (e.g., having differing material properties). In some embodiments, the first material may be a softer or relatively more flexible material than the second material.

For example, the first material or an entirety of the first region114may have a relatively low durometer indicating the relatively low hardness of the material as compared to other relatively stiffer (e.g., rigid) polymers or other types of materials. The first material may have a hardness (e.g., durometer) less than about 100 on the Rockwell R scale, such as less than about 90 on the Rockwell R scale, less than about 75 on the Rockwell R scale, less than about 60 on the Rockwell R scale, and greater than 50 on the Rockwell R scale (e.g., between on the Rockwell R scale 50 and 60, 55 and 65, 60 and 70, 55 and 80, 50 and 90, etc.). The second material or an entirety of the second region116may have a hardness (e.g., durometer) greater than about 90 on the

Rockwell R scale, such as greater than about 100 on the Rockwell R scale, greater than about 110 on the Rockwell R scale, greater than about 120 on the Rockwell R scale, greater than about 130 on the Rockwell R scale, and less than about 150 on the Rockwell R scale (e.g., between on the Rockwell R scale 90 and 140, 100 and 130, 110 and 130, 115 and 125, 90 and 150, etc.).

By way of further example, the first region114may be formed from a material having a type A Shore hardness of less than 100 (e.g., between 80 and 100, 90 and 100, 70 and 100) and the second region116may be formed from a material having a type D Shore hardness of between 75 and 100 (e.g., between 80 and 100, 90 and 100).

In some embodiments, the first material (e.g., an entirety of the first region114) may be a flexible material (e.g., resilient material) and the second material (e.g., an entirety of the second region116) may be a rigid material. For example, the first material may have a modulus of elasticity (e.g., Young's modulus) between about 0.1 GPa and about 2 GPa, such as between about 0.3 GPa and about 1 GPa, between about 0.4 GPa and about 0.9 GPa, or between 0.4 GPa and 0.6 GPa. The second material may have a modulus of elasticity between about 1.5 GPa and about 6 GPa, such as between about 2.0 GPa and about 5 GPa, between about 2.5 GPa and about 4 GPa, or between about 3 GPa and about 4 GPa.

In some embodiments, the second material (e.g., an entirety of the second region116) may have a modulus of elasticity that is more than one times (1×) greater than (e.g., between 1.1× to 5.0× greater, at least 1.25× greater, at least 1.5× greater, at least 1.75×greater, at least 2.0×greater, combinations thereof) the modulus of elasticity of the first material (e.g., an entirety of the first region114).

The first material may be a soft or relatively flexible sealing material, such as a polymer (e.g., plastics, elastomers, rubbers, etc.). In some embodiments, the flexible sealing material may be rubber such as, ethylene propylene diene (EPDM), nitrile rubber (NBR), styrene butadiene rubber (SBR), silicon rubber, butyl rubber, polybutadiene, etc. In some embodiments, the soft sealing material may be a plastic such as, tetrafluoroethylene (TFB), polytetrafluoroethylene (PTFE), modified PTFE (e.g., TFM, DYNEON® TFM 1600, DYNEON® TFM 1700), or reinforced polytetrafluoroethylene (RTFE).

FIG. 2illustrates a cross section of the ball valve100in an open position. In the open position, the port108through the ball102may be substantially aligned with the conduit106through the valve body104such that fluid may pass through the ball valve100. In the open position, the force between the ball102and the seat112may be reduced. When the ball valve100returns to a closed position (FIG. 1), the increase in force between the ball102and the seat112may be introduced suddenly such that the impact (e.g., shock, impulse, etc.) absorbed by the seat112may be greater than the force that the pressure alone would cause when the ball valve100is in a closed position.

The seats112may substantially inhibit or limit flow of fluid around the ball valve100when the ball102is in one or both of the open position and the closed position by defining a seal between the ball102and the valve body104. For example, the seats112may act to at least partially ensure that a majority or entirety of the fluid flow travels through an intended flow path (e.g., through the ball102) while minimizing or entirely preventing fluid from traveling around the outside of the ball102when the ball102is in the open position. Likewise, the seats112may prevent unwanted fluid flow around the ball102when in the closed position.

FIG. 3illustrates an isometric view of a valve seat300, which may be similar and include one or more of the features of the other valve seats discussed herein. Referring toFIGS. 1 and 3, the valve seat300may include a first seat section (e.g., an insert302, seat member, first region, first section) and a second support section (e.g., an outer housing304, support member, second region, second section). The outer housing304may include an outer surface306(e.g., lateral or radial extent, outer wall) and an inner surface308(e.g., radially inner wall). The outer surface306of the outer housing304may be positioned adjacent the valve body104(e.g., bordering, contacting, securing the housing304against the valve body104). For example, the outer housing304may be sized such that an outer diameter of the outer surface306is substantially the same or slightly smaller or even larger than an inner diameter of the valve body104such that the outer housing304sits within, adjacent to or contacting, the valve body104(e.g., while optionally forming an interference fit, press fit, friction fit with the valve body104).

The outer housing304may operate as a spacer providing separation between the insert302and the valve body104while supporting the insert302(e.g., by limiting deformation of the insert302). For example, the outer housing304may enable the insert302to elastically deform (e.g., to conform to the shape of the ball102under loading) without failing (e.g., breaking the seal between the valve seat300and the valve body104), for example, by deforming to an extent that the insert302no longer makes sealing contact with the ball102.

The insert302may be at least partially disposed within the outer housing304. For example, the insert302may be disposed such that an entirety of a width303(e.g., an axial extent) of the insert302is received within the width305(e.g., an axial extent) of the outer housing304. In some embodiments, only a portion of the width303of the insert302may be disposed within the outer housing304, such that a portion of the insert302protrudes in an axial direction from one or more axial sides of the outer housing304.

In some embodiments, the insert302may be at least partially surrounded (e.g., radially surrounded) by the outer housing304, such that an entirety of the insert302is positioned radially within the outer housing304. For example, the insert302may exhibit a diameter that fits within a larger diameter of the outer housing304. In additional embodiments, at least a portion of the insert302may extend beyond an outer portion of the outer housing304.

The insert302may be fitted within the outer housing304. For example, the insert302may be secured to the inner surface308of the outer housing304through an interference fit (e.g., press fit, friction fit, etc.). In some embodiments, the insert302may be otherwise secured to the inner surface308of the outer housing304, for example, with an adhesive (e.g., epoxy, glue, adhesive strips, etc.). or through other known processes such as, plastic welding, friction welding, chemical welding, soldering, intersecting threads, etc.

The insert302may include a seating surface310positioned proximate the ball102and configured to contact and/or form a seal between the insert302and the ball102. The seating surface310may be substantially flat or planar and angled (e.g., relative to the axis of the seat300) such that a leading end312has a larger diameter than a trailing end314(e.g., the seating surface310exhibits a frustoconical shape). In some embodiments, the seating surface310may have a complementary radius to the portion of the ball102which the seating surface310contacts (e.g., substantially the same radius as the contacting portion of the ball102). In some embodiments, the seating surface310may be formed from multiple intersecting frustoconical-shaped surfaces.

The outer housing304may include a secondary seating surface316. For example, the secondary seating surface316may provide another seal between the valve seat300and the ball102if the seating surface310of the insert302fails to form a seal or in addition to the seating surface310of the insert302. As depicted, the secondary seating surface316may exhibit substantially the same shape as the seating surface310of the insert302(e.g., a frustoconical shape configured to engage with a larger diameter portion of the ball102). In some embodiments, the secondary seating surface316may be formed such that the ball102does not contact the secondary seating surface316unless or until a selected level of force (e.g., fluid flow, pressure, etc.) is reached. In some embodiments, the secondary seating surface316may be formed such that the ball102does not contact the secondary seating surface316unless or until the insert302becomes worn, damaged (e.g., plastically deformed), or otherwise cannot form a seal against the ball102.

The outer housing304may be formed from a harder material than the insert302as described above with respect to the first region114and the second region116ofFIG. 1. A softer material may require less force to form a seal. For example, the force required to elastically deform the insert302between the ball102and the outer housing304may be relatively lower. The reduced force may allow the ball102to move more easily against the insert302. However, the softer material on the insert302alone may lack the strength to withstand high pressures present within the valve100, thereby potentially damaging the insert302if used alone. The harder material of the outer housing304may compensate for the reduced strength of the insert302and support the insert302(and the ball102) in environments involving relatively higher forces and pressures. Such hard and soft materials may be similar to the first and second materials described above with respect toFIG. 1.

FIG. 4illustrates the valve seat300ofFIG. 3in an exploded view. Referring toFIGS. 1 and 4, the outer housing304may include a recess320defined by the inner surface308of the outer housing304and a shelf322(e.g., ridge, retention, stop, etc.). The insert302may be secured within the recess320such that the trailing end314of the insert302rests against the shelf322. In some embodiments, the insert302may be secured to or in the outer housing304as described above with respect toFIG. 3. In some embodiments, the pressure provided by the ball102in the valve assembly may maintain the insert302in position. The pressure creating a seal between the ball102and the seating surface310of the insert302may similarly create a seal between an outer portion324of the insert302and the inner surface308of the outer housing304and/or between the trailing end314of the insert302and the shelf322of the housing304.

In some embodiments, an intermediary seal may be included in the valve seat300. The intermediary seal may be another annular ring formed from a polymeric material. In some embodiments, the intermediary seal may be formed from a material that is harder than the insert302and softer than the outer housing304. In some embodiments, the intermediary seal may be formed from an elastomeric material (e.g., rubber) such as, an O-ring or sealing strip. The intermediary seal may be configured to conform to differences in geometry between the outer portion324of the insert302and the inner surface308of the outer housing304.

FIG. 5illustrates a cross-sectional view of a valve seat500, which may be similar and include one or more of the features of the other valve seats discussed herein. Referring toFIGS. 1 and 5, the valve seat500may include an insert502and an outer housing504. The insert502may be disposed within a recess520in the outer housing504where a trailing end514of the insert502rests against a shelf522and an outer radial portion524of the insert502is positioned adjacent or rests against an inner surface508of the outer housing504. As described above with respect toFIGS. 3 and 4, the insert502may be formed from a soft sealing material configured to form a seal between the insert502and the ball102. The outer housing504may likewise be formed from a harder sealing material, as described above. The relatively harder sealing material of the outer housing504may be configured to form a seal between the outer housing504and the ball102. In some embodiments, a seating surface510of the insert502may be configured to form a seal with the ball102. For example, a secondary seating surface516on the outer housing504may define a seal between the outer housing504and the ball102in addition to the seal formed with the insert502or when the seating surface510of the insert502fails to form a seal.

In some embodiments, the insert502may include an end portion (e.g., a leading end512) that spaces the seating surface510from a portion of the outer housing504. For example, the leading end512may define a surface aligned in an axial direction of the seat500that spaces the seating surface510from the outer housing504(e.g., the sealing surface516of the outer housing504) and may act to at least partially align the seating surfaces510,516in a substantially similar angled plane.

In some embodiments, the insert502may include another end portion (e.g., the trailing end514) that spaces the seating surface510from another portion of the outer housing504(e.g., the shelf522).

Although the outer housing502may at least partially be utilized to seal against the valve body104, the harder sealing material of the outer housing504may require a higher amount of force to form a seal than the soft sealing material of the insert502. However, the harder sealing material of the outer housing504may withstand forces due to higher pressures better than the soft sealing material of the insert502. In some embodiments, the seating surface510of the insert502may form a seal against the ball102while the secondary seating surface516of the outer housing504may support the ball102(and the insert502) in, for example, high pressure applications (e.g., to counteract forces applied to the seat500with the ball102).

Similar to that discussed above, the outer housing504may include an outer surface506(e.g., lateral or radial extent, outer wall) that is positioned adjacent a radial portion of the valve body104(e.g., bordering, contacting, securing the housing504against the valve body104). The outer housing504may include an end surface507(e.g., an axial end, an axial outer wall) that is positioned adjacent an axial portion (e.g., an end cap) of the valve body104(e.g., bordering, contacting, securing the housing504against a portion of the valve body104).

In some embodiments, the outer housing504may include a sealing element530(e.g., outer body seal) positioned between the outer housing504and the valve body104to provide a seal between the outer housing504and valve body104. For example, the seat500may provide a seal between the ball102and the valve body104with (e.g., by elastically deforming) both the insert502and the sealing element530.

As depicted, the outer housing504may include a groove532(e.g., slot, recess, etc.) configured to retain the sealing element530. The sealing element530may be at least partially (e.g., partially, substantially, etc.) disposed within the groove532at chamfered surface between the outer surface506ad the end surface507of the outer housing504. In some embodiments, the sealing element530may be formed from substantially similar materials to the insert502. For example, the materials of the sealing element530and the insert502may be selected to elastically deform at substantially the same level of force in order to define the seal in the valve100. For example, the sealing element530may be formed from a polymer material, for example, an elastomeric material, such as rubber (e.g., ethylene propylene diene (EPDM), nitrile rubber (NBR), styrene butadiene rubber (SBR), silicon rubber, butyl rubber, polybutadiene, etc.), neoprene (e.g., polychloroprene, pc-rubber, etc.), polytetrafluoroethylene (PTFE), or polyurethane. In some embodiments, the sealing element530may be an O-ring (e.g., with a circular cross section), a D-ring (e.g., having at least one flat side), or an annular ring with another geometric cross section (e.g., oval, ellipsis, parabolic, square, rectangular, triangle, pentagon, hexagon, octagon, etc.) or an asymmetric cross section.

The sealing element530may create and/or maintain a seal between the valve seat500and the valve body104. The sealing element530may operate as a primary seal substantially inhibiting (e.g., at least partially inhibiting, stopping, preventing, etc.) fluid from passing between the valve seat500(e.g., the outer housing504) and the valve body104(e.g., around an outer portion of the valve seat500). In some embodiments, the sealing element530may operate as a secondary (e.g., backup, fail-safe, etc.) seal to prevent fluid from passing between the valve seat500and the valve body104should another seal (e.g., a seal provided by one or more portions of the outer housing504) between the outer housing504and the valve body104fail.

FIG. 6illustrates a cross-sectional view of a valve seat600, which may be similar and include one or more of the features of the other valve seats discussed herein. Referring toFIGS. 1 and 6, a portion of an outer housing604(e.g., a trailing surface607, such as an axially outer surface) may be configured to define a seal between the valve seat600and the valve body104. As depicted, a sealing element630may be positioned between the outer housing604and the valve body104. For example, the outer housing604may include a slot632(e.g., groove, recess, etc.) defined in the trailing surface607configured to retain the sealing element630. The sealing element630may be at least partially (e.g., partially, substantially, etc.) disposed within the slot632. In some embodiments, the sealing element630may be formed from a relatively softer polymer or elastomeric material similar to the sealing element530described above with respect toFIG. 5. As depicted, the sealing element630may be at least one sealing strip (e.g., substantially flat annular ring). The sealing element630may have a width634that is substantially greater than a height636of the sealing element630.

As depicted, the sealing element630may be positioned between the trailing surface607of the outer housing604and the valve body104. In some embodiments, the sealing element630may be positioned between the outer surface606of the outer housing604and the valve body104or at an interface between the outer surface606and the trailing surface607.

FIG. 7illustrates a cross-sectional view of a valve seat700, which may be similar and include one or more of the features of the other valve seats discussed herein. Referring toFIGS. 1 and 7, a portion of an outer housing704(e.g., a trailing surface707, such as an axially outer surface) may be configured to define a seal between the valve seat700and the valve body104. As depicted, one or more sealing elements730may be positioned between the outer housing704and the valve body104. For example, the outer housing704may include one or more slots732(e.g., groove, recess, etc.) defined in the trailing surface707configured to retain the one or more sealing elements730. The one or more sealing elements730may be at least partially (e.g., partially, substantially, etc.) disposed within the one or more slots732. In some embodiments, the one or more sealing elements730may be formed from a relatively softer polymer or elastomeric material similar to the sealing element530described above with respect toFIG. 5.

As depicted, the one or more sealing elements730may be at least one of an annular sealing ring as described above with respect toFIG. 5or a sealing strip as described above with respect toFIG. 6. In some embodiments, the one or more sealing elements730may include at least two sealing elements730comprising annular sealing rings and/or sealing strips.

In some embodiments, the one or more sealing elements730may be positioned between a trailing surface707of the outer housing704and the valve body104. In some embodiments, the one or more sealing elements730may be positioned between the outer surface706of the outer housing704and the valve body104or at an interface between the outer surface706and the trailing surface707. In some embodiments, the one or more sealing elements730may be positioned on different surfaces of the outer housing704, such as those discussed above.

The embodiments of the present disclosure may provide valve seats having a relatively softer seat for contacting the valve member, which may provide low friction, lower required sealing forces, lower required amounts of torque during actuation, and/or relatively higher chemical resistance. The valve seat also provides a support region having a higher strength (e.g., stiffer) material having a greater resilience to high loads and/or high pressure/temperature than a softer seat. Such a combination or compound seat may be ideally suited to applications involving high pressure and/or high temperature, along with high loads or shock loading.

Valve seats according to embodiments of the present disclosure may further provide support in high pressure systems (e.g., including high pressure fluids and/or shock loading scenarios) while maintaining seals requiring less force to rotate the ball of a ball valve. In high pressure systems, valve seats of soft materials may fail due to deformation, fatigue, or other failures as a result of the large forces associated with high pressures. The higher strength materials used in high pressure systems to compensate for the high pressures may require much greater forces (e.g., torque) to rotate the ball of the ball valve against the seat. The high forces may require more expensive and cumbersome actuators to move the valves. The embodiments of the present disclosure may enable soft seat materials to be used in high pressure applications allowing for a reduction in the amount of torque required to rotate the ball of the ball valve while maintaining the strength required to withstand the large forces associated with the high pressures.

While the present disclosure has been described herein with respect to certain illustrated embodiments, those of ordinary skill in the art will recognize and appreciate that it is not so limited. Rather, many additions, deletions, and modifications to the illustrated embodiments may be made without departing from the scope of the disclosure as hereinafter claimed, including legal equivalents thereof. In addition, features from one embodiment may be combined with features of another embodiment while still being encompassed within the scope of the disclosure as contemplated by the inventor.