Patent Publication Number: US-2022235867-A1

Title: Bonded seat valve

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to PCT Application CN2021/074093, filed Jan. 28, 2021, which is hereby incorporated in their entirety by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to seats for valves. More specifically, this disclosure relates to a bonded seat for a valve. 
     BACKGROUND 
     Valves often have a valve member housed within a valve body, and a valve seat positioned between the valve member and the valve body to form a seal when the valve is placed in a closed configuration. Examples of common valve members include the ball of a ball valve, the disc of a butterfly valve, or the gate of a gate valve. The seat often is made of a resilient member that elastically deforms due to contact with the valve member to form the seal between the valve member and the seat. The elastic deformation produces pressure and friction between the seat and the valve member. Increasing the interference between the valve member and the seat can increase the seal strength and pressure rating of the valve, but doing so also typically increases the friction on the valve member when opening and closing the valve, particularly when the valve is subjected to a pressure differential across the valve member as is often the case when the valve is in the closed position. As the force of friction increases, the valves can become difficult and/or time consuming to operate. Such valves may require manual gearboxes or powered valve actuators because the force required to open the valve is too great for a simple quarter-turn valve handle to be turned manually. 
     SUMMARY 
     It is to be understood that this summary is not an extensive overview of the disclosure. This summary is exemplary and not restrictive, and it is intended to neither identify key or critical elements of the disclosure nor delineate the scope thereof. The sole purpose of this summary is to explain and exemplify certain concepts of the disclosure as an introduction to the following complete and extensive detailed description. 
     Disclosed is a valve seat comprising a first end; a second end positioned opposite from the first end; and a body extending from the first end to the second end, the body defining an inner surface and an outer surface, the inner surface defining a main bore extending through the body from the first end to the second end, the main bore defining a main bore axis, the body defining a shaft bore extending from the inner surface to the outer surface, the shaft bore defining a shaft bore axis positioned perpendicular to the main bore axis, the shaft bore defining an inner shaft opening and an outer shaft opening, the body defining a concave seat bearing surface extending around the inner shaft opening. 
     Also disclosed a valve comprising a valve seat defining an inner seat surface and an outer seat surface, a shaft bore extending through the valve seat from the inner seat surface to the outer seat surface, an inner shaft opening of the shaft bore defined at the inner seat surface, the inner seat surface defining a concave seat bearing surface extending around the inner shaft opening; and a valve member defining an end engaging the concave seat bearing surface, the end defining a valve member end surface, the valve member end surface defining a convex shape. 
     Also disclosed is a valve seat comprising a body defining an inner surface and an outer surface, the inner surface defining a main bore extending through the body, the body defining a shaft bore extending from the inner surface to the outer surface, the shaft bore defining an inner shaft opening, the body defining a concave seat bearing surface extending around the inner shaft opening. 
     Various implementations described in the present disclosure may include additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. The features and advantages of such implementations may be realized and obtained by means of the systems, methods, features particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. The drawings are not necessarily drawn to scale. Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity. 
         FIG. 1  is a perspective view of a prior art valve seat comprising a first end, and second end, and a body. 
         FIG. 2  is a cross-sectional view of the prior art valve seat of  FIG. 1 , taken along line  2 - 2  shown in  FIG. 1 . 
         FIG. 3  is a detailed cross-sectional view of an upper shaft bore of the prior art valve seat of  FIG. 1 , taken along line  3 - 3  shown in  FIG. 1 . 
         FIG. 4  is a perspective view of a valve comprising an improved valve seat, a valve body, a shaft, an upper gland, and a valve member in accordance with one aspect of the present disclosure. 
         FIG. 5  is a perspective view of the valve seat of  FIG. 4 . 
         FIG. 6  is a cross-sectional view of the valve of  FIG. 4 , taken along line  6 - 6  shown in  FIG. 4 . 
         FIG. 7A  is a detailed cross-sectional view of the valve of  FIG. 4 , taken from detail  7  shown in  FIG. 6 . 
         FIG. 7B  is a detailed cross-sectional view of the valve of  FIG. 4 , taken from detail  7  shown in  FIG. 6  in accordance with another aspect of the present disclosure. 
         FIG. 7C  is a detailed cross-sectional view of the valve of  FIG. 4 , taken from detail  7  shown in  FIG. 6  in accordance with another aspect of the present disclosure. 
         FIG. 8  is a cross-section of the valve of  FIG. 4 , taken along line  8 - 8  shown in  FIG. 4 . 
         FIG. 9A  is a detailed cross-sectional view of an upper bearing pad of the valve seat of the valve of  FIG. 4 , taken from detail  9  shown in  FIG. 8 . 
         FIG. 9B  is a detailed cross-sectional view of the upper bearing pad of the valve seat of the valve of  FIG. 4 , taken from detail  9  shown in  FIG. 8  in accordance with another aspect of the present disclosure. 
         FIG. 10A  is a detailed cross-sectional view of the upper bearing pad of the valve seat of  FIG. 4 , taken from detail  9  shown in  FIG. 8 . 
         FIG. 10B  is a detailed cross-sectional view of the upper bearing pad of the valve seat of  FIG. 4 , taken from detail  9  shown in  FIG. 8  in accordance with another aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and the previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this disclosure is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, and, as such, can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. 
     The following description is provided as an enabling teaching of the present devices, systems, and/or methods in its best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the present devices, systems, and/or methods described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present disclosure are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description is provided as illustrative of the principles of the present disclosure and not in limitation thereof. 
     As used throughout, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an element” can include two or more such elements unless the context indicates otherwise. 
     Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. 
     For purposes of the current disclosure, a material property or dimension measuring about X or substantially X on a particular measurement scale measures within a range between X plus an industry-standard upper tolerance for the specified measurement and X minus an industry-standard lower tolerance for the specified measurement. Because tolerances can vary between different materials, processes and between different models, the tolerance for a particular measurement of a particular component can fall within a range of tolerances. 
     As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not. 
     The word “or” as used herein means any one member of a particular list and also includes any combination of members of that list. Further, one should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain aspects include, while other aspects do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular aspects or that one or more particular aspects necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular aspect. 
     Disclosed are components that can be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed, that while specific reference of each various individual and collective combinations and permutations of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods and systems. This applies to all aspects of this application including, but not limited to, steps in disclosed methods. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the disclosed methods. 
     Disclosed is a valve seat and associated methods, systems, devices, and various apparatus. The valve seat can comprise a first end, a second end, and a body. It would be understood by one of skill in the art that the disclosed valve seat is described in but a few exemplary aspects among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom. 
     In overview,  FIGS. 1-3  depict a prior art valve seat  100 . In particular, the valve seat shown is from a Model 12″ 2F2 250B BFV butterfly valve made by Jingmen Pratt Valve Co. Ltd., headquartered in Hubei, China.  FIGS. 4 and 6-9B  depict various aspects of a valve  400  comprising an improved valve seat  100 ′ (referred to as “valve seat  100 ′” hereafter), which can demonstrate various improvements over the prior art valve seat  100  in various aspects.  FIGS. 5, 10A, and 10B  provide various views of the valve seat  100 ′ of  FIG. 4 . 
     Turning to the individual figures,  FIG. 1  is a perspective view of the prior art valve seat  100  comprising a first end  110   a , a second end  110   b , and a body  150 . The body  150  can extend from the first end  110   a  to the second end  110   b . The body  150  can define an inner seat surface  152  and an outer seat surface  154 . 
     The inner seat surface  152  can define a main bore  156  extending through the body  150  from the first end  110   a  to the second end  110   b . The main bore  156  can define a main bore axis  101 . The body  150  can define an upper shaft bore  160   a  and a lower shaft bore  160   b , each extending through the body  150  from the inner seat surface  152  to the outer seat surface  154 . The shaft bores  160   a,b  can share a common shaft bore axis  161 . The shaft bore axis  161  can be perpendicular to the main bore axis  101 . Each shaft bore  160   a  can respectively define an inner shaft opening  162   a,b  and an outer shaft opening  164   a,b , such that each inner shaft opening  162   a,b  can be positioned between the adjacent respective outer shaft opening  164   a,b  and the main bore axis  101 . Each shaft bore  160   a,b  can respectively define a shaft bore surface  166   a,b  extending between the respective shaft openings  162   a,b , 164   a,b . The shaft bore surfaces  166   a,b  can be cylindrical. 
     The inner seat surface  152  can define a cylindrical portion  170  and a pair of bearing pads  168   a,b  (bearing pad  168   a  shown in  FIG. 3 ). The cylindrical portion  170  of the inner seat surface  152  can be substantially cylindrical. The bearing pads  168   a,b  can define a pair of seat bearing surfaces  169   a,b  (seat bearing surface  169   a  shown in  FIG. 3 ) extending around the respective inner shaft openings  162   a,b . The inner shaft openings  162   a,b  can each be defined at an intersection between the respective shaft bore surfaces  166   a,b  and the respective seat bearing surfaces  169   a,b . The seat bearing surfaces  169   a,b  can be planar, and the seat bearing surfaces  169   a,b  can be normal to the shaft bore axis  161 , as shown in greater detail in  FIG. 3 . 
       FIG. 2  is a cross-sectional view of the prior art valve seat  100  of  FIG. 1 , taken along line  2 - 2  shown in  FIG. 1 . The body  150  can define a flange lip  202   a,b  at the ends  110   a,b , respectively. The body  150  can define a sealing portion  210  axially centered between the ends  110   a,b  relative to the main bore axis  101 . The body  150  can define a pair of bore portions  206   a,b  extending between the sealing portion  210  and the adjacent flange lips  202   a,b  and/or ends  110   a,b . The body  150  can define a pair of transition shoulders  214   a,b  extending between the sealing portion  210  and the adjacent bore portions  206   a,b . The transition shoulders  214   a,b  can extend radially outward with respect to the main bore axis  101  from the bore portions  206   a,b  to the sealing portion  210  so that the sealing portion  210  can be thicker than the bore portions  206   a,b  when measured in a radial direction with respect to the main bore axis  101 . 
     The cylindrical portion  170  of the inner seat surface  152  can be parallel to the main bore axis  101 . The sealing portion  210  can define a cylindrical portion  212  of the outer seat surface  154  extending from a first transition shoulder  214   a  of the transition shoulders  214   a,b  to a second transition shoulder  214   b  of the transition shoulders  214   a,b . As shown, the cylindrical portion  212  of the outer seat surface  154  can be parallel to the main bore axis  101 . 
       FIG. 3  is a detailed cross-sectional view of the upper shaft bore  160   a  of the prior art valve seat  100 , taken along line  3 - 3  shown in  FIG. 1 . The bearing pad  168   a  can protrude radially inward from the cylindrical portion  170  of the inner seat surface  152  relative to the main bore axis  101  (shown in  FIG. 1 ). As similarly noted above, the inner shaft opening  162   a  can be defined at an intersection between the shaft bore surface  166   a  and the seat bearing surface  169   a . Specifically, the inner shaft opening  162   a  can be defined by a right-angle corner  362  at the intersection between the shaft bore surface  166   a  and the seat bearing surface  169   a.    
     The outer seat surface  154  can define a boss  364  extending radially outward from the cylindrical portion  212  with respect to the main bore axis  101  (shown in  FIG. 1 ). The boss  364  can define the outer shaft opening  164   a . The boss  364  can define a sidewall thickness T 1 , measured from the shaft bore surface  166   a  radially outward to an outer circumferential surface  366  of the boss  364 , relative to the shaft bore axis  161 . The boss  364  can define a height H, measured from a portion of the outer seat surface  154  surrounding the boss  364  axially outwards to the outer shaft opening  164   a , relative to the shaft bore axis  161 . For the boss  364  of the prior art valve seat  100 , a ratio of the height H divided by the sidewall thickness T 1  can be greater than four (4). The outer circumferential surface  366  can define an outer boss diameter D 1 . A ratio of the outer boss diameter D 1  divided by the sidewall thickness T 1  for the boss  364  can be greater than 23. 
       FIG. 4  is a perspective view of the valve  400  comprising the valve seat  100 ′, a valve body  410 , a shaft  420 , an upper gland  422 , and a valve member  450  in accordance with one aspect of the present disclosure. Discussion of the valve seat  100 ′ may refer back to features disclosed with respect to  FIGS. 1-3  of the prior art valve seat  100  where those structures are similar or identical, as well as to identify differences between the prior art valve seat  100  and the disclosed valve seat  100 ′. 
     The valve body  410  can define a first flange  412   a  and a second flange  412   b  positioned opposite from the first flange  412   a . A main valve bore  411  can extend through the valve body  410  from the first flange  412   a  to the second flange  412   b . The valve seat  100 ′ can be positioned within the main valve bore  411 , and the valve seat  100 ′ can be bonded to the valve body  410 . 
     As demonstrated by the first flange  412   a , the flanges  412   a,b , can define flange faces  414   a,b  (flange face  414   b  shown in  FIG. 6 ). The flange lips  202   a,b  (flange lip  202   b  shown in  FIG. 6 ) of the valve seat  100 ′ can be positioned flush with the flange faces  414   a,b . In other aspects, the flange lips  202   a,b  can stand proud of the adjacent flange faces  414   a,b.    
     The valve body  410  can define an upper gland flange  418  positioned between the flanges  412   a,b . The upper gland flange  418  can receive the shaft  420  and the upper gland  422 , which can form a seal between the valve body  410  and the shaft  420 . The upper gland flange  418  can be configured for mounting a valve actuator (not shown), such as a quarter-turn manual actuator, a gear box, or a motor, for example and without limitation. Mounting the valve actuator to the upper gland flange  418  can compress the upper gland  422 , thereby energizing the upper gland  422 . 
     The shaft  420  can extend through the valve body  410  and through the main valve bore  411 . The shaft  420  can extend through the valve member  450 , as shown in  FIGS. 6 and 8 . As shown in  FIG. 4 , the valve member  450  can be a disc, and the valve  400  can be a butterfly valve. The valve member  450  can be positioned within the main bore  156 . The valve member  450  is shown in a closed position, wherein the valve member  450  can seal with the inner seat surface  152  of the valve seat  100 ′ to block the main bore  156  of the seat  100 ′. The valve member  450  can be rotated about and between the closed position and an open position (not shown), wherein the valve member  450  can be positioned sideways in the main bore  156 , thereby allowing a fluid to pass around the valve member  450  through the main bore  156 . The shaft  420  can be rotationally fixed to the valve member  450 . Rotating the shaft  420 , such as with the valve actuator, can rotate the valve member  450  about and between the closed position and the open position. 
       FIG. 5  is a perspective view of the valve seat  100 ′ of  FIG. 4 . The valve seat  100 ′ can incorporate numerous improvements over the prior art valve seat  100  of  FIG. 1 . 
     One improvement is that in place of the cylindrical portion  212  (shown in  FIG. 2 ) of the prior art valve seat  100 , the outer seat surface  154  of the valve seat  100 ′ can define a circumferential sealing rib  512 , which can extend circumferentially around the sealing portion  210  of the valve seat  100 ′. As shown, the circumferential sealing rib  512  can intersect and support the boss  364 . The circumferential sealing rib  512  is discussed below in greater detail with respect to  FIGS. 6-7C . 
     Another improvement is that the boss  364  can be a reinforced boss  564 , as discussed in greater detail below with respect to  FIG. 10B . 
     Another improvement is that at least one annular rib  566  can be defined within the shaft bores  160   a,b , as demonstrated by upper shaft bore  160   a , wherein the shaft bore surface  166   a  can define the at least one annular rib  566 . The at least one annular rib  566  is discussed below in greater detail with respect to  FIG. 10A . 
     Another improvement is that a shape of the seat bearing surfaces  169   a,b  (seat bearing surface  169   a  shown in  FIG. 3 ) defined by the bearing pads  168   a,b  (bearing pad  168   a  shown in  FIG. 3 ) can be nonplanar, as discussed in greater detail below with respect to  FIGS. 9A-10B . For example, the seat bearing surfaces  169   a,b  can be concavely shaped. 
     Valve seats  100 ′ manufactured in accordance with the present disclosure can comprise one or more of the disclosed improvements. Some aspects may not comprise each of the disclosed improvements. Various aspects of the valve seat  100 ′ can comprise any combination of the disclosed improvements. 
       FIG. 6  is a cross-sectional view of the valve  400  of  FIG. 4 , taken along line  6 - 6  shown in  FIG. 4 . The valve body  410  can define an inner body surface  652  and an outer body surface  654 . The inner body surface  652  can define the main valve bore  411  extending from the first flange  412   a  to the second flange  412   b . The valve seat  100 ′ can be positioned within the main valve bore  411 , and the main valve bore  411  can be substantially coaxial with the main bore  156  of the valve seat  100 ′ about the main bore axis  101 . 
     In some aspects, the valve body  410  can be a casting, which can define a rough surface that can include pores, hairline cracks, and residual roughness imprinted from the mold, such as when cast in a sand-based mold for example and without limitation. The outer seat surface  154  of the valve seat  100 ′ can be bonded to the inner body surface  652  of the valve body  410 . The valve seat  100 ′ can comprise a resilient material, such as a rubber, polymer, or other suitable material, that can engage the rough surface to adhere, or bond, the valve seat  100 ′ to the valve body  410 . The bond between the valve seat  100 ′ and the valve body  410  can also act as a seal that prevents materials, such as fluids, from passing between the valve body  410  and the valve seat  100 ′, such as where the flange lips  202   a,b  overlay a portion of the flanges  412   a,b  positioned radially inward from the flange faces  414   a,b.    
     In the closed position (shown), the valve member  450  can seal with the inner seat surface  152  of the valve seat  100 ′ at the sealing portions  210 . The circumferential sealing rib  512  can be positioned approximately opposite from where the valve member  450  contacts the inner seat surface  152  in the closed position. A center plane  601  can bisect the valve seat  100 ′ and the valve  400  so that the center plane  601  is positioned normal to the main bore axis  101  and equidistant from the first end  110   a  and the second end  110   b  of the valve seat  100 ′. In the present aspect, the center plane  601  can bisect the circumferential sealing rib  512 . 
     The inner body surface  652  of the valve body  410  can define a circumferential sealing groove  612  shaped and sized complimentary to the circumferential sealing rib  512 . The circumferential sealing groove  612  can receive the circumferential sealing rib  512 . The center plane  601  can bisect the circumferential sealing groove  612  in the present aspect. 
       FIGS. 7A-C  are detailed cross-sectional views of the valve  400  of  FIG. 4 , taken from detail  7  shown in  FIG. 6 .  FIGS. 7A-C  demonstrate various cross-sectional shapes of the circumferential sealing rib  512 . 
     Turning to  FIG. 7A , in place of the cylindrical portion  212  (shown in  FIG. 2 ) of the prior art valve seat  100  (shown in  FIG. 2 ) extending from the first transition shoulder  214   a  of the transition shoulders  214   a,b  to the second transition shoulder  214   b , here, the sealing portion  210  of the valve seat  100 ′ can define the circumferential rib  512  extending radially outward with respect to the main bore axis  101  (shown in  FIG. 6 ). The circumferential sealing rib  512  can be centered between a pair of cylindrical sub-portions  711 , each extending from the circumferential sealing rib  512  to the adjacent transition shoulder  214   a,b . In the aspect shown, the circumferential sealing rib  512  of the valve seat  100 ′ and the circumferential sealing groove  612  of the valve body  410  can each define an arcuate cross-sectional shape  712   a . In some aspects, the arcuate cross-sectional shape  712   a  can define a constant radius of curvature, such as an arc of a circle. In some aspects, the arcuate cross-sectional shape  712   a  can define a variable radius of curvature, such as an arc of an oval, ellipse, or other rounded geometric shape. 
       FIG. 7B  illustrates a different shape of the circumferential sealing rib  512  of the valve seat  100 ′ and the circumferential sealing groove  612  of the valve body  410  according to another aspect of the present disclosure. In the aspect shown, the circumferential sealing rib  512  and the circumferential sealing groove  612  can each define a V-shaped cross-sectional shape  712   b . In cross-section, the V-shaped cross-sectional shape  712   b  can comprise a pair of linear sides  714  meeting at a rounded tip  716 . In other aspects, the pair of linear sides  714  can directly intersect to form a pointed tip (not shown). The pair of linear sides  714  can correspond to a pair of frustoconical surfaces  718  of the circumferential sealing rib  512  and circumferential sealing groove  612 . 
       FIG. 7C  illustrates another shape of the circumferential sealing rib  512  of the valve seat  100 ′ and the circumferential sealing groove  612  of the valve body  410  according to yet another aspect of the present disclosure. In the aspect shown, the circumferential sealing rib  512  and the circumferential sealing groove  612  can each define a U-shaped cross-sectional shape  712   c . In cross-section, the U-shaped cross-sectional shape  712   c  can comprise an outer cylindrical portion  720 , a pair of convex transitions  722 , a pair of side portions  724 , and a pair of concave transitions  726 . Each concave transitions  726  can be positioned between one of the side portions  724  and one of the cylindrical sub-portions  711 . Each convex transition  722  can be positioned between one of the side portions  724  and the outer cylindrical portion  720 . The outer cylindrical portion  720  can be parallel to the main bore axis  101  (shown in  FIG. 6 ). The side portions  724  can be linear in the present aspect. In some aspects, the side portions  724  can be parallel to one another and perpendicular to the outer cylindrical portion  720 . In the aspect shown, the side portions  724  can taper towards the outer cylindrical portion  720 . 
     In each of the aspects of  FIGS. 7A-C , the valve member  450  can contact the inner seat surface  152  of the valve seat  100 ′ opposite from the circumferential sealing rib  512 . The valve member  450  can comprise a rigid material, such as a metal for example and without limitation, while the valve seat  100 ′ can comprise a resilient material as discussed above. The valve member  450  can be sized to interfere with the valve seat  100 ′ in the closed position (shown) so that the valve seat  100 ′ elastically deforms due to pressure exerted by the valve member  450 . The pressure exerted by the valve member  450  on the valve seat  100 ′ can be in the radial direction with respect to the main bore axis  101  (shown in  FIG. 6 ). 
     Deformation from the valve member  450  can compress the circumferential sealing rib  512  into the circumferential sealing groove  612 , which can control, or limit, deformation of the valve seat  100 ′ in the sealing portion  210  to create a compressed region  700  at least partially bounded between the valve member  450  and the circumferential sealing groove  612 . In material science and solid mechanics, Poisson&#39;s Effect causes deformation, such as expansion, of a material in directions perpendicular to the direction of compressive loading. Here, as the valve member  450  compresses the valve seat  100 ′ in the radial direction, the compressed region  700  can be biased to expand in the axial direction with respect to the main bore axis  101 , which would partially relieve the compressive stress of the compressed region  700 . However, the circumferential sealing groove  612  can partially confine the compressed region  700  in both the radial and axial directions, thereby maintaining a high degree of compressive stress in the compressed region  700 . Specifically, the compressed region  700  can be maintained in a three-dimensional compressive state, which can provide a more stable and reliable seal between the valve seat  100 ′ and the valve member  450  compared to the prior art valve seat  100  (shown in  FIG. 1 ). 
     By comparison, when the sealing portion  210  of the prior art valve seat  100  is compressed by the valve member  450  in the radial direction with respect to the main bore axis  101  (shown in  FIG. 6 ), Poisson&#39;s Effect can cause the sealing portion  210  to deform in the axial direction, thereby reducing the compressive stress between valve member  450  and the prior art valve seat  100 . 
       FIG. 8  is a cross-section of the valve  400  of  FIG. 4 , taken along line  8 - 8  shown in  FIG. 4 . The shaft  420  can extend through the valve body  410 , the valve seat  100 ′, and the valve member  450 . The valve body  410  can define an upper body shaft bore  820   a  and a lower body shaft bore  820   b , and the shaft  420  can extend through the body shaft bores  820   a,b . The valve  400  can comprise a pair of bearing sleeves  823   a,b . The bearing sleeves  823   a,b  can be respectively positioned within the body shaft bores  820   a,b , and the bearing sleeves  823   a,b  can prevent direct contact between the shaft  420  and the body shaft bores  820   a,b . The bearing sleeves  823   a,b  can comprise a bearing material. For example and without limitation, the bearing material can be chosen for its hardness, such as bronze, its low coefficient of friction, such as polytetrafluoroethylene, or a combination of these properties, such as high density polyethylene. 
     The valve  400  can further comprise a lower gland  822 , a bottom plate  824 , and at least one fastener  826 . The lower gland  822  can form a seal between the shaft  420  and the lower body shaft bore  820   b , similar to how the upper gland  422  can form a seal between the shaft  420  and the upper body shaft bore  820   a . The valve body  410  can define a lower gland flange  818 , and the bottom plate  824  can be coupled to the lower gland flange  818  by the fasteners  826 . The bottom plate  824  can compress the lower gland  822 , thereby energizing the lower gland  822  and the seal formed with the shaft  420  and lower body shaft bore  820   b.    
     The shaft  420  can extend through the valve member  450 , and the valve member  450  can be secured to the shaft  420  by a pin  850 . The pin  850  can rotationally fix the valve member  450  to the shaft  420  so that the shaft  420  can be turned to rotate the valve member  450  about and between the open position (not shown) and the closed position (shown in  FIG. 8 ). 
     The shaft  420  can also extend through the upper shaft bore  160   a  and the lower shaft bore  160   b  of the valve seat  100 ′. The valve member  450  can engage and seal with the bearing pads  168   a,b.    
       FIGS. 9A and 9B  are detailed cross-sectional views of the upper bearing pad  168   a  of the valve seat  100 ′ of the valve  400 , taken from detail  9  shown in  FIG. 8 . The discussion of the upper bearing pad  168   a  can be equally applicable to the lower bearing pad  168   b  (shown in  FIG. 8 ). 
     As shown in  FIG. 9A , the shaft  420  can define a shaft diameter D 2 . 
     The valve member  450  can have an interference fit between the upper bearing pad  168   a  and the lower bearing pad  168   b  (shown in  FIG. 8 ), wherein the valve member  450  can exert axial compressive forces on the bearing pads  168   a,b  relative to the shaft bore axis  161  of the upper shaft bore  160   a . The valve body  410  can define a boss recess  920  where the reinforced boss  564  meets the upper body shaft bore  820   a . The boss recess  920  can be enlarged in the radial direction with respect to the shaft bore axis  161  compared to the upper body shaft bore  820   a , and the boss recess  920  can receive the reinforced boss  564 . Due to the upward axial compressive force of the valve member  450  acting on the upper bearing pad  168   a , the reinforced boss  564  can be compressed within the boss recess  920  and against the shaft  420  in a three-dimensional compressive state. Due to the Poisson Effect, the axial compression of the reinforced boss  564  can induce radial expansion, with respect to the shaft bore axis  161 , which can cause the reinforced boss  564  to seal with the shaft  420 . As noted above, the bonded nature of the valve seat  100 ′ and the valve body  410  can create a seal between the valve seat  100 ′ and the valve body  410 , including between the reinforced boss  564  and the boss recess  920 . The three-dimensional compressive state of the reinforced boss  564  can provide a more stable and reliable seal between the valve seat  100 ′ and the shaft  420 . 
     Compared to the prior art valve seat  100  (shown in  FIG. 1 ) wherein the bearing pad  168   a  defines a seat bearing surface  169   a  that is planar, here, the valve seat  100 ′ can define a seat bearing surface  169   a  that is concave. Specifically, the seat bearing surface  169   a  can be a spherical zone  969   a . In geometry, a spherical segment is the solid formed by cutting a sphere, or ball, with a pair of parallel planes. A spherical zone is the surface defined by the spherical segment. The inner shaft opening  162   a  can be defined at an intersection of the spherical zone  969   a  and the shaft bore surface  166   a.    
     An end  950  of the valve member  450  can define a valve member end surface  951   a . The valve member end surface  951   a  can define a convex shape. Specifically, the valve member end surface  951   a  can be shaped as a spherical zone, complimentary to the spherical zone  969   a.    
       FIG. 9B  demonstrates another concave shape of the seat bearing surface  169   a  according to another aspect of the present disclosure. In the aspect shown, the seat bearing surface  169   a  can be a frustoconical surface  969   b . The inner shaft opening  162   a  can be defined at an intersection of the frustoconical surface  969   b  and the shaft bore surface  166   a , and an angle  962  measured between the shaft bore surface  166   a  and the frustoconical surface  969   b  through the valve seat  100 ′ can be an obtuse angle. 
     The valve member end surface  951   b  defined by the end  950  of the valve member  450  can define a convex shape. Specifically, the valve member end surface  951   b  can be shaped as a frustoconical surface, complimentarily to the frustoconical surface  969   b . In some aspects, the valve member  450  with the valve member end surface  951   a  of  FIG. 9A , shaped as a spherical zone, can be mated with the frustoconical surface  969   b , shown in  FIG. 9B . In some aspects, the valve member  450  with the valve member end surface  951   b  of  FIG. 9B , shaped as a frustoconical surface, can be mated with the spherical zone  969   a , shown in  FIG. 9A . 
     Compared to the planar seat bearing surfaces  169   a,b  ( 169   b  shown in  FIG. 1 ) of the prior art valve  100  (shown in  FIG. 1 ), contact between the convex shapes, such as the spherical zone  969   a  (shown in  FIG. 9A ) and the frustoconical surface  969   b , of the seat bearing surface  169   a  and the complimentarily shaped end  950  can reduce the rotational torque from friction required to rotate the valve member  450  against the seat bearing surface  169   a . Additionally, the convex shapes can prevent the valve seat  100 ′ from shifting relative to the valve member  450  when the valve  400  is pressurized because the convex seat bearing surfaces  169   a  can receive and center the end  950  of the valve member  450 . By preventing seat shift, the convex seat bearing surfaces  169   a  can better resist large pressure differentials across the valve member  450 , such as when the valve member  450  is in the closed position with pressurized fluid acting on only one side of the valve member  450 . 
     As shown in  FIG. 9B , the bearing sleeve  823   a , positioned between the shaft  420  and the upper body shaft bore  820   a , can define a sleeve thickness T 2 , which can also be representative of the bearing sleeve  823   b  (shown in  FIG. 8 ). 
       FIGS. 10A and 10B  are detailed cross-sectional views of the upper bearing pad  168   a  of the valve seat  100 ′, taken from detail  9  shown in  FIG. 8 .  FIG. 10A  further shows the spherical zone  969   a , and  FIG. 10B  further shows the frustoconical surface  969   b.    
     As further shown in  FIG. 10A , rather than the purely cylindrical shaft bore surface  166   a  of the prior art valve seat  100  (shown in  FIG. 1 ), here, the shaft bore surface  166   a  can define at least one annular rib  566  within the upper shaft bore  160   a . Specifically, the shaft bore surface  166   a  can define two annular ribs  566 ; however, in other aspects, the shaft bore surface  166   a  can define greater or fewer than two annular ribs  566 . The shaft bore surface  166   a  can otherwise be cylindrical with the exception of the at least one annular rib  566 . 
     The annular ribs  566  can help to prevent leakage between the shaft  420  (shown in  FIG. 9A ) and the upper shaft bore  160   a  by distributing compressive forces of the shaft bore surface  166   a  against the shaft  420  over a smaller area, thereby increasing the pressure of the seal formed between the shaft  420  and the annular ribs  566  of the shaft bore surface  166   a.    
     Additionally, the annular ribs  566  can reduce contact friction resistance between the valve seat  100 ′ and the shaft  420  because the pattern of contact between the annular ribs  566  and the shaft  420  is of a line-contact. In other words, the pattern of contact between each annular rib  566  and the shaft  420  can be a very thin ring, approaching a theoretical two-dimensional pattern of contact, which can approximate linear contact between the valve seat  100 ′ and the shaft  420 , thereby producing less contact friction resistance than the prior art valve seat  100  (shown in  FIG. 1 ). 
     As shown in  FIG. 10B , the boss  364  of the valve seat  100 ′ can be the reinforced boss  564  previously referenced with respect to  FIG. 5 . The reinforced boss  564  can be cylindrical in shape. As shown, the reinforced boss  564  can define a sidewall thickness T 1  measured between the outer circumferential surface  366  of the reinforced boss  564  and a cylindrical portion  1066  of the shaft bore surface  166   a . The outer circumferential surface  366  can define an outer boss diameter D 1 . The reinforced boss  564  can define a height H measured from a portion of the outer seat surface  154  surrounding the reinforced boss  564  to the outer shaft opening  164   a , in an axially outward direction relative to the shaft bore axis  161 . For the reinforced boss  564 , the ratio of the height H divided by the sidewall thickness T 1  can be between 0.5 and 2. In the aspect shown, the ratio of the height H divided by the sidewall thickness T 1  can be about 1. 
     Additionally, for the reinforced boss  564 , a ratio of the outer boss diameter D 1  divided by the sidewall thickness T 1  can be between 4 and 12. Preferably, the ratio can be between 5.5 and 8.5. In the aspect shown, the ratio can be about 6.3 to 6.8. In the present aspect, a ratio of the outer boss diameter D 1  of the reinforced boss  564  divided by the shaft diameter D 2  of the shaft  420  can be between 1.2 and 2.0. Preferably the ratio of the outer boss diameter D 1  of the reinforced boss  564  divided by the shaft diameter D 2  of the shaft  420  can be between 1.4 and 1.6. In the aspect shown, the ratio of the outer boss diameter D 1  of the reinforced boss  564  divided by the shaft diameter D 2  of the shaft  420  can be about 1.4 to 1.5. Comparatively, a ratio of the outer boss diameter D 1  of the boss  364  (shown in  FIG. 3 ) divided by the shaft diameter D 2  of the shaft  420  can be about 1.04 to 1.05. 
     Referring back to the boss  364  of the prior art valve seat  100 , the sidewall thickness T 1  of the boss  364  can be sized to be approximately equal to the sleeve thickness T 2  (shown in  FIG. 9B ) of the bearing sleeves  823   a,b  (shown in  FIG. 8 ). Rather than being designed for forming a seal with the shaft  420 , the primary purpose of the boss  364  is to accurately position the bearing sleeve  823   a,b  within the body shaft bores  820   a,b  (lower body shaft bore  820   b  shown in  FIG. 8 ). A ratio of the sidewall thickness T 1  of the boss  364  (shown in  FIG. 3 ) divided by the sleeve thickness T 2  of the sleeve bearing  823   a  can be less than 1.5. Comparatively, a ratio of the sidewall thickness T 1  of the reinforced boss  564  divided by the sleeve thickness T 2  of the sleeve bearing  823   a  (shown in  FIG. 9 b   ) can be greater than 3. Preferably, the ratio of the sidewall thickness T 1  of the reinforced boss  564  divided by the sleeve thickness T 2  of the sleeve bearing  823   a  can be greater than 6. In the present aspect, the ratio of the sidewall thickness T 1  of the reinforced boss  564  divided by the sleeve thickness T 2  of the sleeve bearing  823   a  can be greater than 10. 
     Compared to the boss  364  of the prior art valve seat  100  (shown in  FIG. 1 ), the reinforced boss  564  can be configured to form a seal with the shaft  420 . The square and closer-to-square ratios of the sidewall cross-section for the reinforced boss  564  can help to create the three-dimensional stress state discussed above with respect to  FIG. 9A , thereby creating a more stable and reliable seal with the shaft  420  (shown in  FIG. 9A ). 
     Table 1, below, summarizes experimental test results for the valve  400  and valve seat  100 ′. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                   
                 Existing 
                   
               
               
                   
                 Product 
                   
               
               
                   
                 Jingmen 
                   
               
               
                   
                 PRATT Model 
                 Experimental Prototypes 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 12″ 2F2 250B 
                 Prototype 
                 Prototype 
                 Prototype 
                 Prototype 
               
               
                 Features 
                 BFV 
                 #1 
                 #2 
                 #4 
                 #5 
               
               
                   
               
               
                 Circumferential Sealing Rib 
                 None 
                 Arcuate 
                 Arcuate 
                 Arcuate 
                 Arcuate 
               
               
                 512 
                   
                 cross- 
                 cross- 
                 cross- 
                 cross-  
               
               
                   
                   
                 sectional 
                 sectional 
                 sectional 
                 sectional 
               
               
                   
                   
                 shape 712a 
                 shape 712a 
                 shape 712a 
                 shape 
               
               
                   
                   
                   
                   
                   
                 712a 
               
               
                 Seat Bearing Surface 169a,b 
                 Planar 
                 Planar 
                 Spherical 
                 Planar 
                 Spherical 
               
               
                   
                   
                   
                 zone 969a 
                   
                 zone 969a 
               
               
                 Annular Ribs 566 
                 None 
                 Included 
                 Included 
                 Included 
                 Included 
               
               
                 Boss 364 
                 Unreinforced 
                 Reinforced 
                 Reinforced 
                 Reinforced 
                 Reinforced 
               
               
                   
                   
                 boss 564 
                 boss 564 
                 boss 564 
                 boss 564 
               
               
                 Composition of Valve member 
                 N/A 
                 Bronze 
                 Bronze Alloy 
                 Ductile Iron 
                 Ductile 
               
               
                 450 
                   
                 alloy 
                   
                   
                 Iron 
               
               
                 Operating Torque Test 
                   
                   
                   
                   
                   
               
               
                 Results 
                   
                   
                   
                   
                   
               
               
                 Unseating torque @ zero psi 
                 990 
                 750 
                 450 
                 825 
                 700 
               
               
                 (N * m) 
                   
                   
                   
                   
                   
               
               
                 Seating torque @ zero psi 
                 990 
                 750 
                 450 
                 860 
                 700 
               
               
                 (N * m) 
                   
                   
                   
                   
                   
               
               
                 Unseating torque @ 250 psi 
                 N/A 
                 975 
                 525 
                 1150 
                 960 
               
               
                 (N * m) 
                   
                   
                   
                   
                   
               
               
                 Leak Test Results (psi) 
                 275 
                 650 
                 700 
                 700 
                 700+ 
               
               
                   
               
            
           
         
       
     
     As shown above, five prototypes of various aspects of the valve  400  with different combinations of features were created and tested against the prior art Model 12″ 2F2 250B BFV butterfly valve made by Jingmen PRATT. The existing product and the prototypes were tested for operating torque requirements as well as being leak tested. For the operating torque tests, the torque required to open and close the valve member  450  was measured. Unseating torque measures the peak torque required to open the valve from the closed position. Seating torque measures the peak torque required to close the valve from the open position. Unseating torque was tested at ambient pressure as well as with a 250 psi pressure differential across the valve member  450  in the closed position. As shown in Table 1, each of the prototypes improved upon the existing product by requiring less torque to operate the valve at ambient pressure. 
     While no operating torque data is available for the existing product, test results between the different prototypes demonstrate that prototypes with the convex seat bearing surface  169   a,b , such as those shaped as a spherical zone  969   a , required less torque to operate than their counterparts with the planar seat bearing surface  169   a,b . For example, prototypes # 1  and # 2  each comprised a valve member  450  comprising a bronze alloy. The only difference between the two prototypes is that prototype # 2  incorporated the improved spherical zone  969   a  whereas the seat bearing surface  169   a,b  for prototype # 1  is planar, similar to that of the existing product. The test results show that prototype # 2  required less torque to operate across all tests. 
     Looking to prototypes # 4  and # 5 , each of these valves comprised a valve member  450  comprising ductile iron. The only difference between the two prototypes is that prototype # 5  incorporated the improved spherical zone  969   a  whereas the seat bearing surface  169   a,b  for prototype # 4  is planar, similar to that of the existing product. Again, the test results showed that the prototype with the spherical zone  969   a  required less torque to operate across all tests. 
     Turning to the leak test results, the test method comprised securing the prototypes of the valve  400  in a test fixture with the valve members  450  in the closed position. One side of the valve member  450  was exposed to pressurized water, starting at 350 psi with a 5 minute hold period. After 5 minutes, the pressure was increased by 50 psi and again held for 5 minutes. The process was repeated until the valve  400  leaked or the testing limit of the equipment was reached, which was 700 psi. The pressures listed are the pressures at which the valves  400  failed, or began to leak, with the exception of prototype # 5 , which reached the testing limit of the equipment without leaking. 
     As shown, each of the prototypes substantially improved upon the existing product. Again comparing prototype # 1  against prototype # 2  and prototype # 4  against prototype # 5 , the test results show that the prototypes with seat bearing surfaces  169   a,b  formed as spherical zones  969   a  offered improved leak testing performance. While both prototype # 4  and prototype # 5  list 700 psi, prototype # 4  failed at 700 psi while prototype # 5  successfully contained 700 psi, which was the testing limit of the equipment. For this reason, the leak test failure pressure for prototype # 5  is unknown, but is higher than 700 psi. 
     Based on the test results of Table 1, the features of the circumferential sealing rib  512 , a concave seat bearing surface  169   a,b , the inclusion of annular ribs  566 , and the reinforced boss  564  improved the leak test results of the valves  400  while also offering improvements in operating torque requirements. 
     In one exemplary aspect, a valve seat can comprise a first end; a second end positioned opposite from the first end; and a body extending from the first end to the second end. The body can define an inner surface and an outer surface. The inner surface can define a main bore extending through the body from the first end to the second end. The main bore can define a main bore axis. The body can define a shaft bore extending from the inner surface to the outer surface. The shaft bore can define a shaft bore axis positioned perpendicular to the main bore axis. The shaft bore can define an inner shaft opening and an outer shaft opening. The body can define a concave seat bearing surface extending around the inner shaft opening. 
     In a further exemplary aspect, the outer surface can define a circumferential sealing rib extending circumferentially around the body. In a further exemplary aspect, the circumferential sealing rib can define an arcuate cross-sectional shape. In a further exemplary aspect, the circumferential sealing rib can define a V-shaped cross-sectional shape. In a further exemplary aspect, the circumferential sealing rib can define a U-shaped cross-sectional shape. In a further exemplary aspect, the circumferential sealing rib can be axially centered between the first end and the second end relative to the main bore axis. In a further exemplary aspect, the concave seat bearing surface can be a spherical zone. In a further exemplary aspect, the concave seat bearing surface can define a frustoconical surface. In a further exemplary aspect, at least one annular rib can be defined by the body within the shaft bore. 
     In another exemplary aspect, a valve can comprise a valve seat defining an inner seat surface and an outer seat surface. A shaft bore can extend through the valve seat from the inner seat surface to the outer seat surface. An inner shaft opening of the shaft bore can be defined at the inner seat surface. The inner seat surface can define a concave seat bearing surface extending around the inner shaft opening; and a valve member can define an end engaging the concave seat bearing surface. The end can define a valve member end surface. The valve member end surface can define a convex shape. In a further exemplary aspect, the valve can further comprise a shaft extending through the shaft bore. The end can receive the shaft. The valve member can be rotationally fixed to the shaft. 
     In a further exemplary aspect, the valve can further comprise a valve body defining an inner body surface. The valve seat can be bonded to the inner body surface. The inner body surface can define a boss recess. The boss recess can receive a reinforced boss of the valve seat. The reinforced boss can define a sidewall thickness between an outer circumferential surface of the reinforced boss and a shaft bore surface of the shaft bore. The reinforced boss can define an outer shaft opening of the shaft bore. The reinforced boss can define a height between the outer shaft opening and a portion of the outer seat surface surrounding the reinforced boss. A ratio of the height divided by the sidewall thickness can define a value between 0.5 and 2. 
     In a further exemplary aspect, the outer seat surface can define a circumferential sealing rib extending circumferentially around the valve seat; and the valve member can contact and seal with a portion of the inner seat surface positioned opposite from the circumferential sealing rib when the valve member is in a closed position. In a further exemplary aspect, the valve can further comprise a valve body defining an inner body surface. The inner body surface can be bonded to the valve seat. The inner body surface can define a circumferential sealing groove shaped complimentary to the circumferential sealing rib. The circumferential sealing rib can be compressed between the circumferential sealing groove and the valve member in a three-dimensional stress state when the valve member is in the closed position. 
     In a further exemplary aspect, the valve member can be a disc, and the valve can be a butterfly valve. In a further exemplary aspect, the circumferential sealing rib can define an arcuate cross-sectional shape. In a further exemplary aspect, the circumferential sealing rib can define a U-shaped cross-sectional shape. In a further exemplary aspect, the circumferential sealing rib can define a V-shaped cross-sectional shape. In a further exemplary aspect, the concave seat bearing surface can be a spherical zone. In a further exemplary aspect, the concave seat bearing surface can define a frustoconical surface. 
     In another exemplary aspect, a valve seat can comprise a body defining an inner surface and an outer surface. The inner surface can define a main bore extending through the body. The body can define a shaft bore extending from the inner surface to the outer surface. The shaft bore can define an inner shaft opening. The body can define a concave seat bearing surface extending around the inner shaft opening. 
     One should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular embodiments or that one or more particular embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     It should be emphasized that the above-described embodiments are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Any process descriptions or blocks in flow diagrams should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included in which functions may not be included or executed at all, may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. Further, the scope of the present disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure.