Abstract:
Embodiments provide a gate valve including a first body half that defines a first process fluid aperture, a first chest portion, and a first gate support recess that is formed in the first chest portion. A second body half defines a second process fluid aperture that is aligned with the first process fluid aperture, a second chest portion, and a second gate support recess that is formed in the second chest portion. A gate is movable relative to the first body half and the second body half, and a gasket seal includes a flange portion, a body portion, and at least one cutout. The flange portion and the body portion are sized to be compressed between the first body half and the second body half, and the at least one cutout provides for volume transformation of the gasket seal under compression.

Description:
BACKGROUND 
       [0001]    Gate valves are typically used for fluid flow control in pipeline systems. Typical gate valves include a housing, a seal, and a gate that moves between an open position and a closed position to control a flow of process fluid through the gate valve. 
         [0002]    Gate valves tend to experience deflection when arranged in the closed position or a partially closed position. This deflection can increase the wear experienced by the seal and other components of the gate valve. 
         [0003]    Additionally, typical gasket-type seals have a tendency to wear out over time and lose their sealing capability when the gate valve is in the closed position. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    Some embodiments of the invention provide a gate valve includes a first body half that defines a first process fluid aperture, a first chest portion, and a first gate support recess that is Ruined in the first chest portion. A second body half defines a second process fluid aperture that is aligned with the first process fluid aperture, a second chest portion, and a second gate support recess that is formed in the second chest portion. A gate is movable relative to the first body half and the second body half, and a gasket seal includes a flange portion, a body portion, and at least one cutout. The flange portion and the body portion are sized to be compressed between the first body half and the second body half, and the at least one cutout provides for volume transformation of the gasket seal under compression. 
         [0005]    Other embodiments of the invention provide a sealing assembly for a gate valve. The sealing assembly includes a primary seal recess that is formed in the body of the gate valve and includes a primary flange width and a primary body width. A gasket seal includes a body portion that defines a body portion width larger than the primary body width. A flange portion defines a flange portion width that is larger than the primary flange width. A cutout is arranged to provide volume transformation under compression. 
         [0006]    Other embodiments of the invention provide a seal for a gate valve that includes a body portion that defines a body portion width, a flange portion that defines a flange portion width, and a cutout that is arranged to provide volume transformation under compression. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a gate valve according to one embodiment of the invention. 
           [0008]      FIG. 2  is an exploded perspective view of the gate valve of  FIG. 1 . 
           [0009]      FIG. 3  is a top front perspective view of a first body half of the gate valve of  FIG. 1 . 
           [0010]      FIG. 4  is a top back perspective view of the first body half of  FIG. 3 . 
           [0011]      FIG. 5  is an elevational front view of the first body half of  FIG. 3 . 
           [0012]      FIG. 6  is an elevational back view of the first body half of  FIG. 3 . 
           [0013]      FIG. 7  is a sectional view of the first body half of  FIG. 3  taken along the line  7 - 7  of  FIG. 6 . 
           [0014]      FIG. 8  is a top front perspective view of a gasket seal of the gate valve of  FIG. 1 . 
           [0015]      FIG. 9  is a sectional view of the gasket seal of  FIG. 8  taken along the line  9 - 9  of  FIG. 8 . 
           [0016]      FIG. 10  is a top perspective view of a circular gate support of the gate valve of  FIG. 1 . 
           [0017]      FIG. 11  is a sectional view of the gate valve of  FIG. 1  taken along the line  11 - 11  of  FIG. 1 . 
           [0018]      FIG. 12  is a detail view of the gate valve of  FIG. 1  taken within the line  12 - 12  of  FIG. 11 . 
           [0019]      FIG. 13  is a detail view of the gate valve of  FIG. 1  taken within the line  13 - 13  of  FIG. 11 . 
           [0020]      FIG. 14  is a detail view of the gate valve of  FIG. 1  taken within the line  14 - 14  of  FIG. 11 . 
           [0021]      FIG. 15  is a perspective sectional view of the gate valve of  FIG. 1  taken along the line  11 - 11  of  FIG. 1 . 
           [0022]      FIG. 16  is a perspective view of a gate valve according to another embodiment of the invention. 
           [0023]      FIG. 17  is an exploded perspective view of the gate valve of  FIG. 16 . 
           [0024]      FIG. 18  is a top front perspective view of a first body half of the gate valve of  FIG. 16 . 
           [0025]      FIG. 19  is a top back perspective view of the first body half of  FIG. 18 . 
           [0026]      FIG. 20  is an elevational front view of the first body half of  FIG. 18 . 
           [0027]      FIG. 21  is an elevational back view of the first body half of  FIG. 18 . 
           [0028]      FIG. 22  is a perspective view of a flow ring of the gate valve of  FIG. 16 . 
           [0029]      FIG. 23  is a sectional view of the flow ring of  FIG. 22  taken along line  23 - 23  of  FIG. 22 . 
           [0030]      FIG. 24  is a perspective view of a sealing ring of the gate valve of  FIG. 16 . 
           [0031]      FIG. 25  is a sectional view of the sealing ring of  FIG. 24  taken along line  25 - 25  of  FIG. 24 . 
           [0032]      FIG. 26  is a perspective view of a gasket seal of the gate valve of  FIG. 16 . 
           [0033]      FIG. 27  a sectional view of the gasket seal of  FIG. 26  taken along the line  27 - 27  of  FIG. 26 . 
           [0034]      FIG. 28  is a section view of the gate valve of  FIG. 16  taken along the line  28 - 28  of  FIG. 16 . 
           [0035]      FIG. 29  is a detail view of the gate valve of  FIG. 16  taken within the line  29 - 29  of  FIG. 28 . 
           [0036]      FIG. 30  is a perspective view of a jacking assembly of the gate valve of  FIG. 1 . 
           [0037]      FIG. 31  is a perspective view of a jacking assembly of the gate valve of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0039]    The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
         [0040]      FIG. 1  shows a gate valve  110  according to one embodiment. The gate valve  110  includes an actuation system  114 , a valve body assembly  118 , and a gate  122 . The gate  122  includes gate locking apertures  126  and defines a gate axis  130 . The actuation system  114  includes an actuator  134  in communication with a control system (not shown), an actuator mount  138  that couples the actuation system  114  to the valve body assembly  118 , and a lockout system  142 . In one embodiment, the actuator  134  is a linear hydraulic actuator. In other embodiments, the actuator  134  can be an electronic actuator, a pneumatic actuator, a hand wheel and a threaded rod, or a lever. The actuator mount  138  includes fastening rods  146 , an actuator coupling plate  150 , a coupler shaft  154 , and a gate coupling  158  for joining the coupler shaft  154  and the gate  122 . The lockout system  142  includes actuator mount lockout apertures  162  and lockout keys  166 . The actuator mount lockout apertures  162  each include a jacking bolt aperture  163 . In the illustrated embodiment, there are two lockout keys  166 . In other embodiments, there could be more or less than two lockout keys  166 . In the illustrated embodiment, there are eight actuator mount lockout apertures  162 . In other embodiments, there could be more or less than eight actuator mount lockout apertures  162 . 
         [0041]      FIG. 2  shows an exploded view of the gate valve  110  including the actuation system  114 , the valve body assembly  118 , a sealing system  170 , fastening elements  174 , and chest gate supports  178 . The sealing system  170  includes the gate  122 , the gate coupling  158 , packing material  182 , a packing gland  186 , and a primary seal  190 . In the illustrated embodiment, there are four layers of packing material  182 . In other embodiments there could be more or less than four layers of packing material  182 . Each of the layers of packing material  182  includes a packing material aperture  194 . The packing gland  186  includes packing gland fastening apertures  198  and a packing gland gate aperture  202 . 
         [0042]    The valve body assembly  118  includes a first body half  206  and a second body half  206 ′. The first and second body halves  206 ,  206 ′ are symmetric, and the following description of the first body half  206  also applies to the second body half  206 ′, with like parts on the second body half  206 ′ numbered in the prime series. The second body half  206 ′ can include different features that are not discussed herein. For example, in some embodiments, the second body half  206 ′ can include mounting features that are different from the first body half  206  to enable each half to properly fit into the desired piping system. 
         [0043]    As shown in  FIG. 3 , the first body half  206  includes an actuator mounting flange  210 , a first process fluid aperture  214  defining a first process fluid flow axis  218 , port gate supports  226 , body mounting apertures  230  arranged both parallel to the first process fluid flow axis  218  and radially around the first process fluid aperture  214 , and a plumbing flange  234 . The actuator mounting flange  210  includes actuator mounting apertures  238 , and packing mount flange apertures  242 . The plumbing flange  234  defines a plumbing flange surface  246 , which includes flange apertures  250  arranged radially around the plumbing flange surface  246 , enabling the first body half  206  to couple to a pipe (not shown) through which the process fluid flows. 
         [0044]    As shown in  FIG. 4 , the first body half  206  further includes a non-recessed portion or body mating surface  254 , a packing recess  258 , a primary seal recess  262 , a chest portion  266 , two chest projections  270 , and chest gate support recesses  274  arranged in the chest portion  266  radially around the first process fluid flow aperture  214 . The body mating surface  254  of the first body half defines a center plane  278 . The packing recess  258  is recessed into the first body half  206  extending away from the center plane  278 . The primary seal recess  262  is recessed into the first body half  206  extending away from the center plane  278  and includes a primary flange recess  282  and a primary body recess  286 . The chest portion  266  is bound by the first process fluid aperture  214  and the primary seal recess  262 , and defines a chest plane  290 . 
         [0045]    The two chest projections  270  protrude from the chest plane  290  towards the center plane  278  and provide structural support to the flange apertures  250 . The chest gate support recesses  274  are recessed into the first body half  206  from the chest plane  290  extending away from the center plane  278 , and define a circular profile with a gate support diameter. The chest gate support recesses  274  could define other shaped profiles. In the illustrated embodiment, there are three gate support recesses  274 . In other embodiments there could be more or less than three gate support recesses  274 . 
         [0046]    As shown in  FIG. 5 , one embodiment of the first body half  206  includes four port gate supports  226 . In other embodiments, there could be more or less than four port gate supports  226 . Each port gate support  226  defines an outer profile  294  that is semicircular and defines an outer diameter  298 , and an inner profile  302  that is semicircular and defines an inner diameter  306 . Each port gate support  226  also defines a cross sectional profile perpendicular to the first process fluid flow axis  218  that changes from the inner profile  302  to the outer profile  294 . The area of the cross sectional profile increases exponentially from the inner profile  302  to the outer profile  294 , so that the cross sectional profile remains substantially semicircular. An outer surface  310  of each port gate support  226  connects the inner profile  302  to the outer profile  294  linearly so that the outer shape is generally frustoconical. 
         [0047]    As shown in  FIG. 7 , a port gate support angle  314  is defined between the first process fluid flow axis  218  and the outer surface  310  of each port gate support  226 . According to one embodiment, the port gate support angle  314  is approximately fifteen degrees. In other embodiments, the port gate support angle  314  could be between ten and twenty five degrees. As shown in  FIG. 4 , each port gate support  226  overhangs into the first process fluid aperture  214 . According to one embodiment, as shown in  FIG. 7 , all the port gate supports  226  are arranged below a halfway height  318  of the first process fluid aperture  214 . In other embodiments, the port gate supports  226  could be arranged above or below the halfway height  318  of the process fluid aperture. 
         [0048]    As shown in  FIG. 8 , the primary seal  190  includes an upper gland portion  322 , a primary flange portion  326 , and a primary body portion  330 . The upper gland portion  322  includes an upper gate aperture  334 , an upper surface  338 , an upper flange portion  342 , and upper surface apertures  346 . In one embodiment, the upper gate aperture  334  defines a substantially rectangular shape to conform to the geometry of the gate  122 . In other embodiments, the upper gate aperture  334  can define another shape to conform to another geometry of a different gate. 
         [0049]    As shown in  FIG. 9 , the primary flange portion  326  includes rounded edges and defines a primary flange width  350 . The primary body portion  330  includes a gate sealing surface  354 , cutouts  358 , and defines a primary body width  362 . The gate sealing surface  354  is configured to receive the gate  122 . Each cutout  358  defines a substantially trapezoidal shape and a cutout depth  370 . As shown in  FIG. 8 , each cutout  358  extends around the primary seal  190 . The cutout depth  370  is approximately thirteen percent of the primary body width  362 . In other embodiments, the cutout depth  370  could be between five and twenty percent of the primary body width  362 . The cutouts  358  are designed into the profile of the primary seal  190  in order to allow the seal material to flow or transform when primary seal  190  is compressed during assembly. In one embodiment, the cutout  358  defines a substantially trapezoidal shape. In other embodiments, the cutout  358  can define a square or rectangular shape, a triangular shape, or an arcuate shape. During compression the primary seal  190  undergoes a volume transformation wherein the volume remains the same, but is oriented differently. 
         [0050]    As shown in  FIG. 10 , the chest gate supports  178  are configured to be received within the chest gate support recesses  274 . According to one embodiment, the chest gate supports  178  have a circular profile and are generally cylindrical. The chest gate supports  178  define a chest gate support depth  374  and a chest gate support diameter  378 , where the chest gate support depth  374  is approximately thirty-three percent of the chest gate support diameter  378 . In one embodiment, the chest gate supports  178  have chamfered edges. In other embodiments, the chest gate supports  178  can have rounded or square edges. The chest gate supports  178  are fabricated from a material that has a high resistance to corrosion, and a low coefficient of friction. 
         [0051]      FIG. 11  illustrates an assembled gate valve  110 . The primary seal  190  is installed onto the first body half  206  by inserting the primary seal  190  into the primary seal recess  262  so that the primary flange portion  326  is inserted into the primary flange recess  282  and the primary body portion  330  is inserted into the primary body recess  286 . The chest gate supports  178  are installed into the first body half  206  by inserting the chest gate supports  178  into the chest gate support recesses  274 . 
         [0052]    The chest gate supports  178  are then inserted into the second body half  206 ′, and the second body half  206 ′ is engaged with the first body half  206  so that the primary seal  190  is received within the primary seal recess  262 ′ of the second body half  206 ′. Once the primary seal  190  is seated, the fastening elements  174  are installed through the body mounting apertures  230 ,  230 ′ as shown in  FIG. 2 , and tightened to join the first body half  206  and the second body half  206 ′. 
         [0053]    As also shown in  FIG. 11 , the packing material  182  are placed into the packing recesses  258 ,  258 ′, and are then compressed into the packing recesses  258 ,  258 ′ by the packing gland  186 . As shown in  FIG. 2 , once the packing gland  186  is installed onto the valve body assembly  118 , the fastening elements  174  are inserted through the packing gland fastening apertures  198  and into the corresponding packing gland flange apertures  242 ,  242 ′ on the actuator mounting flanges  210 ,  210 ′ and are then tightened to further compress the packing material  182  into the packing recesses  258 ,  258 ′. 
         [0054]    The gate  122  is then inserted into the aligning packing gland gate aperture  202 , packing material apertures  194 , and upper gate aperture  334  of the primary seal  190 . The gate  122  is moveable between a first or open position where the gate  122  does not block any of the first process fluid aperture  214  and process fluid is allowed to flow through the first process fluid aperture  214  uninhibited and a second or closed position where the gate  122  blocks the first process fluid aperture  214  and process fluid is substantially inhibited from flowing through the first process fluid aperture  214 . In the second position, the gate  122  forms an effective seal with the gate sealing surface  354  on the primary seal  190 . The gate  122  moves between the open position and the closed position along the gate axis  130  and within a gate path defined along the gate axis  130 . 
         [0055]    As shown in  FIGS. 1 and 2 , the actuator  134  is coupled to the actuator coupling plate  150  and the coupler shaft  154 . The actuator coupling plate  150  is attached to the fastening rods  146 . Each of the fastening rods  146  are inserted into the corresponding actuator mounting apertures  238  and are then tightened to join the actuation system  114  to the valve body assembly  118 . The gate  122  is then coupled to the coupler shaft  154  with the gate coupling  158 . Each of the actuator mount lockout apertures  162  are coupled to the fastening rods  146  (e.g., by welding) and are arranged so that the lockout keys  166  can be inserted through two corresponding actuator mount lockout apertures  162  substantially parallel to the first process fluid flow axis  218 . 
         [0056]      FIG. 12  illustrates in further detail the port gate supports  226  and their arrangement in the valve body assembly  118 . During operation, the process fluid imparts a differential pressure across the gate  122  of the gate valve  110  when the gate  122  is in the closed position. The differential pressure across the gate  122  causes the gate  122  to deflect away from the gate axis  130 . In one embodiment, when the gate  122  deflects it contacts the port gate supports  226  and the port gate supports  226  constrain the deflection so that the gate  122  is maintained along the gate axis  130  and within the gate path for the entire travel length of the gate  122 . The general frustoconical shape of the port gate supports  226  gradually increases in cross sectional area from the inner profile  302  to the outer profile  294 , reducing the wear from the process fluid during operation when the gate  122  is in the first position. The port gate supports  226  are also arranged on both the first body half  206  and the second body half  206 ′, resulting in the total occlusion of the process fluid from the port gate supports  226  gradually increasing and then gradually decreasing, further reducing wear from the process fluid during operation when the gate  122  is in the open position. 
         [0057]      FIG. 13  illustrates in further detail the chest gate supports  178  and their arrangement in the valve body assembly  118 . The chest gate supports  178  are press fit into the chest gate support recesses  274 ,  274 ′ in the chest portions  266 ,  266 ′ of the first and second body halves  206 ,  206 ′. In other embodiments, the chest gate supports  178  are maintained in the chest gate support recesses  274 ,  274 ′ by other mechanical arrangements such as an adhesive. Similar to the port gate supports  226 , the chest gate supports  178  constrain the deflection of the gate  122  during operation when the gate  122  is in the closed position, and also when the gate  122  is between the open and closed positions. 
         [0058]    In one embodiment, the chest gate supports  178  constrain the deflection so that the gate  122  is maintained along the gate axis  130  and within the gate path for the entire travel length of the gate  122 . The chest gate supports  178  also substantially eliminate contact between the gate  122  and the first and second body halves  206 ,  206 ′ during actuation of the gate  122 . During actuation of the gate  122 , the process fluid imparts a differential pressure, as described above, across the gate  122 , while the gate  122  is moving between the open and closed positions, causing the gate  122  to deflect. This deflection causes the gate  122  to come into sliding contact with the chest gate supports  178 . To reduce wear on the gate  122  and chest gate supports  178  resulting from this sliding contact, the chest gate supports  178  are made of a non-abrasive and wear resistant. 
         [0059]      FIG. 14  illustrates in further detail the primary seal  190  and its arrangement in the valve body assembly  118 . The primary seal  190  is arranged between the first body half  206  and the second body half  206 ′, within the primary seal recesses  262 ,  262 ′. The primary body width  362  is wider than a primary body space  382  between the primary body recesses  286 ,  286 ′ when the valve body assembly  118  is assembled. The primary flange width  350  is also wider than a flange body width  386  between the primary flange recesses  282 ,  282 ′ when the valve body assembly  118  is assembled. As the fastening elements  174  are tightened, the first and second body halves  206 ,  206 ′ compress the primary seal  190 . During operation, this compression provides an effective seal between the first and second body halves  206 ,  206 ′. The cutouts  358  allow the primary body portion  330  to undergo a slight shape change. This shape change allows for the gate sealing surface  354  to wrap slightly around the gate  122  in the closed position, providing a secure and effective seal between the gate  122  and the gate sealing surface  354 . 
         [0060]      FIG. 15  illustrates the operation of the gate  122  in the valve body assembly  118 . The actuation system  114  actuates the gate  122  between the open position and the closed position to control a flow of process fluid. In both the open and closed positions, the gate  122  contacts the upper gate aperture  334  creating an effective seal between the upper gate aperture  334  on the primary seal  190  and the gate  122 . In the closed position, the gate  122  also contacts the gate sealing surface  354  on the primary seal  190 . The primary seal  190  is compressed by the first and second body halves  206 ,  206 ′. The gate  122  further compresses the primary seal  190 , and the cutouts  358  allow the gate sealing surface  354  on the primary seal  190  to wrap slightly around the gate  122 , creating an effective seal between the gate  122  and the gate sealing surface  354 . In the closed position, the first process fluid aperture  214  is completely blocked by the gate  122 , and process fluid is substantially inhibited from flowing through the first process fluid aperture  214 . 
         [0061]      FIG. 16  shows a gate valve  1110  according to another embodiment. The gate valve  1110  includes an actuation system  1114 , a valve body assembly  1118 , and a gate  1122 . The gate  1122  defines a gate axis  1130 . The actuation system  1114  includes an actuator  1134  in communication with a control system (not shown), an actuator mount  1138  that couples the actuation system  1114  to the valve body assembly  1118 , and a lockout system  1142 . The actuator mount  1138  includes fastening rods  1146 , an actuator coupling plate  1150 , a coupler shaft  1154 , and a gate coupling  1158  for joining the coupler shaft  1154  and the gate  1122 . 
         [0062]    The lockout system  1142  includes actuator mount lockout apertures  1162 , lockout keys  1166 , and an adjustment feature in the form of lockout jacking bolts  1167 . Each of the actuator mount lockout apertures  1162  includes a jacking bolt aperture  1163 . In the illustrated embodiment, there are two lockout keys  1166 . In other embodiments, there could be more or less than two lockout keys  1166 . In the illustrated embodiment, there are eight actuator mount lockout apertures  1162 . In other embodiments, there could be more or less than eight actuator mount lockout apertures  1162 . 
         [0063]      FIG. 17  shows an exploded view of the gate valve  1110  including the actuation system  1114 , the valve body assembly  1118 , a sealing system  1170 , fastening elements  1174 , and flow ring systems  1175 ,  1175 ′ are clearly visible. The sealing system  1170  includes the gate  1122 , the gate coupling  1158 , packing material  1182 , a packing gland  1186 , and a primary seal  1190 . In the illustrated embodiment, there are five layers of packing material  1182 . In other embodiments, there could be more or less than five layers of packing material  1182 . Each of the packing material  1182  includes a packing material aperture  1194 . One flow ring system  1175  is discussed below. The other flow ring system  1175 ′ includes the same features and is referenced with prime numbers in the drawings. The flow ring system  1175  includes an external flow ring  1195 , a liner  1196 , an internal ring or sealing plate  1197 , and a sealing ring  1199 . 
         [0064]    The valve body assembly  1118  includes a first body half  1206  and a second body half  1206 ′. The first and second body halves  1206 ,  1206 ′ are symmetric, and the following description of the first body half  1206  also applies to the second body half  1206 ′, with like parts on the second body half  1206 ′ numbered in the prime series. 
         [0065]    As shown in  FIG. 18 , the first body half  1206  includes an actuator mounting flange  1210 , a first process fluid aperture  1214  defining a first process fluid flow axis  1218 , body mounting apertures  1230  arranged both parallel to the first process fluid flow axis  1218  and radially around the first process fluid aperture  1214 , and a plumbing flange  1234 . The actuator mounting flange  1210  includes actuator mounting apertures  1238 . The plumbing flange  1234  includes an external ring mounting recess  1235 , which includes external ring mounting apertures  1236 , and defines a plumbing flange surface  1246 . The plumbing flange surface  1246  includes flange apertures  1250  arranged radially around the plumbing flange surface  1246 , that enable the first body half  1206  to couple to a pipe (not shown) through which the process fluid flows. 
         [0066]    As shown in  FIG. 19 , the first body half  1206  further includes a non-recessed portion  1254 , a primary recessed portion  1255 , and a packing recess  1258 . The non-recessed portion  1254  of the first body half  1206  defines a center plane  1278 . The primary recessed portion  1255  is recessed into the first body half  1206  extending away from the center plane  1278 , defines a primary recess plane  1279 , and includes a sealer projection  1280 . The sealer projection  1280  protrudes away from the primary recess plane  1279  toward the center plane  1278 . The packing recess  1258  is recessed into the primary recessed portion  1255 , extending away from the center plane  1278 . 
         [0067]    As shown in  FIGS. 20 and 21 , the first body half  1206  further includes a sealing ring recess  1281  and a center seal recess  1283 . The sealing ring recess  1281  extends around the first process fluid aperture  1214  and is further recessed into the external ring mounting recess  1235  on the plumbing flange  1234 . The center seal recess  1283  is recessed into the non-recessed portion  1254 , away from the center plane  1278 , and extends around the primary recessed portion  1255 , terminating where the primary recessed portion  1255  meets the packing recess  1258 . 
         [0068]    As shown in  FIGS. 22 and 23 , the external flow ring  1195  includes an external surface  1284 , a mating surface  1285 , and mating chamfers  1287 . The external surface  1284  includes external surface apertures  1288  and flow ring mounting aperture recesses  1289 . Each flow ring mounting aperture recess  1289  includes a flow ring mounting aperture  1291  (one is visible in  FIG. 22 ). 
         [0069]    As shown in  FIGS. 24 and 25 , each of the sealing plates  1197 ,  1197 ′ include a sealing plate body mating surface  1292 , a sealing plate gate mating surface  1293 , narrow channels  1295  and a sealing plate process fluid aperture  1296 . Each of the sealing plates  1197  are configured to be received within the primary recessed portion  1255  of the first and second body halves  1206 ,  1206 ′ between the respective first process fluid aperture  1214  and the sealer projection  1280 . 
         [0070]    As shown in  FIGS. 26 and 27 , the primary seal  1190  includes an upper gland portion  1322 , a primary flange portion  1326 , and a primary body portion  1330 . The upper gland portion  1322  includes an upper gate aperture  1334 , an upper stiffener plate  1335 , an upper surface  1338 , and an upper flange portion  1342 . The upper gate aperture  1334  defines a substantially rectangular shape to conform to the geometry of the gate  1122 . In other embodiments, the upper gate aperture  1334  can define another shape to conform to another geometry of a different gate. 
         [0071]    As shown in  FIG. 27 , the primary flange portion  1326  defines a primary flange width  1350 . The primary body portion  1330  includes a gate sealing surface  1354 , a reinforcing substrate  1355 , cutouts  1358 , and defines a primary body width  1362 . The gate sealing surface  1354  is configured to receive the gate  1122 . According to one embodiment, the gate sealing surface  1354  has chamfered edges  1363 . In other embodiments, the gate sealing surface  1354  can have rounded or square edges. Each cutout  1358  defines a substantially trapezoidal shape and a cutout depth  1364 . Each cutout  1358  extends around the primary seal  1190  (as shown in  FIG. 26 ). 
         [0072]    As shown in  FIG. 28 , the gate valve  1110  is assembled by installing a flow ring system  1175 ,  1175 ′ in each of the first body half  1206  and the second body half  1206 ′. One flow ring system  1175  installation is discussed below; the second flow ring system  1175 ′ is installed in a similar manner. The sealing ring  1199  is placed into the corresponding sealing ring recess  1281 , and the external flow ring  1195  is inserted and fastened to the external ring mounting apertures  1236  (not pictured in  FIG. 28 ). With the external flow ring  1195  installed, the liner  1196  is fitted over the external flow ring  1195  to provide a sealed surface. The primary seal  1190  is then inserted and the sealing plates  1197  are installed, and the two body halves  1206 ,  1206 ′ are fastened together. The gate  1122  and the rest of the gate valve  1110  are then assembled and operated similar to gate valve  110  discussed above. 
         [0073]    The flow ring system  1175  allows passage of material through the inlet and/or outlet and improves the valve  1110  construction methods by combining features for external flow ring  1195  and sealing plate  1197  replacement, external flow ring  1195  axial rotation, transfer of axial loads from the gate  1122  to the valve body halves  1206 ,  1206 ′, and elimination of pressure boundary requirements for the external flow ring  1195 . These features improve service life and reduce maintenance needs. The flow ring system  1175  meets the requirements of the gate valve  1100  (e.g., compliant to MSS-SP-135 and ASME B16.34). The internal ring in the form of the sealing plate  1197  and the external flow ring  1195  are replaceable if they become damaged or excessively worn during service. During valve  1110  service or maintenance, portions of the flow ring system  1175  may develop signs of wear as materials are passed through, especially when corrosive or high-abrasion materials are used. Typically, locations of wear are in the bottom portions of the flow ring system  1175 . Longevity of the flow ring system  1175  is extended via axial rotation, allowing worn portions to be relocated to the side or top extents of the process fluid aperture  1214 . The flow ring system  1175  also provides for axial loads from the gate  1122  to be absorbed by the internal ring  1197  then onto the body halves  1206 ,  1206 ′, making the valve  1100  eligible for use in dead-end service when sealing is allowed when the gate  1122  is in the closed position while pipe flanges are absent or disconnected. The flow ring system  1175  is not configured as part of a connected pipe flange, and the pipe flange is no longer utilized as a valve component with a restraining surface that maintains a pressure differential. In another embodiment, the flow ring system  1175  can include an internal ring  1197  that is fastened to an inner portion of each body half  1206 ,  1206 ′ in a manner similar to the external flow ring  1195 . The second flow ring system  1175 ′ provides the same advantages as the first flow ring system  1175  discussed above. 
         [0074]      FIGS. 30 and 31  illustrate operation of the lockout systems  142 ,  1142  of the gate valve  110  and the gate valve  1110 , respectively. Lockout apertures  162 ,  1162  are generally aligned with the gate locking apertures  126 ,  1126  of gate  122 ,  1122  along gate axis  130 ,  1130 . Lockout jacking bolts  167 ,  1167  are threadably engaged with jacking apertures  163 ,  1163  and are used to adjust the position of engagement with lockout keys  166 ,  1166 . The inclusion of the jacking bolts  167 ,  1167  allows the lockout apertures  162 ,  1162  to be installed during assembly of the gate valve  110 ,  1110 . The lockout apertures  162 ,  1162  do not need to be as exactly placed as prior art lockout apertures because the jacking bolts  167 ,  1167  are adjusted in the field to match the lockout positions of the gate  122 ,  1122  in place. In other words, the jacking bolts  167 ,  1167  can be adjusted (e.g., threaded in or out of the jacking apertures  163 ,  1163 ) to take up slack in the lockout system  142 ,  1142 . The ability to install (e.g., weld) the lockout apertures  162 ,  1162  in a factory or assembly line setting and later adjust the jacking bolts  167 ,  1167  in the field greatly improves ease of installation and functionality. 
         [0075]    It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. Particularly, portions or components of the gate valve  110  may be combined with any portions or components of the gate valve  1110  described above. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. 
         [0076]    Various features and advantages of the invention are set forth in the following claims.