Patent Publication Number: US-2018045323-A1

Title: Ball valve system and method

Description:
CROSS-REFERENCE BACKGROUND 
     This application claims priority from and the benefit of European Patent Application Serial No. EP16275111.9, entitled “BALL VALVE SYSTEM AND METHOD,” filed Aug. 9, 2016, which is hereby incorporated by reference in its entirety for all purposes. 
     BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     Ball valves are employed to open or close to enable or block a flow of fluid in a variety of applications. Typical ball valves may include a body, an adapter, a rotatable ball disposed within the body and the adapter, and a stem coupled to the ball. Trunnion ball valves use seats that physically contact the ball of the ball valve. However, as the ball rotates within the ball valve from a closed position to an open position, the fluid under pressure drives the seat into the ball, thereby increasing torque needed to move the ball to the open position and/or causing wear on contacting surfaces of the ball and/or the seat, for example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein: 
         FIG. 1  is a cross-sectional side view of a ball valve, in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional side view of a portion of the ball valve of  FIG. 1  taken within line  2 - 2 , wherein a seat contacts a ball of the ball valve; 
         FIG. 3  is a cross-sectional side view of the portion of the ball valve of  FIG. 2 , wherein the seat is separated from the ball of the ball valve; 
         FIG. 4  is a flow chart of a method for controlling a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 5  is a schematic diagram of a hydraulic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 6  is a schematic diagram of another hydraulic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 7  is a schematic diagram of another hydraulic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 8  is a schematic diagram of another hydraulic system having an electronic controller and that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 9  is a schematic diagram of a hydraulic booster charger that may be used to supply hydraulic fluid to the hydraulic systems of  FIGS. 5-8 , in accordance with an embodiment of the present disclosure; 
         FIG. 10  is a schematic diagram of a pneumatic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 11  is a schematic diagram of another pneumatic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 12  is a schematic diagram of another pneumatic system that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 13  is a schematic diagram of another pneumatic system having an electronic controller and that is configured to control a position of the seat of the ball valve of  FIG. 1 , in accordance with an embodiment of the present disclosure; and 
         FIG. 14  is a cross-sectional side view of an alternative arrangement of components within the portion of the ball valve of  FIG. 2 , in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     Certain embodiments of the present disclosure include systems and methods configured to adjust a seat of a ball valve. In particular, the systems and methods disclosed herein may be configured to drive the seat away from a ball of the ball valve as the ball rotates through a portion of its path between a closed position and an open position. In certain embodiments, the systems and methods may drive the seat to reduce a contact force between contacting surfaces of the seat and the ball as the ball rotates through a portion of its path and/or to separate (e.g., create a gap or clearance between) the seat from the ball as the ball rotates through a portion of its path. The systems and methods disclosed herein may advantageously enable the ball valve to be opened under full differential pressure, increase operating speeds, increase sealing reliability, reduce wear on components of the ball valve, increase life of the components, and/or reduce actuator size, cost, and weight, for example. The ball valve may be utilized as part of any suitable fluid-handling system, such as an energy-acquisition or processing system (e.g., a hydrocarbon-production or processing system, such as a subsea or surface oil or gas well, a pipeline, a natural-gas processing terminal, a refinery, or a natural-gas powered electrical plant, or the like). 
     Turning now to the figures,  FIG. 1  is a cross-sectional side view of a ball valve  10 , in accordance with an embodiment. The ball valve  10  includes a housing  11 , which may be formed by an annular body  12  and an annular adapter  14 . In the illustrated embodiment, the body  12  and the adapter  14  of the ball valve  10  are configured to mate with each other such that a seal is created between the body  12  and the adapter  14 . The ball valve  10  includes a ball  16  configured to rotate between the illustrated open position  24  (e.g., approximately 90 degrees) and a closed position (e.g., approximately 0 degrees) about a rotational axis  18 , as shown by arrow  22 . As shown, the ball  16  is coupled to a stem  20  such that rotation of the stem  20  (e.g., via a hydraulic, pneumatic, or electronic actuator) causes the ball  16  to rotate. 
     In the open position  24 , the ball valve  10  enables fluid flow through the ball valve  10 . As shown, in the open position  24 , a bore  30  of the ball  16  is aligned with a bore  32  of the body  12  and a bore  34  of the adapter  14 , such that fluid may pass through the ball valve  10 . In general, a fluid  36  may enter through either the body  12  or the adapter  14  and exit through the other. For example, in the illustrated embodiment, the fluid  36  enters the bore  32  of the body  12  from a first fluid line or passageway, flows through the bore  30  of the ball  16 , and exits the bore  34  of the adapter  14  into a second fluid line or passageway. In the closed position, the bore  30  of the ball  16  is rotated perpendicular to the bores  32 ,  34  of the body  12  and the adapter  14 , thereby substantially blocking the flow of the fluid  36  through the ball valve  10 . In the closed position, a cavity pressure within a cavity  47  of the ball valve  10  may be less than a line pressure in the bore  32  of the body  12 . 
     As illustrated in  FIG. 1 , the ball valve  10  also includes two annular seats, a first seat  38  (e.g., a first annular seat or an upstream annular seat) positioned between the ball  16  and the body  12 , and a second seat  40  (e.g., a second annular seat or a downstream annular seat) positioned between the ball  16  and the adapter  14 . During operation of the ball valve  10 , the seats  38 ,  40  create respective seals between the ball  16  and the body  12  and between the ball  16  and the adapter  14 . In the illustrated embodiment, a retainer  42  (e.g., annular retainer) is coupled to the body  12  proximate to the first seat  38 . A space  44  (e.g., an annular space, a sealed space) is defined between the first seat  38  and the retainer  42 , and an opening  46  (e.g., channel or passageway) is provided through the body  12  to enable fluid (e.g., working fluid, such as a pressurized gas or liquid) flow into and out of the space  44 . As discussed in more detail below, a hydraulic, pneumatic, or electronic control system may adjust the fluid flow into and out of the space  44  as the ball  16  rotates between the closed position and the open position  24 . In certain embodiments, the system may adjust the fluid flow to cause a reduction in a contact force between contacting surfaces of the first seat  38  and the ball  16  as the ball  16  rotates and/or to separate the first seat  38  from the ball  16  as the ball  16  rotates (e.g., creating an intermediate gap or clearance). 
     As shown, the ball valve  10  may include injection ports  48  that are configured to align with and enable fluid communication with injection channels  50  in the seats  38 ,  40 . The injection ports  48  and injection channels  50  facilitate the delivery of lubricating or sealant fluids to the interfaces between the seats  38 ,  40  and the ball  16 . The lubricating fluids reduce the frictional forces generated between the ball  16  and the seats  38 ,  40  when the ball  16  is rotated between the open position  24  and the closed position. To facilitate discussion, the ball valve  10  and its components may be described with reference to an axial axis or direction  52 , a radial axis or direction  54 , and a circumferential axis or direction  56 . 
       FIG. 2  is a cross-sectional side view of a portion of the ball valve  10  of  FIG. 1  taken within line  2 - 2 . In the illustrated embodiment, the ball valve  10  is in a closed position  58  (e.g., approximately 0 degrees). In the closed position  58 , the bore  30  of the ball  16  is rotated perpendicular to the bores  32 ,  34  of the body  12  and the adapter  14 , thereby substantially blocking the flow of the fluid  36  through the ball valve  10 . Furthermore, when the ball valve  10  is in the closed position  58 , a contacting surface  72  (e.g., sealing face) of the first seat  38  contacts an outer surface  74  of the ball  16  and forms a seal  76  (e.g., annular seal) with the ball  16 . In certain embodiments, the contacting surface  72  is part of an insert  70  (e.g., annular insert or annular seal) coupled to a body  75  of the first seat  38 . 
     When the ball valve  10  is in the closed position  58 , the seal  76  and a main seal  78  (e.g., annular seal) substantially block a flow of the fluid  36  across the first seat  38 . In certain circumstances, after the ball valve  10  reaches the closed position  58 , the cavity pressure within the cavity  47  of the ball valve  10  is relieved or reduced (e.g., via a decrease in the pipeline downstream pressure or a valve or other pressure relief system). Accordingly, a pressure on a first side  80  (e.g., upstream side or in the bore  32  of the body  12 ) of the first seat  38  may be higher than a pressure on a second side (e.g., downstream side or within the cavity  47  of the ball valve  10 ) of the first seat  38 , which causes the first seat  38  to maintain contact with the ball  16 . For example, in certain embodiments, the fluid  36  exerts a force  62  on an axially-facing surface  60  (e.g., annular surface) of the first seat  38  and/or the fluid  36  travels through the injection channels  50 , as shown by arrows  64 , to exert a force  68  on an axially-facing surface  66  (e.g., annular surface) of the first seat  38  to drive the first seat  38  toward the ball  16 . Additionally or alternatively, a biasing force  82  (e.g., spring force) exerted on the first seat  38 , such as by a biasing member  84  (e.g., spring) positioned between opposed axially-facing surfaces of the body  12  and the first seat  38 , may drive the first seat  38  toward the ball  16 . 
     In some embodiments, the first seat  38  may include a passageway  94  that enables fluid flow from the cavity  47  to a space  96  (e.g., annular space) between the body  12  and the first seat  38  and that is configured to reduce incidence of hydraulic lock. One or more passageways  94  may be provided at discrete locations circumferentially about the first seat  38  and may extend along the axial axis  52 . As shown, the body  12  includes a shoulder  98  (e.g., an annular axially-facing surface) that is configured to block and/or to limit axial movement of the first seat  38  relative to the body  12 , which in turn may protect the biasing member  84 . 
     In certain circumstances, a large differential pressure (e.g., more than 30, 50, 70, or 100 megapascals (MPa) and/or more than 10, 20, 30, 40, or 50 percent) may exist across the ball valve  10  when the ball valve  10  is in the closed position  58 . Without the disclosed embodiments, while rotating the ball valve  10  from the closed position  58  toward the open position  24 , flow of the fluid  36  through the ball valve  10  may cause a high localized force at the interface between the first seat  38  and the ball  16  and/or cause the first seat  38  to be pushed into a slightly cocked or tilted position within the bore  30  of the ball  16 , thereby potentially damaging these components and/or increasing torque requirements for opening the ball valve  10 . Similarly, while rotating the ball valve  10  from the open position  24  to the closed position  58 , a high localized force may exist at the interface between the first seat  38  and the ball  16 . Advantageously, the disclosed systems and methods are configured to drive the first seat  38  away from the ball  16  as the ball  16  moves through a portion of its path between the closed position  58  and the open position  24  (e.g., over a portion of an opening stroke and/or a closing stroke). For example, the disclosed systems and methods may be configured to flow fluid into the space  44 , which is sealed by multiple annular seals  90 , such that the fluid exerts a force  92  on the first seat  38  (e.g., an axially-facing surface  86 ) that drives the first seat  38  away from the ball  16 . 
     In some embodiments, the system is configured to flow fluid into the space  44  at a pressure such that the force  92  exerted on the first seat  38  reduces the contact force (e.g., by greater than approximately 20, 30, 40, 50, 60, 70, 80, or 90 percent) between the first seat  38  and the ball  16  without separating the first seat  38  from the ball  16  (e.g., a portion of the first seat  38  remains in contact with the ball  16 ) as the ball  16  moves through a portion of its path between the closed position  58  and the open position  24 . In some embodiments, the system is configured to flow fluid into the space  44  at a pressure such that the force  92  exerted on the first seat  38  separates the first seat  38  from the ball  16  as the ball  16  moves through a portion of its path between the closed position  58  and the open position  24 . For example,  FIG. 3  is a cross-sectional side view of the portion of the ball valve  10  of  FIG. 2  with the first seat  38  separated from the ball  16  by a gap  99  (e.g., annular gap). 
     As discussed in more detail below, in certain embodiments, the system is configured to flow fluid into the space  44  at a first pressure as the ball  16  rotates through a first portion of the path from the closed position  58  toward the open position  24  (e.g., a first portion of the opening stroke, such as between approximately 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, 0 to 5, 5 to 30, 5 to 25, 5 to 20, or 5 to 15 degrees, or through at least or approximately 5, 10, 15, 20, 25, or 30 degrees at or near the beginning of the opening stroke). The system may be configured to flow fluid into the space  44  at a second pressure, different from the first pressure, as the ball  16  rotates through a second portion of the path from the closed position  58  to the open position  24  (e.g., a second portion of the opening stroke, such as between approximately 5 to 90, 5 to 85, 10 to 90, 10 to 85, 15 to 90, 15 to 85, 20 to 90, 20 to 85, 25 to 90, 25 to 85, 30 to 90, or 30 to 85 degrees, or through at least or approximately 40, 50, 60, 70, 80, or 85 degrees in the middle of or near or at the end of the opening stroke). In some such embodiments, the first pressure is less than the second pressure, such as at least or approximately 10, 20, 30, 40, 50, 60, 70, or 80 percent less than the second pressure. In some embodiments, the first pressure may be configured to cause a reduction in the contact force between the first seat  38  and the ball  16  without separating the first seat  38  from the ball  16 , while the second pressure may be configured to cause a further reduction in the contact force between the first seat  38  and the ball  16  and/or cause the first seat  38  to separate from the ball  16 . For example, in some embodiments, the fluid may be provided to the space  44  at the first pressure to reduce the contact force as the ball  16  rotates from approximately 0 to 15 degrees, and the fluid may be provided to the space  44  at the second pressure to separate the first seat  38  from the ball  16  as the ball rotates from approximately 15 to 90 degrees. 
     In certain embodiments, fluid may be vented from the space  44  (e.g., the space  44  may be depressurized) while the ball  16  is in the closed position  58 , the open position  24 , and/or during the closing stroke, thereby enabling the first seat  38  to seal against the ball  16 . In some embodiments, fluid may be provided to the space  44  (e.g., at a third pressure, the first pressure, or the second pressure) as the ball  16  rotates through a portion of the path from the open position  24  to the closed position  58  (e.g., a portion of the closing stroke, such as between approximately 15 to 0, 10 to 0, 5 to 0, or 3 to 0 degrees or through at least or approximately 1, 2, 3, 4, 5, 10, 15, 20 or 25 degrees at or near the end of the closing stroke). 
       FIG. 4  is a flow diagram of an embodiment of a method  100  for adjusting the first seat  38  of the ball valve  10 . The method  100  includes various steps represented by blocks. Although the flow chart illustrates the steps in a certain sequence, it should be understood that the steps may be performed in any suitable order and certain steps may be carried out simultaneously, where appropriate. Further, certain steps or portions of the method  100  may be omitted and other steps may be added. As discussed in more detail below, the method  100  may be performed by a system, such as a hydraulic, pneumatic, or electronic control system, which may include one of more valves, fluid sources, conduits, and/or a controller (e.g., electronic controller having a processor, memory, and instructions). Furthermore, steps or portions of the method  100  may be performed by separate devices or systems. 
     As shown, in step  102 , an actuator drives the stem  20  to rotate the ball  16  from the closed position  58  toward the open position  24  (e.g., the opening stroke). In step  104 , while the ball  16  is in the first portion of the opening stroke (e.g., between approximately 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, 0 to 5, 5 to 30, 5 to 25, 5 to 20, or 5 to 15 degrees, or through at least or approximately 5, 10, 15, 20, 25, or 30 degrees at or near the beginning of the opening stroke, or through approximately 5 to 25, 10 to 20, or 5 to 15 degrees of the opening stroke), fluid is provided to the space  44 . In some embodiments, the fluid is provided to the space  44  at a first pressure, which may be configured to reduce or eliminate the contact force between the first seat  38  and the ball  16 . In step  106 , while the ball  16  is in the second portion of the opening stroke (e.g., between approximately 5 to 90, 5 to 85, 10 to 90, 10 to 85, 15 to 90, 15 to 85, 20 to 90, 20 to 85, 25 to 90, 25 to 85, 30 to 90, or 30 to 85 degrees, or through at least or approximately 40, 50, 60, 70, 80, or 85 degrees in the middle of or near or at the end of the opening stroke), fluid is provided to the space  44 . In some embodiments, the fluid is provided to the space  44  at a second pressure different from the first pressure. In some embodiments, the second pressure is greater than the first pressure and is configured to further reduce the contact pressure and/or to separate or further separate the first seat  38  from the ball  16 , as discussed above. 
     In step  108 , when the ball  16  reaches a predetermined position (e.g., the open position  24 ), fluid flow to the space  44  is blocked and/or the space  44  is vented (e.g., depressurized), thereby enabling the first seat  38  to seal against the ball  16 . In step  110 , the ball  16  may rotate from the open position  24  toward the closed position  58  (e.g., the closing stroke), such as via a spring return actuator. In some embodiments, the space  44  may remain vented as the ball  16  rotates through a first portion of the closing stroke (e.g., between approximately 90 to 15, 90 to 10, 90 to 5, or 90 to 3 degrees, or through at least or approximately 50, 60, 70, 80, 85 degrees at or near the beginning of the closing stroke). In step  112 , while the ball  16  is in a second portion of the closing stroke (e.g., between approximately 15 to 0, 10 to 0, 5 to 0, or 3 to 0 degrees, or through at least or approximately 1, 2, 3, 4, 5, 10, 15, 20 or 25 degrees at or near the end of the closing stroke, or through approximately 1 to 15, 2 to 10, or 3 to 5 degrees of the closing stroke), fluid is provided to the space  44  (e.g., at a third pressure, the first pressure, or the second pressure) to reduce the contact pressure and/or to separate the first seat  38  from the ball  16 . However, in some embodiments, the space  44  may remain vented as the ball  16  rotates through the entirety of the closing stroke (e.g., as the ball  16  rotates from the open position  24  to the closed position  58 ). It should be understood that in some embodiments, multiple different pressures may be applied to the space  44  during different portions of the closing stroke. 
     With the foregoing in mind,  FIGS. 5-13  illustrate schematic diagrams of various systems that may be configured to adjust the first seat  38  of the ball valve  10 , such as by carrying out some or all of the steps of the method  100  of  FIG. 4 .  FIG. 5  is a schematic diagram of a system  120  (e.g., hydraulic system) that is configured to adjust a position of the first seat  38  of the ball valve  10 . As shown, the system  120  is fluidly coupled to the opening  46  of the ball valve  10  via a conduit  122 , and the system  120  includes a fluid source  124  (e.g., hydraulic fluid source), a cam-operated valve  126 , a valve  128  (e.g., pilot valve), and a valve  130  (e.g., solenoid valve). 
     The cam-operated valve  126  and the valve  128  adjust fluid flow from the fluid source  124  to the opening  46 . For example, in the illustrated embodiment, the valve  128  may fluidly couple a first port  131  to a second port  133  to enable fluid flow through the valve  128  toward the opening  46  during the opening stroke, and the valve  128  may vent the opening  46  while the ball  16  is in the closed position  58 , the open position  24 , and/or during the closing stroke. The cam-operated valve  126  may fluidly couple a first port  140  to a second port  142  to enable fluid flow through the cam-operated valve  126  toward the opening  46  during a portion of the rotational path of the ball  16  (e.g., between approximately 5 to 90, 5 to 85, 15 to 90, or 15 to 85 degrees, or through at least or approximately 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, or 80 degrees). Thus, together these valves  126 ,  128  enable fluid to flow to the opening  46  as the ball rotates through the portion of its rotational path during the opening stroke. In some embodiments, the cam-operated valve  126  may fluidly couple the second port  142  to a third port  143  during other portions of the rotational path of the ball  16  (e.g., between approximately 0 to 5, 0 to 15, or 85 to 90 degrees), thereby blocking fluid flow toward the opening  46  during the other portions of the opening stroke. 
     With the foregoing in mind, the illustrated embodiment depicts the system  120  while the ball  16  is in the closed position  58 . As shown, while the ball valve  10  is in the closed position  58 , the opening  46  is vented through the valve  128 . Thus, the first seat  38  is in contact with the ball  16  while the ball valve  10  is in the closed position  58 , as discussed above with respect to  FIG. 2 . In operation, actuation of the valve  130  provides a fluid flow (e.g., from a pneumatic fluid source) through a conduit  132  to adjust an actuator  134  that drives the stem  20  to rotate the ball  16  from the closed position  58  toward the open position  24 . Actuation of the valve  130  also provides a fluid flow through a conduit  136  to adjust the valve  128  to a position in which the valve  128  fluidly couples the first port  131  to the second port  133 . 
     In the illustrated embodiment, rotation of the stem  20  (e.g., in response to actuation of the valve  130 ) controls the cam-operated valve  126 . During the portion of the opening stroke, the cam-operated valve  126  is adjusted to a position in which the first port  140  is fluidly coupled to the second port  142 . Thus, during the portion of the opening stroke, the cam-operated valve  126  enables fluid to flow from the fluid source  124 , through a conduit  144 , through the cam-operated valve  126  (e.g., across ports  140 ,  142 ), through a conduit  138 , through the valve  128 , and through the conduit  122  to the opening  46 . In some embodiments, the fluid may be provided to the opening  46  at a pressure that reduces the contact force between the first seat  38  and the ball  16  without separating the first seat  38  from the ball  16 . In some embodiments, the fluid may be provided to the opening  46  at a pressure that causes the first seat  38  to separate from the ball  16  (e.g., creating an intermediate gap or clearance). Thus, the system  120  may be configured to drive the first seat  38  away from the ball  16  during the portion of the opening stroke. 
     As noted above, the cam-operated valve  126  may fluidly couple the second port  142  to the third port  143  during other portions of the rotational path of the ball  16 , thereby blocking fluid flow toward the opening  46  during the other portions of the opening stroke and/or when the ball reaches a predetermined position (e.g., the open position  24 ) during the opening stroke. In certain embodiments, the ball  16  is driven from the open position  24  to the closed position  58  via a spring return actuator  146 . In some such embodiments, the valve  130  may be turned off to enable the spring return actuator  146  to drive the ball  16  toward the closed position  58 . Additionally, when the valve  130  is turned off, the valve  128  may resume the illustrated position in which the opening  46  is vented through the valve  128 . In some embodiments, the opening  46  may remain vented through the valve  128  in this manner during the closing stroke. 
       FIG. 6  is a schematic diagram of another system  150  (e.g., hydraulic system) that is configured to adjust a position of the first seat  38  of the ball valve  10 . The system  150  of  FIG. 6  includes certain features of the system  120  of  FIG. 5 . For example, the system  150  includes the conduit  122  that fluidly couples the system  150  to the opening  46  of the ball valve  10 , the fluid source  124 , the cam-operated valve  126 , the valve  128 , and the valve  130 . The system  150  also includes a pressure regulator  152  and a valve  154  (e.g., diverter valve). 
     In the system  150 , the valve  128  may fluidly couple the first port  131  to the second port  133  to enable fluid flow through the valve  128  toward the opening  46  during the opening stroke, and the valve  128  may vent the opening  46  while the ball  16  is in the closed position  58 , the open position  24 , and/or during the closing stroke. The cam-operated valve  126  may fluidly couple a first port  156  to a second port  158  during a portion of the rotational path of the ball  16  (e.g., a first portion, such as between approximately 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, 0 to 5, 5 to 30, 5 to 25, 5 to 20, or 5 to 15 degrees, or through at least approximately 5, 10, 15, 20, 25, or 30 degrees). Thus, the cam-operated valve  126  may fluidly couple the first port  156  to the second port  158  during the portion of the opening stroke. In some embodiments, the cam-operated valve  126  may fluidly couple the first port  156  to a third port  159  during other portion(s) of the rotational path of the ball  16  (e.g., a second portion of the opening stroke, such as between approximately 5 to 90, 5 to 85, 10 to 90, 10 to 85, 15 to 90, 15 to 85, 20 to 90, 20 to 85, 25 to 90, 25 to 85, 30 to 90, or 30 to 85 degrees, or through at least approximately 40, 50, 60, 70, 80, or 85 degrees. Thus, the cam-operated valve  126  may fluidly couple the first port  156  to a third port  159  during the other portion(s) of the opening stroke. Together, the valves  126 ,  128 ,  154  may enable fluid to flow at one pressure (e.g., the first pressure) to the opening  46  during the portion of the opening stroke, enable fluid to flow at another pressure (e.g., the second pressure) to the opening  46  during the other portion(s) of the opening stroke, and/or vent the opening  46  while the ball  16  is in the closed position  58 , the open position  24 , and/or during the closing stroke. 
     With the foregoing in mind, the illustrated embodiment depicts the system  150  while the ball  16  is in the closed position  58 . As shown, while the ball  16  is in the closed position  58 , the opening  46  is vented through the valve  128 . Thus, the first seat  38  is in contact with the ball  16  while the ball  16  is in the closed position  58 , as discussed above with respect to  FIG. 2 . In operation, actuation of the valve  130  provides a fluid flow (e.g., from a pneumatic fluid source) through the conduit  132  to adjust the actuator  134  that drives the stem  20  to rotate the ball  16  from the closed position  58  toward the open position  24 . Actuation of the valve  130  also provides a fluid flow through the conduit  136  to adjust the valve  128  to a position in which the valve  128  fluidly couples the first port  131  to the second port  133 . Thus, during the opening stroke, the valve  128  fluidly couples the first port  131  to the second port  133 , and enables fluid flow from the fluid source  124 , through the pressure regulator  152 , through the valve  154 , through a conduit  138 , through the valve  128 , and through the conduit  122  to the opening  46  at a first pressure set or regulated by the pressure regulator  152 . 
     In the illustrated embodiment, rotation of the stem  20  (e.g., in response to actuation of the valve  130 ) controls the cam-operated valve  126 . During the portion of the opening stroke, the cam-operated valve  126  fluidly couples the first port  156  to the second port  158 . During the other portions of the opening stroke, the cam-operated valve  126  fluidly couples the first port  156  to the third port  159 , thereby enabling fluid flow from the fluid source  124 , through a conduit  160 , through the cam-operated valve  126  (e.g., across ports  156 ,  159 ), and through a conduit  162  to adjust a position of the valve  154 , which in turn enables fluid to flow from the fluid source  124 , through a conduit  164 , through the valve  154 , through the conduit  138 , through the valve  128 , and through the conduit  122  to the opening  46  at a second pressure. Thus, the system  150  may be configured to provide the fluid at the first pressure to the opening  46  over the portion of the opening stroke and/or to provide the fluid at the second pressure to the opening over other portion(s) of the opening stroke. 
     As discussed above, in some such embodiments, the first pressure is less than the second pressure, such as at least or approximately 10, 20, 30, 40, 50, 60, 70, or 80 percent less than the second pressure. In some embodiments, the first pressure may be configured to cause a reduction in the contact force between the first seat  38  and the ball  16  without separating the first seat  38  from the ball  16 , while the second pressure may be configured to cause a further reduction in the contact force between the first seat  38  and the ball  16  and/or cause the first seat  38  to separate from the ball  16 . Thus, the system  150  may be configured to supply fluid at various pressures to the opening  46  to drive the first seat  38  away from the ball  16  during certain portions of the opening stroke. 
     In certain embodiments, the ball  16  is driven from the open position  24  to the closed position  58  via the spring return actuator  146 . In some such embodiments, the valve  130  may be turned off to enable the spring return actuator  146  to drive the ball  16  toward the closed position  58 . Additionally, when the valve  130  is turned off, the valve  128  may resume the illustrated position in which the opening  46  is vented through the valve  128 . In some embodiments, the opening  46  may remain vented through the valve  128  in this manner during the closing stroke. 
       FIG. 7  is a schematic diagram of another system  180  (e.g., hydraulic system) that is configured to adjust a position of the first seat  38  of the ball valve  10 . The system  180  of  FIG. 7  includes certain features of the system  120  of  FIG. 5  and the system  150  of  FIG. 6 . For example, the system  180  includes the conduit  122  that fluidly couples the system  180  to the opening  46  of the ball valve  10 , the fluid source  124 , the cam-operated valve  126 , the valve  128 , the valve  130 , the pressure regulator  152 , and the valve  154 . As shown, the system  180  may include a second cam-operated valve  182 , a third cam-operated valve  184 , and a valve  198 . The system  180  may be configured to adjust the first seat  38  during the opening stroke in the manner set forth above with respect to  FIG. 5 . As discussed in more detail below, the system  180  may be configured to provide fluid to the opening  46  to adjust the first seat  38  during the closing stroke. 
     Similar to the system  150  of  FIG. 5 , in the system  180 , the valve  128  may fluidly couple the first port  131  to the second port  133  to enable fluid flow through the valve  128  toward the opening  46  during the opening stroke. The valve  128  may fluidly couple the second port  133  to a third port  135  while the ball  16  is in the closed position  58 , the open position  24 , and/or during the closing stroke. The cam-operated valve  126  may fluidly couple the first port  156  to the second port  158  during the portion of the opening stroke (e.g., a first portion, such as between approximately 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, 0 to 5, 5 to 30, 5 to 25, 5 to 20, or 5 to 15 degrees, or through at least or approximately 5, 10, 15, 20, 25, or 30 degrees near or at the beginning of the opening stroke). In some embodiments, the cam-operated valve  126  may fluidly couple the first port  156  to the third port  159  during other portion(s) of the opening stroke (e.g., a second portion of the opening stroke, such as between approximately 5 to 90, 5 to 85, 10 to 90, 10 to 85, 15 to 90, 15 to 85, 20 to 90, 20 to 85, 25 to 90, 25 to 85, 30 to 90, or 30 to 85 degrees, or through at least or approximately 40, 50, 60, 70, 80, or 85 degrees in the middle of or near or at the end of the opening stroke). 
     As shown, the system  180  includes the second cam-operated valve  182  and the third cam-operated valve  184 , which may be configured to affect fluid flow to the opening  46  during the closing stroke. In particular, the second cam-operated valve  182  may fluidly couple a first port  186  to a second port  188  during a respective portion of the path of the ball  16  (e.g., between approximately 0 to 3, 0 to 5, 0 to 10, or 0 to 15 degrees, or through at least or approximately 1, 2, 3, 4, 5, 10, or 15 degrees). In some embodiments, the second cam-operated valve  182  may fluidly couple the second port  188  to a third port  189  during other respective portion(s) of the path (e.g., between approximately 3 to 90, 5 to 90, 10 to 90, or 15 to 90 degrees, or through at least or approximately 85, 80, or 75 degrees). In some embodiments, the third cam-operated valve  184  may fluidly couple a first port  190  to a second port  192  during the entirety of the path of the ball  16  or over a respective portion of the path of the ball  16  (e.g., between approximately 0 to 3, 0 to 5, 0 to 10, or 0 to 15 degrees, or through at least or approximately 1, 2, 3, 4, 5, 10, or 15 degrees). In some embodiments, the third cam-operated valve  184  may fluidly couple the second port  192  to a third port  193  while the ball  16  is in the closed position  58  or during other respective portion(s) of the path (e.g., between approximately 3 to 90, 5 to 90, 10 to 90, or 15 to 90 degrees, or through at least or approximately 85, 80, or 75 degrees). The respective portions of the path of the ball  16  through which the second cam-operated valve  182  fluidly couples the first port  186  to the second port  188  and the third cam-operated valve  184  fluidly couples the first port  190  to the second port  192  overlap to enable fluid flow through both valves  182 ,  184  during a corresponding portion of the path of the ball  16 . Together, the valves  126 ,  128 ,  154 ,  182 ,  184 ,  198  may enable fluid to flow at one pressure (e.g., the first pressure) to the opening  46  during the portion of the opening stroke, enable fluid to flow at another pressure (e.g., the second pressure) to the opening  46  during the other portion(s) of the opening stroke, enable fluid to flow (e.g., at a third pressure, the first pressure, or the second pressure) to the opening  46  during a portion of the closing stroke, and/or vent the opening  46  while the ball  16  is in the closed position  58 , the open position  24 , and/or during other portion(s) of the closing stroke. 
     With the foregoing in mind, the illustrated embodiment depicts the system  180  while the ball  16  is in the closed position  58 . As shown, while the ball  16  is in the closed position  58 , the opening  46  is vented through the valve  128  and the valve  198 . Thus, the first seat  38  is in contact with the ball  16  while the ball valve  10  is in the closed position  58 , as discussed above with respect to  FIG. 2 . Similar to the system  150  of  FIG. 6 , actuation of the valve  130  provides a fluid flow (e.g., from a pneumatic fluid source) through the conduit  132  to adjust the actuator  134  that drives the stem  20  to rotate the ball  16  from the closed position  58  toward the open position  24 . Actuation of the valve  130  also provides a fluid flow through the conduit  136  to adjust the valve  128  to a position in which the valve  128  fluidly couples the first port  131  to the second port  133 . Thus, during the opening stroke, the valve  128  fluidly couples the first port  131  to the second port  133 , and enables fluid flow from the fluid source  124 , through the valve  154 , through the conduit  138 , through the valve  128 , and through the conduit  122  to the opening  46 . While the valve  154  is in the illustrated position during the opening stroke, the fluid flows through the pressure regulator  152  and is provided to the opening  46  at one pressure (e.g., the first pressure) set or regulated by the pressure regulator  152 . 
     In the illustrated embodiment, rotation of the stem  20  (e.g., in response to actuation of the valve  130 ) controls the cam-operated valve  126 . Similar to the system  150  of  FIG. 5 , during the portion of the opening stroke, the cam-operated valve  126  fluidly couples the first port  156  to the second port  158 . During the other portions of the opening stroke, the cam-operated valve  126  fluidly couples the first port  156  to the third port  159 , thereby enabling fluid flow from the fluid source  124 , through a conduit  160 , through the cam-operated valve  126  (e.g., across ports  156 ,  159 ), and through a conduit  162  to adjust a position of the valve  154 , which in turn enables fluid to flow from the fluid source  124 , through a conduit  164 , through the valve  154 , through the conduit  138 , through the valve  128 , and through the conduit  122  to the opening  46  at a second pressure. Thus, the system  180  may be configured to provide the fluid at the first pressure to the opening  46  over the portion of the opening stroke and/or to provide the fluid at the second pressure to the opening over other portion(s) of the opening stroke. 
     In certain embodiments, the ball  16  is driven from the open position  24  to the closed position  58  via the spring return actuator  146 . In some such embodiments, the valve  130  may be turned off to enable the spring return actuator  146  to drive the ball  16  toward the closed position  58 . Additionally, when the valve  130  is turned off, the valve  128  may resume the illustrated position. Thus, the valve  128  may be in the illustrated position while the ball  16  is in the closed position and/or during the entirety of the closing stroke. Additionally, the valve  198  may be in the illustrated position to enable venting the opening  46  while the ball  16  is in the closed position  58  and over at least some of the closing stroke. As discussed in more detail below, when the valve  128  is in the illustrated position, the second cam-operated valve  182 , the third cam-operated valve  184 , and the valve  198  may affect fluid flow to the opening  46  and may cause adjustment of the first seat  38  during the closing stroke. 
     In some embodiments, the third cam-operated valve  184  fluidly couples the first port  190  to the second port  192  over the entirety of the closing stroke or over a portion of the closing stroke. During a respective portion of the closing stroke, the second cam-operated valve  182  may be adjusted to a position in which the first port  186  is fluidly coupled to the second port  188 . When the second cam-operated valve  182  and the third cam-operated valve  184  are in such positions, fluid may flow from the fluid source  124 , through a conduit  194 , through the third cam-operated valve  184  (e.g., across ports  190 ,  192 ), through the second cam-operated valve  186  (e.g., across ports  186 ,  188 ), through a conduit  196  to adjust a position of the valve  198 , which in turn enables fluid to flow from the pressure regulator  152 , through a conduit  200 , through the valve  198 , through the conduit  178 , through the valve  128 , and through the conduit  122  to the opening  46 . In some such embodiments, the pressure regulator  152  may be configured to provide fluid at a pressure (e.g., the first pressure) that reduces the contact force between the first seat  38  and the ball  16  without separating these components from one another or at a pressure (e.g., the second pressure) that further reduces the contact force and/or causes separation of the first seat  38  from the ball  16  as the ball valve  16  moves to the closed position  58 . In some embodiments, the fluid may be provided to the opening  46  during the closing stroke at a third pressure different from both the first or second pressures applied during the opening stroke. Thus, in some embodiments, when the ball  16  rotates through a portion of its path or reaches a predetermined position (e.g., 2, 3, 4, 5, 10, or 15 degrees) during the closing stroke, fluid may drive the first seat  38  away from the ball  16 , thereby reducing torque needed to close the ball valve  10  and/or reducing wear on the components, for example. 
     As noted above, the second-cam operated valve  182  may be configured to fluidly couple the first port  186  to the second port  188  while the ball  16  is positioned between approximately 0 to 3, 0 to 5, 0 to 10, or 0 to 15 degrees, or through at least or approximately 1, 2, 3, 4, 5, 10, or 15 degrees at or near the end of the closing stroke. Furthermore, the third cam-operated valve  184  may be configured to fluidly couple the first port  190  to the second port  192  during the entirety of the closing stroke or while the ball  16  is positioned between approximately 0 to 90, 5 to 90, 10 to 90, or 15 to 90 degrees, or through at least or approximately 1, 2, 3, 4, 5, 10, or 15 degrees at or near the end of the closing stroke. As noted above, the respective portions of the path of the ball  16  through which the second cam-operated valve  182  fluidly couples the first port  186  to the second port  188  and the third cam-operated valve  184  fluidly couples the first port  190  to the second port  192  overlap to enable fluid flow through both valves  182 ,  184 , as well as fluid flow to the opening  46 , during the corresponding portion of the closing stroke 
     By way of specific example to facilitate discussion, the cam-operated valve  126  may fluidly couple the first port  156  to the third port  159  while the ball  16  is positioned between approximately 5 and 90 degrees. Thus, upon initial actuation of the valve  130  and until the ball  16  reaches approximately 5 degrees, fluid flows from the fluid source  124  to the opening  46  at the first pressure regulated by the pressure regulator  152 . When the ball  16  is rotated to approximately 5 degrees, the cam-operated valve  126  and the diverter valve  154  adjust, thereby causing fluid to flow from the fluid source  124  at the second pressure. The fluid may be provided to the opening  46  at the second pressure until the valve  130  is turned off, as this causes the valve  128  to block flow from the conduit  138  and instead to fluidly couple the second port  133  to the third port  135 . The opening  46  may be vented through the valves  128  and  198  while the ball  16  is in the open position  24 . During the closing stroke, the third cam-operated valve  84  may fluidly couple the first port  190  to the second port  192 . When the ball  16  is rotated to approximately 3 degrees, the second cam-operated valve  82  may be adjusted to fluidly couple the first port  186  to the second port  188 , thereby enabling fluid to flow through both valves  182 ,  184  and causing the valve  198  to adjust, which in turn provides fluid from the fluid source  124  to the opening  46  at a pressure (e.g., the first pressure or other set pressure) regulated by the pressure regulator  152 . When the ball  16  reaches the closed position  58 , the third cam-operated valve  184  may adjust to fluidly couple the second port  192  to the third port  192 , thereby enabling venting of the opening  46 . Thus, the system  180  may be configured to supply fluid at various pressures to the opening  46  to drive the first seat  38  away from the ball  16  during certain portions of the opening stroke and/or certain portions (e.g., at the end) of the closing stroke. 
     The numerical values provided in this example and throughout the disclosure are intended to be exemplary, and it should be understood that the cam-operated valves  126 ,  184 ,  186  may be adjusted at various stages of the opening and/or closing strokes. Furthermore, to the extent that adjustment of the cam-operated valves  126 ,  182 ,  184  is discussed in the context of the opening and closing strokes, it should be understood that the cam-operated valves  126 ,  182 ,  184  may be adjusted based on the position of the ball  16  regardless of whether the ball  16  is being rotated toward the open position  24  or the closed position  58 , but that the effect of the cam-operated valve  126 ,  182 ,  184  on the first seat  38  is enabled or blocked based on the position of the valve  128 . In certain embodiments, additional cam-operated valves may be provided to provide various pressures (e.g., more than 3, 4, or 5 different pressures) through the opening and/or closing strokes. Additionally, to the extent that certain examples refer to moving from a fully open position to a fully closed position, or from a fully closed position to a fully open position, it should be understood that the embodiments disclosed herein may be adapted to apply pressure to the space  44  as the ball  10  rotates between intermediate positions, or between an intermediate position and a fully closed position or a fully open position, for example. 
       FIG. 8  is a schematic diagram of another system  210  (e.g., hydraulic system) having an electronic controller  212  that is configured to adjust a position of the first seat  38  of the ball valve  10 . The system  210  of  FIG. 8  includes certain features of the system  120  of  FIG. 5 , the system  150  of  FIG. 6 , and the system  180  of  FIG. 7 . For example, the system  210  includes the conduit  122  that fluidly couples the system  210  to the opening  46  of the ball valve  10 , the fluid source  124 , the valve  130 , and the pressure regulator  152 . The system  210  also includes a valve  214  (e.g., shuttle valve), a valve  216  (e.g., diverter valve), a valve  218 , (e.g., diverter valve), and a sensor  220 . 
     The illustrated embodiment depicts the system  210  while the ball valve  10  is in the closed position  58 . As shown, while the ball valve  10  is in the closed position  58 , the opening  46  is vented through the valves  214 ,  216 ,  218 . Thus, the first seat  38  is in contact with the ball  16  while the ball  16  is in the closed position  58 , as discussed above with respect to  FIG. 2 . In operation, actuation of the valve  130  provides a fluid flow (e.g., from a pneumatic fluid source) through the conduit  132  to adjust the actuator  134  that drives the stem  20  to rotate the ball  16  from the closed position  58  toward the open position  24 . 
     The sensor  220  may monitor a position of the stem  20  and provide a signal indicative of the position of the ball  16  to the controller  212 . The controller  212  may control the valves  214 ,  216 ,  218  to adjust fluid flow to the opening  46  based on the signal. For example, during a first portion of the opening stroke (e.g., such as between approximately 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, 0 to 5, 5 to 30, 5 to 25, 5 to 20, or 5 to 15 degrees, or through at least approximately 5, 10, 15, 20, 25, or 30 degrees near or at the beginning of the opening stroke), the controller  212  may control the valve  216  to fluidly couple a first port  222  to a second port  224 . Thus, during the portion of the opening stroke, the valve  216  enables fluid flow from the fluid source  124 , through the pressure regulator  152 , through the valves  216 ,  214 , and through the conduit  122  to the opening  46  at a pressure (e.g., the first pressure) set or regulated by the pressure regulator  152 . During a second portion of the opening stroke (e.g., such as between approximately 5 to 90, 5 to 85, 10 to 90, 10 to 85, 15 to 90, 15 to 85, 20 to 90, 20 to 85, 25 to 90, 25 to 85, 30 to 90, or 30 to 85 degrees, or through at least approximately 40, 50, 60, 70, 80, or 85 degrees in the middle of or at the end of the opening stroke), the controller  212  may control the valve  218  to fluidly couple a first port  230  to a second port  232 . Thus, during the second portion of the opening stroke, the valve  218  enables fluid flow from the fluid source  124 , through the valves  218 ,  214 , and through the conduit  122  to the opening  46  at another pressure (e.g., the second pressure). In some embodiments, the controller  212  may be configured to vent the space  44  when the ball valve  16  reaches the open position  24 . 
     The controller  212  of the present embodiments includes a processor, such as the illustrated microprocessor  240 , and a memory device  242 . The controller  212  may also include one or more storage devices and/or other suitable components. The processor  240  may be used to execute instructions or software. Moreover, the processor  240  may include multiple microprocessors, one or more “general-purpose” microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processor  240  may include one or more reduced instruction set (RISC) processors. 
     The memory device  242  may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as ROM. The memory device  242  may store a variety of information and may be used for various purposes. For example, the memory device  242  may store processor-executable instructions (e.g., firmware or software) for the processor  240  to execute, such as instructions for processing the signals from the sensor  220  to determine a position of the stem  20 . The storage device(s) (e.g., nonvolatile storage) may include read-only memory (ROM), flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The storage device(s) may store data (e.g., characteristics of the hydraulic fluid, thresholds, etc.), instructions (e.g., software or firmware for processing the signals, etc.), and any other suitable data. The controllers, processors, and memory devices disclosed herein may have any of the above-described features. Additionally, it should be understood that any of the systems  120 ,  150 ,  180  may be adapted to include the controller  212  to control one or more valves in accordance with the techniques of the present disclosure. 
       FIG. 9  is a schematic diagram of a hydraulic booster charger system  250  that may be used to supply hydraulic fluid to the hydraulic systems of  FIGS. 5-8 . The hydraulic booster charger system  250  may be part of the fluid source  124  and is configured to provide the fluid at a particular pressure to adjust the first seat  38  of the ball valve  10 . 
       FIGS. 10-13  illustrate schematic diagrams of systems that utilize a pneumatic system to adjust the position of the first seat  38  of the ball valve  10 . In particular,  FIG. 10  is a schematic diagram of a system  300  (e.g., pneumatic system). The system  300  is configured to provide a fluid flow (e.g., pressurized gas) from a pneumatic header  302  to adjust the seat  38  in a similar manner as described above with respect to  FIG. 5 . For example, as shown, the system  300  includes the cam-actuated valve  126 , the valve  128 , the valve  130  that are configured to adjust the fluid flow to drive the first seat  38  away from the ball  16  during the portion of the opening stroke, and other components. 
       FIG. 11  is a schematic diagram of another system  320  (e.g., pneumatic system) that is configured to control a position of the first seat  38  of the ball valve  10 . The system  320  is configured to provide a fluid flow (e.g., pressurized gas) from the pneumatic header  302  to adjust the seat  38  in a similar manner as described above with respect to  FIG. 6 . For example, as shown, the system  320  includes the cam-actuated valve  126 , the valve  128 , the valve  130 , the valve  154 , and the pressure regulator  152  that are configured to supply fluid to the opening  46  at various pressures to drive the first seat  38  away from the ball  16  during certain portions of the opening stroke, and other components. 
       FIG. 12  is a schematic diagram of a system  340  (e.g., pneumatic system) that is configured to control a position of the first seat  38  of the ball valve  10 . The system  340  is configured to provide a fluid flow (e.g., pressurized gas) from the pneumatic header  302  to adjust the seat  38  in a similar manner as described above with respect to  FIG. 7 . For example, as shown, the system  340  includes the cam-actuated valve  126 , the second cam-actuated valve  182 , the third cam-actuated valve  184 , the valve  128 , the valve  130 , the valve  154 , the valve  198 , and the pressure regulator  152  that are configured to supply fluid to the opening  46  at various pressures to drive the first seat  38  away from the ball  16  during certain portions of the opening stroke and during certain portions of the closing stroke, and other components. 
       FIG. 13  is a schematic diagram of a system  360  (e.g., pneumatic system) having an electronic controller  212  and that is configured to control a position of the first seat  38  of the ball valve  10 . The system  360  is configured to provide a fluid flow (e.g., pressurized gas) from the pneumatic header  302  to adjust the seat  38  in a similar manner as described above with respect to  FIG. 8 . For example, as shown, the system  360  includes the valve  130 , the valves  214 , the valve  216 , the valve  218 , the sensor  220 , and the pressure regulator  152  that are configured to supply fluid to the opening  46  at various pressures to drive the first seat  38  away from the ball  16  during certain portions of the opening stroke and during certain portions of the closing stroke, and other components. 
     It should be understood that the method  100  of  FIG. 4  and the various systems described with respect to  FIGS. 5-13  may be utilized with ball valves having various structural features. For example, the opening  46  and the space  44  may be located at any suitable position that enables the fluid to exert the force  92  on the first seat  38  to drive the first seat  38  away from the ball  16 .  FIG. 14  is a cross-sectional side view of an alternative arrangement of components within the portion of the ball valve  10  of  FIG. 2 . In the illustrated embodiment, the retainer  42  is coupled to the body  12  of the ball valve  10 . The space  44 , which is sealed by multiple annular seals  90 , is configured to receive fluid via the opening  46 . The fluid exerts the force  92  on the first seat  38 , thereby driving the first seat  38  away from the ball  16 . For example, in the illustrated embodiment, the force  92  exerted by the fluid in the space  44  drives the first seat  38  axially away from the ball, causing the first seat  38  to separate from the ball  16  by the gap  99 . 
     While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. 
     The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).