Patent Publication Number: US-2022220833-A1

Title: Inline fracturing valve systems and methods

Description:
BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. 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 embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     In order to meet consumer and industrial demand for natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired subterranean resource is discovered, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, fluid conduits, and the like, that control drilling or extraction operations. 
     Additionally, such wellhead assemblies may use a fracturing tree and other components to facilitate a fracturing process and enhance production from a well. As will be appreciated, resources such as oil and natural gas are generally extracted from fissures or other cavities formed in various subterranean rock formations or strata. To facilitate extraction of such resources, a well may be subjected to a fracturing process that creates one or more man-made fractures in a rock formation. This facilitates, for example, coupling of pre-existing fissures and cavities, allowing oil, gas, or the like to flow into the wellbore. Such fracturing processes typically include injecting a fracturing fluid—which is often a mixture including proppant (e.g., sand) and water—into the well to increase the well&#39;s pressure and form the man-made fractures. The high pressure of the fluid increases crack size and crack propagation through the rock formation to release oil and gas, while the proppant prevents the cracks from closing once the fluid is depressurized. During fracturing operations, fracturing fluid may be routed via fracturing lines (e.g., pipes) to fracturing trees or other assemblies installed at wellheads. Conventional fracturing trees have valves that can be opened and closed to control flow of fluid through the fracturing trees into the wells. 
     SUMMARY 
     Certain aspects of some embodiments disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below. 
     Embodiments of the present disclosure generally relate to valves for controlling fluid flow. More specifically, some embodiments relate to frac valves for controlling the flow of fracturing fluid in fracturing systems. In some instances, the frac valves may be provided in a wellhead assembly (e.g., in a fracturing tree) or a fluid supply system (e.g., a fracturing manifold) to control the flow of fracturing fluid during fracturing operations at a wellsite. A frac valve may be provided as an inline frac valve having an actuator and seal that are positioned within a flow bore of the valve such that the actuator can move the seal between open and closed positions to control flow through the valve. In some embodiments, flow-by conduits in the actuator facilitate flow of fluid past the actuator within the flow bore when the valve is open. 
     Various refinements of the features noted above may exist in relation to various aspects of the present embodiments. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of some embodiments without limitation to the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of certain embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  generally depicts a fracturing system having valves for controlling flow in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a sectioned perspective view of an inline valve having an actuator and seal installed within a flow bore of the valve in accordance with one embodiment; 
         FIG. 3  is an axial cross-section of the valve of  FIG. 2  in accordance with one embodiment; 
         FIG. 4  is a radial cross-section of the valve of  FIG. 2  showing the actuator having circumferentially spaced flow-by conduits in accordance with one embodiment; 
         FIG. 5  depicts the actuator and seal of the valve of  FIG. 2  in an open position that allows flow through the valve via the flow-by conduits in accordance with one embodiment; 
         FIG. 6  depicts the actuator and seal of the valve of  FIG. 2  in a closed position that blocks flow through the valve in accordance with one embodiment; 
         FIG. 7  is an axial cross-section of an inline frac valve having an actuator and seal installed within a flow bore of the valve, with the seal shown in an open position allowing flow through the valve, in accordance with one embodiment; 
         FIG. 8  is a radial cross-section of the valve of  FIG. 7  showing an annular flow-by area surrounding the actuator in accordance with one embodiment; 
         FIG. 9  depicts the seal of the valve of  FIG. 7  in a closed position that blocks flow through the valve in accordance with one embodiment; 
         FIG. 10  depicts an inline frac valve having seals on opposite faces of an actuator installed within a flow bore of the valve, with the actuator and seals in an open position that allows flow through the valve via flow-by conduits in the actuator, in accordance with one embodiment; 
         FIG. 11  depicts the valve of  FIG. 10  with one of the face seals moved to a closed position that blocks flow through the valve in accordance with one embodiment; 
         FIG. 12  depicts the valve of  FIGS. 10 and 11  with the other of the face seals moved to a closed position that blocks flow through the valve in accordance with one embodiment; 
         FIG. 13  depicts an inline frac valve like that of  FIG. 10  but with a single face seal on the actuator and angled flow-by conduits in accordance with one embodiment; 
         FIG. 14  depicts the valve of  FIG. 13  with the actuator and face seal in a closed position that blocks flow through the valve in accordance with one embodiment; 
         FIGS. 15 and 16  depict additional seal configurations for the actuator of  FIG. 13  in accordance with some embodiments; 
         FIG. 17  depicts a valve as an actuatable plug assembly installed within a bore of a wellhead in accordance with one embodiment; 
         FIG. 18  is a detail view of the actuatable plug assembly of  FIG. 17  and shows an actuator, seal carrier, and seal in an open position that allows flow through the assembly in accordance with one embodiment; 
         FIG. 19  is a detail view of the seal and the seal carrier and generally depicts flow-by slots in the seal carrier that facilitate flow through the assembly when the seal and seal carrier are in the open position in accordance with one embodiment; and 
         FIG. 20  is a detail view like that of  FIG. 18  but with the actuator, seal carrier, and seal in a closed position that blocks flow through the assembly in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Specific embodiments of the present disclosure are described below. In an effort to provide a concise description of these 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. 
     When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, any use of “top,” “bottom,” “above,” “below,” other directional terms, and variations of these terms is made for convenience, but does not require any particular orientation of the components. 
     Turning now to the present figures, an example of a fracturing system  10  is provided in  FIG. 1  in accordance with certain embodiments. The fracturing system  10  facilitates extraction of natural resources, such as oil or natural gas, from a subterranean formation via a well  12  and a wellhead  14 . Particularly, by injecting a fracturing fluid into the well  12 , the fracturing system  10  increases the number or size of fractures in a rock formation or strata to enhance recovery of natural resources present in the formation. Well  12  is a surface well in some embodiments, but it will be appreciated that resources may be extracted from other wells  12 , such as platform or subsea wells. 
     The fracturing system  10  includes various components to control flow of a fracturing fluid into the well  12 . For instance, the fracturing system  10  depicted in  FIG. 1  includes a wellhead assembly  16  that receives fracturing fluid from a fluid supply system  22 . In some embodiments, the wellhead assembly  16  includes one or more frac valves  18  to control flow of fracturing fluid into the well  12 . More particularly, the wellhead assembly  16  can include a fracturing tree  20  having one or more frac valves  18 . Various examples of frac valves are described below in accordance with the present techniques. In some embodiments, a fracturing tree  20  may include one or more of these frac valves to control flow of fracturing fluid through the tree  20  into the well  12  (or from the well  12  in some instances, such as during a flowback operation). Any of the described frac valves could be used as an upper master valve or a lower master valve of the fracturing tree  20 , for instance. The sizes and pressure ratings of the frac valves  18  may vary depending on the intended application. But in at least some embodiments the frac valves  18  have large bores, such as a nominal bore diameter of seven and one-sixteenth inches (approximately 18 cm) and are constructed for high pressure applications, such as up to 15,000 psi (approximately 100,000 kPa). Those skilled in the art will appreciate that the fracturing tree  20  could include other elements, such as connection blocks, wing valves, a swab valve, and a frac head. In other embodiments, the wellhead assembly  16  may include one or more frac valves  18  without a fracturing tree mounted over the wellhead  14 . 
     The fracturing fluid supply system  22  may also (or instead) include one or more frac valves  18  for controlling flow of fracturing fluid to the well  12 . The frac valves  18  of the fracturing fluid supply system  22  may be provided in the form of a frac valve described below or in any other suitable form. In some embodiments, the fracturing fluid supply system  22  includes trucks that pump the fracturing fluid to the wellhead assembly  16 , but any suitable sources of fracturing fluid and manners for transmitting such fluid to the wellhead assembly  16  may be used. In some instances, the fracturing fluid supply system  22  includes a fracturing manifold for distributing fracturing fluid to multiple wells  12  via respective wellhead assemblies  16 . The fracturing manifold may include frac valves  18  to control flow of fracturing fluid to the individual wells  12 . 
     In some embodiments, a frac valve  18  of the fracturing system  10  is embodied by one of the valves  30  described below. Various examples of valves  30  are described below as frac valves  30  for controlling flow of fracturing fluids. But it will be appreciated that the various valves  30  described herein could also or instead be used in other applications to convey other fluids. As described in greater detail below, the valves  30  can include inline actuators and seals positioned within flow paths of the valves to selectively control flow through the valves. 
     In  FIGS. 2 and 3 , a frac valve  30  is shown including an actuator  32  and a seal  34  positioned within a bore  36  of a housing  38 , which may also be referred to as a conduit  38 . In at least some instances, the housing  38  of the frac valve  30  includes multiple bodies (e.g., spools  40  and  42  in  FIGS. 2 and 3 ) to facilitate installation of internal components, such as the actuator  32  and the seal  34 , within the bore  36 . It will be appreciated that such multiple bodies may be connected in any suitable manner. The spools  40  and  42 , for instance, are depicted in  FIGS. 2 and 3  as having external connection flanges that can be fastened together, such as by studs and nuts or a clamp. In other instances, however, the housing  38  could be provided in other forms, such as a side- or top-entry valve body with a cover or a single-piece body. 
     In operation, the actuator  32  moves the seal  34  between open and closed positions to control flow of fracturing fluid between ends  44  and  46  of the bore  36 . While fracturing fluid could flow in either direction through the valve  30 , in at least some instances the end  44  of the bore  36  is used as an inlet of the valve  30  and the end  46  of the bore  36  is used as an outlet of the valve  30 . In some embodiments, including that shown in  FIGS. 2 and 3 , the seal  34  is carried by a seal carrier  52  that is coupled to the actuator  32 . 
     Flow-by holes  50  extend through the actuator  32  and the seal carrier  52  to facilitate flow of fracturing fluid through the bore  36  of the valve  30  when the seal  34  is in an open position. Although one example of a valve  30  having twelve circumferentially spaced flow-by holes  50  is depicted in  FIG. 4 , any other suitable number of flow-by holes  50  may be used. The size, shape, and orientation of the flow-by holes  50  may also vary in other embodiments. 
     In some embodiments, the flow-by holes  50  collectively provide a flow area similar to that of the inlet flow bore. That is, in the case of flow through the valve  30  from end  44  to end  46 , the sum of the cross-sectional area of each flow-by hole  50  (measured perpendicular to the flow axis of that hole  50 ) may be within ten, five, three, two, or one percent of the cross-sectional area of the bore  36  at the end  44  (measured perpendicular to the flow axis of the bore  36  at the end  44 ), for instance. Further, in one embodiment the sum of the cross-sectional area of each flow-by hole  50  is equal to the cross-sectional area of the bore  36  at the end  44 . 
     As noted above, the position of the seal  34  is controlled via the actuator  32 . In the example of  FIGS. 2-4 , the actuator  32  is a piston with a piston head  54  (here an annular piston head provided as a circumferential flange) that facilitates hydraulic control of the actuator  32  and the seal  34 . Hydraulic control fluid may be routed into a chamber  62  (via port  64 ) on one side of the piston head  54  to push the actuator  32  in one direction (to the left in  FIG. 3 ) and may be routed into a chamber  66  (via port  68 ) on an opposite side of the piston head  54  to push the actuator  32  in the opposite direction (to the right in  FIG. 3 ). In this manner, the actuator  32  and the seal  34  may be moved between an open position depicted in  FIG. 5  and a closed position depicted in  FIG. 6 . It will be appreciated that control fluid may be vented from either of chamber  62  or  66  as control fluid is pumped into the other of these chambers. The apparatus can also include any suitable wipers, seals, or gaskets, examples of which include seals  70  and gasket  72 . 
     The actuator  32 , the seal  34 , and the seal carrier  52  are shown positioned within the flow path of the valve  30 , inline with the ends  44  and  46  along a central axis of the bore  36 . The actuator  32 , the seal  34 , and the seal carrier  52  may be moved axially along the central axis between open and closed positions. With the seal  34  in an open position that allows flow, fracturing fluid may enter the housing  38  through the end  44  of the bore  36 , flow past the seal  34  through an opening between the seal  34  and an opposing sealing surface  76  (e.g., a tapered sealing surface along the bore  36 ), flow through the seal carrier  52  and the actuator  32  via the flow-by holes  50 , and exit the housing  38  through the end  46  of the bore  36 . In some embodiments, including that of  FIGS. 2 and 3 , the seal  34  and seal carrier  52  are tapered to facilitate flow of the fracturing fluid from the end  44  of the bore  36  to the flow-by holes  50 . The actuator  32  may be used to close the seal  34  against the sealing surface  76 , such as shown in  FIG. 6 , to block flow through the valve  30 . 
     In at least some embodiments, the seal  34  is an elastomer (e.g., rubber) seal that is energized when compressed against the sealing surface  76  by the actuator  32 . But the seal  34  may be made of any other suitable material, such as another polymer or metal, in other embodiments. The housing  38 , the actuator  32 , and the seal carrier  52  may be formed of metal (e.g., carbon or stainless steel) or any other suitable material. Although the seal carrier  52  could be permanently joined to the actuator  32  (e.g., via welding) or formed integrally with the actuator  32  (e.g., as a single forged or cast body), in at least some embodiments, the seal carrier  52  is removable from the actuator  32  to facilitate maintenance. For example, the seal  34  can be molded onto or otherwise affixed to the seal carrier  52  and, when the seal  34  is worn or otherwise damaged, the seal carrier  52  can be removed from the actuator  32  and replaced by a new seal carrier  52  and seal  34 . In other instances, the seal  34  may be independently removable (from the seal carrier  52 ), allowing a replacement seal  34  to be used with the seal carrier  52  and the actuator  32 . 
     Another embodiment of a valve  30  is depicted in  FIGS. 7-9 . In this embodiment, the actuator  32  includes a hydraulic cylinder with an enclosed piston head  54  coupled to the seal carrier  52  and seal  34  by a piston rod  82 . Like the embodiment of  FIGS. 2 and 3 , the seal  34  (e.g., an elastomer seal) may be moved between an open position ( FIG. 7 ) and a closed position ( FIG. 9 ) to allow or block flow in either direction by routing control fluid (e.g., hydraulic control oil) into chamber  62  or chamber  66 . The cylinder body of the actuator  32  in  FIG. 7  includes a port  84  coupled to receive control fluid from the port  64  via control line  86 , as well as a port  88  coupled to receive control fluid from the port  68  via control line  90 . Although depicted as a hydraulic actuator, the actuator  32  may take other forms, such as an electric actuator or pneumatic actuator, in different embodiments. 
     In the presently depicted embodiment, the actuator  32  is positioned within the bore  36  inline with the seal  34 , the seal carrier  52 , and the flow path through the valve  30  such that fracturing fluid flows through a flow-by area  94  around the exterior of the actuator  32  when the seal  34  is in an open position (e.g., as shown in  FIG. 7 ). The actuator  32  is shown in  FIG. 8  as having a round exterior surface without flow-by conduits, but the actuator  32  could have flow-by conduits (e.g., a fluted body with exterior flow-by slots) in other examples. In at least some instances, the cross-sectional area of the flow-by area  94  is within ten, five, three, two, or one percent, or is equal to, the cross-sectional area of the bore  36  at the end  44  (each measured in a plane perpendicular to the direction of mass flow). The actuator  32  may be secured at a location within the bore  36  in any suitable manner, such as with radially extending legs  96  that may be received in mating recesses in the spool  40  or welded in place. 
     In some embodiments, the actuator  32  itself carries the seal  34  without a separate seal carrier  52 . Some examples of such embodiments are depicted in  FIGS. 10-16 . In  FIGS. 10-12 , for instance, the valve  30  is shown with an actuator  32  that carries two seals  34  and is installed within the bore  36  inline with the flow path. The actuator  32 , which includes flow-by holes  50 , can be moved between open and closed positions by injecting control fluid into chambers  62  and  66  through ports  64  and  68 . 
     The two seals  34  in  FIGS. 10-12  are face seals carried on opposite sides of the actuator that are transverse to the bore  36 . This arrangement allows bidirectional sealing in the valve  30 , in which the actuator  32  can be moved in either of two opposing axial directions to block flow through the bore  36 . The actuator  32  and the seals  34  are shown in an open position in  FIG. 10  to allow fracturing fluid to flow through the bore  36  via the flow-by holes  50 . A control fluid may be routed into the chamber  62  to drive the actuator  32  to the closed position depicted in  FIG. 11 , in which the seal  34  on the left side of the actuator  32  is compressed against an opposing sealing surface  102  to block flow though the bore  36  (by isolating the flow-by holes  50  from the end  46  of the bore  36 ). Likewise, a control fluid may be routed into the chamber  66  to drive the actuator  32  in an opposite direction to the closed position depicted in  FIG. 12 , in which the seal  34  on the right side of the actuator  32  is compressed against an opposing sealing surface  104  to block flow through the bore  36  (by isolating the flow-by holes  50  from the end  44  of the bore  36 ). The pressures in chambers  62  and  66  may be equalized to hold the actuator  32  and the seals  34  in an open position to allow flow. The sealing surfaces  102  and  104  may be stop shoulders of spools  40  and  42 , as shown in  FIGS. 10-12 , or any other suitable surfaces. 
     As discussed above, the number, size, shape, and orientation of the flow-by holes  50  in the actuator  32  may vary between embodiments. The flow-by holes  50  (e.g., twelve or sixteen holes) can be spaced circumferentially about the actuator  32  radially outward of the seals  34 . In some instances, the valve  30  can be constructed such that the flow-by holes  50  collectively provide a flow-by area that is within ten, five, three, two, or one percent, or is equal to, the cross-sectional area of the bore  36  at the end  44  or  46  of the bore  36  upstream of the actuator  32 . 
     As shown in  FIGS. 13 and 14 , the inline actuator  32  carries a seal  34  on just one side transverse to the bore  36 . This arrangement provides unidirectional sealing, in which the actuator  32  is closed in a single direction to block flow through the valve  30 . More specifically, the actuator  32  can be moved between an open position ( FIG. 13 ) and a closed position ( FIG. 14 ), in which the seal  34  seals against the opposing sealing surface  104  to block flow through the bore  36 . While the actuator  32  can have straight flow-by holes  50  (like those shown in  FIGS. 3 and 10 ), the flow-by holes  50  in  FIGS. 13 and 14  are instead angled with respect to the axis of the bore  36 . 
     The seal  34  can be made of any suitable material. In some embodiments, the seal  34  is an elastomer, thermoplastic, or other non-metal seal. In some other embodiments, the seal  34  may be a metal seal. Further, a combination of metal and non-metal seals  34  may be used in some instances. The seal  34  may also have any suitable shape. In  FIGS. 10-14 , for example, the seal  34  can be shaped as a disc positioned radially inward of the flow-by holes  50 . The seal  34  can be inset within a recess of the actuator  32 , such as also shown in  FIGS. 10-14 . In other instances, such as that depicted in  FIG. 15 , the seal  34  extends radially beyond the flow-by holes  50 . In one embodiment, the seal  34  is a layer (e.g., an elastomer layer) formed on or otherwise affixed to a transverse side of the actuator  32  and the flow-by holes  50  extend through the seal layer. In another embodiment generally depicted in  FIG. 16 , the seal  34  is an annular seal received in a groove in a transverse face of the actuator  32 . 
     An additional embodiment of a valve  30  is depicted in  FIGS. 17-20  in the form of an actuatable plug assembly  112  installed within a bore  114  of the wellhead  14 , which is shown having a lower spool  116  (e.g., a casing head) with side ports  118  and an upper spool  120 . The plug assembly  112  includes a plug body  124  (which may also be referred to as a housing) that houses the actuator  32 , the seal  34 , and the seal carrier  52  (e.g., a poppet). Movement of the actuator  32  can be hydraulically controlled via ports  64 ,  68 ,  84 , and  88 , as described above, and the seal carrier  52  is attached to move synchronously with the actuator  32  to open ( FIG. 18 ) or close ( FIG. 20 ) the seal  34  against a sealing surface  76  of the plug body  124 . A retainer  126  retains the actuator  32  in the plug body  124 . In some instances, including that shown in  FIGS. 17 and 18 , the retainer  126  is threaded into the plug body  124  and set screw  128  inhibits further rotation of the retainer  126  in operation. 
     The plug assembly  112  may be installed within the wellhead  14  in any suitable manner. As one example, in  FIGS. 17 and 18  the plug assembly  112  is landed on a landing shoulder  132  of the spool  116  and is retained with lock screws  134 . As presently depicted, the lock screws  134  extend into the bore  114  and have tapered ends that drive an energizing ring  136  downward to energize an annular seal  138  between the plug body  124  and the spool  116 . 
     In operation, the seal  34  (e.g., an elastomer seal or other polymeric seal, or a metal seal) moves between open and closed positions to control flow between a central bore  142  and a port  144  in the plug body  124 . While a single port  144  is presently shown, the plug body  124  may include additional ports  144  in some instances. As generally depicted in  FIG. 19 , the seal carrier  52  is a fluted poppet that is installed within the flow path through the valve  30  and has flow-by slots  148  in its exterior surface. When the seal  34  is opened, fluid can flow through an opening between the seal  34  and the sealing surface  76  and through the flow-by slots  148 , thus allowing fluid to pass between the bore  142  and the port  144 . The seal  34  can be closed against the sealing surface  76  to block flow. 
     Like the flow-by holes  50  discussed above, the number, size, shape, and orientation of the flow-by slots  148  in the seal carrier  52  may vary. The flow-by slots  148  may be spaced circumferentially about the exterior of the seal carrier  52 . In some instances, these flow-by slots  148  may collectively provide a flow-by area that is within ten, five, three, two, or one percent, or is equal to, the cross-sectional area of the bore  142  at another location, such as at a cylindrical portion of the bore  142  below the tapered sealing surface  76  in  FIG. 18 . 
     While the actuatable plug assembly  112  is shown installed within a wellhead  14  in  FIGS. 17, 18, and 20 , it will be appreciated that the plug assembly  112  could be installed in other locations, such as within spools  40  and  42 , a fracturing tree (e.g., as a lower or upper master valve), a manifold, or a flowline. Similarly, the valves  30  depicted in  FIGS. 2-16  can be used in a fracturing tree, in a manifold, in a flowline, as a plug within a wellhead  14 , or in any other suitable location. In some embodiments, the presently disclosed inline valves may be used in place of gate valves in fracturing trees or fracturing manifolds. In contrast to gate valves that are regularly greased during a fracturing operation to displace proppant and debris from gate cavities within the valve bodies, the presently disclosed inline valves could be used with little or no greasing during a fracturing operation. 
     The actuator  32  of the various embodiments described above can take any suitable form, such as a hydraulic actuator, a manual actuator, an electric actuator, or a pneumatic actuator, or combinations thereof. In at least some embodiments, the actuator  32  of a valve  30  is an internal actuator positioned within the flow path through the valve  30 , actuation is within the valve body, and the valve  30  does not have an external actuator for controlling flow through the valve. 
     While the aspects of the present disclosure 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. But 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.