Patent Publication Number: US-2023151902-A1

Title: Modular value assembly

Description:
BACKGROUND 
     Field of the Disclosure 
     The disclosure relates generally to fluid control valves and more specifically to fluid control valve assemblies with modular and interchangeable components. 
     Related Technology 
     Pressure regulators and pressure regulating valves are used in myriad industrial and residential applications for controlling the downstream pressure of a fluid. For example, in chemical processing plants or oil refineries, pressure regulating valves are used to manipulate a flowing fluid to compensate for increases or decreases in demand, or other load disturbances, and thus keep the fluid pressure regulated. Similarly, pressure regulating valves may be used in plumbing fixtures to maintain a pre-determined pressure of fluid that automatically adjusts to variations in demand, such as anti-scald valves in showers or faucets. By controlling downstream pressure, pressure regulating valves compensate for variations in downstream demand. For example, as downstream demand increases, pressure regulating valves open to allow more fluid to flow through the pressure regulating valve, thus maintaining a relatively constant downstream pressure. On the other hand, as downstream demand decreases, pressure regulating valves close to reduce the amount of fluid flowing through the pressure regulating valve, again maintaining a relatively constant downstream pressure. 
     Generally, pressure regulating valves include a cast valve body that houses valve trim. The valve trim is held in the valve body by a bonnet that is attached to the valve body. Valve bodies are generally designed to accommodate a particular type of valve trim and/or a particular upstream and downstream flow configuration. If the valve trim or the downstream flow configuration needs to be changed, a new valve housing is required. 
     SUMMARY OF THE DISCLOSURE 
     According to some aspects, a modular valve assembly, or a method of configuring a modular valve assembly, advantageously reduces part number while increasing reconfiguration flexibility. Furthermore, by separating end connections from a center core, the number of needed center core patterns is reduced, which increases pattern flexibility and the possible custom configurations available. 
     In one exemplary arrangement, a modular valve assembly includes a bonnetless main core comprising a main core housing having a main core inlet and a main core outlet, a first releasable connection is disposed proximate the main core inlet and a second releasable connection is disposed proximate the main core outlet. A first inlet end connection includes a first inlet end connection housing and a first inlet end flow passage through the first inlet end connection housing. The first inlet end flow passage includes a curved portion that changes a direction of the first inlet end flow passage between 30 and 120 degrees. A second inlet end connection includes a second inlet end connection housing and a second inlet end flow passage through the second inlet end connection housing. The second inlet end connection passage is substantially straight, changing direction flow direction by less than 10 degrees. A first outlet end connection includes a first outlet end connection housing and a first outlet end flow passage through the first outlet end connection housing. The first outlet end flow passage includes an angled portion. A second outlet end connection passage includes a second outlet end connection housing and a second outlet end flow passage through the second outlet end connection housing. The second outlet end passage is substantially straight, changing fluid flow direction by less than 10 degrees. When the first inlet end connection is releasably connected to the first releasable connection and the first outlet end connection is releasably connected to the second releasable connection, the first inlet end connection, the bonnetless main core, and the first outlet end connection form an in-line valve configuration, where a flow direction at an inlet of the first inlet end connection and a flow direction at an outlet of the first outlet end connection change direction by less than 10 degrees. When the second inlet end connection is releasably connected to the first releasable connection and the second outlet end connection is releasably connected to the second releasable connection, the second inlet end connection, the bonnetless main core, and the second outlet and connection form an angled valve configuration, where a flow direction at an inlet of the second inlet end connection and a flow direction at an outlet of the second end connection change by more than 45 degrees. 
     In another exemplary arrangement, a method of configuring a modular valve assembly includes providing a bonnetless main core having a first releasable connection and a second releasable connection. A first inlet end connection includes a first inlet end flow passage having a curved portion that changes a direction of the first inlet end flow passage between 30 and 120 degrees. A second inlet end connection includes a second inlet end flow passage that is substantially straight, changing direction by less than 10 degrees. A first outlet end connection includes a first outlet end flow passage including an angled portion that changes direction of the first outlet end connection passage by between 30 and 120 degrees. A second outlet end connection passage includes a second outlet end flow passage that is substantially straight, changing direction by less than 10 degrees. 
     Either the first inlet end connection is releasably attached to the first releasable connection and the first outlet end connection is attached to the second releasable connection to form an in-line valve configuration; or the second inlet end connection is releasably attached to the first releasable connection and the second end connection is releasably attached to the second releasable connection to form an angled valve configuration. 
     In accordance with the teachings of the disclosure, any one or more of the foregoing aspects and/or exemplary aspects of a modular valve assembly may further include any one or more of the following optional forms. 
     In some optional forms, one of the first releasable connection or the second releasable connection comprises an external flange. 
     In other optional forms, one of the first inlet end connection or the second inlet end connection comprises an external flange. 
     In other optional forms, one of the first outlet end connection or the second outlet end connection comprises an external flange. 
     In other optional forms, one of the first releasable connection or the second releasable connection comprises a clamp. 
     In other optional forms, one of the first releasable connection or the second releasable connection comprises a sealing ring. 
     In other optional forms, the bonnetless main core comprises a stem opening. 
     In other optional forms, a valve trim is disposed in the bonnetless main core. 
     In other optional forms, the valve trim comprises a clamped cage. 
     In other optional forms, one end of the clamped cage includes an outer sealing flange that cooperates with the first releasable connection to secure the one end of the clamped cage in the bonnetless main core. 
     In other optional forms, an auxiliary core includes an auxiliary core housing having an auxiliary core inlet, a first auxiliary core outlet and a second auxiliary core outlet, the second auxiliary core outlet being releasably connected to the bonnetless main core inlet at the first releasable connection, thereby forming a 3-way valve configuration. 
     In other optional forms, a clamped cage extends from the bonnetless main core to the auxiliary core. 
     In other optional forms, the clamped cage comprises an external flange cooperates with the first releasable connection to secure the clamped cage in the bonnetless main core and in the auxiliary core. 
     In other optional forms, the bonnetless main core comprises a substantially flat mounting surface. 
     In other optional forms, a centralized data acquisition system is mounted to the substantially flat mounting surface. 
     In other optional forms, one of the first inlet end connection or the second inlet end connection is clamped to the first releasable connection. 
     In other optional forms, one of the first outlet end connection or the second outlet end connection is clamped to the second releasable connection. 
     In other optional forms, an auxiliary core is releasably attached to the first releasable connection to form a three-way valve configuration. 
     In other optional forms, the auxiliary core is clamped to the first releasable connection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which: 
         FIG.  1    is a cross-sectional view of a modular valve assembly including a bonnetless main core, a first inlet connector, and a first outlet connector, oriented in an in-line configuration. 
         FIG.  2    is a cross-sectional view of a modular valve assembly including the bonnetless main core from  FIG.  1   , a second inlet connector, and a second outlet connector, oriented in an angled configuration. 
         FIG.  3    is a cross-sectional view of a modular valve assembly including the bonnetless main core from  FIG.  1   , an auxiliary core, a third inlet connector, and a third outlet connector, oriented in a three-way configuration. 
         FIG.  4    is a cross-sectional view of a first embodiment high flow/low flow valve comprising a modular valve assembly. 
         FIG.  5    is a cross-sectional view of a second embodiment of a high flow/low flow valve comprising a modular valve assembly. 
         FIG.  6    is a cross-sectional view of a third embodiment of a high flow/low flow valve comprising a modular valve assembly. 
         FIG.  7    is a cross-sectional view of a high flow valve plug of the high flow/low flow valve of  FIG.  6   . 
     
    
    
     DETAILED DESCRIPTION 
     Certain examples are shown in the above-identified figures and described in detail below. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, any features from any exemplary embodiment may be included with, a replacement for, or otherwise combined with other features to form other embodiments. 
     In the embodiments described below, any feature or structure described with respect to a single embodiment in a figure may be combined and arranged with any other embodiment illustrated in any other figure, or in any non-illustrated embodiments constructed in accordance with the teachings of the disclosure. 
     Turning now to  FIG.  1   , a modular valve assembly  1000  includes a bonnetless main core  1010  comprising a main core housing  1012  having a main core inlet  1016  and a main core outlet  1014 . In other embodiments, the main core inlet  1016  and the main core outlet  1014  may be reversed. A first releasable connection  1022  is disposed proximate the main core inlet  1016  and a second releasable connection  1024  is disposed proximate the main core outlet  1014 . 
     A first inlet end connection  1030  is releasably attached to the first releasable connection  1022 . The first inlet end connection  1030  comprises a first inlet end connection housing  1032  and a first inlet end flow passage  1034  through the first inlet end connection housing  1032 . The first inlet end flow passage  1034  includes a curved portion  1036  that changes a direction of the first inlet end flow passage between 30 and 120 degrees as measured between a longitudinal axis A of the main core housing  1012 , and a direction of flow B that enters the first inlet flow passage  1034 . In the embodiment illustrated in  FIG.  1   , the flow passage changes direction by approximately 90 degrees. 
     A first outlet end connection  1040  comprising a first outlet end connection housing  1042  and a first outlet end flow passage  1044  through the first outlet end connection housing  1042 . The first outlet end flow passage  1044  includes an angled portion  1046 . 
     When the first inlet end connection  1030  is releasably attached to the first releasable connection  1022  and the first outlet end connection  1040  is releasably attached to the second releasable connection  1024 , the first inlet end connection  1030 , the bonnetless main core  1010  and the first outlet end connection  1040  form an in-line valve configuration. An in-line valve configuration is defined herein as a valve configuration where any change in flow direction measured between incoming flow at an inlet  1038  of the first inlet end connection and outlet flow at an outlet  1048  of the first outlet end connection is 10 degrees or less. 
     The first releasable connection  1022  includes an external flange  1050  and the second releasable connection  1024  also includes an external flange  1052 . Similarly, the first inlet end connection  1030  includes an external flange  1054  and the first outlet end connection  1040  also includes an external flange  1056 . The external flanges  1050 ,  1052 ,  1054 ,  1056 , advantageously allow the first inlet end connection  1030  and the first outlet end connection  1040  to be held in a fluid tight releasable connection against the bonnetless main core  1010 . 
     An inlet external clamp  1060  releasably secures the external flange  1054  of the first inlet end connection  1030  against the external flange  1050  of the first releasable connection  1022 . Likewise, an outlet external clamp  1062  releasably secures the external flange  1056  of the first outlet end connection  1040  against the external flange  1052  of the second releasable connection  1024 . An optional sealing ring  1064  may be clamped by the second releasable connection  1024  to enhance fluid sealing. While not illustrated in  FIG.  1   , a similar sealing ring may be located in the first releasable connection  1022 . 
     The bonnetless main core  1010  includes a stem opening  1070 . A stem  1072  may extend from an actuator (not shown) to a valve plug  1074 . The valve plug  1074  is moved within the bonnetless main core  1010  to control fluid flow through the bonnetless main core  1010 . A valve trim, such as a cage  1076  is also disposed in the bonnetless main core  1010  and cooperates with the valve plug  1074  to control the flow of fluid through the bonnetless main core  1010 . In the embodiment of  FIG.  1   , the cage  1074  is a clamped cage that includes an outer sealing flange  1078  at one end of the cage  1074 . The outer sealing flange  1078  is captured by the first releasable connection  1022  to secure the clamped cage  1076  in the bonnetless main core  1010 . 
     Turning now to  FIG.  2   , a modular valve assembly  2000  includes the bonnetless main core  1010  of  FIG.  1   . Any features discussed above with respect to the bonnetless main core  1010  of  FIG.  1    apply equally to the embodiment of  FIG.  2    and are not discussed again for the sake of brevity. 
     A second inlet end connection  2030  is releasably attached to the first releasable connection  1022 . The second inlet end connection  2030  comprises a second inlet end connection housing  2032  and a second inlet end flow passage  2034  through the second inlet end connection housing  2032 . The second inlet end flow passage  2034  is substantially straight and aligned with the longitudinal axis A of the main core housing  1012 . Substantially straight and aligned is defined as deviating 10 degrees or less from the longitudinal axis A. 
     A second outlet end connection  2040  is releasably attached to the second releasable connection  1024 . The second outlet end connection  2040  comprises a second outlet end connection housing  2042  and a second outlet end flow passage  2044  through the second outlet end connection housing  2042 . The second outlet end flow passage  2044  is substantially straight and perpendicular to the longitudinal axis A of the main core housing  1012 . Substantially straight and perpendicular is defined as deviating less than 10 degrees along the second outlet end flow passage  2044  and being oriented between 80 degrees and 100 degrees relative to the longitudinal axis A. 
     When the second inlet end connection  2030  is releasably attached to the first releasable connection  1022  and the second outlet end connection  2040  is releasably attached to the second releasable connection  1024 , the second inlet end connection  2030 , the bonnetless main core  1010  and the second outlet end connection  2040  form an angled valve configuration. An angled valve configuration is defined herein as a valve configuration where any change in flow direction measured between incoming flow at an inlet  2038  of the second inlet end connection  2030  and outlet flow at an outlet  2048  of the second outlet end connection  2040  is 30 degrees or more, for example approximately 90 degrees as illustrated in  FIG.  2   . 
     By changing the first and second inlet end connections  1030 ,  2030  and the first and second outlet end connections  1040 ,  2040 , the bonnetless main core  1010  may be rapidly reconfigured from an in-line valve to an angled valve. The disclosed modular valve assembly therefore produces multiple and flexible valve configurations with fewer parts that can be rapidly changed in the field to accommodate changing needs. 
     Turning now to  FIG.  3   , a modular valve assembly  3000  includes the bonnetless main core  1010  of  FIG.  1   . Any features discussed above with respect to the bonnetless main core  1010  of  FIGS.  1  and  2    apply equally to the embodiment of  FIG.  3    and are not discussed again for the sake of brevity. 
     In the embodiment of  FIG.  3   , an auxiliary core  3080  is removably attached to the first releasable connection  1022 . The auxiliary core  3080  includes an auxiliary core inlet  3086 , a first auxiliary core outlet  3084  and a second auxiliary core outlet  3085 . The first auxiliary core outlet  3084  is located adjacent to the bonnetless core inlet  1016  proximate the first releasable connection  1022 . The second auxiliary core outlet  3085  is located opposite the first auxiliary core outlet  3084 . The auxiliary core  3080  also includes a third releasable connection  3025 . 
     A third inlet end connection  3030  is releasably attached to the third releasable connection  3025 . The third inlet end connection  3030  comprises a third inlet end connection housing  3032  and a third inlet end flow passage  3034  through the third inlet end connection housing  3032 . The third inlet end flow passage  3034  includes an angled portion  3037 . 
     A third outlet end connection  3040  is releasably attached to the second releasable connection  1024 . The third outlet end connection  3040  comprises a third outlet end connection housing  3042  and a third outlet end flow passage  3044  through the third outlet end connection housing  3042 . The third outlet end flow passage  3044  includes an angled portion  3046 . 
     In other embodiments, the first, second, and third inlet connections  1030 ,  2030 ,  3030 , may be substituted for one another to achieve a desired flow configuration. Similarly, the first, second, and third outlet connections  1040 ,  2040 ,  3040 , may be substituted for one another to achieve a desired flow configuration. 
     When the auxiliary core  3080  is releasably connected to the bonnetless main core  1010 , a three-way valve configuration is advantageously produced. In the embodiment of  FIG.  3   , a clamped cage  3076  extends through both the bonnetless main core  1010  and through the auxiliary core  3080 . The clamped cage  3076  includes an external flange  3078  that is captured by the first connection  1022  to locate and secure the clamped cage  3076  within the bonnetless main core  1010  and within the auxiliary core  3080 . 
     Referring now to  FIGS.  1 - 3   , any of the embodiments described above may be configured and reconfigured rapidly by changing or adding parts as described below. The bonnetless main core  1010  is the base element for all configurations. As described above, when the first inlet end connection  1030  is releasably connected to the first releasable connection  1022 , and the first outlet end connection  1040  is releasably connected to the second releasable connection  1024 , an in-line valve is produced as illustrated in  FIG.  1   . 
     To reconfigure the valve assembly into an angled valve assembly, the first inlet end connection  1030  and the first outlet end connection  1040  are removed from the first releasable connection  1022  and the second releasable connection  1024 , respectively. Then, the second inlet end connection  2030  is releasably connected to the first releasable connection  1022  and the second outlet end connection  2040  is releasably connected to the second releasable connection  1024 , and an angled valve assembly is formed, as illustrated in  FIG.  2   . 
     To reconfigure the modular valve assembly into a three-way valve, the second inlet connection  2030  is removed from the first releasable connection  1022  and the second outlet connection  2040  is removed from the second releasable connection  1024 . The auxiliary core  3080  is releasably connected to the first releasable connection  1022 . This alone forms a three-way valve, as illustrated in  FIG.  3   . However, one or more inlet and outlet end connections may be added to adapt the three-way valve to needed configurations. 
     Returning now to  FIG.  1   , the bonnetless main core  1010  may optionally include a substantially flat top mounting surface  1086 . The substantially flat top mounting surface advantageously provides space and stability for mounting monitoring or control elements, such as a centralized data acquisition system  1088 . Alternatively sensors, could be mounted on the substantially flat top mounting surface. 
     The modular valve assemblies described above may advantageously be quickly modified to include optional internal components, such as cavitation protection, orifice plates, flow straightening devices, etc. The bonnetless main core described above may also be combined with other end connections, such as varied size end connections, expanded outlet end connections, angle bodies, globe bodies, articulating joints. 
     The modular valve assembly described above may be advantageously configured or reconfigured into different types of valves, rapidly and in the field without special tools. In some examples, the modular valve assembly may be used to form high flow/low flow valves, as described below. 
     Turning now to  FIG.  4   , a first embodiment of a high flow/low flow valve  10  is illustrated. The high flow/low flow valve  10  comprises a valve body  12 , which may comprise multiple interchangeable segments  12   a ,  12   b ,  12   c ,  12   d . The interchangeable segments  12   a ,  12   b ,  12   c ,  12   d , may include outwardly curved flanges that cooperate with flanges on other segments to form a continuous valve body  12  when connected with one another, for example with brackets (not shown in  FIG.  1   ). As a result, individual segments  12   a ,  12   b ,  12   c ,  12   d , may be substituted or interchanged without the need for replacing the entire valve body  12 . 
     The valve body  12  includes a fluid inlet  16  and a fluid outlet  14  connected to one another by a fluid passageway  18 . In other embodiments, the fluid inlet and fluid outlet may be reversed. The fluid passageway  18  in the illustrated embodiment may include a first inlet branch  18   a  and a second inlet branch  18   b.    
     A low flow valve seat  20  is disposed in a low flow port  23  of the fluid passageway  18 . A high flow valve seat  22  is disposed in a high flow port  21  of the fluid passageway  18 , and the high flow valve seat  22  is separated from the low flow valve seat  20  within the fluid passageway  18 . In the illustrated embodiment of  FIG.  4   , the high flow valve seat  22  may be part of an integrated high flow trim assembly  24  that also includes a high flow clamped cage  26 . In other embodiments, the high flow trim assembly  24  may include other types of cages, seat rings, plug guides, etc. 
     A low flow valve plug  30  is disposed in the fluid passageway  18  upstream of the low flow valve seat  20 . The low flow valve plug  30  cooperates with the low flow valve seat  20  to control fluid flow through the low flow valve seat  20 . A low flow trim assembly  32  may include, for example, the low flow valve seat  20  and a post guide  34 . In other embodiments, other types of trim may be included in the low flow trim assembly  32 . While the high flow trim assembly  24  and the low flow trim assembly  32  are illustrated in the current embodiments as being different structures, in some embodiments similar types of trim assembly structures may be employed between the high flow trim assembly  24  and the low flow trim assembly  32 . For example, in some alternate embodiments, both the high flow trim assembly  24  and the low flow trim assembly  32  may comprise cages. 
     A high flow valve plug  36  is disposed in the fluid passageway  18  upstream of the high flow valve seat  22 . The high flow valve plug  36  cooperates with the high flow valve seat  22  to control fluid flow through the high flow valve seat  22 . 
     A low flow actuator  50  is operatively connected to the low flow valve plug  30 , the low flow actuator  50  moving the low flow valve plug  30  relative to the low flow valve seat  20  to control fluid flow through the low flow valve seat  20 . The low flow actuator  50  is configured to move the low flow plug  30  independently of the high flow valve plug  36 . 
     Similarly, a high flow actuator  52  is operatively connected to the high flow valve plug  36 , the high flow actuator  52  moving the high flow valve plug  36  relative to the high flow valve seat  22  to control fluid flow through the high flow valve seat  22 . The high flow actuator  52  is configured to move the high flow valve plug  36  independently of the low flow valve plug  30 . 
     The high flow/low flow valve  10  described above may be used to control a wide range of fluid flow conditions through the valve body  12 . For example, when only a relatively low flow rate is needed, and/or one which requires precise control, the low flow valve plug  30  and the low flow valve seat  20  are ideally suited for fluid control. Initially, the high flow valve plug  36  is positioned relative to the high flow valve seat  22  at between 5% and 20% of the fully open high flow valve plug  36  travel. In some embodiments, the high flow valve plug  36  is positioned relative to the high flow valve seat  22  between 5% and 15%, and more particularly about 10%, of the full high flow valve plug  36  travel. Thereafter, the low flow valve plug  30  may be moved relative to the low flow valve seat  20  to precisely control low levels of fluid flow through the low flow valve seat  20 . When downstream flow requirements require near maximum flow through the low flow valve seat  20 , the low flow valve plug  30  may approach a fully open position to maximize fluid flow thorough the low flow valve seat  20 . As the low flow valve plug  30  approaches fully open, the high flow valve plug  36  may be moved relative to the high flow valve seat  22  to increase overall fluid flow through the valve body  12  to greater than the maximum fluid flow through the low flow valve seat  20  alone. In other embodiments, the high flow valve plug  36  begins in a closed position (preventing fluid flow through the high flow valve seat  22 ) and the low flow valve plug  30  controls fluid flow until downstream requirements exceed the maximum flow rate through the low flow valve seat  20 , at which point the low flow valve plug  30  is positioned fully open and the high flow valve plug  36  and the high flow valve seat  22  control fluid flow above the maximum low flow rate. 
     In the illustrated embodiment of  FIG.  4   , low flow valve seat  20  defines a low flow restriction (e.g., a maximum low flow port fluid flow) in the low flow port  23  and the high flow valve seat  22  defines a high flow restriction (e.g., a maximum high flow port fluid flow) in the high flow port  21 , and the maximum low flow port fluid flow is between 5% and 25%, preferably between 10% and 20%, and more preferably about 15%, of the maximum high flow port fluid flow. The disclosed relative sizing between the maximum low flow port fluid flow and the maximum high flow port fluid flow advantageously produces a crossover band of fluid flow before the low flow port reaches 100% fluid flow and the high flow port begins opening to take over when the low flow port reaches its maximum fluid flow. This crossover band reduces chattering of the low flow valve plug  30  if a control signal cycles around the crossover band. 
     Turning now to  FIG.  5   , a second embodiment of a high flow/low flow valve  110  is illustrated. Elements of the embodiment of  FIG.  5    that correspond to identical elements in the embodiment of  FIG.  4    are numbered exactly 100 greater that the embodiment of  FIG.  4   . For example, the valve body of  FIG.  5    is numbered  112 , while the valve body of  FIG.  4    is numbered  12 . 
     The high flow/low flow valve  110  illustrated in  FIG.  5    includes a valve body  112  having a fluid inlet  114  and a fluid outlet  116  connected to one another by a fluid passageway  118 . In other embodiments, the fluid inlet  114  and the fluid outlet  116  may be reversed. The valve body  112  may comprise multiple interchangeable segments  112   a ,  112   b ,  112   c ,  112   d . The interchangeable segments  112   a ,  112   b ,  112   c ,  112   d , may include outwardly curved flanges that cooperate with flanges on other segments to form a continuous valve body  112  when connected with one another, for example with brackets (not shown in  FIG.  5   ). As a result, individual segments  112   a ,  112   b ,  112   c ,  112   d , may be substituted or interchanged without the need for replacing the entire valve body  112 . The valve body  112  includes a fluid inlet  114  and a fluid outlet  116  connected to one another by a fluid passageway  118 . 
     A valve seat  119  is disposed in the fluid passageway  118 . The valve seat  119  includes a high flow side  122  and a low flow side  120 . In the illustrated embodiment of  FIG.  5   , the valve seat  119  may be part of an integrated high flow trim assembly  124  that also includes a high flow clamped cage  126 . In other embodiments, the high flow trim assembly  124  may include other types of cages, seat rings, plug guides, etc. 
     A low flow valve plug  130  is disposed in the fluid passageway  118  downstream of the valve seat  120 . The low flow valve plug  130  cooperates with the low flow side  120  of the valve seat  119  to control fluid flow through the valve seat  119 . A low flow trim assembly  132  may include, for example, a post guide  134 . In other embodiments, other types of trim may be included in the low flow trim assembly  132 . While the high flow trim assembly  124  and the low flow trim assembly  132  are illustrated in the current embodiments as being different structures, in some embodiments similar types of trim assembly structures may be employed between the high flow trim assembly  124  and the low flow trim assembly  132 . For example, in some alternate embodiments, both the high flow trim assembly  124  and the low flow trim assembly  132  may comprise cages. 
     A high flow valve plug  136  is disposed in the fluid passageway  118  upstream of the valve seat  119 . The high flow valve plug  136  cooperates with the high flow side  122  of the valve seat  119  to control fluid flow through the valve seat  119 . 
     A low flow actuator  150  is operatively connected to the low flow valve plug  130 , the low flow actuator  150  moving the low flow valve plug  130  relative to the valve seat  119  to control fluid flow through the valve seat  119 . The low flow actuator  150  is configured to move the low flow plug  130  independently of the high flow valve plug  136 . 
     Similarly, a high flow actuator  152  is operatively connected to the high flow valve plug  136 , the high flow actuator  152  moving the high flow valve plug  136  relative to the valve seat  119  to control fluid flow through the valve seat  119 . The high flow actuator  152  is configured to move the high flow valve plug  136  independently of the low flow valve plug  130 . 
     The high flow/low flow valve  110  described above with respect to  FIG.  5   , may be used to control a wide range of fluid flow conditions through the valve body  112 . For example, when only a relatively low flow rate is needed, and/or one which requires precise control, the low flow valve plug  130  and the low flow side  120  of the valve seat  119  are ideally suited for fluid control. Initially, the high flow valve plug  136  is positioned away from the high flow side  122  of the valve seat  119  to a position that matches a crossover capacity of the low flow side  120 , which in the illustrated embodiment is between 80% and 100% of the low flow valve plug  130  travel. This crossover capacity advantageously allows for a smooth transition between the low flow side  120  and the high flow side  122 . Thereafter, the low flow valve plug  130  may be moved relative to the low flow side  120  of the valve seat  119  to precisely control low levels of fluid flow through the valve seat  119 . When downstream flow requirements require more flow than the maximum flow controllable by the low flow valve plug  130 , the low flow valve plug  130  approaches a fully open position to maximize fluid flow thorough the valve seat  119 . Once the low flow valve plug  130  approaches the fully open position, the high flow valve plug  136  may be moved relative to the high flow side  122  of the valve seat  119  to increase overall fluid flow through the valve body  112  to greater than the maximum fluid flow controllable by the low flow valve plug  130  alone. 
     Turning now to  FIGS.  6  and  7   , a third embodiment of a high flow/low flow valve  210  is illustrated. Elements of the embodiment of  FIGS.  6  and  7    that correspond to identical elements in the embodiment of  FIG.  4    or  FIG.  5    are numbered exactly 100 or 200 greater that the embodiment of  FIG.  4    or  FIG.  5   . For example, the valve body of  FIG.  6    is numbered  212 , while the valve body of  FIG.  4    is numbered  12  and the valve body of  FIG.  5    is numbered  112 . 
     The high flow/low flow valve  210  comprises a valve body  212  having a fluid inlet  214  and a fluid outlet  216  connected to one another by a fluid passageway  218 . In other embodiments, the fluid inlet  214  and the fluid outlet  216  may be reversed. The valve body  212  may comprise multiple interchangeable segments  212   a ,  212   b ,  212   c ,  212   d . The interchangeable segments  212   a ,  212   b ,  212   c ,  212   d , may include outwardly curved flanges that cooperate with flanges on other segments to form a continuous valve body  212  when connected with one another a mechanical joint retention mechanism, for example by clamps or brackets  213 . As a result, individual segments  212   a ,  212   b ,  212   c ,  212   d , may be substituted or interchanged without the need for replacing the entire valve body  212 . 
     A valve seat  219  is disposed in the fluid passageway  218 . The valve seat  219  includes a high flow side  222  and a low flow side  220 . In the illustrated embodiment of FIG.  6 , the valve seat  219  may be part of an integrated high flow trim assembly  224  that also includes a high flow clamped cage  226 . In other embodiments, the high flow trim assembly  224  may include other types of cages, seat rings, plug guides, etc. 
     A high flow valve plug  236  is disposed in the fluid passageway  218  proximate valve seat  219 . The high flow valve plug  236  cooperates with the high flow side  222  of the valve seat  219  to control fluid flow through the valve seat  219 . The high flow valve plug  236  includes a hollow passageway  237  that forms part of the fluid passageway  218 . An opening  239  of the hollow passageway  237  forms a low flow valve seat  221 . 
     A low flow valve plug  230  is disposed in the fluid passageway  218  proximate the valve seat  219 . The low flow valve plug  230  cooperates with the low flow valve seat  221  to control fluid flow through the hollow passageway  237 . A low flow trim assembly  232  may include, for example, the low flow valve plug  230  and the low flow valve seat  221 . In other embodiments, other types of trim may be included in the low flow trim assembly  232 , such as plug guides, cages, etc. While the high flow trim assembly  224  and the low flow trim assembly  232  are illustrated in the current embodiment as being different structures, in some embodiments similar types of trim assembly structures may be employed between the high flow trim assembly  224  and the low flow trim assembly  232 . For example, in some alternate embodiments, both the high flow trim assembly  224  and the low flow trim assembly  232  may comprise cages. 
     A low flow actuator  250  is operatively connected to the low flow valve plug  230 , the low flow actuator  250  moving the low flow valve plug  230  relative to the low flow valve seat  239  to control fluid flow through the low flow valve seat  239 . The low flow actuator  250  is configured to move the low flow plug  230  independently of the high flow valve plug  236 . 
     Similarly, a high flow actuator  252  is operatively connected to the high flow valve plug  236 , the high flow actuator  252  moving the high flow valve plug  236  relative to the valve seat  219  to control fluid flow through the valve seat  219 . The high flow actuator  252  is configured to move the high flow valve plug  236  independently of the low flow valve plug  230 . 
     The high flow/low flow valve  210  described above with respect to  FIG.  6   , may be used to control a wide range of fluid flow conditions through the valve body  212 . For example, when only a relatively low flow rate is needed, and/or one which requires precise control, the low flow valve plug  230  and the low flow valve seat  221  are ideally suited for fluid control. Initially, the high flow valve plug  236  is positioned against the valve seat  219 . Thereafter, the low flow valve plug  230  may be moved relative to the low flow valve seat  221  to precisely control low levels of fluid flow through the opening  239  and thus through the hollow passageway  237 . When downstream flow requirements require more flow than the maximum flow controllable by the low flow valve plug  230 , the low flow valve plug  230  may be positioned in a fully open position. Once the low flow valve plug  230  is fully open, the high flow valve plug  236  may be moved relative to the valve seat  219  to increase overall fluid flow through the valve body  212  to greater than the maximum fluid flow controllable by the low flow valve plug  230  alone. 
     Although certain high flow/low flow valves have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, while the invention has been shown and described in connection with various preferred embodiments, it is apparent that certain changes and modifications, in addition to those mentioned above, may be made. This patent covers all embodiments of the teachings of the disclosure that fairly fall within the scope of permissible equivalents. Accordingly, it is the intention to protect all variations and modifications that may occur to one of ordinary skill in the art.