Patent Publication Number: US-2023151890-A1

Title: High flow/low flow valve

Description:
BACKGROUND 
     Field of the Disclosure 
     The disclosure relates generally to fluid control valves and more specifically to fluid control valves with a high flow control member and a low flow control member. 
     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. 
     One type of pressure regulating valve is the double port regulator. Double port regulators include a fluid flow path beginning at a single fluid inlet that branches into two fluid control ports. The fluid flow path typically rejoins into a single fluid exit after the two fluid control ports. Each fluid exit port has its own valve plug and valve seat. The valve plugs are joined and synchronized in operation by a single actuator. Double port regulators have the advantage of providing high flow rates. However, double port regulators suffer from the problems of requiring very tight machining tolerances to assure that both seats completely simultaneously shut off when the valve is closed. Moreover, double port regulators do not have different controls for high flow and low flow conditions. 
     SUMMARY OF THE DISCLOSURE 
     According to some aspects, a high flow/low flow valve, or a method of operating a high flow/low valve, advantageously produces multiple flow levels of operation, and thus a wide range of operational capabilities. The high flow/low flow valves and method described herein may be advantageously employed in control valves with active control from DCS systems. 
     In one exemplary arrangement, a high flow/low flow valve includes a valve body having a fluid inlet and a fluid outlet connected to one another by a fluid passageway. The fluid passageway includes a first branch and a second branch. A low flow valve seat is disposed in the fluid passageway and a high flow valve seat is disposed in the fluid passageway, the high flow valve seat being separated from the low flow valve seat. A low flow valve plug is disposed in the fluid passageway, the low flow valve plug cooperating with the low flow valve seat to control fluid flow through the low flow valve seat. A high flow valve plug is disposed in the fluid passageway, the high flow valve plug cooperating with the high flow valve seat to control fluid flow through the high flow valve seat. A low flow actuator is operatively connected to the low flow valve plug and a high flow actuator is operatively connected to the high flow valve plug. 
     In another exemplary arrangement, a high flow/low flow valve includes a valve body having a fluid inlet and a fluid outlet connected to one another by a fluid passageway. A valve seat is disposed in the fluid passageway. A low flow valve plug is disposed in the fluid passageway proximate the valve seat, the low flow valve plug cooperating with the valve seat to control fluid flow through the valve seat. A high flow valve plug is disposed in the fluid passageway proximate valve seat, the high flow valve plug cooperating with the valve seat to control fluid flow through the valve seat. A low flow actuator is operatively connected to the low flow valve plug and a high flow actuator operatively connected to the high flow valve plug. 
     In another exemplary arrangement, a high flow/low flow valve includes a valve body having a fluid inlet and a fluid outlet connected to one another by a fluid passageway. A high flow valve seat is disposed in the fluid passageway. A high flow valve plug is disposed in the fluid passageway proximate high flow valve seat, the high flow valve plug cooperating with the high flow valve seat to control fluid flow through the high valve seat. The high flow valve plug includes a hollow passageway that forms part of the fluid passageway. An opening of the hollow passageway forms a low flow valve seat. A low flow valve plug is disposed in the fluid passageway proximate valve seat, the low flow valve plug cooperating with the low flow valve seat to control fluid flow through the hollow passageway. A low flow actuator is operatively connected to the low flow valve plug and a high flow actuator operatively connected to the high flow valve plug. 
     In another exemplary arrangement, a method of operating a high flow/low flow valve includes positioning a high flow valve plug relative a high flow valve seat at about 15% of the fully open travel of the high flow valve plug, moving a low flow valve plug relative to a low flow valve seat to control fluid flow through the low flow valve seat, positioning the low flow valve plug to between 80% and 100% of the fully open position of the low flow valve plug to maximize fluid flow thorough the low flow valve seat, and after positioning the low flow valve plug, moving the high flow valve plug relative to the high flow valve seat to increase overall fluid flow through the valve to greater than the maximum fluid flow through the low flow valve seat. 
     In another exemplary embodiment, a method of operating a high flow/low flow valve includes positioning a high flow valve plug relative to a high flow side of a valve seat produce a fluid flow through the valve seat equal to 80% or greater of a maximum fluid flow through a low flow side of the valve seat when a low flow valve plug is in a fully open position, moving the low flow valve plug relative to the low flow side valve seat to control fluid flow through the valve seat, positioning the low flow valve plug to 80% or greater of the fully open position to maximize fluid flow thorough the valve seat, and after the low flow valve plug is positioned, moving the high flow valve plug relative to the high flow side of the valve seat to increase overall fluid flow through the valve seat to greater than the maximum fluid flow through the low flow side of the valve seat when the low flow valve plug is in the fully open position. 
     In accordance with the teachings of the disclosure, any one or more of the foregoing aspects and/or exemplary aspects of a high flow/low flow valve may further include any one or more of the following optional forms. 
     In some optional forms, the high flow/low flow valve may include a high flow trim and a low flow trim. 
     In other optional forms, the high flow/low flow valve may include a high flow trim that is a different type trim than a low flow trim. 
     In yet other optional forms, the high flow trim comprises a clamped cage. 
     In yet other optional forms, the low flow trim comprises one of a skirt guided plug or a clamped cage. 
     In yet other optional forms, the low flow valve seat defines a low flow restriction and a maximum low flow port fluid flow, and the high flow valve seat defines a high flow restriction and a maximum high flow port fluid flow, 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. 
     In yet other optional forms, the low flow valve plug is independently positionable relative to the high flow valve plug. 
    
    
     
       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 first embodiment high flow/low flow valve according to the disclosure. 
         FIG.  2    is a cross-sectional view of a second embodiment of a high flow/low flow valve according to the disclosure. 
         FIG.  3    is a cross-sectional view of a third embodiment of a high flow/low flow valve according to the disclosure. 
         FIG.  4    is a cross-sectional view of a high flow valve plug of the high flow/low flow valve of  FIG.  3   . 
     
    
    
     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. 
     The high flow/low flow valves described herein are well suited for use in control valves with active control from a distributed control system (DCS). 
     Turning now to  FIG.  1   , 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.  1   , 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 embodiment 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, 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.  2   , a second embodiment of a high flow/low flow valve  110  is illustrated. Elements of the embodiment of  FIG.  2    that correspond to identical elements in the embodiment of  FIG.  1    are numbered exactly 100 greater that the embodiment of  FIG.  1   . For example, the valve body of  FIG.  2    is numbered  112 , while the valve body of  FIG.  1    is numbered  12 . 
     The high flow/low flow valve  110  illustrated in  FIG.  2    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.  2   ). 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.  2   , 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 embodiment 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.  2   , 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.  3  and  4   , a third embodiment of a high flow/low flow valve  210  is illustrated. Elements of the embodiment of  FIGS.  3  and  4    that correspond to identical elements in the embodiment of  FIG.  1    or  FIG.  2    are numbered exactly 100 or 200 greater that the embodiment of  FIG.  1    or  FIG.  2   . For example, the valve body of  FIG.  3    is numbered  212 , while the valve body of  FIG.  1    is numbered  12  and the valve body of  FIG.  2    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.  3   , 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.  3   , 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 from 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.