Abstract:
A valve comprising sealing members configured to allow the valve to achieve an open position, a closed position, lower seat clean position and an upper seat clean position is described. A method including opening a valve, closing a valve, moving the valve to a lower seat clean position, and moving the valve to an upper seat clean position is described.

Description:
CLAIM FOR PRIORITY 
       [0001]    The present application is a Non-Provisional application that claims priority to U.S. Provisional Patent Application No. 61/709,776, filed Oct. 4, 2012, entitled Double Seat Valve with Isolated Vent Chambers, the disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to the field of valves and more particularly to double seat valves with cleanable seats. 
       BACKGROUND OF THE INVENTION 
       [0003]    Double seat block and bleed valves are in wide use in industry, for example in the food, dairy, beverage, pharmaceutical and biotechnology businesses. One example of such a double seat valve is a valve that is operated in connection with two flow conduit paths. In some applications, such as, for example, the industries mentioned above, it is desirable sometimes to interrupt the flow of the material and instead flush the system using a clean-in-place solution. One way this is sometimes accomplished is that the process material continues to flow through one conduit, while the clean-in-place solution flows through the other conduit. 
         [0004]    In such systems, it is desirable that the process material be very well sealed and segregated from the clean-in-place solution so that the process material and the clean-in-place solution do not contact one another. In one example of such type of system, each conduit has a respective seat, and each conduit has a respective closing member or stem (usually as a reciprocating flanged valve stem), and the closing members can each be axially moved between a position sealing the seat and a position opening the seat. In the cleaning position, a valve associated with a respective conduit is opened when cleaning solution is in the conduit, and the cleaning solution is thus permitted to move from the conduit and exit through a drain. This cleaning process can occur while the other valve is closed, and process material is flowing through the other conduit. 
       SUMMARY OF THE INVENTION 
       [0005]    Some embodiments of the invention relate to the field of valves and more particularly to double seat valves with cleanable seats. 
         [0006]    In one embodiment of the present invention, a valve assembly is provided comprising: a valve body having an interior space; a conduit in fluid communication with said interior space; an upper stem assembly; a lower stem assembly; a vent space disposed between said upper stem assembly and said lower stem assembly; a resilient sealing surface disposed within said vent space; at least one blocker stop that extends from said upper stem assembly; a first side channel that extends through said lower upper stem assembly that is in fluid communication with said interior space; and a center channel that extends through said lower upper stem assembly that is in fluid communication with said vent space. 
         [0007]    Another embodiment of the present invention, a valve assembly is provided, comprising: a valve body having an interior space; a conduit in fluid communication with said interior space; an upper stem assembly; a lower stem assembly; a vent space disposed between said upper stem assembly and said lower stem assembly; a resilient sealing surface disposed within said vent space; at least one blocker stop that extends from said upper stem assembly; a first side channel that extends through said lower upper stem assembly that is in fluid communication with said interior space; a center channel that extends through said lower upper stem assembly that is in fluid communication with said vent space; an actuator assembly connected to said valve assembly, said actuator assembly comprising: a rod connected to the lower valve assembly and connected to the upper valve assembly, wherein said rod translates said lower valve assembly and said upper valve assembly to an open position and a closed position; a thread piston threadably engaged to said rod; a spring that biases said piston; an actuating sleeve through which said rod extends; and a base that mounts to said valve assembly. 
         [0008]    In yet another embodiment of the present invention, a method for cleaning a valve assembly having a valve body is provided, comprising the steps of: translating an upper stem assembly in a first direction to a first position against a sealing surface of the valve body away from a vent space; translating a lower stem assembly in an opposite, second direction to a second, opposite position; extending at least one stop from the upper stem assembly to provide a positive stop for the upper stem assembly against the vent space; and flowing a first cleaning fluid through a side channel that extends through the lower and upper stem assembly and into an interior space of the valve body. 
         [0009]    In another embodiment of the present invention, a valve assembly is provided comprising: means for translating an upper stem assembly in a first direction to a first position against a sealing surface of the valve body away from a vent space; means for translating a lower stem assembly in an opposite, second direction to a second, opposite position; means for extending at least one stop from the upper stem assembly to provide a positive stop for the upper stem assembly against the vent space; and means for flowing a first cleaning fluid through a side channel that extends through the lower and upper stem assembly and into an interior space of the valve body. 
         [0010]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
         [0011]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
         [0012]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a diagrammatic view of a valve according to an embodiment of the invention, showing the valve in the completely closed position 
           [0014]      FIG. 2  is a cross-sectional partial view of a portion of the valve of  FIG. 1 . 
           [0015]      FIG. 3  is a diagrammatic view of a valve, showing the valve in an open position. 
           [0016]      FIG. 4  is a cross-sectional partial view of a lower portion of the valve in a lower seat cleaning position. 
           [0017]      FIG. 5  is a cross-sectional partial view of a lower portion of the valve in an upper seat cleaning position. 
           [0018]      FIG. 6  is a partial cross-sectional view of some of the internal components of the valve. 
           [0019]      FIG. 7  is a partial isometric view of some of the internal components of the valve. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The invention relates to the field of valves and more particularly to seat valves with cleanable seats. Various embodiments of the present invention provide for an advantageous seat valve which prevents or substantially prevents mixing of materials in two different conduits, even when one of the conduits is being used for the clean-in-place (CIP) operation and has a central opening to permit drainage of clean-in-place fluid. Some preferred embodiments will now be described with reference to the drawing figures, in which like reference numbers refer to like parts throughout. 
         [0021]    Referring now to  FIGS. 1-3 , it will be appreciated that  FIG. 1  is an overall schematic cross-sectional view of a mix proof valve  10 , with  FIG. 2  being a partial view at a larger scale of an upper portion  15  of the valve  10  of  FIG. 1 .  FIG. 1  illustrates the valve  10  in a closed position where  FIG. 3  illustrates the valve  10  in an open position. 
         [0022]    The illustrated valve  10 , according to the preferred embodiment, includes a valve body  12 . The valve body  12  defines a chamber or interior portion  14 . The valve  10  is configured to selectively permit fluid access between the interior  20  of a conduit  18  and the interior  14  of the valve body  12 . As shown in  FIG. 1  the upper stem assembly  16  is in a closed position thereby denying fluid access between the interior  20  of the conduit  18  and the interior  14  of the valve body  12 . 
         [0023]    In some embodiments, the conduit  18  may be used for flowing foodstuffs. At certain times it may be desired to divert some of the foodstuffs contained within the interior  20  of the conduit  18  into the valve body  12 . During such time, the valve  10  will achieve an open position as shown in  FIG. 3 . The small horizontal lines represent the foodstuffs that may be present in the interior  20  of the conduit  18  only as shown  FIG. 1  and in both the interior  20  of the conduit  20  and in the interior  14  of the valve body  12  as shown in  FIG. 3 . 
         [0024]    The lower portion  13  of the valve  10  will now be described. A rod  50  operates the upper stem assembly  16 . Axial movement of the rod  50  causes axial movement of the upper stem assembly  16 . The upper stem assembly  16  includes blocker stops  24  and a resilient sealing surface  45 . A vent separator  28  is located below the upper stem assembly  16 . The vent separator  28  includes a resilient sealing feature  44  which, in some embodiments, may be an O-ring. The lower valve stem assembly  40  may also have a resilient sealing surface  60  which, in some embodiments, may also be an O-ring. The three resilient sealing surfaces  44 ,  45  and  60  all may seal against the sealing surface  62  of the valve body  12 . 
         [0025]    The lower valve stem assembly  40  has side channels  64  and an interior channel  66 . The side channels  64  in the interior channel  66  may be used when the valve  10  is undergoing a cleaning procedure. The lower valve stem assembly  40  may also include a cleaning space  65  which may be fluidly connected to the side channels  64  and the interior channel  66 . 
         [0026]    The valve  10  is in a closed position shown in  FIG. 1 . The lower stem assembly  40  is positioned in the valve body  12  by force generated by a supplemental spring  41 . 
         [0027]      FIG. 2  illustrates an upper part  15  of the valve  10 , including components that actuate or move the valve stems  26  and  40 . The lower end of  FIG. 2  shows a rod  50  which is the same rod  50  as shown in the lower portion  13  of the valve  10 . The rod  50  is ultimately connected to be able to move the lower valve stem  24 . Movement of the rod  50  corresponds to the same movement by the lower valve stem  24 . 
         [0028]    A housing base  30  is provided. The housing base  30  provides a mounting point for some components that are described below. The rod  50  is threadably engaged with a thread piston  48  (also referred to as a lower seat clean piston  48 ). A main spring  39  biases the lower seat clean piston  48  downwards. The actuating sleeve  34  has an expanded diameter region or collar  33  that rests in an abutting relationship with center piston  36 . Thus, any upward movement of the actuating sleeve  34  is restrained by the position of the center piston  36 . Further, the center piston  36  has an upper disc portion  36 ′. 
         [0029]    The main spring  39  abuts against the disc  36 ′, and therefore the travel of the lower seat clean piston  48  is limited by the position of the disc  36 ′. The collar  33  of the sleeve  34  also has a lower shoulder which abuts with a face of the upper seat clean piston  37 . Thus, downward movement of the sleeve  34  is limited by the position of the upper seat clean piston  37 . Supply ports  35 ,  38  and  56  are provided and their operation will now be discussed below with reference to  FIG. 3 . 
         [0030]    The actuation of various components within the valve  10  will now be described, in particular the valve closed position, the upper seat lift position (or upper seat clean position), the lower seat lift (or lower seat clean) position and the valve open position. These positions are particularly illustrated in FIGS.  1  and  3 - 5 . 
         [0031]      FIG. 1  shows the valve assembly  10  in a closed position. In this position, it is not necessary to supply any pneumatic pressure to any of the ports  35 ,  38  or  56 . In this position, the spring  39  provides a downward biasing force on the disc  36 ′. A supplemental spring  41  is trapped between the lower seat clean piston  48  and the top of sleeve  34  which slides over the rod  50 . A non-galling material  41 ′ is provided. Therefore, the supplemental spring  41  provides a biased spring pressure tending to push apart the lower seat clean piston  48  from the collar  33 , the sleeve  34 , and the upper seat clean piston  37 . 
         [0032]    In  FIG. 1  the upper disc  36 ′ is biased downwards and by virtue of its shoulder connection with the valve open center piston  36 , the piston  36  is biased downwards via the collar  33  until it pushes the upper seat clean piston  37  downward. The upper seat clean piston  37  is still spaced above the housing base  30  because the upper stem  26  is fully seated in a closed position so that no further downward travel is permitted. Further, because of the expansion force provided by the intermediate spring  41 , the center piston  36  is spaced downwardly from the lower seat clean piston  48 . Accordingly, it will be appreciated that in this closed position shown in  FIG. 1 , the force of the spring  39  is being applied to the disc  36 ′ and thus to the center piston  36  and to the collar  33  and through the sleeve  34  to urge the upper stem  26  downward into a fully seated position. On the other hand, the force of the supplemental spring  41  is urging the lower seat clean piston  48  upwards flush against the disc  36 ′, thereby locating the rod  50  so that the lower stem  24  is in a seated closed position also. 
         [0033]      FIG. 3  illustrates an open valve position. In this position, pressure is applied to port  38 , thereby urging the upper seat clean piston  37  into a fully downward position. However, this fully downward position of the upper seat clean piston  37  does not affect the operation of the device, because the remaining components travel upwards, as described below. The application of the pressure to port  38  urges the center piston  36  upwards. The center piston  36  pushes upwards on the lower seat clean piston  48  and compresses the spring  39  to retract the rod  50 . Retracting the rod  50  upwards necessarily moves the lower valve stem  40  upwards. Thus, the lower valve stem  40  pushes upwards onto the vent separator  28 , and the vent separator  28  is pushed upwards causing the O-ring  44  to be squeezed between the upper stem assembly  16  and the lower valve stem assembly  40 . Squeezing the O-ring  44  between the upper stem assembly  16  and the lower valve stem assembly  40  causes a vent space  45  to be closed. Therefore, there is no fluid communication between the upper valve stem assembly  16 , the lower valve stem assembly  40 , and the vent separator  28 . The O-ring  44  a provides a seal between the upper valve stem assembly  16  and the vent separator  28 . Therefore, none of the material inside chamber  18  is able to pass into any gap between these three components  16 ,  28 , and  40 , and this material does not drain into the hollow cleaning space  65  of the lower stem  40 . 
         [0034]    It will be appreciated that an upper seal  17  is provided to seal between the conduct  18  and the sleeve  34 , and a lower seal  19  is provided to seal between the lower valve stem assembly  40  and the valve body  12 . 
         [0035]      FIG. 4  illustrates the lower portion  13  in a lower seat clean position. As shown in  FIG. 4 , the upper stem assembly  16  is in a closed position against the sealing surface  62  of the valve body  12 . As the lower valve stem assembly  40  is pushed down for cleaning, the blocker stops  24  are pushed in a downward direction. The blocker stops  24  come partially out of the upper stem assembly  16 . The blocker stops  24  provide a positive stop to prevent the vent separator  28  from sealing against the upper stem assembly  16  during a lower seat clean operation. The O-ring  44  located on the vent separator  28  is also in a sealing position with respect to the sealing surface  62 . 
         [0036]    The cleaning solution represented by the vertical dashes located within the interior  14  of the valve body  12  is separated from whatever liquid is in the conduit  18  interior  20 . The cleaning solution (represented by the vertical dashes) is also present in the side channels  64  and cleaning space  65  of the lower valve stem assembly  40 . The vent area  47  located between the vent separator  28  and the upper stem assembly  16  is completely sealed by the O-ring  44  from the cleaning solution or whatever fluid is located in the interior  14  of the valve body  12  and the side channel  64 . As result, no cleaning fluid or whatever fluid is located in the interior  14  of the valve body  12  can get into the vent space  47 . 
         [0037]    While that there may be some incidental cleaning solution located in the interior channel  66 , by and large the cleaning solution will not enter the channel  66  because air or any other fluid that may be present within the channel  66  cannot be vented into the vent space  47  between the vent separator  28  and the upper stem assembly  16  due to the sealing action of the O-ring  44 . The vent area  47  between the upper stem assembly  16  and the vent separator  28  is completely sealed from liquid that may be in the interior channel  66  during a clean and place procedure due to action of the separator bolt  46  will which will be described in more detail below. As result, the vent space  47  is sealed from cleaning solution that may be present in the interior  14  of the valve body  12  by virtue of the O-ring  44  and the separator bolt  46 . 
         [0038]    As can be seen in  FIG. 3 , the lower valve stem assembly  40  has moved to a lower position moving the O-ring  60  mounted on the lower valve stem assembly  40  lower on the sealing surface  62  permitting the lower part of the sealing surface  62  to be exposed to cleaning solution contained within the interior  14  of the valve body  12 . As result, the lower portion of the valve seat (aka sealing surface  62 ) is cleaned. 
         [0039]      FIG. 5  illustrates a lower portion  13  in an upper seat clean position. The upper stem assembly  16  has moved to an upper position and is disengaged from the sealing surface  62 . The blocker stops  24  have retreated back into the upper stem assembly  16 . The vent separator  28  is attached to the upper stem assembly  16  with a separator bolt  46  that allows the separator to move for cleaning when the upper valve stem  26  (See  FIGS. 1-3 ) is stroked for the upper clean procedure. The lower valve stem assembly  40  has its O-ring seal  60  engaged with the sealing surface  62 . The O-ring  44  on the vent separator  28  is also engaged with the sealing surface  62 . Due to the O-rings  60  and  44 , the interior  14  of the valve body  12  is fluidly isolated from the conduit  18  interior  20 . 
         [0040]    Because the upper stem assembly  16  is spaced from the vent separator  28 , the vent area  47  has become enlarged. Furthermore the vent area  47  is now in fluid communication with the interior channel  66  of the lower valve stem assembly  40 . The vent area  47  is also in fluid communication with the conduit in  18  interior  20 . As shown in  FIG. 5 , cleaning solution (represented by the vertical lines) is present in the conduit  18  interior  20 , the vent space  47 , the interior channel  66 , and the cleaning space  65 . Because the cleaning solution is in contact with an upper portion of the ceiling surface  62  this position is referred to as the upper seat clean position. Any fluids that may be inside channel  64  are isolated from the interior  14  of valve body  12  by the O-ring  60  located on the lower valve stem assembly  40 . 
         [0041]      FIG. 6  is a partial cross-sectional view of interior components of the valve  10 .  FIG. 6  illustrates an upper stem assembly  16  and the blocker stops  24 . C The blocker stops  24  have been removed from the upper stem assembly for the sake of clarity. Normally the blocker stops  24  are located within cavities in the upper stem assembly  16 . The upper stem assembly  16  also includes a resilient sealing surface  45  which, in some embodiments, may be in O-ring. A vent separator  28  is also illustrated. The vent separator  28  is equipped with a resilient sealing surface which, in some embodiments, is in O-ring. The vent separator  28  is attached to the rod  50 . A separator bolt  46  contains holes  52 . The holes  52  extend through the separator bolt  46 . The lower valve stem assembly  40  also contains holes  54 . When the valve stem assembly  40  is moved to an upper position, the holes  54  may align with the holes  52  in the separator bolt  46  thereby permitting fluid access between outside of the separator bolt  46  through the holes  52  and  54  into the interior channel  66  of the lower valve stem assembly  40 . While the view shown in  FIGS. 6 and 7  show the holes  54  of the lower valve stem assembly  40  and the holes  52  of the separator bolt  46  to be out of alignment,  FIG. 5  shows the holes  52  and  54  in alignment which provides a fluid access between the interior channel  66  and the vent area  47 . In  FIG. 6  also shows the side channel  64  and the resilient sealing surface  60  both located out in on the lower valve stem assembly  40 . 
         [0042]      FIG. 7  illustrates an isometric view of the features shown in cross-section in  FIG. 6 . The upper stem assembly  16  is shown with the blocker stops  24  extended out of the upper stem assembly. As stated above, the blocker stops  24  are normally located within the upper stem assembly  16 . However they are shown in  FIGS. 6 and 7  out of the upper stem assembly  16  in order to better illustrate the blocker stops  24 . The vent separator  28  is shown as well as the O-ring  44  encompassing about the vent separator  28  the separator bolt  46  is illustrated along with the holes  52  within the vent separator bolt  46 . The lower valve stem assembly  40  as illustrated along with the O-ring  60  located on the lower valve stem assembly  40 . The holes  54  in the lower valve stem assembly  40  are also shown. As discussed above, the holes  54  in the lower valve stem assembly  40  provide fluid access to the interior channel  66  with in the lower valve stem assembly  40  as best shown in  FIG. 6 . 
         [0043]    The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.