Abstract:
A valve having a cartridge that fits within the valve housing and that may be replaced without removing the valve housing from adjoining equipment. The cartridge contains a wedge having curved surfaces and a driver to rotate the wedge from an open to a closed position. When the wedge rotates to the closed position a seal is formed on the convex surface of the wedge and a sealing assembly is moved to form a seal around the outlet of the valve housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/658,548, filed Mar. 4, 2005. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an improved valve for use in the control of fluids in a pipeline. The valve of the present invention is particularly useful in high pressure pipelines. More specifically, the present invention is directed to a new, novel and non-obvious valve in which the valve components are housed in a cartridge which facilitates repair by permitting quick removal and replacement without requiring that the housing of the valve be removed from the pipeline. 
     2. Description of Related Art 
     Ball valves, plug valves and the like are well known to those skilled in the art. A common characteristic of these valves is that they may be moved between their fully open and fully closed positions by quick rotation through an angle of not more than about ninety degrees (90 degrees). 
     A simple plug valve comprises a rotatable, tapered plug having a bore therethrough disposed in a complementary housing. The plug valve permits fluid flow to be fully stopped by rotating the plug not more than about ninety degrees (90 degrees). However, these valves offer only minimal graduated control of fluid flow achieved by setting the plug at intermediate positions. Further, plug valves require modification for use in high-pressure environments. 
     A ball valve comprises a rotatable ball having a bore therethrough corresponding to the fluid flow path, together with a seat for sealing with the ball surface. Ball valves operate similarly to the previously described plug valves and offer similar advantages and disadvantages. 
     Presently lesser known, but offering significant advantages over conventional ball and plug valves, is my hemi-wedge valve described in U.S. Pat. No. 4,962,911, which is hereby incorporated by reference. In short, the hemi-wedge valve includes a curved wedge comprising a tapered, spherical thin section rotatable through the fluid path together with a fixed thrust ball for displacing the distal side of the wedge longitudinally toward the seat as the wedge is rotated between its open and closed positions. 
     The hemi-wedge comprises a wedge having curved sides so that a first, convex side forms a curved sealing surface with the seat of the valve and a second, concave side forms a curved thrust surface for cooperation with a complementary curved, fixed surface on the thrust ball. An important feature of the hemi-wedge valve is the fact that the thickness of the wedge increases from its leading end to its trailing end. The wedge includes a bore forming a part of the fluid path through its thinner, leading end and is solid at its thicker, trailing end. Rotation of the hemi-wedge through about ninety degrees (90 degrees) into the fluid path gradually closes the fluid path by blocking it with the thicker, solid end of the wedge. 
     An improvement for use with the hemi-wedge valve described in U.S. Pat. No. 4,962,911 is my valve driver described in U.S. Pat. No. 5,333,834, which is hereby incorporated by reference. This valve driver can turn the rotatable valve member of a ball, plug or hemi-wedge valve. The improved valve driver combines the features and advantages of a conventional free-floating valve element with those of a conventional valve element rigidly connected to an actuator and trunnion. The valve described in U.S. Pat. No. 5,333,834 provides a rotatable valve member which is maintained centered along the actuator axis to avoid cocking while being sufficiently free to float into sealing engagement with the valve seat. These benefits are achieved by loosely holding the rotatable valve member within the yoke or cradle of the valve driver described therein. 
     One common shortcoming of the foregoing valves is that they do not facilitate quick and easy repair or maintenance in the field. Typically, in order to repair or replace a failed component, e.g., a leaking seat, the entire valve must be removed from a pipeline. Such a repair procedure is generally expensive, time-consuming and often requires disassembly of a portion of the pipeline to completely remove the valve housing and install a new or rebuilt valve. With the valve housing often having been welded or bolted into place, it is necessary to shut down the pipeline, remove the housing, repair or replace the valve, install a new or repaired valve and perform appropriate tests to ensure that the integrity of the pipeline has not been compromised. 
     Accordingly, there has been a long-felt, but unfulfilled need for an improved valve incorporating an easily replaceable cartridge assembly which may be quickly and easily removed and replaced in a valve body without requiring any cutting of the pipeline. Those skilled in the art have long sought and will appreciate the novel and non-obvious features of the present invention and the improved valve resulting therefrom. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Other features and intended advantages of the present invention will be more readily apparent by reference to the following detailed description in connection with the accompanying drawings wherein: 
         FIG. 1  is an exploded perspective view illustrating a valve driver, thrust ball and hemi-wedge for use in a high-pressure, hemi-wedge cartridge valve in accord with the present invention as illustrated in  FIG. 4 ; 
         FIG. 2  is a top view illustrating from left to right the hemi-wedge, driver and thrust ball of  FIG. 1  for use in a high-pressure, hemi-wedge cartridge valve in accord with the present invention as illustrated in  FIG. 4 ; 
         FIG. 3  is a cross-sectional illustration from left to right of the hemi-wedge, driver and thrust ball of  FIGS. 1 and 2 ; 
         FIG. 4  is an exploded perspective view of a high-pressure, hemi-wedge cartridge valve in accord with the present invention illustrating its main, internal components; and 
         FIG. 5  is an exploded perspective view of a high-pressure, hemi-wedge cartridge valve in accord with the present invention. 
     
    
    
     While the invention will be described in connection with the presently preferred embodiment, it will be understood that it is not intended to limit the invention to this embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included in the spirit of the invention and as defined in the appended claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention presents a new, novel and non-obvious, high-pressure, hemi-wedge cartridge valve. In the valve of the present invention, the valve components are housed in a cartridge which may be easily removed from the valve housing without requiring that the housing be detached from a pipeline. In the valve of the present invention, the rotatable valve member, preferably a hemi-wedge valve, is disposed within a cartridge to permit rapid repair of damaged valves by merely removing the housing cover, replacing the cartridge and re-installing the valve cover. While the preferred embodiment of the present invention comprises a hemi-wedge valve, the cartridge design of the present invention may also be employed with conventional ball and plug valves. 
     A presently preferred embodiment of a hemi-wedge, valve driver and thrust ball for use in the present invention is illustrated in  FIGS. 1-3 . These figures illustrate a hemi-wedge  50  and thrust ball  60  typical of those disclosed in connection with my improved hemi-wedge valves described and claimed in U.S. Pat. Nos. 4,962,911 and 5,333,834, which have been incorporated herein by reference. The construction, operation and advantages of my hemi-wedge valve are set forth in detail in the specifications of those patents. Those unfamiliar with my hemi-wedge valve are referred thereto. 
     Briefly, the hemi-wedge valve is opened and closed by rotation of hemi-wedge  50  through an angle of about ninety degrees (90 degrees) over the curved surface of thrust ball  60 . Hemi-wedge  50  moves in response to rotation of driver  10 . As the thicker, trailing edge of hemi-wedge  50  is rotated into the fluid path, thrust ball  60  forces the leading or distal surface of hemi-wedge  50  to the left and convex surface  54  into sealing engagement with a seat on the outlet side of the housing (not shown). 
     Valve driver  10  of the present invention comprises drive stem  12  having keyway  14  at one end thereof for cooperation with any conventional external actuator (not shown). Drive stem  12  is connected at its opposite end with a driver  10  having a top plate  34  with shoulders  22  from which arms  20  are suspended. Arms  20  are positioned to straddle the fluid flow path through the valve. In the presently preferred embodiment, arms  20  are positioned so that they do not enter or cross the fluid path during rotation of the rotatable valve member, e.g., hemi-wedge  50 , between its open and closed positions. In the presently most preferred embodiment, arms  20  are joined around the fluid flow path to bottom plate  32  of driver  10 . In that embodiment, driver  10  further includes a trunnion  36  on the exterior of bottom plate  32  and aligned with drive shaft  12  for use in centering both the driver and carried rotatable valve member within the valve. Central opening  24  between arms  20  of driver  10  is designed to receive thrust ball  60 . Thrust ball  60  includes central bore  62  that forms a part of the fluid pathway through the valve. 
     Optionally, driver  10  further includes one or more dogs  30  positioned to engage cooperating slots  56  in hemi-wedge  50 . See  FIGS. 2 and 3 . Dogs  30 , along with contact surfaces  26  and  38 , transmit the actuating force applied to driver  10  to the rotatable valve member, e.g., hemi-wedge  50 . Dogs  30  are smaller than slots  56  so that they are able to move freely therein. Accordingly, dogs  30  do not rigidly connect arms  20  and driver  10  to hemi-wedge  50 . Thus, the rotatable valve member, e.g., hemi-wedge  50 , is free to float to seek the best seal. In a presently preferred embodiment, a plurality of dogs  30  is employed to more evenly distribute the actuating force applied to hemi-wedge  50  by drive element  18 . 
     Contact surfaces  26  of drive element  18  contact and push contact surfaces  58  of hemi-wedge  50  between the open and closed positions. When closing the valve, the actuating force is transmitted through driver  10  to hemi-wedge  50  via contact surface  38  to push hemi-wedge  50  to the closed position. When opening the valve, the actuating force is transmitted through driver  10  to hemi-wedge  50  via contact surface  26  to push hemi-wedge  50  to the open position. However, the opening force is also transmitted to hemi-wedge  50  via dogs  30  which pull the hemi-wedge via slots  56 . By both pushing and pulling the hemi-wedge, driver  10  prevents the hemi-wedge from becoming cocked. It should be noted that the preceding description of a hemi-wedge valve is provided merely as an example, and any number of valve designs known in the art are acceptable for use with the present invention. 
     As previously mentioned, the components forming the valve of the present invention are housed in an easily removable cartridge. The main internal components of valve cartridge  400  according to the present invention are illustrated in exploded perspective in  FIG. 4 . Within valve cartridge  400  is a hemi-wedge valve assembly of the type previously described with reference to  FIGS. 1-3 . This assembly includes valve driver  10 , drive stem  12 , hemi-wedge  50  and thrust ball  60 . 
     In  FIG. 4  fluid pathway  402  is illustrated extending from fluid inlet  404  in inlet retainer plate  406 , through thrust ball  60  and on to fluid outlet  408  in seat plate  410 . As will be understood by those skilled in the art, when the hemi-wedge  50  is positioned so that bore  52  is disposed in the fluid path, i.e., in an open position, fluid may flow through cartridge  400  via fluid pathway  402 . 
     Disposed along the fluid pathway  402  between thrust ball  60  and inlet retainer plate  406  is spacer  422  which helps maintain the position and spacing of thrust ball  60  within fluid pathway  402 . The inlet retainer plate  406  provides a wall for retaining the components of cartridge  400  on the inlet side and includes a bore therethrough forming fluid inlet  404 . On the outlet side of cartridge  400 , outlet retainer plate  410  holds the seat assembly  412 - 420  in place, while allowing fluid to exit cartridge  400  through fluid outlet  408 . Forming the bottom of cartridge  400  is base plate  442 . Any conventional fastening means, e.g., screws  424 , may be used to secure the inlet and outlet retainer plates  406 ,  410  to base plate  442  and to a similar top plate (not shown) extending from the bottom of bonnet  426 . Those skilled in the art will recognize that cartridge  400  also may include optional side plates (not shown) affixed between plates  406  and  410  to fully enclose the valve assembly within cartridge  400 . 
     Extending along the fluid pathway  402  from hemi-wedge  50  in the direction of outlet retainer  410  is a seat assembly comprising a set of elements  412 - 420  that aid in providing a high-pressure seal when the hemi-wedge  50  is in the closed position. In physical contact with the hemi-wedge  50  is a seat  414  which provides the seal in the closed position. While it is preferred that seat  414  be formed of metal to provide a tight metal-to-metal seal, other materials suitable for the intended operating environment, e.g., O-rings made of rubber or hard plastics such as polytetrafluoroethylene (PTFE such as Teflon®) might be used. Seat  414  is disposed in an appropriate groove on the inlet side of spacer  416 . Surrounding seat  414  is retaining ring  412  which helps maintain seat  414  in place, preventing blow out of the seat during opening and closing of hemi-wedge  50 . 
     On the opposite or outlet side of spacer  416  is a second groove for receiving another seal element  418 . Like seat  414  seal element  418  is an O-ring which may be formed of any appropriate material, e.g., rubber, plastic such as PTFE or metal. Seal element  418  is maintained in place by retaining ring  420 . When installing the cartridge  400  into housing  450 , the complete seat assembly must be disposed fully within the periphery of the cartridge, i.e., seal  418  cannot extend beyond the exterior surface of outlet retaining plate  410  through outlet  408 . After installation, however, and upon closing of the valve, the seat assembly, and particularly seal  418  may be forced outwardly through outlet  408  beyond the exterior surface of plate  410  to provide a seal about the outlet of housing  450 . 
     The dimension of multi-element seat assembly  412 - 420  along the fluid flow path can be easily adjusted to the exact length required for any particular valve cartridge by selecting spacer  416  from a plurality of spacers having different thicknesses. Thus, minor differences in dimensions between valves can be easily accommodated while maintaining the desired tolerances. Using a simple repair kit having a plurality of spacers  416  of varying thickness, a technician will readily be able to change a defective seat assembly  412 - 420  while maintaining strict adherence to the tight tolerances found in these high, pressure valves. Thus, quick repair of defective cartridges is facilitated by this multi-element valve seat assembly. 
     Positioned above valve driver  10  is bonnet  426 . Bonnet  426  includes opening  432  through which drive stem  12  extends. To maintain alignment and ensure a tight seal between bonnet  426  and drive stem  12 , thrust bushing  428  and shaft seal  430  are positioned below bonnet  426  and around drive stem  12 . The bonnet  426  also has a series of symmetrically disposed holes  434  about its periphery. These bonnet holes  426  correspond to holes  440  symmetrically positioned around a flange on the top of valve housing  450 . A plurality of bonnet bolts  436  are extended through bonnet holes  434  and into holes  440  to fasten cartridge  400  to valve housing  450 . An appropriate seal, e.g., an O-ring (not shown) disposed in groove  438  in the flange about the top of housing  450 , seals the completed valve assembly. 
     On the bottom of cartridge  400  is cartridge base plate  442 . Interposed between base plate  442  and driver  10  is driver thrust bushing  444 , which aids in maintaining the alignment of the driver  10  within the valve cartridge  400 . A top plate (not shown), but similar to base plate  442  extends from the lower side of bonnet  426 . The cartridge  400  is held together by a plurality of screws  424  extending through and attaching inlet retainer plate  406  and outlet retainer plate  410  to the top plate (not shown) and base plate  442 . 
       FIG. 5  shows a perspective view of a valve  100  in accordance with the present invention. The assembled valve cartridge  400  of  FIG. 4  is shown, along with valve housing  450 . As previously described, cartridge  400  houses valve components including the valve driver  10 , drive stem  12 , hemi-wedge  50  and thrust ball  60 . Of note in  FIG. 5 , drive stem  12  extends above the bonnet  426  for cooperation with a conventional actuator to control operation of the valve  100 . 
     A plurality of holes  504  are symmetrically disposed about the periphery of pipeline connecting flanges  502  extending from both sides of valve housing  450 . These flange holes  504  may be utilized to connect valve  100  to a pipeline. Alternatively, valve  100  may be welded into a pipeline. Those skilled in the art will recognize that valve  100  may be incorporated into any pipeline where it is desired to be able to adjust flow through the line by use of a quarter-turn valve. 
     Valve housing  450  also includes flange  510  having a plurality of holes  440  symmetrically disposed about its periphery. Further, valve housing  450  includes an internal cavity  506 , sized to accommodate cartridge  400  below bonnet  426 . It is preferable that flange  510  and internal cavity  506  be designed to closely fit the form of cartridge  400 . When cartridge  400  is inserted within housing  450 , the retainer plates  406  and  410  of cartridge  400  should be adjacent the sides of the internal cavity  506  and correspond closely to the dimensions of slots  462  and  464 , respectively. When valve  100  is fully assembled, the bonnet  426  rests upon flange  510  forming the top of housing  450 , while the main portion of cartridge  400  carrying the valve components is disposed within internal cavity  506 . 
     Valve housing  450  has a fluid pathway  402  that allows a pipeline fluid to flow through housing  450 . To allow fluid to pass through the assembled valve  100 , fluid pathway  402  preferably aligns with and has roughly the same diameter as pathway  402  through cartridge  400  as shown in  FIG. 4 . 
     To fasten valve body  438  to cartridge  400 , a plurality of bonnet bolts  436  are extended through holes  432  disposed symmetrically about the periphery of the bonnet and into corresponding holes  440  symmetrically disposed about flange  510  of housing  450 . It should be noted that, while any conventional fastening means may be employed to secure cartridge  400  within housing  450 , one of the advantages of the present invention is that the cartridge  400  is quickly and easily removable from housing  450  for convenient field repair. Accordingly, those skilled in the art will recognize that fastening means which are difficult to disengage or which could damage the various components of valve  100  are not preferred. 
     According to one embodiment of the present invention, cartridge  400  is designed so that it will fit within housing  450  in only a single, desired orientation. That is, the cartridge  400  may only be inserted into housing  450  facing in a single direction with respect to the housing. This prevents a technician from installing valve cartridge  400  backwards or sideways in a pipeline. As will be understood by those skilled in the art, if the perimeter of the cartridge base plate  434  forms a rectangle or square, and if the opening in flange  510  and the cavity  506  of housing  450  have corresponding dimensions, the cartridge  400  may fit into housing  450  in at least two different orientations. In this case, the cartridge  400  could be placed into housing  450  backwards or sideways. Such incorrect installation could prove disastrous in a high-pressure pipeline transporting flammable or explosive materials. To prevent such incorrect installation, the perimeter of cartridge  400  is preferably shaped with some irregularity, while the opening in flange  510  and the cross-section of cavity  506  are formed to correspond to and receive that irregularity in only one orientation. 
     This may be illustrated by a very simple embodiment, where the dimension of inlet retainer plate  406  across the flow path is slightly smaller then the dimension of outlet retainer plate  410  across the flow path. The openings in flange  510  and the cross-section of cavity  506  are configured to correspond to the cross section of cartridge assembly  400  defined by plates  406 ,  410  and  442 . Slots  462  and  464  across the flow path of cavity  506  are formed with dimensions corresponding to plate  406  and  410 , respectively. In this example, slot  462  is sufficiently wide to receive plate  406 , but not wide enough to receive plate  410 . The dimension of slot  462  across the inlet side of cavity  506  will correspond to that of inlet retainer plate  406 , while that of slot  464  on the outlet side of cavity  506  will correspond to that of outlet retainer plate  410 . The cartridge  400  will, accordingly, only fit within housing  450  in a single orientation, thus, preventing a technician from installing a cartridge with an incorrect orientation. 
     The foregoing description of the invention has been directed in primary part to a particular, preferred embodiment in accordance with the requirements of the patent statutes and for purposes of illustration. It will be apparent, however, to those skilled in the art that many modifications and changes in the specifically described valve  100  may be made without departing from the scope and spirit of the invention. For example, while the presently preferred system for ensuring that cartridge  400  is installed with the correct orientation employs the use of retainer plates  406  and  410  of differing dimensions, together with cooperating slots  462  and  464  of similar dimensions in cavity  506 , many other similar systems might be employed to achieve the desired result. A groove might be formed in the opening of flange  510  and/or a side of cavity  506  for cooperation with a tongue extending from a side of base plate  442  or one of retainer plates  406  or  410 . This is only one example of the many ways to achieve the desired result of preventing the installation of a cartridge in an incorrect orientation. Therefore, the invention is not restricted to the preferred embodiment illustrated but covers all modifications that may fall within the scope of the following claims.