Abstract:
An improved manifold and valve cartridges suitable for high power (over 600 hp) reciprocating pumps for water blast or jet applications are disclosed. In one aspect, the disclosed valve cartridges are compact and mounted axially along a seat member that has a central bore in addition to suction and discharge seats. The seat member can also be provided a plurality of radially arranged bores for allowing suction flow to the pump. A spool valve assembly can be mounted through the seat member bore, and can include a valve spool, a spherical suction valve member, a compression spring, and compression-locked rings. The spool valve can include a closed flanged end that engages with the seat member discharge seat. In operation, the compression spring continuously pushes the spool valve closed flanged end against the discharge seat and pushes the suction valve member against the suction seat to retain a normally closed position.

Description:
TECHNICAL FIELD 
     This invention relates to high power reciprocating pumps of the type used in high flow and high pressure water blast and jet applications, and more particularly to an improved manifold and valve cartridges for lower ownership cost. 
     BACKGROUND 
     Generally, an industrial reciprocating pump consists of three or five crankshaft-driven plungers to compress and eject fluid. A manifold is also often used to cap the open ends of the multiple plunger boxes and manage the flow during operation based on suction or discharge strokes. Traditionally, manifold pockets are provided in the manifold that communicate with the plunger chamber. Within the pockets, two individual check valves are provided to serve the suction and discharge functions, respectively. Such an arrangement can be cumbersome, as many parts are involved that can be difficult to service. Other systems involving axially combined two-valve cartridges have been developed as well. 
     However, as the water blast and jet industry demands higher and higher power on pumps, many new challenges have arisen. For example, high dynamic loads associated with such increases can have a significant effect on durability. Additionally, high flow requires either more plungers or larger plungers, but the former will lead to more parts and wider power frame structure while the latter will result in larger plungers and valves with ultimately higher dynamic loads. Thus improvements in valve cartridges and manifolds are desired. 
     SUMMARY 
     Accordingly an objective of the concepts provided in this disclosure is to improve the valve cartridge on dynamic loads, to enable easier fabrication and to provide a more durable configuration. Another objective is to provide a manifold to house different sizes of valve cartridges for higher flow or higher pressure from the demand of higher power, and particularly for pumps meeting or exceeding 600 horsepower. In accord with the above, the present disclosure is especially directed to an improved valve cartridge received inside the manifold of a high pressure reciprocating pump, as already illustrated generally in U.S. Pat. No. 5,231,323, the entirety of which is incorporated by reference herein. In one aspect, the valve cartridge of the disclosure is disposed between the manifold block and an adjacent plunger box and can be easily removed and replaced when folding down the manifold block. 
     The valve cartridge of the present disclosure is compact and constructed around a seat member. The seat member has a central bore and two ends that are used as suction and discharge seats, respectively. The front-end seating face is for suction and is provided with a plurality of radially arranged bores or holes that provide fluid communication between an annular suction chamber and the plunger chamber. As presented, a spool valve assembly is mounted through the bore. It includes a valve spool, a spherically-shaped suction valve member, a compression spring and compression-locked rings to secure the spring on the spool. The compression spring will continuously push the two valve members against the seat member mating seat surfaces to maintain a normally closed position. In one aspect, the valve spool is T-shaped, where the enlarged diameter end has tapered seat surface and the spool body has a central bore and a plurality of lateral slots extending through the wall for fluid communication. In a compression stroke, the pressurized water from the plunger chamber pushes on the closed end of the valve spool, forcing the spring compressed and letting the valve open. Then water will flow through the lateral slots at the discharge end of the spool into the discharge passage of the manifold block. 
     In one aspect, a suction valve is placed at the end of the seat member facing the plunger box and inserted on the valve spool. A compression spring is then installed between the open end of the spool and the suction valve, so that the suction valve normally closes the plurality of suction holes in the seat member. In a suction stroke, the supply water, communicating through the plurality of suction holes, acts on the suction valve member and causes the valve to retreat by forcing the spring compressed. As a result, a portion of the supply water flows in from the spool inner bore through the adjacent plurality of slots in the spool while another portion flows in from the outer edges of the member. Such a two-way flow pattern not only reduces flow restriction but also improves reliability. Additionally, using a spherical surface on the suction valve seat can improve sealing and tolerance to dynamic loading. 
     The disclosed valve cartridge is compact, lightweight, and has lower flow restrictions than typical known systems, and also provides an opportunity to increased size and capacity with lower dynamic damage. Notably, another benefit of the disclosed designs is an increased flow without adding more plungers. 
     Another feature of the disclosed designs is that the outside cylindrical profile of the seat member is generally stepped and sealed by radial sealing means, such as O-ring seals. Accordingly a manifold is made with multiple-stepped bore pockets. The combination leads to a single manifold for housing serial sizes of valve cartridges, resulting in fewer parts to own, carry and operate. A further feature is to provide a pilot passage in the manifold so that whenever changes a different size of valve cartridge will be able to operate a pressure. 
     A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the examples disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments are described with reference to the following s, which are not necessarily drawn to scale, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
         FIG. 1  is a fragmentary cross-sectional view through a high pressure reciprocating pump showing the valve cartridge, manifold and adjacent plunger box having features that are examples of aspects in accordance with the principles of the present disclosure. 
         FIG. 2  is a cross-sectional view of valve cartridge, manifold and adjacent plunger box of  FIG. 1  wherein the components are in a suction mode of operation. 
         FIG. 3  is a cross-sectional view of valve cartridge, manifold and adjacent plunger box of  FIG. 1  wherein the components are in a discharge mode of operation. 
         FIG. 4  is a cross-sectional and exploded perspective view of the valve cartridge shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional perspective view of a second valve cartridge usable in the manifold of  FIG. 1 , but that is smaller than the valve cartridge shown in  FIG. 1 . 
         FIG. 6  is a perspective view of the manifold of  FIG. 1  showing that the cartridges of  FIG. 1  and  FIG. 5  can be installed in the same manifold pocket. 
         FIG. 7  is a cross-sectional view of manifold and adjacent plunger box of  FIG. 1  with the second valve cartridge of  FIG. 5  installed in the manifold. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
     Manifold Design 
     Referring to  FIG. 1 , a fluid end  10  of a high pressure reciprocating pump is shown as including a mounting block  13  for housing plunger box  9  and a manifold block  15  bolted to the pump fluid end  10  by fasteners  17 . As shown, a plunger  8  reciprocally slides inside the plunger box  9  to create suction and compression strokes. In one aspect, the manifold block  15  has one or more pockets  18 , each of which defines a plurality of differently sized, stepped bores  21 ,  22 ,  23 , and  24  to accommodate the installation of variously sized and configured valve cartridges  20 ,  20 A within the same manifold  15 . The stepped bores  21 ,  22 ,  23 , and  24  can also provide sealing surfaces with seals mounted on the valve cartridges  20 ,  20 A. 
     With reference to  FIG. 6 , it can be seen that manifold block  15  is provided with three pockets  18  and three valve cartridges  20  (or  20 A), although it should be understood that more or fewer pockets  18  may be provided without departing from the concepts presented herein. For further details of fluid end  10 , reference is made to the aforementioned U.S. Pat. No. 6,231,323, the entirety of which is incorporated by reference herein. 
     In the embodiment presented, the manifold block  15  is shown as being operably connected to a suction port manifold  16  from which fluid can be drawn into the pump (e.g. plunger  8 , plunger box  9 ) through the manifold block  15 . With reference to  FIG. 2 , suction fluid flows from a laterally extending suction fluid port  37  in the suction port manifold  16 , through a passageway  36  in the manifold block  15 , and into an annular chamber  35  defined by bore  22 . As configured, the valve cartridge  20  controls the flow of fluid from the annular chamber  35  into the plunger box  9 . It is noted that the suction port manifold  16  may be made from a variety of materials, such as aluminum or an engineered plastic or polymer. The materials for the manifold block  15  and the suction port manifold  16  may be the same or different materials. 
     The manifold block  15  is also shown as including a laterally extending discharge port  32  configured as a through hole in the manifold block  15 . The discharge port  32  provides a common exit passageway for pressurized fluid from the pump through each pocket  18 . With reference to  FIG. 1 , discharge fluid flows from an annular discharge chamber  31  defined by bore  24  to the discharge port  32  via an internal passageway  26 . In one embodiment, passageway  26  is configured as a plurality of small holes. As configured, the valve cartridge  20  controls the flow of fluid from the plunger box  9  to the annular chamber  31 . 
     Adjacent to the discharge chamber  31 , the manifold block  15  is provided with a passageway  33  that may be used for gauging or for by-pass valve mounting, as well as a local pulsation dumper. The manifold block  15  is also provided with a passageway  39  that functions as a weep hole to indicate if there is leakage on the discharge or suction seals of the valve cartridge  20 . The manifold block  15  can also be provided with a built-in pilot pressure passage  38 , as shown at  FIG. 7 , for automatically sensing the change on different sizes of cartridges  20 ,  20 A. 
     As discussed previously, fasteners  17 , which may be machine bolts or screws, are used to clamp the manifold block  15  to the mounting block  13 . Due to high pressure, especially high pulsation forces acting on the valve cartridge  20 , it is preferable to have a self-clamping feature (discussed later) designed into the manifold  15  so that there is less demand on pre-tension and fatigue life to the fasteners  17 . 
     Valve Cartridge Design 
     Referring to the perspective view provided at  FIGS. 4 and 5 , the valve cartridge  20  can be seen in further detail. Additionally, a differently sized valve cartridge  20 A is shown at  FIGS. 5 and 7 . As many of the features of the smaller cartridge  20 A are shared with the cartridge  20 , it should be understood that the description for the cartridge  20  is applicable and fully incorporated by reference into the description for the smaller cartridge  20 A. 
     In one aspect, the valve cartridge  20  includes a seat member  50  having a central bore  52  that functions as the main body of the valve cartridge  20 . As shown, the seat member  50  is provided with a plurality of equally radially spaced bores  61  extending from an outside annular face  54  of the seat member  50  to a suction seat surface  51  of the seat member  50 . The suction seat surface  51  can be shaped as a round groove and divided into portions, for example an inner band  51 A and outer band  51 B. A round groove is preferable to connect the bores  61  on the suction seat surface  51  to improve flow restriction and structural stress concentration. In addition, it is preferable that the seat surface  51  has a spherical-shape for better sealing and higher impact resistance. A spherical-shaped seat also gives rotational freedom on the suction valve, which makes the suction valve more tolerant to high flow situations. 
     The outside profile of the seat member  50  can be stepped and provided with seals, for example radial O-ring seals or other types of seals. In the embodiment shown, the outside annular surface  54  is formed as a first step having a first seal  87 . A second step  55  is also provided on the opposite side of the radially spaced bores  61 , and is provided with a second seal  88 . Taken together, the first and second seals  87 ,  88  seal the annular suction chamber  35 . The second step  55  is also provided with an O-ring  90  along with a back-up ring  89  that together are configured to seal high pressure from the discharge chamber  31 . The seat member  50  is also provided with a third step  56  which may also be provided with a seal. 
     Additionally, as the seat member  50  and the pocket cavity  18  in the manifold  15  each have a stepped profile, the configuration allows the use of different sizes of cartridges  20  by sealing at different step shoulders. For example, a comparison of  FIGS. 4 and 5  illustrates that, for bigger cartridges  20 , which are useful for higher flow applications, the high pressure seals  89  and  90  are placed at shoulder  55 . Alternatively, for smaller cartridges  20 A, which are useful for higher pressure applications, the back-up ring  89  and seal  90  are located at shoulder  56 . 
     The seat member  50  may also be provided with a face seal  91  for providing a seal between the plunger box  9  and the front face  50   a  of the seat member  50 . As mentioned previously, a self-clamping feature can be provided that is effective in reducing the leak tendency on the face seal  91 . As presented herein, the self-clamping feature is ensured by designing the diameter of the face seal  91 , shown as an O-ring, slightly smaller than the diameter of the discharge chamber  31 , preferably at a ratio of about 1:1.05 to about 1:1.2, to cause a bias pressure difference. It is noted that the diameter of the face seal  91  is at least equal to the interior diameter of the plunger box  9 , and thus the diameter of the discharge chamber  31  is greater than the internal diameter of the plunger box. It is also noted that for differently sized valve cartridges (e.g.  20 A), the diameter of face seal  91  would change according to the aforementioned ratios. 
     The valve cartridge  20  is also shown as being provided with a spool valve assembly  30  that is mounted through the bore  52  of the seat member  50 . In the exemplary embodiment shown, the spool valve assembly  30  includes a valve spool  70 , a suction valve member  80 , a compression spring  84  and compression-locked rings  85 ,  86  which secure the spring  84  onto the spool  70 . As explained in further detail later, the assembled spool valve assembly  30  and seat member  50  operate to allow fluid from the suction port manifold  16  to enter the plunger box  9  and to block fluid from exiting the plunger box  9  via the discharge port  32  when the plunger causes a vacuum in the plunger box. Likewise, the assembled spool valve assembly  30  and seat member  50  operate to block fluid from entering the plunger box  9  via the suction port manifold  16  and to allow fluid to exit the plunger box  9  via the discharge port  32  when the plunger  8  causes a compressive force in the plunger box  9 . 
     As presented, the valve spool  70  is provided as a generally cylindrical tube with a circumferential wall  73  extending between an open end  72  and a closed flanged end  71 . The open end  72  can be provided with a groove or threads to engage with the compression-locked rings  85 ,  86  while the closed flanged end  71  is configured to seat against a discharge seat surface  57  on the seat member  50 . Taken together, the valve spool closed flanged end  71  and the seat member  50  form a discharge valve. In one aspect, the valve spool  70  defines an interior volume  60  and is provided a first set of radially spaced slots  62  and a second set of radially spaced slots  63  providing passageways into the interior volume  60 . 
     The suction valve member  80  is preferably provided with a spherical seat surface  80 A and has a bore  82  that allows the suction valve member  80  to freely slide along the valve spool  70 . In one aspect, the seat surface  80 A is complementarily shaped to match the contour of the seat surface  51  to form a suction valve, wherein the suction valve member  80  is able to block fluid flow from passing through the bores  61 . The suction valve member  80  may be retained by a conical compression spring  84 , which is retained on the open end the valve spool  70  by the retainer  85  and secured by a securing member  86 , for example a C-shaped or preferably 2-piece split lock ring with a tapered jamming interface. The securing member  86  may also be a single O-ring shaped snap ring. 
     In operation, the compression spring  84  consistently acts on the suction valve member  80  towards a closed position against the seat member  50 . This same acting force also simultaneously urges the closed flanged end  71  of the valve spool  70  towards a closed position against the seat surface  57  of the seat member  51 . Accordingly, for either the suction valve member  80  or the valve spool  70  to become opened, a pressure or vacuum fluid force created by the plunger  8  must first overcome the biasing force of the compression spring  84 . Necessarily, only one of the suction or discharge valves of the valve cartridge  20  can be acted on to open at any given time based on whether a vacuum or pressure condition exists in the plunger chamber  34   
     With reference to  FIG. 7 , it can be highly desirable to have a safety lock or control feature when swapping the vale cartridges  20 ,  20 A due to a possible pressure rating limitations of the cartridges  20 ,  20 A.  FIG. 7  illustrates such a pilot pressure port  38 , which can be used to automatically sense the pressure change. For example, when using a bigger cartridge  20 , back-up ring  89  and seal  90  are on the shoulder bore  55 , thereby preventing pressurized fluid from reaching port  38 . On the hand, if a smaller cartridge  20 A is used, as is shown in  FIG. 7 , the back-up ring  89  and seal  90  will be on shoulder  56 , and thus the pressure will not reach port  38 . Accordingly, the pressure at port  38  can be utilized to detect the installation of a differently sized valve cartridge which can then enable the pump or system to implement a safety lock or control feature. 
     Operation 
     With reference to  FIG. 2 , the valve cartridge  20  is in a suction position during the suction stroke of the plunger  8 . As plunger  8  retreats in a direction away from the valve cartridge  20 , the plunger chamber  34  defined by the plunger box  9  and plunger  8  turns into a vacuum condition. As the vacuum condition increases and overcomes the compression force of the spring  84 , the suction valve member  80  is moved to an open position away from the suction seat surface  51  to open suction passage  61 . Consequently, fluid from the suction port  37  flows into annular chamber  35  via passage  36 , and then through suction passage  61  and into the plunger chamber  34 . This flow occurs in two ways. First, an inward flow through the adjacent slots  62  on the valve spool bore  30  is developed. Second, an outward flow  64  over the outer circumference of the suction valve member  80  is developed. During the suction stroke, the compression spring  84  retains the valve spool flanged closed end  71  in a closed seated position on the discharge seat surface  57  such that fluid cannot be drawn from the discharge port  32  and into the plunger chamber  34 . 
     During a compression stroke of plunger  8 , as shown in  FIG. 3 , the plunger  8  is moving towards the manifold  15 . In this mode of operation, the compression spring  84  forces the suction valve member  80  closed to block passages  61 . Additionally, as the pressurized fluid exceeds the spring force of the spring  84 , the fluid acts on the closed end  71  of valve spool to unseat the closed end  71  from the seat surface  57  on the seat member  50 . Consequently, the discharge valve will open and rest on bottom face  26  of manifold block  15  at which point the pressurized fluid flows through bore  33 , lateral slots  63  and seat  71  into discharge chamber  31 , and then discharge port  32 . 
     The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the disclosure.