Abstract:
A valve assembly for use in high pressure pumps is designed for easy replacement for example in the suction inlet here for a high pressure pump. The design utilizes a combination of screw threads and a locking member to provide structural strength for the valve to be placed in and withdrawn from the inlet bore.

Description:
BACKGROUND OF INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to high pressure fluid pumps and in particular to an arrangement for allowing easy access to and repair/replacement of suction valves located within the pump housing. 
         [0003]    2. Description of Related Art 
         [0004]    High pressure reciprocating piston pumps have been used in the oil industry for several purposes such as hydraulic fracturing, cementing, and other well treating processes. Typical pump assemblies are disclosed in U.S. Pat. No. 6,544,012 issued to Blaine. The pumps generally include a power end and a fluid end. The power end includes a power source and linkage for reciprocating a plurality of plungers within the fluid end of the pump. The fluid end includes a suction manifold, a plurality of intake or suction valves, a plurality of output valves and a discharge header. The fluid pressure within the pump chamber can be in excess of fifteen thousand psi and the fluid being pumped often contains abrasive materials such as sand. Consequently the valves are subject to extreme conditions which cause failures and require regular service and replacement. It is therefore desirable to construct the valve assembly so as to be easily accessible and replaceable in a short period of time. 
         [0005]    Current methods for accessing the suction valves include providing a bore with a plug as shown in U.S. Pat. No. 7,681,589 at  38  and  40  in  FIG. 1 . Another method is disclosed by Blume in the above mentioned U.S. Pat. No. 6,544,012 that includes providing a threaded suction valve seat retainer  135 . However in high pressure applications the threads on the valve seat retainer are not sufficient to withstand the force within the pump chamber. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention overcomes the above mentioned deficiencies in the prior art by providing a suction valve assembly that is modular in nature and is secured in place by using a dual locking arrangement which distributes forces delivered by the pumping system between a threaded valve seat collar and a locking ring which includes a plurality of accurate segments. The invention may be applied to a stem guided valve type suction valve or to a “crows feet” guide suction valve. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0007]      FIG. 1  is a perspective view of the fluid end of a typical high pressure pump. 
           [0008]      FIG. 2  is a cross sectional view taken along line  2  of  FIG. 1 . 
           [0009]      FIG. 3  is a cross sectional view of a valve according to an embodiment of the invention. 
           [0010]      FIG. 4  is a perspective view of the valve seat and stem guide shown in  FIG. 3 . 
           [0011]      FIG. 5  is a perspective view of one of the segments of the locking ring. 
           [0012]      FIG. 6  is a cross sectional view of a flow diverter for the valve according to the invention. 
           [0013]      FIG. 7  is a cross sectional view of a “crows feet” valve assembly according to a second embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIG. 1  illustrates a conventional fluid end  10  of a high pressure pump. The fluid end includes an inclined top surface  20  having a plurality of bores  12  for receiving outlet valve mechanisms which are not shown. Fluid end  10  has a planar front side  11  and a rear side  13  that is adapted to be bolted to the power end. Suitable bores  14 ,  15  are provided for receiving threaded studs with nuts. A horizontally extending outlet passageway  16  is in fluid communication with each of the outlet chambers  21  of the pump as shown in  FIG. 2 . Fluid end  10  further includes a lower extending inclined portion  19 . A plurality of inlet ports  22  are located in portion  19 . Planar front side portion  11  externals vertically between inclined surfaces  20  and  19  when the pump is secured to a truck bed. The rear side  13  of the fluid end includes a plurality of bores  23  for receiving the pistons (not shown) which are driven by the power end of the pump. The arrangement of the pistons, the fluid inlet, and the fluid outlet is commonly referred to as the “Y” design for a frac pump as shown in  FIG. 2 . However, a “T” configuration as known in the art could also be used. 
         [0015]      FIG. 2  illustrates the interior details of a typical pump chamber including suction inlets  22 , outlet chamber  21  and outlet passageway  16 . Suction valves (not shown) are located within bores  22  and outlet valves not shown) are located in bores  12 . A plurality of bores  23  are adapted to receive the pump plungers which are driven by the power end of the pump. 
         [0016]    A valve assembly according to an embodiment of the invention is illustrated in  FIG. 3 . Valve assembly  51  includes a threaded valve seat collar  50 , a locking ring  34  which includes a plurality of locking elements  74 , valve stem  39  which includes a valve insert member  45  and a spring retaining member  36 . 
         [0017]    Valve seat collar  50  is threaded at  52  so as to be threadly received in inlet bore  33  of fluid end  31 . Valve seat collar  50  includes a valve stem guiding member  35  which is supported by arms  47  that extend between the inner portion of the valve seat collar and valve stem guiding member  35 , see  FIG. 4 . Valve seat collar  50  also includes a shoulder  48  and an annular ridge  32  that cooperates with the locking elements  74  to help secure the valve seat collar within the bore in a manner to be discussed below. A spring  37  which may be a coil spring is disposed between a shoulder  46  on the valve stem guide  35  and a shoulder  38  provided on spring retaining member  36 . A locking pin not shown holds spring retaining member  36  on valve stem  39 . Member  36  could also be threaded or welded to valve member  39 . The spring is biased to urge upper portion  44  with insert member  45  into engagement with valve seat  41  provided on the valve seat collar  50 . 
         [0018]    Locking elements  74  are shown in  FIG. 5  and include an arcuate, generally rectangular shaped body  71 . At its outer surface the edges of the top and bottom portions are beveled at  72 ,  73  to allow the segments to more easily be located within groove  40  in the bore  33  of the fluid end. A flow diverter  80  as shown in  FIGS. 6 and 6   a  is positioned within the bore  33  at its opening. 
         [0019]    A U-shaped seal  120  which includes an O-ring  121  positioned within the U-shaped channel is positioned between valve seat collar  50  and a recess in the inlet bore as shown in  FIG. 3 . These seals are available from Marco Rubber &amp; Plastic Products, Inc., among others. 
         [0020]    The manner of installing the valve assembly into the fluid end is as follows. Initially locking elements  74  are not placed within the suction inlet bore. The valve assembly including valve seat collar  50 , valve stem  39  with spring  37  and spring retainer  36  are threaded into bore  33  using a suitable tool that has complimentary ridges that align with grooves  61  provided on the valve seat collar. The assembly is threaded into the bore to a point where the end shoulder  48  of valve seat collar  50  passes the inner top portion of groove  40 . A plurality of locking segments for example four are now positioned in the groove  40 . [Valve seat collar  50  is backed out of the bore  33  to seat against the locking elements  74 .] In this position the high pressure within the chamber during compression is withstood by both the threads  52  on the valve seal collar and the locking elements  74  within annular groove  40 . The flow diverter  80  as shown in  FIG. 6A  is then placed within the inlet bore  33  and held in place by a suction manifold plate  101  attached to fluid end  31  by any suitable means such as a bold and nut. Annular ridge  82  of the flow diverter keeps locking elements  74  within groove  40 . 
         [0021]    To remove and repair or replace the suction valve assembly, the manifold cover plate  101  and flow diverter  80  are removed from the suction manifold. The valve removal tool is inserted into the valve seat collar to slightly screw member  50  into the valve inlet bore. At this point locking elements  74  may be removed from groove  40  and are withdrawn. Valve assembly  51  can now be entirely removed by screwing valve seat collar  50  out of bore  33 . A new or refurbished valve assembly can now be installed as described above. 
         [0022]    A second embodiment of the invention is illustrated in  FIG. 7  wherein like components have the same reference member as the embodiment illustrated in  FIGS. 3-6 . Fluid end  31  includes inlet bore  95  having a recessed groove  40 . Valve seat collar  51  in this embodiment includes a first portion  69 , a second portion  90 , and a third portion  107 . A valve member  85  has a lower portion  87  which cooperates with a frusto-conical valve seat surface  103  on an interior surface of valve seat collar  51 . 
         [0023]    A spring guide and support member  92  is threaded at  140  into upper portion  107  of the valve seat collar  51 . A spring  93  is supported between spring, guide  88  and a shoulder  84  provided on the valve element  85  as shown in  FIG. 7 . 
         [0024]    Valve seat collar  51  is externally threaded at  111  and cooperates with internal threads  94  provided in bore  95 . An O-ring  122  is captured within a groove  123  in inlet bore  95  and abuts against a beveled end portion  141  of valve seat collar  51 . 
         [0025]    To position the valve assembly within intake bore  95 , spring guide and support member  92  is threaded into valve seat collar  51 . Spring  93 , valve member  85 , and valve seat collar  51  are then placed within the bore and valve seat collar  51  is threaded into the bore  95  to a position where portion  90  clears groove  40 . These elements may be formed as a single cartridge unit that is preassembled. Next locking elements  74  are positioned within the groove  40  as shown in  FIG. 7  to further support the valve assembly within the bore. After the locking elements are placed within groove  40 , the flow diverter and locking ring retainer  80  is positioned within bore  95  such that annular ridge  82  of the retainer is located between locking segments  74  and lower portion  69  of the valve seat collar. Valve seat collar Si is backed out of the bore  33  to seat against the locking elements  74 . This arrangement prevents the locking segments from moving out of groove  40 . Retainer  80  is held in position by a suction manifold plate  101  that is bolted or otherwise secured to fluid end  31 . Removal can be accomplished simply by reversing the installation process beginning by removing the suction plate, retainer  80  and locking segments  74 . The remaining valve assembly may they be removed as a unit out of inlet bore  95 . 
         [0026]    Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.