Abstract:
A tool for inserting a plump plunger through a packing in a fluid end of a plunger pump enables easy and rapid insertion of the plunger through the packing without damaging the packing or the pump plunger.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This is the first application filed for the present invention.  
         MICROFICHE APPENDIX  
         [0002]    Not applicable.  
         TECHNICAL FIELD  
         [0003]    The invention relates to pump maintenance and, in particular, to a tool for inserting a pump plunger through an aperture in a packing in a plunger pump.  
         BACKGROUND OF THE INVENTION  
         [0004]    Plunger pumps are used for pumping oil or other fluids, including slurries. Plunger pumps operate by rapidly reciprocating one or more plunger(s) in a pump chamber. As the plunger(s) reciprocates, check valves on opposite sides of the pump chamber co-operate to draw the fluid from a source. The pump plunger(s) is surrounded by a packing that provides a fluid seal at a top of the pump chamber. It is necessary from time to time to change the packing that provides the seal around the plunger(s). For example, the packing in heavily-used industrial pumps has to be changed at least once every two or three months. When the packing in a plunger pump is changed, the plunger is released from a drive mechanism and removed from the pump in a manner that is well known in the art. The old packing is removed, new packing is installed and the plunger is inserted through the new packing. Since the fit between the packing and the plunger must be fluid tight, inserting a plunger through new packing can be difficult, especially if the plunger is not perfectly aligned with an aperture in a center of the packing for receiving the plunger. Consequently, plunger installation is generally easier if two people cooperate to do the job. One person holds the plunger in alignment while the other person drives the plunger through the new packing using a hammer, or the like. Some plunger pumps have two to five plungers, so changing the packing is a time-consuming task. Furthermore, if the plunger is not well aligned with the aperture in the packing, insertion of the plunger can damage the packing and shorten its service life.  
           [0005]    There is therefore a need for a tool that simplifies and facilitates the procedure for installation of a plunger in a plunger pump.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a tool for inserting a pump plunger through an aperture in a packing in a fluid end of a plunger pump. The tool comprises a plunger guide attachable to the plunger pump, the plunger guide having an engagement end, an axial bore for centering the pump plunger with respect to the aperture and guiding the pump plunger as it is inserted, the engagement end having at least two connectors for removable attachment of a load plate; and, a threaded rod for engaging a threaded bore in the load plate, wherein rotation of the rod in a first direction when the load plate is attached to the connectors applies a drive force to an end of the pump plunger to insert the pump plunger through the aperture.  
           [0007]    In accordance with a further aspect of the invention, the plunger guide includes an external thread for connecting the plunger guide to a plunger installation port in the plunger pump.  
           [0008]    The threaded rod has a first end that contacts a top end of the plunger and a second end for transmitting a force to rotate the threaded rod.  
           [0009]    In accordance with one embodiment of the invention, the load plate includes slots that receive the connectors to removably connect the load plate to the plunger guide. The connector has a first end connected to the plunger guide and a second, L-shaped end that engages the slots of the load plate.  
           [0010]    In accordance with another embodiment of the invention, the load plate includes bores that receive the connectors to removably connect the load plate to the plunger guide. The connector may be a bolt or a T-bar that passes through the bores in the load plate and is connected to a plunger guide. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:  
         [0012]    [0012]FIG. 1 is a schematic diagram of a fluid end of a plunger pump, with an attached tool in accordance with the invention for inserting a plunger through a packing in the plunger pump;  
         [0013]    [0013]FIG. 2 is a schematic diagram illustrating a side elevational view of the plunger guide of the tool shown in FIG. 1;  
         [0014]    [0014]FIG. 3 is a schematic diagram illustrating a top plan view of the plunger guide shown in FIG. 2;  
         [0015]    [0015]FIG. 4 is a top plan view of a load plate shown in FIG. 1, the load plate including slots for receiving connectors associated with the plunger guide;  
         [0016]    [0016]FIG. 5 is a top plan view of another embodiment of the load plate, which includes bores for receiving connectors that are connected to the plunger guide;  
         [0017]    [0017]FIG. 6 is a top plan view of yet another embodiment of the load plate, which includes a bore in one end and a slot in the other end for receiving connectors that are connected to the plunger guide; and  
         [0018]    [0018]FIG. 7 is a side elevational view of two different connectors for retaining the load plate shown in FIG. 5.  
         [0019]    It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    [0020]FIG. 1 is a schematic diagram of a fluid end  8  of a plunger pump with a tool  10  tool in accordance with the invention. The tool  10  is used to insert a pump plunger  12  through an aperture  14  in a packing  16  in the fluid end of the plunger pump  8 . The tool  10  includes a plunger guide  18 , connectors  20 , a load plate  22 , and a plunger insertion screw  24 .  
         [0021]    The operation of the tool  10  to insert the pump plunger  12  through the packing  16  is simple and easily and rapidly accomplished by one person. The plunger guide  18  is threaded into a plunger installation port  26  in the fluid end  8  of the plunger pump. The pump plunger  12  is inserted into an axial bore  28  in the plunger guide  18  until a driven end of the pump plunger  12  contacts the packing  16 . The axial bore  28  has a diameter that is only slightly larger than a diameter of the pump plunger  12 , so that the pump plunger is centered over the aperture  14  in the packing  16  and guided into the aperture  14  as it is inserted through the packing  16 . The load plate  22  is connected to the plunger guide  18  by the connectors  20 . Bottom ends of the connectors  20  threadedly engage threaded bores in the plunger guide  18  and the upper ends are connected to the load plate  22 . When torque is applied to the plunger insertion screw  24 , which is threaded through a threaded bore  25 , plunger insertion screw  24  causes a drive force to be applied to the pump end of the pump plunger  12 . When a torque of sufficient magnitude and duration is applied to plunger insertion screw  24 , the pump plunger  12  is inserted through the aperture  14  in the packing  16 . Since the pump plunger  12  is accurately aligned with the aperture  14  in the packing  16 , the pump plunger is easily inserted without damaging the packing  16 .  
         [0022]    [0022]FIG. 2 is a side view of the plunger guide  18  which includes a threaded top end  32  that is screwed into the pump plunger installation port  26  (FIG. 1), and a bottom end  34  that extends the axial bore  28  to ensure that the pump plunger  12  is accurately guided as it is inserted through the packing  16 .  
         [0023]    [0023]FIG. 3 is a top plan view of the plunger guide  18 , which includes the axial  28  for guiding the pump plunger  12  and two threaded bore  36  for receiving the connectors  20 .  
         [0024]    [0024]FIG. 4 is a top plan view of one embodiment of the load plate  22  shown in FIG. 1. In this embodiment, the load plate  22  includes slots  38  in opposite side edges. The slots  38  receive top ends of the connectors  20  shown in FIG. 1. The top ends  37  of the connectors  20  are L-shaped. The shape of the slots is designed to receive the L-shaped ends  37  of the connectors to removably attach the load plate  22  to the plunger guide  18 .  
         [0025]    Another embodiment of the load plate  22  is shown in FIG. 5. The load plate  22   b  is attached to the plunger guide using bolts  40  or the like. The bolts are inserted through bores  46  in the load plate  22   b  and screwed into the threaded bores  36  (FIG. 3) in the top end of the plunger guide  18 . The L-shaped connectors  20  shown in FIG. 1 can also be used with the load plate  22   b.    
         [0026]    [0026]FIG. 6 is a top plan view of yet another embodiment of the load plate  22  shown in FIG. 1. The load plate  22   c  shown in FIG. 6 includes a bore  46  in one end, and a slot  38  in the opposite end. The bore  46  receives, for example, an L-shaped connector  20  (FIG. 1) or a bolt  40  (FIG. 5). The slot  38  receives, for example, the L-shaped connector  20 . The load plate  22   c  permits a pump plunger  12  (FIG. 1) to be inserted into the axial bore  28  of the plunger guide  18  without removing the load plate  22   c . To accomplish this, the load plate  22   c  is rotated about the connector inserted through the bore  46  to expose to axial bore  28  in the plunger guide  18 , as will be understood by those skilled in the art. After a pump plunger  12  is inserted, the load plate is rotated back so that the other connector engages the slot  38 , and the pump plunger  12  is inserted through the aperture  14  in the packing  16 , as described above. This embodiment of the load plate  22   c  permits the tool  10  to remain in an assembled condition at all times, so that parts are less likely to be disassociated and lost.  
         [0027]    [0027]FIG. 7 illustrates an alternate embodiment of the plunger insertion screw  24 . A threaded screw  42 , adapted to threadedly engage the bore  25  of the load plate  22 , includes a handle  44  received in a radial bore through the threaded screw  42 . The handle  44  provides leverage to permit the threaded screw  42  to be turned to insert the pump plunger  12  through the aperture  14 .  
         [0028]    The tool in accordance with the invention greatly facilitates the insertion of pump plungers through new packings in plunger pumps. The job is easily performed by a single person in a very short period of time. Since the pump plunger is accurately aligned with the aperture in the packing, regardless of an orientation of the pump, the pump plunger is consistently inserted without damage to the packing. Furthermore, since the pump plunger is only subjected to a constant axial force, it is never damaged as can happen if it is driven through the packing using a hammer and punch.  
         [0029]    The embodiments of the invention described above are intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.