Patent Publication Number: US-2016245280-A1

Title: Device interlocking with a compartment

Description:
RELATED APPLICATION DATA 
     This application claims priority to U.S. Provisional Application No. 62/118,366 filed Feb. 19, 2015, the contents of which are fully incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention concerns a device adapted for interlocking engagement with a compartment in a fluid end housing of a pump and an anti-rotation cap. 
     High pressure reciprocating pumps, such as the pump described in US publication 2014/0086774 have fluid ends. The fluid ends have a housing. The housing has a discharge bore, a suction bore, a further bore, and a cross bore intersection. The further bore is associated with a pumping member such as a piston or plunger. The further bore shown in US publication 2014/0086774 is associated with a plunger. The discharge bore, the suction bore, and the further bore each open into the cross-bore intersection. A suction valve assembly is in the suction bore and a discharge valve assembly is in the discharge bore. In a well-known manner, during the upstroke of the pumping member, fluid is taken into the housing over the suction valve and into the suction bore and cross-bore intersection. During the pumping member&#39;s downs stroke, the fluid taken in is discharged through the discharge bore and over the discharge valve assembly and out the fluid end housing. 
     The fluid end housing also has a valve access bore or conduit. The valve access conduit/bore allows for the removal and installation of the discharge and suction valve assemblies from the housing. During operation, the valve access conduit is sealed off with a valve cover. The cover is held in place by a retainer. The retainer is threadably engaged to the housing. 
     SUMMARY 
     A portion of a housing delimits a compartment. The compartment has a plurality of projection compartments with void spaces and a plurality of lock compartments with void spaces. The lock compartment void spaces and projection compartment void spaces are arranged in a circumferential direction in an alternating pattern with one another. Preferably every lock compartment is between, in the circumferential direction, a pair of projection compartments and every projection compartment is between, in the circumferential direction, a pair of lock compartments. Preferably the projection compartment between the pair of lock compartments is the only projection compartment in a space delimited in the circumferential direction by the pair of lock compartments, and the lock compartment between the pair of projection compartments is the only lock compartment in a space between the pair of projection compartments. 
     A device has a plurality of projections which extend radially outward relative to a central device axis. The device is selectively moveable while in the compartment from an unlocked orientation to a locked orientation and vice versa by relative rotational movement of less than 480 degrees. In the unlocked orientation each projection is in a different one of the projection compartments. In the locked orientation, each retainer projection is in a different one of the lock compartments. In the locked orientation the compartment and device are interlocked. 
     Each projection of the device has a surface axially spaced, in a first direction along the central device axis, from a second end of the device. The surface is inclined and helical. The incline, going in a second circumferential direction (counterclockwise) around the device central axis, extends away from the second end of the device in the first axial direction along the device central axis. The incline is helical. The helical form of the incline has a pitch. Each projection also has a surface which is oppositely facing from said inclined surface. In one embodiment of the device the inclined surface is inclined relative to the oppositely facing surface. In one embodiment the projection increases in thickness along the helical incline. 
     In one construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore, a first opening at a first end of the interior bore, and a shoulder that divides the interior bore into a plunger bore and an outer bore. A plurality of overhangs is formed as part of the housing and extends into the outer bore, a plunger is positioned within the space and is operable to reciprocate along an axis within the plunger bore, and a valve cover is coupled to the housing and positioned to engage the shoulder to close the first opening. A valve cover retainer is positioned within the outer bore and includes a plurality of projections arranged to selectively engage the plurality of overhangs to sandwich the valve cover retainer between the valve cover and the housing to lock the valve cover into engagement with the shoulder. 
     In another construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore and a shoulder that divides the interior bore into a plunger bore and an outer bore, a plunger positioned within the plunger bore and operable to reciprocate along an axis within the plunger bore, and a plurality of overhangs formed as part of the housing and extending into the outer bore, the plurality of overhangs and the shoulder cooperating to define a plurality of projection compartments therebetween. A valve cover is coupled to the housing and is positioned to engage the shoulder and a valve cover retainer is positioned within the outer bore. The valve cover retainer includes a plurality of projections selectively disposed within the plurality of compartments to lock the valve cover into engagement with the shoulder. 
     In still another construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore and a shoulder that divides the interior bore into a plunger bore and an outer bore, a plunger positioned within the plunger bore and operable to reciprocate along an axis within the plunger bore, and a plurality of overhangs formed as part of the housing. The plurality of overhangs extend into the outer bore and are spaced apart from one another to define a plurality of void spaces with each void space being between each adjacent two of the plurality of overhangs. The plurality of overhangs and the shoulder cooperate to define a plurality of projection compartments therebetween. A valve cover is coupled to the housing and positioned to engage the shoulder. A valve cover retainer includes a plurality of projections aligned with the plurality of void spaces such that the valve cover retainer is movable axially along the axis to an installed unlocked position within the outer bore, and wherein the valve cover is rotatable about the axis from the installed unlocked position to an installed locked positon within the outer bore, wherein in the installed locked position the plurality of projections are disposed within the plurality of compartments to lock the valve cover into engagement with the shoulder. A cap includes a plurality of interference projections selectively positioned within the plurality of voids to inhibit rotation of the valve cover retainer from the installed locked position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of a representational device in a representational fluid end housing exemplifying features of the present invention; the features of the housing such as the plunger bore, discharge bore, suction bore and cross bore intersection are omitted for simplicity; the device is in the unlocked position; 
         FIG. 2 a    is a sectional view of the portion of the fluid end housing shown in  FIG. 1  taken along view line  2 - 2  of  FIG. 1  wherein the device is not sectioned but a representational cover in the housing is sectioned; 
         FIG. 2 b    is a sectional view of the portion of the fluid end housing shown in  FIG. 1  taken along view line  2 - 2  of  FIG. 1  wherein the device is not sectioned but a representational cover in the housing is sectioned, and the cover is configured to seat on a portion of the housing and is seated on a portion of the housing making the cover in  FIGS. 2 a  and 2 b    different from each other; 
         FIG. 3  is the top view of the device in the portion of the fluid end housing shown in  FIG. 1 ; the device is in the locked position; 
         FIG. 4 a    is a sectional view of the fluid end housing shown in  FIG. 3  taken along view line  4 - 4  of  FIG. 3  wherein the device is not sectioned but the cover in the housing portion is sectioned; 
         FIG. 4 b    is the sectional view of the fluid end housing shown in  FIG. 3  taken along view line  4 - 4  of  FIG. 3  wherein the device is not sectioned but a valve cover in the housing portion is sectioned, and the cover is the same as the cover in  FIG. 2 b    accept the cover is seated on a portion of the housing making the cover in  FIGS. 4 a  and 4 b    different from each other; 
         FIG. 5 a    is the sectional view of the fluid end housing shown in  FIG. 1 , exclusive of the device; 
         FIG. 5 b    is an isometric view of the section shown in  FIG. 5   a;    
         FIG. 6  is a representational close up of the sectional view shown in  FIG. 5 a      
         FIG. 7 a    is a side view of the device shown in  FIG. 1 ; 
         FIG. 7 b    is a top view of the device shown in  FIG. 7   a;    
         FIG. 7 c    is a bottom view of the device shown in  FIG. 7   a;    
         FIG. 7 d    is an isometric top view of the device shown in  FIG. 7   a;    
         FIG. 8  is a top isometric view of the representational device and fluid end housing shown in  FIG. 1  and further including a representational interference exploded therefrom; 
         FIG. 9 a    is a top and side isometric view of the interference shown in  FIG. 8 ; 
         FIG. 9 b    is a bottom view of the interference shown in  FIG. 9   a;    
         FIG. 10  is a sectional view of a representational fluid end housing having a suction bore, discharge bore, further bore and valve access bore useable in connection with the retainer and valve cover of  FIG. 2 ; it is exclusive of the details of the compartment shown in the above figures; 
         FIG. 11  is a sectional view and partially exploded view of a representational device, valve assembly, and fluid end housing. 
         FIG. 12  is a sectional view of a representational stuffing box exploded from a sectional view of a representational fluid end housing; 
     
    
    
     DETAILED DESCRIPTION 
     While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, and is not intended to limit the invention to the specific embodiment illustrated. 
       FIGS. 1-6  show a device  20  having second portion  65  which is a coupling portion. The coupling portion comprises projections  28 . Although the device is described herein with reference to a variety of retainers, a stuffing box, a discharge pipe and suction pipe, the term device as used herein is any device having a portion disposable in a compartment wherein the disposable portion comprises a coupling portion. The device could simply be a coupling comprising structure embodying the inventive features of projections  28 . The device  20  shown in  FIGS. 1-8  is a retainer and more particularly a valve cover retainer. The device  20  is disposed in a complimentary compartment  32  and the device is rotated from an unlocked to a locked position and vice versa. 
     In connection with the device  20  and compartment  32 ,  FIGS. 1-6  also show a cover  22  and a housing  25  which form part of the fluid end assembly  24  of a positive displacement reciprocating pump. The housing  25  can be called a portion of a fluid end housing. The housing portion  25  can alternatively be called a housing  25  which is a generic housing to illustrate the features of the invention. The housing  25  shown in some of the figures omits some features of the housing such as the plunger bore, discharge bore, suction bore and cross bore intersection are omitted for simplicity. The device  20  comprises a shape which forms a generally equilateral triangle with junctions  28   a.  The junctions are rounded and elongated in the circumferential  1  direction around central retainer axis  38 . The shape in the radial direction has a generally equilateral triangular perimeter with rounded junctions. If the perimeter sides, exclusive of the rounded junctions, were continued until they intersect, the perimeter would form an equilateral triangle. The generally triangular shape of the device comprises three projections  28  which extend radially outward relative to and from a radially inward portion  36  of the device. The radial inward portion is a central body. Each projection  28  ends at a rounded junction  28   a.  The rounded junctions are at an apex of each projection. 
     The device  20  is disposed in compartment  32  of the housing  25 . The compartment  32  can be a device compartment and more particularly a retainer compartment. Although the compartment is described herein with reference to a variety of compartment types, it could be any compartment. The compartment  32 , described herein, because it includes projection compartments  32   b  and lock compartments  32   d,  is an inclusive compartment. 
     The compartment  32  comprises a receiver  32   a  which itself comprises a plurality of projection compartments  32   b.  The compartment  32  comprises a lock  32   c  which itself comprises a plurality of lock compartments  32   d.  In an unlocked orientation, see  FIGS. 1 and 2 , each of the projections  28  are in a different one of the projection compartments  32   b.  In the locked orientation, see  FIGS. 3 and 4 , each projection  28  is in one of the lock compartments  32   d.  The device  20  is selectively moveable from the unlocked orientation to the locked orientation and vice versa. The change in orientation from the unlocked to the locked orientation and vice versa is achieved by relative circumferential movement, rotational relative movement, between the device  20  and the compartment  32  and/or projections compartments  32   b  and/or lock compartments  32   d  in a range of between only 10 and 270 degrees and preferably 60 degrees. In any event the rotation is less than 480 degrees. To provide the rotational relative movement from the unlocked to the locked orientation, the device  20  is first rotated by hand and then further rotated with a tool. To further secure the device in the locked orientation a removable interference  34  is used. The device  20 , compartment  32 , and interference  34  have constructions which allow for easy installation of the device  20  to the fluid end housing  25  and removal of the device  20  from the fluid end housing  25 . 
     Now in more detail, the device  20  can comprise three sides  20   a.  Each side  20   a  converges towards at least two other sides  20   a.  A perpendicular bisector of each side  20   a  intersects with a junction  28   a  joining the other two sides  20   a.  Accordingly each side  20   a  has a midpoint. A straight line can be drawn at a right angle to any side  20   a  from the midpoint of the side to which the right angle is drawn and the line will intersect the junction  28   a  joining of the two other sides  20   a.    
     The device has a radial outward portion, second portion  65 . The radially outward portion of the device, the second portion  65 , extends away from and outward of the radially inward portion  36  of the device, the device first portion  36 . The inward first portion  36  at its second end  36   b  can have a circular perimeter within the triangular perimeter and tangent to each of the three sides forming the triangular perimeter. Inward portion  36  at a first end  36   a  has a circular perimeter. The radially outward portion, second portion  65 , comprises a plurality of sections or portions. Each of the sections or portions, relative to the first portion  36 , is a projection which extends radially outward relative to said first portion  36  and the central device axis  38 . The device projections  28  extend in the radial direction at the second end  36   b  of the first portion  36  away from the perimeter at the second end. The projections  28  also extend radially away from a perimeter of an intermediate portion  36   c  of the first portion  36 . The intermediate portion is between the first  36   a  and second  36   b  ends. The projections  28  comprise a plurality of adjacent pairs of projections arranged around central axis  38  of the retainer. 
     As shown in  FIGS. 1-4 , the device  20  is disposed in a void space  33  delimited by the housing  25 . The void space is open to a bore  40  which can also be called a conduit  40  and is separated from that bore by a shoulder  41 . The conduit/ bore is a valve access bore. The compartment  32  comprises the void space  33 . The compartment  32  also comprises surfaces delimiting the void space  33 . The void space  33  can also be considered part of the bore  40 . The compartment void space  33  opens through an external surface  42  of said housing  25 . The surface is recessed. The compartment  32  is joined to, integral with and part of the housing  25 . The compartment  32  comprises the receiver  32   a  and the lock  32   c.  The receiver and lock are each joined to, integral with, and part of the housing. They are joined to and integral with each other. The lock  32   c  can be called a coupler. 
     As noted, the receiver  32   a  comprises the plurality of projection compartments  32   b . Each projection compartment  32   b  comprises a void space  32   b ′. The projection compartment void spaces  32   b ′ form part of the compartment  32  void space  33 . Each projection compartment comprises surfaces  58   a,    70   a,  and  76  which delimit the compartment&#39;s void space. 
     Also as noted the lock  32   c  comprises the plurality of lock compartments  32   d.  Each lock compartment  32   d  comprises a void space  32   d ′. Each lock compartment void space  32   d ′ forms part of the compartment void space  33 . Each lock compartment comprises surfaces  58   b ,  70   b,    78  delimiting the compartment&#39;s void space  32   d ′. There is a plurality of adjacent pairs of lock compartments  32   d  around axis  52 . There is a plurality of adjacent pairs of projection compartments  32   b  around axis  52 . A different lock compartment  32   d  and its void space  32   d ′ is between, in the circumferential direction, each pair of adjacent projection compartments  32   b  and their void space  32   b ′ and a different projection compartment  32   b  and its void space is between, in the circumferential direction, each pair of adjacent lock compartments  32   d  and their void space. Each projection compartment void space  32   b ′ between an adjacent pair of lock compartment  32   d  void spaces  32   d ′ is open to at least one of the lock compartment void spaces  32   d ′ of the adjacent pair. The at least one lock compartment void space  32   d ′ is on the side of the projection compartment void space  32   b ′ in the first circumferential or angular direction  50 . The first circumferential direction is clockwise In the present example each of the pair of adjacent lock compartment void spaces  32   d ′ are open to the projection compartment void space  32   b ′ between the adjacent pair. The lock compartments  32   d  and their void spaces  32   d ′and the projection compartments  32   b  and their void spaces  32   b ′ are in an alternating pattern, in the circumferential direction, around central axis  52  of retainer compartment  32 . 
     In  FIGS. 1 and 2  the device  20  is in the unlocked orientation. In  FIGS. 3 and 4  the device  20  is in a locked orientation. In the unlocked orientation the device  20  is in the receiver  32   a.  Each projection  28  is in a different one of the projection compartments  32   b  and its void space  32   b ′. The device first portion  36  is in a portion  39  of the compartment  32  radially inward of the projection compartments  32   b  and their void spaces  32   b ′. The first portion  36  is over and overlaps the cover  22  which in  FIGS. 1-5  is a valve cover. In the unlocked orientation, the device  20  and its projections  28  are completely removable from the compartment  32 . They are removable along a first direction  46  away from and out the compartment  32 , the projection compartments  32   b,  and the radially inward portion  39  of the compartment  32  without rotation of the device  20  relative to the housing  25  or lock  32   c  or lock compartments  32   d.  The first direction  46  is a direction along axis  38 . In the unlocked orientation the device  20  is moveable in the first circumferential direction  50  around axis  38  and  52 . It is rotatable around axis  38  and  52  in the first circumferential direction  50 . 
     In the locked orientation, the device  20  is in the lock  32   c.  Each projection  28  is in one of the lock compartments  32   d  and its void space  32   d ′ and in a different one of the lock compartments  32   d  and its void space  32   d ′. Each projection  28  is between surfaces  58   b,  and  78  that delimit the lock compartment void space. The first portion  36  of the device  20  is in the radial inward portion  39  of the compartment  32  when the device  20  is in the locked orientation. The first portion  36  is not in any lock compartment  32   d  when the device  20  is in the locked orientation. In the locked orientation, the device  20  is restrained and prevented from being removed from the compartment  32  and lock compartments  32   d  in the first direction  46 . The restraint occurs until the device  20  is oriented into the unlocked orientation. In the locked orientation the retainer is moveable in a second circumferential direction  54  around axis  38  and  52 . It is rotatable around the axes in the second circumferential direction  54 . 
     The lock  32   c  restrains the device  20  from moving in the first axial direction  46 . In the locked orientation the device  20  is engaged with the cover  22  such that the cover  22  is prevented from falling out of the conduit  40 . The device  20  keeps the cover  22  in sealing engagement with the portion of the housing  25  forming the conduit  40  so as to close and seal off a portion of the conduit  40  from the external environment. The portion sealed off is between the cover  22  and a cross bore intersection  48  in the fluid end housing  25 . 
     The device  20  is placed in an unlocked orientation by aligning the device  20  and then disposing the device in the receiver  32   a.  The device  20  is aligned by orienting the projections  28  of the device over and to overlap the projection compartments  38   b  and their void spaces. The device  20  is then moved in a second direction  56  towards a seat  58   a  of the compartment  32 . The second direction  56  is along central axis  52 . The second direction is opposite the first direction  46 . The phrase a direction along an axis or axial direction or axially as used herein is broad enough to include a direction having a vector in the axis&#39; direction. The phrase a direction along a radius or radial direction or radially is broad enough to include a direction having a vector in the radius&#39; direction. The device  20  is moved in the second direction  56  until the movement is prohibited. The movement can be prohibited by seat  58   a  of the retainer compartment  32  which delimits the retainer compartment void space  33  and projection compartment void space  32   b ′ in the second axial direction  56 . Alternatively the movement can be prohibited by a member seated on seat  58   a  such as cover  22 . The device, to be oriented to the locked orientation from the unlocked orientation is moved around its axis  38  or axis  52  in the first circumferential direction  50 , rotated, until the rotation is restrained and prevented. When the circumferential movement is completely restrained, it is in the locked position. To provide the rotational movement from the unlocked to the locked orientation, the device  20  is first rotated by hand and then further rotated with a tool. To go from the unlocked to the locked orientation requires rotation and circumferential movement of the device  20  around the axes  38  and  52  in a range which can be between 10 and 270 degrees in the first circumferential direction  50 . In the present example it is rotated 60 degrees. In any event the rotation should be less than 480 degrees. 
     From the locked orientation, the device is easily orientated back to the unlocked orientation by moving the device in the circumferential direction around its axis in the second circumferential direction  54 , rotating the device, until the projections  28  are aligned with the projection compartments  32   b.  They are aligned when the projections  28  are free of the retainer lock compartments  32   b.  The projections are free when removable from the projection compartment void spaces  32   b ′ in the first axial direction  46  without further rotation of the device  20 . To place the device in the unlocked orientation from the locked orientation the device is rotated, circumferentially moved around the axes  38  or  52 . The rotation can be in a range of between 10 and 270 degrees in the second circumferential direction  54  achieve the alignment and place the device  20  in the unlocked position from the locked position. In the present example it is rotated 60 degrees. In any event it should be rotated less than 480 degrees. To provide the rotational movement from the locked to the unlocked orientation, the device  20  is first rotated with a tool. 
     The facilitate rotation of the device between the locked and unlocked orientation, the device has a coupling  100  The coupling  100  shown is a recess opening through the device first end  20   b  and first portion first end  36   a  . A sidewall delimiting the recess in the radial direction comprises a plurality of flat surfaces around retainer axis  38  in a hex pattern. Other coupling structures such as a hex bolt protrusion, spline, a series of holes, or anything that allows a fastener to be torqued can be used. 
     To further secure the retainer in the locked orientation the removable interference  34  is used. The interference  34  fits between adjacent pairs of junctions  28   a.  A different interference projection  34   a  of the interference  34  fits between each adjacent pair of junctions  28   a.  Rotation of the interference  34  with the device  20  is prevented by a stop  60 . The stop  60  comprises portions of the structure delimiting the housing  25  and compartment&#39;s void space  33 . 
     Now referring to the device  20  in more detail, first end  36   a  of the first portion  36  is at a first end  20   b  and top of the device  20  and the second end  36   b  of the first portion  36  is at a second end  20   c  and bottom of the device  20 . The second portion  65  of the device which comprises projections  28  has a first end  65   a  and a second end  65   b.  The second portion  65  has a height measured in the axial direction from its first end  65   a  to its second end  65   b  which is less than the height of the device measured in the axial direction from the first end  20   b  of the device to the second end  20   c  of the device. The axial height of the second portion  65  is also less than the axial height of the first portion  36  wherein the first portion is measured from the first end  36   a  of the first portion to second end  36   b  of the first portion. The height of the second portion  65  in the axial direction is the height of the projections  28  in the axial direction. Surfaces  28   b  of the radially outward projections  28  of the second portion  65  are axially spaced from the device second end  20   c  and first end  20   b.  At least a portion of each surface  28   b  is at the first end  65   a  of the second portion. 
     The first portion  36  comprises a raised portion  36   d.  It is raised in the axial direction relative to surfaces  28   b.  The raised portion  36   d  includes a plurality of curved sections  67  and a plurality of flat  68  sections all around axis  38 . The curved sections  67  form a plurality of adjacent pairs of curved sections and the flat sections  68  form a plurality of pairs of flat sections. Each flat section  68  is between, in the circumferential direction, a pair of adjacent curved sections  67  and each curved section  67  is between, in the circumferential direction, a pair of adjacent flat  68  sections. The curved sections  67  and flat sections  68  are around axis  38  in an alternating pattern. The curved  67  and flat  68  sections are part of a continuous sidewall of the raised portion. The raised portion  36   d  has a circumferential and circular rim proximate the retainer first end  20   b  and first portion first end  36   a.  The flat sections  68  are equally spaced along the outer circumferential rim of the raised portion so that their center will align with the midpoint of sides  20   a  in the upward direction. Each of the flat sections  68  of the raised portion  36   d  are at a respective different side  20   a  and seamless with its respective side  20   a.  The flat sections  68  are placed to aid installation of interference  34 . 
     The surfaces  28   b  of the projections  28  are external surfaces. Each of the surfaces  28   b  has at least a portion that is inclined and helical. The helical incline, going in the second circumferential direction  54 , extends up in the direction away from the device second end  20   c  towards the device first end  20   c  in the first axial direction  46 . Accordingly each projection has a helically inclined portion as just described. The pitch of the helical form is . 269  inches. The pitch is the increase in height in the first direction  46  if the helical form was carried for  360  degrees around the device axis in the second circumferential direction. The angle of incline extending up in the first axial direction, as measured along a radius of the projection, which corresponds to the pitch, is from 0.6 to 0.8 degrees. The angle is generally greatest at the base and smallest at the apex of the projection. The incline is measured relative to a plane normal to the device central axis. It is believed the minimum pitch could be 0.003 inches with the average helical angle of incline ranging from 0.007 degrees to 5 degrees depending on the radius of the device. The incline is relative to a surface of the projection at the projections second end  65   b.  The surface is opposite the inclined surface  28   b.  The projection along the incline increases in thickness in the second circumferential direction and along the axis of the retainer in the first direction. Each projection  28  also has a beveled leading edge which facilitates easy rotation by the user when they install the valve retainer into the housing. 
     In more detail, each projection compartment  32   b  and lock compartment  32   d  comprises a respective sidewall  70   a    70   b.  The projection compartment sidewalls  70   a  and lock compartment sidewalls  70   b  are curved around axis  52 . Each sidewall  70   a  delimits a respective different void space  32   b ′ of each projection compartment in the radial direction. Each sidewall  70   b  delimits a respective different void space  32   d ′ of each lock compartment in the radial direction. Each sidewall  70   a,    70   b  is part of a continuous, circumferential seamless sidewall. 
     Each lock compartment comprises a structure  74  which projects radially inward relative to its respective compartment sidewall  70   b.  The structures  74  are overhangs. There is a plurality of adjacent pairs of overhangs  74 . Each overhang  74  has an inclined and helical portion  78 . The helically inclined portion  78  comprises a seat facing surface. The helical portion  78  has an incline, going in the second circumferential direction, extending upwards in the first axial direction  46  away from a seat  58   b  and towards the void space opening through the housing surface  42 . The incline is helical. The helical incline is best seen in  FIG. 6 . The pitch of the helical form of the incline is 0.269 inches. The pitch is the increase in height in the first direction  46  if the helical form was carried for 360 degrees around the retainer compartment axis in the second circumferential direction. The angle of incline extending up in the first axial direction, as measured along a radius of the overhang, which corresponds to the pitch, is from 0.6 to 0.8 degrees. The angle is generally greatest at the base and smallest at the apex of the overhang  74 . The incline is measured relative to a plane normal to the retainer compartment central axis. The incline is measured relative to a plane normal to the retainer compartment central axis. It is believed the minimum pitch could be 0.003 inches with the average angle of incline ranging from 0.007 degrees to 5 degrees depending on the radius of the device. The incline is relative to a surface of the overhang opposite the inclined surface  78 . The overhang along the inclined portion increases in thickness in the second circumferential direction and along the axis of the compartment in the first direction. The helical portion  78  of an overhang  74  and helical portion  28   b  of the projection creates a downward force on the projections of the device when the device is rotated from the unlocked to the locked position. The downward force helps hold the device  20  in place and puts it in engagement with the cover  22 . 
     Each projection compartment  32   b  comprises a circumferentially delimiting side surface from each of a pair of adjacent overhangs  74 . Each circumferentially delimiting side surface of its respective projection compartment  32   b,  delimits the void space of that projection in the circumferential direction. Each projection compartment comprises an axially elongated sidewall  76  which delimits each compartment&#39;s void space in the radial direction. Each axially elongated sidewall  76  projects in the axial direction away from its compartment&#39;s sidewall  70   a  and towards the housing surface  42  through which the retainer compartment void space  33  opens. The elongated sidewalls  76  are about the same radial distance from axis  52  as are sidewalls  70   a.  Thus each projection compartment sidewall  70   a  and elongated sidewall  76  forms a single sidewall which is seamless. There is a plurality of adjacent pairs of elongated sidewalls  76 . Each elongated sidewall  76  is between, in the circumferential direction, a pair of adjacent overhangs  74 . Each overhang  74  is between, in the circumferential direction, a pair of adjacent elongated sidewalls  76 . The sidewalls  76  and overhangs  74  are arranged in alternating pattern around axis  52 . 
     Each projection compartment  32   b  includes a seat  58   a  and each lock compartment  32   d  also includes a seat  58   b.  Each seat  58   a,    58   b  extends away from its respective compartment&#39;s sidewall in the radial direction. Each projection compartment seat  58   a  delimits the projection compartment void space  32   b ′ in the axial direction. Each lock compartment seat  58   b  is axially spaced from its overhang  74  and delimits the compartment&#39;s void space  32   d ′ in the axial direction. Each seat  58   a,    58   b  of its respective compartment can support a cover as shown in  FIGS. 2 b , 4 b   ,  11  or supports a projection as shown in  FIGS. 2 a  and 4 a    or support the first inward portion  36  as shown in  FIG. 12 . The seats  58   a,    58   b  form a continuous and seamless seat. The cover  22  can be oriented in the conduit  40  such that its upper surface is aligned with the seat  58   a,    58   b  of each compartment. The cover  22  could be constructed to have an engaging surface facing the seat  58   a,    58   b  and engaged with the seats  58   a,    58   b.  See  FIGS. 2 b  and 4 b   . The cover upper surface would be above and overlap the seat  58   a,    58   b.  The second end  20   c  of the device is in engagement with the valve cover upper surface when the device  20  is in the locked or locked orientation. 
     The retainer compartment  32  comprises the continuous side wall  70   a,    70   b,  continuous seat  58   a,    58   b,  overhangs  74 , and elongated sidewalls  76 . Although the seat  58   a,    58   b  are shown to engage the device  20  at the device&#39;s second end  20   c.    
     After the device  20  is installed in the housing  25 , the interference  34 , which can be called an anti-rotation cap, is installed. The structural details of the anti-rotation cap are shown in  FIGS. 8, 9   a - 9   b.  Anti-rotation cap projections  34   a  make an angle with an axis of the interference and extend from a first end  34   b  the interference towards a second end  34   c  in the axial direction. A carrier  34   d,  which can be a plate, carries the projections  34   a.  The carrier  34   d  is at the first end  34   b.  Each projection  34   a,  towards the second end  34   c  has a nub  34   e.  The nub is a curved portion of the projection  34   a.  The interference  34  includes the same number of projections  34   a  as there are device projections  28 . Carrier  34   d  has a continuous edge that includes straight segments  34   d ′ and curved segments  34   d ″. The projections  34   a  are arranged around the central axis of the interference  34 . One projection  34   a  is at each curved segment  34   d ″. The carrier  34   d  has a first layer  34   g  integral and seamless with the projections  34   a.  The carrier has a second layer  34   f  coupled to the first layer  34   g.  The second layer  34   f  provides a grasping structure to hold the carrier  34 . When the anti-rotation cap is installed each interference projection  34   a  is between, in the circumferential direction, a different pair of junctions  28   a  of retainer projections  28  and along a different side  20   a.  When installed each projection  34   a  is at a different projection compartment  32   b.  Also when installed the nub  34   e  of each projection is in a void space of a cutout region. Each cutout region  32   b ″ is at a projection compartment. The cutout is formed in the housing  25 . The nubs  34   e  are snapped into the cutout region  32   b ″ void spaces by moving the interference in the second axial direction  56 . The anti-rotation cap prevents the device  20  from rotating during the pumps operation. This reduces the fatigue on the device and it allows it to be used for longer periods of time than those disclosed in the prior art. 
     In  FIG. 10  the housing  25  is shown with a discharge bore  25   a,  a suction bore  25   b,  a further bore  25   c,  and cross bore intersection  48 . The further bore  25   c  is associated with a pumping member such as a piston or plunger. The discharge bore  25   a,  the suction bore  25   b,  and the further bore  25   c  each open into the cross-bore intersection  48 . A suction valve assembly, not shown, is in the suction bore and a discharge valve assembly, not shown in  FIG. 10 , is in the discharge bore. In a well-known manner, during the upstroke of the pumping member, not shown, fluid is taken into the housing  25  over the suction valve and into the suction bore  25   b  and cross-bore intersection  48 . During the pumping member&#39;s downs stroke, the fluid taken in is discharged through the discharge bore  25   a  and over the discharge valve assembly and out the fluid end housing  25 . 
     The fluid end housing  25  also has the bore or conduit  40  which in  FIG. 1-10  is a valve access bore. The conduit/bore  40  allows for the removal and installation of the suction valve assembly from the housing  25 . During operation, the conduit  40  is sealed off with cover  22 . The cover is held in place by device  20 . The device is engaged to the housing in the locked orientation as described above. The fluid end housing  25  in  FIG. 10  for simplicity omits the details of the compartment  32 . The compartment would however be configured in the fluid end at around area  101 . The compartment  32  can be considered a portion of the fluid end housing  25  or a separate component attached the housing  25 . In either case it is carried by a portion of the fluid end housing  25 . 
     The device  20  can also be configured as a retainer  320  for discharge valve cover  110  that has been configured to embody a discharge gage connector. Of course it could be configured to retain other types of valve covers. Features of device  320  correspond to features found in device  20 . Device  320  has a different shape than the device  20  shown in  FIGS. 1-7 . For instance device  320  does not have sides which correspond to sides  20   a.  The corresponding features when called out in  FIG. 11  are indicated with the same reference number as those used for device  20  except a “3” proceeds the number. Thus projection  28  for device  20  corresponds to projection  328  for device  320 . Notably device  320  has a central hole  114  to receive a portion of the discharge valve cover  110  which embodies the discharge gage connector. The central hole  114  is within first portion  336  and delimited by a portion of first portion  336 . 
     As shown in  FIG. 11  the valve cover  110  serves as a cover and a spring retainer for the discharge valve assembly  112 . The discharge valve assembly  112  is in discharge bore  25   a  which as shown in  FIG. 11  is specially configured for the valve assembly  112  and specially configured with a type of compartment  332  to receive device  320 . The compartment  332  receives the device  320  as indicated by  FIG. 11 . In  FIG. 11  compartment  332  opens through an external surface  342  of the housing  25  and opens into a portion of the discharge bore  25   a . The fluid end housing  25  shown in  FIG. 11  would also have a suction bore, a valve access bore, a further bore, and a cross bore intersection. The compartment  332  in  FIG. 11  is a retainer compartment and it is configured like compartment  32  and is a type of the compartment  32  set forth in  FIGS. 1-6 . Features of compartment  32  correspond to features found in compartment  332 . The corresponding features when called out in  FIG. 11  are indicated with same reference number as those used for compartment  32  except a “3” precedes the number. Thus overhang  74  for compartment  32  corresponds to overhang  374  for compartment  332 . 
     The fluid end housing  25  shown in  FIG. 10  has a non-descript stuffing box  102  which has an open area or bore  102   a  which opens into and is adjacent to a portion of the plunger bore  25   c.  The stuffing box has an open end  102   b  opposite the open area. The open end opens through an external surface  242 . The open end  102   b  is bounded by a flange. The stuffing box  102  holds a plurality of seals, packing (not shown). The packing would be disposed around a reciprocating member such a plunger. The plunger would reciprocate in the stuffing box  102  and in the packing. The seals (packing) would prevent the water from escaping from the fluid end housing around the plunger as it reciprocates in the plunger bore. In  FIG. 10 , the stuffing box  102  is integral and seamless with the portion of the fluid end housing to which it is coupled. 
     In some cases, such as in  FIG. 12 , the stuffing box  420  is coupled to a compartment  532  of the fluid end housing  25 . In either case the stuffing box can be considered a portion of the fluid end housing  25  or a component attached to the fluid end housing  25 . In either case it is carried by a portion of the fluid end housing  25 . The stuffing box  102  can be considered an entry portion of the further bore  25   c  or an entry way into the bore  25   c.    
       FIG. 12  shows stuffing box  420  designed to be removably coupled to compartment  532  of the fluid end housing  25 . The stuffing box  420  itself has a compartment  232  to receive a device like device  20 . The device, which is a retainer, holds the packing in the stuffing box  420 . The device is a type of device  20 . The device for the stuffing box would primarily differ from device  20  shown in  FIGS. 1-7  in that it would have a central hole represented by dashed lines  220  in  FIGS. 7 b  and 7 c    to receive the plunger. The compartment  232  of the stuffing box which receives the device has the same features as compartment  32 . Again the corresponding features use the same reference numbers except the reference numbers for compartment  232  are preceded by a “2”. Thus overhang  74  of compartment  32  is shown as  274  for compartment  232 . As shown, compartment  232  has projection compartments  232   b.  Each compartments  232   b  has void space  232   b ′ and seat  258   a.  The compartment also has lock compartments  232   d.  Each compartment has void space  232   d ′, overhang  274 , inclined portion  278  and seat  258   b.  The compartment opens through external surface  242 . The compartment  232  opens into a portion of the stuffing box opening  102   a.  The compartment  232  is shown as an integral feature of the stuffing box  420 . It could be a separate component. In either case it would be carried by a portion of the stuffing box  420 . It would also thus be carried by a portion of the fluid end housing  25 . 
     The stuffing box  420  shown in  FIG. 12  is itself another type of device  20 . The device  420  shown in  FIG. 11  is similar to device  20  shown  FIGS. 1-6 . Again the corresponding features use the same reference numbers except the reference numbers for device  420  are preceded by a “ 4 ”. Thus projection  28  of device  20  is shown as  428  for device  420 . Notably device  420  has a central hole  102   a  to receive the packing and plunger. The central hole  102   a  is within first portion  436  and delimited by first a portion of first portion  436 . The first portion is a stuffing box body. Device  420  includes an attachment portion in the form of coupling features embodied by projections  28 . Accordingly the stuffing box  420  comprises a plurality of projections  428  spaced around a central long axis of the stuffing box. Each projection  428  is configured like projections  28 . The projections  428  are arranged about stuffing box body like projections  28  are arranged about the radially inward first portion  36 . 
     The stuffing box  420  is coupled to a portion of the fluid end  25  by way of an attachment portion in the form of a compartment  532  which is like compartment  32 . The compartment  532  opens through an external surface  542  of the fluid end housing  25  and opens into a portion of further bore  25   c  which corresponds generally to bore  25   c  in  FIG. 10 . The further bore in this case is a plunger bore. Again the corresponding features use the same reference numbers except the reference numbers for compartment  532  are preceded by a “5”. Thus overhang  74  of compartment  32  is shown as  574  for compartment  532 . 
     A discharge pipe or suction pipe are other types of devices  20 . They could be configured to embody the coupling features embodied by projections  28 . The pipes would comprise a plurality of projections spaced around a central long axis of the pipe. Each projection would be configured like projections  28 . The projections would be arranged about the pipe body like projections  28  are arranged about the radially inward first portion  36 . 
     The suction pipe or discharge pipe would be coupled to a portion of the fluid end  25  by way of a respective compartment configured like compartment  32 . 
     Preferably the device  20  regardless of type such as stuffing box  420 , or retainer  320  is seamless. At least the projections of the device are seamless with the central body of the device. Similarly the compartment  32  is preferably seamless. At least the overhang portions  74  of the lock compartments  32   d  are seamless with the portion of the compartment  32  from which they project. 
     The projections  28 ,  328 , and  428  of their respective devices have been described with a construction that increases in thickness to provide the inclined helical surface  28   b,    328   b  and  428   b.  The helical inclined surface  28   b,    328   b,  and  428   b  could be provided with a projection with a construction that does not increase in thickness. It could have a uniform and constant thickness. In this case the entire projection would be angled relative to a plane normal to the central axis of the device. The inclined projection could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. Thus the projection of constant thickness still has inclined surface  28   b,    328   b , and  428   b  which could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. In this case the central body of the device would provide support for the device in the axial direction. It is believed this structure is not as satisfactory. 
     The overhangs  74 ,  274 ,  374  and  574  of their respective lock compartments have been described with a construction that increases in thickness to provide the inclined helical surface  78 ,  278 ,  378  and  578 . The helical inclined surface  78 ,  278 ,  378  and  578  could be provided with an overhang with a construction that does not increase in thickness. It could have a uniform and constant thickness. In this case the entire overhang would be angled relative to a plane normal to the central axis of the compartment. The inclined overhang could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. Thus the overhang of constant thickness still has inclined surface  78 ,  278 ,  378  and  578  which could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. It is believed this structure is not as satisfactory.