US20130202458A1

US20130202458A1 - Pump fluid cylinder including load transfer shoulder and valve seat for same

Info

Publication number: US20130202458A1
Application number: US13/756,715
Authority: US
Inventors: Joseph H. Byrne; Mark Christopher Dille; Jacob A. Bayyouk
Original assignee: SPM Flow Control Inc
Current assignee: SPM Oil and Gas Inc
Priority date: 2012-02-03
Filing date: 2013-02-01
Publication date: 2013-08-08
Also published as: CN104169579A; WO2013116634A1; CA2863654A1

Abstract

According to one aspect, a pump assembly includes a fluid cylinder, and the fluid cylinder includes a fluid passage that defines a tapered internal shoulder of the fluid cylinder. The tapered internal shoulder defines a first frusto-conical surface. A valve controls flow of fluid through the fluid passage. The valve includes a valve seat, which includes a seat body disposed in the fluid passage, and a bore formed through the seat body and through which fluid flows. The seat body includes inlet and outlet end portions, wherein the fluid flows into the bore at the inlet end portion and flows out of the bore at the outlet end portion. The inlet end portion of the seat body defines a second frusto-conical surface. In one embodiment, the second frusto-conical surface engages the first frusto-conical surface to distribute and transfer loading.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S. provisional patent application No. 61/594,493, filed Feb. 3, 2012, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates in general to pump assemblies and, in particular, a reciprocating pump assembly including a fluid cylinder and valve seats.

BACKGROUND OF THE DISCLOSURE

Reciprocating pump assemblies typically include fluid end blocks or fluid cylinders and inlet and outlet valves disposed therein. During operation, the inlet and outlet valves typically experience high loads and frequencies. In some cases, valve seats of the inlet and outlet valves, as well as portions of the fluid cylinder engaged therewith, may be subjected to highly concentrated cyclic loads and thus may fatigue to failure. Therefore, what is needed is an apparatus or method that addresses one or more of the foregoing issues, among others.

SUMMARY

In a first aspect, there is provided a pump assembly that includes a fluid cylinder having a first axis and a second axis perpendicular thereto. The fluid cylinder includes a first fluid passage through which fluid flows along the first axis, the first fluid passage defining a first tapered internal shoulder of the fluid cylinder, the first tapered internal shoulder defining a first frusto-conical surface, the first frusto-conical surface defining a first angle from the second axis; The pump assembly further includes a first valve to control flow of fluid through the first fluid passage. The first valve includes a first valve seat disposed in the first fluid passage. The first valve seat includes a seat body that includes an inlet end portion and an outlet end portion opposed thereto along the first axis, the inlet end portion of the seat body defining a second frusto-conical surface, the second frusto-conical surface defining a second angle from the second axis; and a bore formed through the seat body and through which fluid flows in a direction along the first axis and perpendicular to the second axis; wherein the fluid flows into the bore at the inlet end portion of the seat body and flows out of the bore at the outlet end portion of the seat body; wherein each of the first and second angles ranges from about 10 degrees to about 45 degrees measured from the second axis; and wherein the second frusto-conical surface of the inlet end portion engages the first frusto-conical surface of the fluid cylinder to distribute and transfer loading between the second and first frusto-conical surfaces.
In an exemplary embodiment, the second axis intersects the seat body at an intersection, the intersection defining a first diameter of the seat body; wherein the seat body defines an axially-extending outside surface extending along the first axis from the inlet end portion to the outlet end portion, the axially-extending outside surface defining a second diameter of the seat body; wherein the second diameter of the seat body is greater than the first diameter of the seat body; and wherein the second frusto-conical surface extends between the intersection and the axially-extending outside surface.
In certain exemplary embodiments, the second frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially towards the outlet end portion.
In another exemplary embodiment, the inlet end portion of the seat body defines an end surface that faces axially away from the outlet end portion; wherein the second axis is coplanar with the end surface; wherein the second frusto-conical surface extends from the end surface to the outside surface.
In certain exemplary embodiments, the inlet end portion includes an annular portion that extends from the intersection in an axial direction away from the outlet end portion.
In an exemplary embodiment, the second frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.
In another exemplary embodiment, the inlet end portion includes an annular portion that extends from the intersection in an axial direction away from the outlet end portion.
In yet another exemplary embodiment, the fluid passage includes a first passage portion defining a first inside diameter of the fluid cylinder; and a second passage portion defining a second inside diameter of the fluid cylinder; wherein the second inside diameter is less than the first inside diameter; wherein the valve seat body is disposed in the second passage portion; and wherein at least a portion of the second passage portion is positioned along the first axis between the first passage portion and the first tapered internal shoulder.
In a second aspect, there is provided a valve seat adapted to be disposed within a fluid cylinder of a pump assembly. The valve seat has a first axis and a second axis perpendicular thereto. The valve seat includes a seat body that includes an inlet end portion and an outlet end portion opposed thereto along the first axis, the inlet end portion of the seat body defining a frusto-conical surface, the frusto-conical surface defining an angle from the second axis; and a bore formed through the seat body and through which fluid flows in a direction along the first axis and perpendicular to the second axis; wherein the fluid flows into the bore at the inlet end portion of the seat body and flows out of the bore at the outlet end portion of the seat body; and wherein the angle ranges from about 10 degrees to about 45 degrees measured from the second axis.
In certain exemplary embodiments, the second axis intersects the seat body at an intersection, the intersection defining a first diameter of the seat body; wherein the seat body defines an axially-extending outside surface extending along the first axis from the inlet end portion to the outlet end portion, the axially-extending outside surface defining a second diameter of the seat body; wherein the second diameter of the seat body is greater than the first diameter of the seat body; and wherein the frusto-conical surface extends between the intersection and the axially-extending outside surface.
In an exemplary embodiment, the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially towards the outlet end portion.
In another exemplary embodiment, the inlet end portion of the seat body defines an end surface that faces axially away from the outlet end portion; wherein the second axis is coplanar with the end surface; and wherein the frusto-conical surface extends from the end surface to the outside surface.
In yet another exemplary embodiment, the inlet end portion includes an annular portion that extends from the intersection in an axial direction away from the outlet end portion.
In certain exemplary embodiments, the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.
In another exemplary embodiment, the inlet end portion includes an annular portion that extends from the intersection in an axial direction away from the outlet end portion.
In a third aspect, there is provided a fluid cylinder for a pump assembly, and the fluid cylinder has a first axis and a second axis perpendicular thereto. The fluid cylinder includes a first fluid passage in which a first valve is adapted to be disposed and through which fluid flows along the first axis. The fluid passage includes a first passage portion defining a first inside diameter of the fluid passage; and a second passage portion extending from the first passage portion, the second passage portion defining a second inside diameter of the fluid passage; wherein the second inside diameter is less than the first inside diameter. A tapered internal shoulder is defined by the fluid passage, the tapered internal shoulder defining a frusto-conical surface, the frusto-conical surface defining an angle from the second axis; wherein the angle ranges from about 10 degrees to about 45 degrees measured from the second axis; and wherein at least a portion of the second passage portion is positioned along the first axis between the first passage portion and the first tapered internal shoulder. A pressure chamber is in fluid communication with the first fluid passage.
In an exemplary embodiment, the second axis intersects the fluid passage at an intersection, the intersection defining a third diameter of the fluid passage; wherein the second passage portion defines an axially-extending cylindrical inside surface extending along the first axis, the axially-extending cylindrical inside surface having the second diameter; wherein the second diameter of the fluid passage is greater than the third diameter of the fluid passage; and wherein the frusto-conical surface extends between the intersection and the axially-extending cylindrical inside surface.
In another exemplary embodiment, the frusto-conical surface extends from the intersection to the cylindrical inside surface in an angular direction, an axial component of which extends axially towards the first passage portion.
In certain exemplary embodiments, the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.
In other exemplary embodiments, the fluid cylinder includes a second fluid passage in which a second valve is adapted to be disposed and through which fluid flows along the first axis; and a fluid outlet passage in fluid communication with the pressure chamber via the second fluid passage.
Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the inventions disclosed.

DESCRIPTION OF FIGURES

The accompanying drawings facilitate an understanding of the various embodiments.

FIG. 1 is an elevational view of a reciprocating pump assembly according to an exemplary embodiment, and the pump assembly includes a fluid cylinder assembly.

FIG. 2 is a sectional view of the fluid cylinder assembly of FIG. 1 according to an exemplary embodiment, the fluid cylinder assembly includes a fluid cylinder and inlet and outlet valves, and each of the inlet and outlet valves includes a valve seat.

FIG. 3 is an enlarged view of a portion of the section view of FIG. 2, according to an exemplary embodiment.

FIG. 4 is a partial sectional view of respective portions of the valve seat and the fluid cylinder, according to another exemplary embodiment.

FIG. 5 is a partial sectional view of respective portions of the valve seat and fluid cylinder, according to yet another exemplary embodiment.

FIG. 6 is a partial sectional view of respective portions of the valve seat and fluid cylinder, according to still yet another exemplary embodiment.

DETAILED DESCRIPTION

In an exemplary embodiment, as illustrated in FIG. 1, a reciprocating pump assembly is generally referred to by the reference numeral 10 and includes a power end portion 12 and a fluid end portion 14 operably coupled thereto. The power end portion 12 includes a housing 16 in which a crankshaft (not shown) is disposed, the crankshaft being operably coupled to an engine or motor (not shown), which is adapted to drive the crankshaft. The fluid end portion 14 includes a fluid end block or fluid cylinder 18, which is connected to the housing 16 via a plurality of stay rods 20. The fluid cylinder 18 includes a fluid inlet passage 22 and a fluid outlet passage 24, which are spaced in a parallel relation. A plurality of cover assemblies 26, one of which is shown in FIG. 1, is connected to the fluid cylinder 18 opposite the stay rods 20. A plurality of cover assemblies 28, one of which is shown in FIG. 1, is connected to the fluid cylinder 18 opposite the fluid inlet passage 22. A plunger rod assembly 30 extends out of the housing 16 and into the fluid cylinder 18. In several exemplary embodiments, the pump assembly 10 is freestanding on the ground, is mounted to a trailer that can be towed between operational sites, or is mounted to a skid.
In an exemplary embodiment, as illustrated in FIG. 2 with continuing reference to FIG. 1, the plunger rod assembly 30 includes a plunger 32, which extends through a bore 34 formed in the fluid cylinder 18, and into a pressure chamber 36 formed in the fluid cylinder 18. In several exemplary embodiments, a plurality of parallel-spaced bores may be formed in the fluid cylinder 18, with one of the bores being the bore 34, a plurality of pressure chambers may be formed in the fluid cylinder 18, with one of the pressure chambers being the pressure chamber 36, and a plurality of parallel-spaced plungers may extend through respective ones of the bores and into respective ones of the pressure chambers, with one of the plungers being the plunger 32. At least the bore 34, the pressure chamber 36, and the plunger 32 together may be characterized as a plunger throw. In several exemplary embodiments, the reciprocating pump assembly 10 includes three plunger throws (i.e., a triplex pump assembly), or includes four or more plunger throws.
As shown in FIG. 2, the fluid cylinder 18 includes inlet and outlet fluid passages 38 and 40 formed therein, which are generally coaxial along an axis 42. The fluid inlet passage 22 is in fluid communication with the pressure chamber 36 via the inlet fluid passage 38. The pressure chamber 36 is in fluid communication with the fluid outlet passage 24 via the outlet fluid passage 40. The fluid inlet passage 38 includes an enlarged-diameter portion 38 a and a reduced-diameter portion 38 b extending downward therefrom (the diameter of the enlarged-diameter portion 38 a is greater than the diameter of the reduced-diameter portion 38 b). The fluid inlet passage 38 defines a tapered internal shoulder 43 so that the reduced-diameter portion 38 b is positioned along the axis 42 between the enlarged diameter portion 38 a and the tapered internal shoulder 43. The tapered internal shoulder 43 defines a frusto-conical surface 44 of the fluid cylinder 18. The reduced-diameter portion 38 b defines an inside surface 46 of the fluid cylinder 18, the inside surface 46 having the diameter of the reduced-diameter portion 38 b. Similarly, the fluid outlet passage 40 includes an enlarged-diameter portion 40 a and a reduced-diameter portion 40 b extending downward therefrom. The fluid outlet passage 40 defines a tapered internal shoulder 48 so that the reduced-diameter 40 b is axially positioned between the enlarged-diameter portion 40 a and the tapered internal shoulder 48. The tapered internal shoulder 48 defines a frusto-conical surface 50 of the fluid cylinder 18. The reduced-diameter portion 40 b defines an inside surface 52 of the fluid cylinder 18.
An inlet valve assembly, or inlet valve 54, is disposed in the fluid passage 38, and engages at least the frusto-conical surface 44 and the inside surface 46. Similarly, an outlet valve assembly, or outlet valve 56, is disposed in the fluid passage 40, and engages at least the frusto-conical surface 50 and the inside surface 52. In an exemplary embodiment, each of valves 54 and 56 is a spring-loaded valve that is actuated by a predetermined differential pressure thereacross.
A counterbore 58 is formed in the fluid cylinder 18, and is generally coaxial with the axis 42. The counterbore 58 defines an internal shoulder 58 a and includes an internal threaded connection 58 b adjacent the internal shoulder 58 a. A counterbore 60 is formed in the fluid cylinder 18, and is generally coaxial with the bore 34 along an axis 62. The counterbore 60 defines an internal shoulder 60 a and includes an internal threaded connection 60 b adjacent the internal shoulder 60 a. In several exemplary embodiments, the fluid cylinder 18 may include a plurality of parallel-spaced counterbores, one of which may be the counterbore 58, with the quantity of counterbores equaling the quantity of plunger throws included in the pump assembly 10. Similarly, in several exemplary embodiments, the fluid cylinder 18 may include another plurality of parallel-spaced counterbores, one of which may be the counterbore 60, with the quantity of counterbores equaling the quantity of plunger throws included in the pump assembly 10.
A plug 64 is disposed in the counterbore 58, engaging the internal shoulder 58 a and sealingly engaging an inside cylindrical surface defined by the reduced-diameter portion of the counterbore 58. An external threaded connection 66 a of a fastener 66 is threadably engaged with the internal threaded connection 58 b of the counterbore 58 so that an end portion of the fastener 66 engages the plug 64. As a result, the fastener 66 sets or holds the plug 64 in place against the internal shoulder 58 a defined by the counterbore 58, thereby maintaining the sealing engagement of the plug 64 against the inside cylindrical surface defined by the reduced-diameter portion of the counterbore 58. The cover assembly 28 shown in FIGS. 1 and 2 includes at least the plug 64 and the fastener 66. In an exemplary embodiment, the cover assembly 28 may be disconnected from the fluid cylinder 18 to provide access to, for example, the counterbore 58, the pressure chamber 36, the plunger 32, the fluid passage 40 or the outlet valve 56. The cover assembly 28 may then be reconnected to the fluid cylinder 18 in accordance with the foregoing. In several exemplary embodiments, the pump assembly 10 may include a plurality of plugs, one of which is the plug 64, and a plurality of fasteners, one of which is the fastener 66, with the respective quantities of plugs and fasteners equaling the quantity of plunger throws included in the pump assembly 10.
A plug 68 is disposed in the counterbore 60, engaging the internal shoulder 60 a and sealingly engaging an inside cylindrical surface defined by the reduced-diameter portion of the counterbore 60. In an exemplary embodiment, the plug 68 maybe characterized as a suction cover. An external threaded connection 70 a of a fastener 70 is threadably engaged with the internal threaded connection 60 b of the counterbore 60 so that an end portion of the fastener 70 engages the plug 68. As a result, the fastener 70 sets or holds the plug 68 in place against the internal shoulder 60 a defined by the counterbore 60, thereby maintaining the sealing engagement of the plug 68 against the inside cylindrical surface defined by the reduced-diameter portion of the counterbore 60. The cover assembly 26 shown in FIGS. 1 and 2 includes at least the plug 68 and the fastener 70. In an exemplary embodiment, the cover assembly 26 may be disconnected from the fluid cylinder 18 to provide access to, for example, the counterbore 60, the pressure chamber 36, the plunger 32, the fluid passage 38, or the inlet valve 54. The cover assembly 26 may then be reconnected to the fluid cylinder 18 in accordance with the foregoing. In several exemplary embodiments, the pump assembly 10 may include a plurality of plugs, one of which is the plug 68, and a plurality of fasteners, one of which is the fastener 70, with the respective quantities of plugs and fasteners equaling the quantity of plunger throws included in the pump assembly 10.
A valve spring retainer 72 is disposed in the enlarged-diameter portion 38 a of the fluid passage 38. The valve spring retainer 72 is connected to the end portion of the plug 68 opposite the fastener 70. In an exemplary embodiment, and as shown in FIG. 2, the valve spring retainer 72 is connected to the plug 68 via a hub 74, which is generally coaxial with the axis 62.
In an exemplary embodiment, as illustrated in FIG. 3 with continuing reference to FIGS. 1 and 2, the inlet valve 54 includes a valve seat 76 and a valve member 78 engaged therewith. The valve seat 76 includes a seat body 80 having an inlet end portion 81 and an outlet end portion 82. The seat body 80 is disposed in the reduced-diameter portion 38 b of the fluid passage 38. A bore 83 is formed through the seat body 80 and is coaxial with an axis 84, which is aligned with the axis 42 when the inlet valve 54 is disposed in the fluid passage 38, as shown in FIG. 3. The outlet end portion 82 is axially opposed to the inlet end portion 81 along the axis 84 and thus along the axis 42. The bore 83 defines an inside surface 85 of the seat body 80. An outside surface 86 of the seat body 80 contacts the inside surface 46 defined by the fluid passage 38. In an exemplary embodiment, the outside surface 86 may be cylindrical. In an exemplary embodiment, the outside surface 86 may be slightly conical. A sealing element, such as an o-ring, may be disposed in an annular groove formed in the outside surface 86, and the o-ring may sealingly engage the inside surface 46. The fluid cylinder 18 and valve seat 76 have axes 88 and 90, respectively. The axes 88 and 90 are coaxial when the inlet valve 54 is disposed in the fluid passage 38, as shown in FIG. 3. The axes 88 and 90 are perpendicular to the axes 42 and 84, respectively.
A frusto-conical surface 91 is defined by the inlet end portion 81 of the seat body 80. The frusto-conical surface 91 defines an angle 92 from the axis 90 and thus also from the axis 88. Similarly, the frusto-conical surface 44 defines an angle 93 from the axis 88 and thus also from the axis 90. In an exemplary embodiment, each of the angles 92 and 93 ranges from about 10 degrees to about 45 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, each of the angles 92 and 93 ranges from about 15 degrees to about 45 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, the angles 92 and 93 are equal as measured from the aligned axes 88 and 90. In an exemplary embodiment, each of the angles 92 and 93 is about 30 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, the angles 92 and 93 are not equal as measured from the aligned axes 88 and 90. An end surface 94 is defined by inlet end portion 81 of the seat body 80. The end surface 94 faces axially away from the outlet end portion 82. The end surface 94 is coplanar with the aligned axes 88 and 90. The frusto-conical surface 91 extends from the intersection between the seat body 80 and the aligned axes 88 and 90, which intersection corresponds to the end surface 94, to the outside surface 86 in an angular direction, an axial component of which extends axially towards the outlet end portion 82. Likewise, the frusto-conical surface 44 extends from the intersection between the fluid passage 38 and the aligned axes 88 and 90, and to the inside surface 46 in an angular direction, an axial component of which extends axially towards the enlarged-diameter portion 38 a.
A diameter 95 a is defined by the intersection between the seat body 80 and the aligned axes 88 and 90; similarly, a diameter of the fluid passage 38 generally corresponding, or about equal, to the diameter 95 a is defined by the intersection between the fluid passage 38 and the aligned axes 88 and 90. A diameter 95 b is defined by the outside surface 86; the diameter of the reduced-diameter portion 38 b of the fluid passage 38 generally corresponds, or is about equal, to the diameter 95 b. The diameter 95 b is greater than the diameter 95 a.
The outlet end portion 82 defines a tapered surface 96, which extends angularly upward from the inside surface 85. In an exemplary embodiment, the tapered surface 96 extends at an angle relative to the aligned axes 42 and 84, which angle ranges from about 15 degrees to about 45 degrees.
The seat body 80 of the valve seat 76 is disposed within the reduced-diameter portion 38 b of the fluid passage 38 so that the outside surface 86 of the seat body 80 engages the inside surface 46 of the fluid cylinder 18. In an exemplary embodiment, the seat body 80 forms an interference fit, or is press fit, in the portion 38 b of the fluid passage 38 so that the valve seat 76 is prevented from being dislodged from the fluid passage 38. As noted above, a sealing element, such as an o-ring, may be disposed in an annular groove formed in the outside surface 86, and the o-ring may sealingly engage the inside surface 46.
The valve member 78 includes a central stem 98, from which a valve body 100 extends radially outward. An outside annular cavity 102 is formed in the valve body 100. A seal 104 extends within the cavity 102, and is adapted to sealingly engage the tapered surface 96 of the valve seat 76, under conditions to be described below. A plurality of circumferentially-spaced legs 106 extend angularly downward from the central stem 98, and slidably engage the inside surface 85 of the seat body 80. In several exemplary embodiments, the plurality of legs 106 may include two, three, four, five, or greater than five, legs 106. A lower end portion of a spring 108 is engaged with the top of the valve body 100 opposite the central stem 98. As shown in FIG. 2, the upper end portion of the spring 108 is engaged with the valve spring retainer 72. The valve member 78 is movable, relative to the valve seat 76 and thus the fluid cylinder 18, between a closed position (shown in FIG. 3) and an open position (not shown), under conditions to be described below.
In an exemplary embodiment, the seal 104 is molded in place in the valve body 100. In an exemplary embodiment, the seal 104 is preformed and then attached to the valve body 100. In several exemplary embodiments, the seal 104 is composed of one or more materials such as, for example, a deformable thermoplastic material, a urethane material, a fiber-reinforced material, carbon, glass, cotton, wire fibers, cloth, and/or any combination thereof. In an exemplary embodiment, the seal 104 is composed of a cloth which is disposed in a thermoplastic material, and the cloth may include carbon, glass, wire, cotton fibers, and/or any combination thereof. In several exemplary embodiments, the seal 104 is composed of at least a fiber-reinforced material, which can prevent or at least reduce delamination. In an exemplary embodiment, the seal 104 has a hardness of 95 A durometer or greater, or a hardness of 69 D durometer or greater. In another exemplary embodiment, the seal 104 has a hardness of 95 A durometer or lesser. In several exemplary embodiments, the valve body 100 is much harder and more rigid than the seal 104.
The outlet valve 56 is identical to the inlet valve 54 and therefore will not be described in further detail. Features of the outlet valve 56 that are identical to corresponding features of the inlet valve 54 will be given the same reference numerals as that of the inlet valve 54. The outlet valve 56 is disposed in the fluid passage 40, and engages the fluid cylinder 18, in a manner that is identical to the manner in which the inlet valve 54 is disposed in the fluid passage 38, and engages the fluid cylinder 18, with one exception involving the spring 108 of the outlet valve 56; more particularly, the upper portion of the spring 108 of the outlet valve 56 is compressed against the bottom of the plug 64, rather than being compressed against a component that corresponds to the valve spring retainer 72, against which the upper portion of the spring 108 of the inlet valve 54 is compressed.
In operation, in an exemplary embodiment, with continuing reference to FIGS. 1-3, the plunger 32 reciprocates within the bore 34, reciprocating in and out of the pressure chamber 36. That is, the plunger 32 moves back and forth horizontally, as viewed in FIG. 2, away from and towards the axis 42. In an exemplary embodiment, the engine or motor (not shown) drives the crankshaft (not shown) enclosed within the housing 16, thereby causing the plunger 32 to reciprocate within the bore 34 and thus in and out of the pressure chamber 36.
As the plunger 32 reciprocates out of the pressure chamber 36, the inlet valve 54 is opened. More particularly, as the plunger 32 moves away from the axis 42, the pressure inside the pressure chamber 36 decreases, creating a differential pressure across the inlet valve 54 and causing the valve member 78 to move upward, as viewed in FIGS. 2 and 3, relative to the valve seat 76 and the fluid cylinder 18. As a result of the upward movement of the valve member 78, the spring 108 is compressed between the valve body 100 and the valve spring retainer 72, the seal 104 disengages from the tapered surface 96, and the inlet valve 54 is thus placed in its open position. Fluid in the fluid inlet passage 22 flows along the axis 42 and through the fluid passage 38 and the inlet valve 54, being drawn into the pressure chamber 36. To flow through the inlet valve 54, the fluid flows into the bore 83 at the inlet end portion 81, through the bore 83 and along the aligned axes 42 and 84, and out of the bore 83 at the outlet end portion 82. During this time, the outlet valve 56 is in its closed position, with the seal 104 of the valve member 78 of the outlet valve 56 engaging the tapered surface 96 of the valve seat 76 of the outlet valve 56. Fluid continues to be drawn into the pressure chamber 36 until the plunger 32 is at the end of its stroke away from the axis 42. At this point, the differential pressure across the inlet valve 54 is such that the spring 108 of the inlet valve 54 is not further compressed, or begins to decompress and extend, forcing the valve member 78 of the inlet valve 54 to move downward, as viewed in FIGS. 2 and 3, relative to the valve seat 76 and the fluid cylinder 18. As a result, the inlet valve 54 is placed in, or begins to be placed in, its closed position, with the seal 104 sealingly engaging, or at least moving towards, the tapered surface 96.
As the plunger 32 moves into the pressure chamber 36 and thus towards the axis 42, the pressure within the pressure chamber 36 begins to increase. The pressure within the pressure chamber 36 continues to increase until the differential pressure across the outlet valve 56 exceeds a predetermined set point, at which point the outlet valve 56 opens and permits fluid to flow out of the pressure chamber 36, along the axis 42 and through the fluid passage 40 and the outlet valve 56, and into the fluid outlet passage 24. As the plunger 32 reaches the end of its stroke towards the axis 42 (i.e., its discharge stroke), the inlet valve 54 is in, or is placed in, its closed position, with the seal 104 sealingly engaging the tapered surface 96.
The foregoing is repeated, with the reciprocating pump assembly 10 pressurizing the fluid as the fluid flows from the fluid inlet passage 22 and to the fluid outlet passage 24 via the pressure chamber 36. In an exemplary embodiment, the pump assembly 10 is a single-acting reciprocating pump, with fluid being pumped across only one side of the plunger 32.
In an exemplary embodiment, during the above-described operation of the reciprocating pump assembly 10, the taper of each of the surfaces 44 and 91 balances the loading forces applied thereagainst. In an exemplary embodiment, the loading is distributed across the surfaces 44 and 91, reducing stress concentrations.
In an exemplary embodiment, as illustrated in FIG. 4 with continuing reference to FIGS. 1-3, the end surface 94 is omitted from the inlet end portion 81. Instead, the inlet end portion 81 includes an annular portion 108 that extends from the intersection between the seat body 80 and the aligned axes 88 and 90 in an axial direction away from the outlet end portion 82. An end surface 110 is defined by the annular portion 108 of the inlet end portion 81. The end surface 110 faces axially away from the outlet end portion 82. In an exemplary embodiment, the operation of the pump assembly 10 with the exemplary embodiment of the valve seat 76 illustrated in FIG. 4 is identical to the operation of the pump assembly 10 with the exemplary embodiment of the valve seat 76 illustrated in FIG. 3. The annular portion 108 facilitates the removal of the valve seat 76 from the fluid cylinder 18.
In an exemplary embodiment, as illustrated in FIG. 5 with continuing reference to FIGS. 1-4, the tapered internal shoulder 43 and the frusto-conical surface 44 are omitted. Instead, the fluid inlet passage 38 defines a tapered internal shoulder 43′ so that the majority of the reduced-diameter portion 38 b is axially positioned between the enlarged diameter portion 38 a and the tapered internal shoulder 43′. The tapered internal shoulder 43′ defines a frusto-conical surface 44′ of the fluid cylinder 18. The frusto-conical surface 91 is omitted in favor of a frusto-conical surface 91′, which is defined by the inlet end portion 81 of the seat body 80. The frusto-conical surface 91′ extends from the intersection between the seat body 80 and the aligned axes 88 and 90, and to the outside surface 86 in an angular direction, an axial component of which extends axially away the outlet end portion 82. Likewise, the frusto-conical surface 44′ extends from the intersection between the fluid passage 38 and the aligned axes 88 and 90, and to the inside surface 46 in an angular direction, an axial component of which extends away from the enlarged-diameter portion 38 a. The frusto-conical surface 91′ defines an angle 92′ from the axis 90 and thus also from the axis 88. Similarly, the frusto-conical surface 44′ defines an angle 93′ from the axis 88 and thus also from the axis 90. In an exemplary embodiment, each of the angles 92′ and 93′ ranges from about 10 degrees to about 45 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, each of the angles 92′ and 93′ ranges from about 15 degrees to about 45 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, the angles 92′ and 93′ are equal as measured from the aligned axes 88 and 90. In an exemplary embodiment, each of the angles 92′ and 93′ is about 30 degrees measured from the aligned axes 88 and 90. In an exemplary embodiment, the angles 92′ and 93′ are not equal as measured from the aligned axes 88 and 90. In an exemplary embodiment, the operation of the pump assembly 10 with the respective exemplary embodiments of the valve seat 76 and the fluid cylinder 18 illustrated in FIG. 5, is identical to the operation of the pump assembly 10 with the respective exemplary embodiments of the valve seat 76 and the fluid cylinder 18 illustrated in FIG. 3. The annular portion 108 facilitates the removal of the valve seat 76 from the fluid cylinder 18.
In an exemplary embodiment, during operation of the pump assembly 10 using any of the foregoing embodiments of the inlet valve 54, downwardly directed axial loads along the axis 42 are applied against the top of the valve body 100. This loading is usually greatest as the plunger 32 moves towards the axis 42 and the outlet valve 56 opens and permits fluid to flow out of the pressure chamber 36, through the fluid passage 40 and the outlet valve 56, and into the fluid outlet passage 24. As the plunger 32 reaches the end of its stroke towards the axis 42 (its discharge stroke), the inlet valve 54 is in, or is placed in, its closed position, and the loading applied to the top of the valve body 100 is transferred to the seal 104 via the valve body 100. The loading is then transferred to the valve seat 76 via the seal 104, and then is distributed and transferred to the tapered internal shoulder 43 or 43′ of the fluid cylinder 18 via the engagement of the surface 91 or 91′ against the surface 44 or 44′. The tapering of the surface 91 or 91′ and the surface 44 or 44′ facilitates this distribution and transfer of the downwardly directed axial loading to the fluid cylinder 18 in a balanced manner, thereby reducing stress concentrations in the fluid cylinder 18 and the valve seat 76.
In several experimental exemplary embodiments, experimental analyses were conducted on two experimental exemplary embodiments of combinations of the valve seat 76 and the fluid cylinder 18. Experimental Exemplary Embodiment #1, for which finite element analysis (FEA) was conducted, was the combination of the valve seat 76 and the fluid cylinder 18 as illustrated in FIG. 6. As shown in FIG. 6, the tapered internal shoulder 43 of the fluid cylinder 18 is omitted. The seat body 80 of the valve seat 76 includes an enlarged-diameter portion 112 and a reduced-diameter portion 114 extending downwardly therefrom. An external shoulder 116 defines an axially-facing surface 118 that faces axially towards the inlet end portion 81. The axially-facing surface 118 engages an axially-facing surface 120 of the fluid cylinder 18, which is defined by the enlarged-diameter portion 38 a and faces axially away from the inlet end portion 81. Experimental Exemplary Embodiment #2, for which FEA was conducted, was the combination of the valve seat 76 and the fluid cylinder 18 as illustrated in FIG. 3. Using a loading of about 17 ksi, the maximum experimental stresses were determined in each of Experimental Exemplary Embodiments #1 and #2. For Experimental Exemplary Embodiment #1, the maximum von-Mises stress in response to the engagement of the valve seat 76 with the fluid cylinder 18 was about 142 ksi at about Point A shown in FIG. 6. For Experimental Exemplary Embodiment #2, the maximum von-Mises stress in response to the engagement of the valve seat 76 with the fluid cylinder 18 was about 78 ksi at about Point B, and about 78 ksi at about Point C (Points B and C are shown in FIG. 3).
In several exemplary embodiments, variations may be made to the valve member 100, or the valve member 100 may be omitted in favor of another valve member that does not include the plurality of legs 106. In several exemplary embodiments, the valves 54 and 56 may be configured to operate in the presence of highly abrasive fluids, such as drilling mud, and at relatively high pressures, such as at pressures of up to about 15,000 psi or greater. In several exemplary embodiments, instead of, or in addition to being used in reciprocating pumps, the valves 54 and 56 or the components thereof, such as the valve seat 76, may be used in other types of pumps and fluid systems. Correspondingly, instead of, or in addition to being used in reciprocating pumps, the fluid cylinder 18 or features thereof may be used in other types of pumps and fluid systems.
In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “left” and right”, “front” and “rear”, “above” and “below” and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.
In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.
In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.
Furthermore, invention(s) have described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s). Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.

Claims

What is claimed is:

1. A pump assembly, comprising:

a fluid cylinder having a first axis and a second axis perpendicular thereto, the fluid cylinder comprising a first fluid passage through which fluid flows along the first axis, the first fluid passage defining a first tapered internal shoulder of the fluid cylinder, the first tapered internal shoulder defining a first frusto-conical surface, the first frusto-conical surface defining a first angle from the second axis; and

a first valve to control flow of fluid through the first fluid passage, the first valve comprising a first valve seat disposed in the first fluid passage, the first valve seat comprising:

a seat body comprising an inlet end portion and an outlet end portion opposed thereto along the first axis, the inlet end portion of the seat body defining a second frusto-conical surface, the second frusto-conical surface defining a second angle from the second axis; and

a bore formed through the seat body and through which fluid flows in a direction along the first axis and perpendicular to the second axis;

wherein the fluid flows into the bore at the inlet end portion of the seat body and flows out of the bore at the outlet end portion of the seat body;

wherein each of the first and second angles ranges from about 10 degrees to about 45 degrees measured from the second axis; and

wherein the second frusto-conical surface of the inlet end portion engages the first frusto-conical surface of the fluid cylinder to distribute and transfer loading between the second and first frusto-conical surfaces.

2. The pump assembly of claim 1, wherein the second axis intersects the seat body at an intersection, the intersection defining a first diameter of the seat body;

wherein the seat body defines an axially-extending outside surface extending along the first axis from the inlet end portion to the outlet end portion, the axially-extending outside surface defining a second diameter of the seat body;

wherein the second diameter of the seat body is greater than the first diameter of the seat body; and

wherein the second frusto-conical surface extends between the intersection and the axially-extending outside surface.

3. The pump assembly of claim 2, wherein the second frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially towards the outlet end portion.

4. The pump assembly of claim 3, wherein the inlet end portion of the seat body defines an end surface that faces axially away from the outlet end portion;

wherein the second axis is coplanar with the end surface; and

wherein the second frusto-conical surface extends from the end surface to the outside surface.

5. The pump assembly of claim 3, wherein the inlet end portion comprises an annular portion that extends from the intersection in an axial direction away from the outlet end portion.

6. The pump assembly of claim 2, wherein the second frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.

7. The pump assembly of claim 6, wherein the inlet end portion comprises an annular portion that extends from the intersection in an axial direction away from the outlet end portion.

8. The pump assembly of claim 1, wherein the fluid passage comprises:

a first passage portion defining a first inside diameter of the fluid cylinder; and

a second passage portion defining a second inside diameter of the fluid cylinder;

wherein the second inside diameter is less than the first inside diameter;

wherein the valve seat body is disposed in the second passage portion; and

wherein at least a portion of the second passage portion is positioned along the first axis between the first passage portion and the first tapered internal shoulder.

9. A valve seat adapted to be disposed within a fluid cylinder of a pump assembly, the valve seat having a first axis and a second axis perpendicular thereto, the valve seat comprising:

a seat body comprising an inlet end portion and an outlet end portion opposed thereto along the first axis, the inlet end portion of the seat body defining a frusto-conical surface, the frusto-conical surface defining an angle from the second axis; and

wherein the fluid flows into the bore at the inlet end portion of the seat body and flows out of the bore at the outlet end portion of the seat body; and

wherein the angle ranges from about 10 degrees to about 45 degrees measured from the second axis.

10. The valve seat of claim 9, wherein the second axis intersects the seat body at an intersection, the intersection defining a first diameter of the seat body;

wherein the frusto-conical surface extends between the intersection and the axially-extending outside surface.

11. The valve seat of claim 10, wherein the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially towards the outlet end portion.

12. The valve seat of claim 11, wherein the inlet end portion of the seat body defines an end surface that faces axially away from the outlet end portion;

wherein the second axis is coplanar with the end surface; and

wherein the frusto-conical surface extends from the end surface to the outside surface.

13. The valve seat of claim 11, wherein the inlet end portion comprises an annular portion that extends from the intersection in an axial direction away from the outlet end portion.

14. The valve seat of claim 10, wherein the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.

15. The valve seat of claim 14, wherein the inlet end portion comprises an annular portion that extends from the intersection in an axial direction away from the outlet end portion.

16. A fluid cylinder for a pump assembly, the fluid cylinder having a first axis and a second axis perpendicular thereto, the fluid cylinder comprising:

a first fluid passage in which a first valve is adapted to be disposed and through which fluid flows along the first axis, the fluid passage comprising:

a first passage portion defining a first inside diameter of the fluid passage; and

a second passage portion extending from the first passage portion, the second passage portion defining a second inside diameter of the fluid passage;

wherein the second inside diameter is less than the first inside diameter;

a tapered internal shoulder defined by the fluid passage, the tapered internal shoulder defining a frusto-conical surface, the frusto-conical surface defining an angle from the second axis;

wherein the angle ranges from about 10 degrees to about 45 degrees measured from the second axis; and

wherein at least a portion of the second passage portion is positioned along the first axis between the first passage portion and the first tapered internal shoulder;

and

a pressure chamber in fluid communication with the first fluid passage.

17. The fluid cylinder of claim 16, wherein the second axis intersects the fluid passage at an intersection, the intersection defining a third diameter of the fluid passage;

wherein the second passage portion defines an axially-extending cylindrical inside surface extending along the first axis, the axially-extending cylindrical inside surface having the second diameter;

wherein the second diameter of the fluid passage is greater than the third diameter of the fluid passage; and

wherein the frusto-conical surface extends between the intersection and the axially-extending cylindrical inside surface.

18. The fluid cylinder of claim 17, wherein the frusto-conical surface extends from the intersection to the cylindrical inside surface in an angular direction, an axial component of which extends axially towards the first passage portion.

19. The valve seat of claim 10, wherein the frusto-conical surface extends from the intersection to the outside surface in an angular direction, an axial component of which extends axially away from the outlet end portion.

20. The valve seat of claim 16, further comprising:

a second fluid passage in which a second valve is adapted to be disposed and through which fluid flows along the first axis; and

a fluid outlet passage in fluid communication with the pressure chamber via the second fluid passage.