U.S. patent application number 16/483468 was filed with the patent office on 2020-01-09 for fluid end with removable dual-valve cartridge.
This patent application is currently assigned to TSC MANURFACTURING AND SUPPLY, LLC. The applicant listed for this patent is TSC MANUFACTURING AND SUPPLY, LLC. Invention is credited to Ian HAAS, Daniel B. Johnson, Paul Kleypas.
Application Number | 20200011317 16/483468 |
Document ID | / |
Family ID | 63040061 |
Filed Date | 2020-01-09 |
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United States Patent
Application |
20200011317 |
Kind Code |
A1 |
HAAS; Ian ; et al. |
January 9, 2020 |
FLUID END WITH REMOVABLE DUAL-VALVE CARTRIDGE
Abstract
A fluid end assembly is described herein with a flow box having
an inlet manifold having an inlet opening, an outlet manifold
having an outlet opening, and a housing between the inlet manifold
and the outlet manifold; and a valve cartridge removably disposed
in the housing. In one embodiment, the valve cartridge includes a
sleeve with a first end and a second end; a valve seat at each of
the first and second ends; a first valve disposed in the sleeve at
the first end; and a second valve disposed in the sleeve at the
second end.
Inventors: |
HAAS; Ian; (Houston, TX)
; Kleypas; Paul; (Houston, TX) ; Johnson; Daniel
B.; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TSC MANUFACTURING AND SUPPLY, LLC |
Houston |
TX |
US |
|
|
Assignee: |
TSC MANURFACTURING AND SUPPLY,
LLC
Houston
TX
|
Family ID: |
63040061 |
Appl. No.: |
16/483468 |
Filed: |
January 30, 2018 |
PCT Filed: |
January 30, 2018 |
PCT NO: |
PCT/US2018/015833 |
371 Date: |
August 5, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62454411 |
Feb 3, 2017 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 39/1046 20130101;
F04B 53/10 20130101; F04B 53/1092 20130101; F04B 53/007
20130101 |
International
Class: |
F04B 39/10 20060101
F04B039/10; F04B 53/10 20060101 F04B053/10 |
Claims
1. A fluid end assembly, comprising: a flow box with an inlet
manifold having an inlet opening, an outlet manifold having an
outlet opening, and a housing between the inlet manifold and the
outlet manifold; and a valve cartridge removably disposed in the
housing, the valve cartridge comprising: a first valve seat at a
first end of the cartridge assembly and a second valve seat spaced
apart from the first end; a first valve disposed in the cartridge
assembly at the first end; a second valve disposed adjacent to the
second valve seat; a first resilient member disposed between the
first and second valves in contact with the first valve and the
second valve; and a second resilient member disposed between the
second valve and a second end of the cartridge assembly opposite
the first end.
2. The fluid end assembly of claim 1, wherein each valve seat
engages with a sleeve disposed in the housing.
3. The fluid end assembly of claim 2, wherein the sleeve has a
first lip extending radially inward at a first end of the sleeve,
the first valve seat has a lip that extends radially outward, and
the lip of the first valve seat engages the first lip.
4. The fluid end of claim 3, wherein the sleeve has a second end
opposite from the first end, the second valve seat has a lip that
extends radially outward, and the lip of the second valve seat
engages with the second end of the sleeve.
5. The fluid end of claim 1, wherein the first valve seat is
connected to the second valve seat by a plurality of posts.
6. The fluid end of claim 5, wherein each of the first and second
valves has a stem, the stem of the second valve is hollow, and the
stem of the first valve is disposed within the stem of the second
valve.
7. The fluid end of claim 6, wherein the first resilient member is
disposed within the stem of the second valve.
8. The fluid end of claim 1, wherein the first valve has a first
stem, the second valve has a second stem that is hollow, the first
stem fits within the second stem, and the first resilient member is
disposed within the second stem.
9. A valve cartridge, comprising: a cage comprising a first valve
seat and a second valve seat; a first valve disposed in the cage,
the first valve having a first stem and a first plug portion; a
second valve disposed in the cage, the second valve having a second
stem and a second plug portion, wherein the second stem is hollow
and the first stem fits within the second stem; a first resilient
member disposed within the second stem between the first stem and
the second plug portion; and a second resilient member disposed
between the second plug portion and the cage, wherein the second
valve seat is between the first plug portion and the second plug
portion.
10. The valve cartridge of claim 9, wherein the first valve seat
and the second valve seat are connected by a plurality of
posts.
11. The valve cartridge of claim 10, wherein the cage further
comprises a top plate with an alignment bore, and the second valve
has a rear stem that fits within the alignment bore.
12. The valve cartridge of claim 11, wherein the second resilient
member contacts the second plug portion and the top plate.
13. The valve cartridge of claim 12, further comprising a first
groove along a bottom surface of the cage and a second groove
around a periphery of the second valve seat.
14. The valve cartridge of claim 13, wherein the second valve seat
is connected to the top plate by a plurality of posts.
15. A valve cartridge, comprising: a first valve aligned with a
second valve; a first valve seat at a first end of the valve
cartridge adjacent to the first valve; a second valve seat between
the first valve and the second valve; and a resilient member
between the first valve and the second valve in contact with the
first valve and the second valve.
16. The valve cartridge of claim 15, further comprising a second
resilient member between the second valve and a second end of the
valve cartridge opposite from the first end.
17. The valve cartridge of claim 16, wherein the first valve has a
first stem, the second valve has a second stem that is hollow, and
the first stem fits within the second stem.
Description
FIELD
[0001] Embodiments described herein relate to fluid ends for high
pressure pumps.
BACKGROUND
[0002] High pressure pumps used in industries such as oil and gas
have a plurality of linear force members, such as pistons or
plungers, coupled to a crankshaft that rotates to cause the linear
force member to reciprocate. The linear force member heads extend
and retract inside a fluid end that channels the fluid flow powered
by the linear force members. The flow channel of the fluid end is
typically perpendicular to the stroke axis of the linear force
member. During the suction phase of the stroke, the linear force
member retracts producing a vacuum inside the fluid end. A suction
valve inside the fluid end on the inlet side has fluid pressure on
one side of the valve and internal pressure of the fluid end on the
other side. As the linear force member retracts, declining pressure
on the internal side of the suction valve causes the suction valve
to retract, allowing fluid into the fluid end. During the power
phase of the stroke, the linear force member then advances raising
the pressure on the fluid in the fluid end. The pressure reseats
the suction valve, closing the inlet side of the fluid end. A
discharge valve inside the fluid end on the discharge side has line
pressure on the outside of the valve and internal pressure of the
fluid end on the inside of the valve. As the linear force member
increases pressure inside the fluid end, the discharge valve opens,
allowing fluid from the fluid end to flow through the valve into
the line, exiting the fluid end. The stroke then repeats, with the
discharge valve closing and the suction valve opening again.
[0003] The valves must seat and seal during each stroke to avoid
fluid flow in the wrong direction. Typically, the valves use
springs to bias each valve closed. Spring constants are chosen such
that pressures developed upstream, downstream, and within the fluid
end cause the valves to open at appropriate times and the springs
cause the valves to close when the pressure equalizes. The valves
are typically held in place by a fluid end cap that fastens to the
fluid end and seals fluid into the assembly.
[0004] In conventional fluid ends, the valves seat directly against
portions of the fluid end. The fluid end is a sizable object that
can house two, three, or more valve assemblies, each comprising a
suction and discharge valve. Every stroke of the linear force
member results in a valve contacting a portion of the fluid end,
which must be shaped to match the valve shape and form a seal. This
causes wear on the fluid end and valves, which must eventually be
replaced. If a valve is damaged, the fluid end cap must be removed
and the valve extracted. Specialized tools are frequently needed to
extract the valves. Further, the fluid end must be specially
designed to fit the shape of the valves. There is a need for a
fluid end that does not require such specialized design and
handling.
SUMMARY
[0005] Embodiments described herein provide a fluid end assembly,
comprising a flow box with an inlet manifold having an inlet
opening, an outlet manifold having an outlet opening, and a housing
between the inlet manifold and the outlet manifold; and a valve
cartridge removably disposed in the housing, the valve cartridge
comprising a first valve seat at a first end of the cartridge
assembly and a second valve seat spaced apart from the first end; a
first valve disposed in the cartridge assembly at the first end; a
second valve disposed adjacent to the second valve seat; a first
resilient member disposed between the first and second valves in
contact with the first valve and the second valve; and a second
resilient member disposed between the second valve and a second end
of the cartridge assembly opposite the first end.
[0006] Other embodiments described herein provide a valve
cartridge, comprising a cage comprising a first valve seat and a
second valve seat; a first valve disposed in the cage, the first
valve having a first stem and a first plug portion; a second valve
disposed in the cage, the second valve having a second stem and a
second plug portion, wherein the second stem is hollow and the
first stem fits within the second stem; a first resilient member
disposed within the second stem between the first stem and the
second plug portion; and a second resilient member disposed between
the second plug portion and the cage, wherein the second valve seat
is between the first plug portion and the second plug portion.
[0007] Other embodiments described herein provide a valve
cartridge, comprising a first valve aligned with a second valve; a
first valve seat at a first end of the valve cartridge adjacent to
the first valve; a second valve seat between the first valve and
the second valve; and a resilient member between the first valve
and the second valve in contact with the first valve and the second
valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above-recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0009] FIG. 1 is a front view of a fluid end assembly coupled to a
pump.
[0010] FIG. 2 is a cross-sectional view of a fluid end assembly
according to one embodiment.
[0011] FIG. 3 is a cross-sectional view of a sleeve used in the
fluid end assembly of FIGS. 1 and 2.
[0012] FIG. 4A is a cross-sectional view of a fluid end assembly
400 according to another embodiment.
[0013] FIG. 4B is a close-up view of the valve cartridge of FIG.
4A.
[0014] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements
disclosed in one embodiment may be beneficially utilized on other
embodiments without specific recitation.
DETAILED DESCRIPTION
[0015] FIG. 1 is a front view of a fluid end assembly 100 coupled
to a pump 102. The fluid end assembly 100 includes a flow box 104
with an inlet 106, which is a suction side, and an outlet 108,
which is a discharge side. The flow box 104 includes an inlet
manifold (not visible in FIG. 1) and an outlet manifold 110. Fluid
being pumped flows into the flow box 104 through the inlet 106 into
the inlet manifold, through valves to be described further below,
into the outlet manifold 110, and through the outlet 108. Piping is
typically connected to the inlet 106 and the outlet 108 to carry
fluid to and from the flow box 104.
[0016] A plurality of valve cartridges 112 is disposed in the flow
box 104 dividing the inlet manifold from the outlet manifold 110.
In the embodiment of FIG. 1, three valve cartridges 112 are shown,
but the fluid end assembly 100 may include any number of valve
cartridges 112. A fluid end cap 118 is removably attached to the
flow box 104, typically at an upper region thereof, or at the
outlet or discharge side thereof, to enclose the fluid end assembly
100. When the fluid end cap 118 is removed, the valve cartridges
112 are removable from the flow box 104 by lifting the valve
cartridges 112 from the flow box 104 through the outlet
manifold.
[0017] The fluid end assembly 100 is coupled to a casing 114 of the
pump at a force end 116 thereof. The fluid end assembly 100 has a
plurality of openings (not visible in FIG. 1) for accommodating
linear force members disposed in the pump casing 114 such that the
linear force members can apply pressure to fluid inside the fluid
end assembly 100. The linear force members are coupled to a power
module 120, which may include a crankshaft. The power module 120
causes the linear force members to reciprocate, extending toward
and away from the fluid end 104 through an adapter 122. Openings
(not visible) in the adapter 122 register with the openings in the
flow box 104 to allow the linear force members to pressurize fluid
in the flow box 104.
[0018] FIG. 2 is a cross-sectional view of one of the valve
cartridges 112 in operating position in the flow box 104. The valve
cartridge 112 includes a first valve 201 and a second valve 200.
The first valve 201 is disposed in a sleeve 206, at a first end 210
thereof, and the second valve 200 is disposed adjacent to a second
end 212 of the sleeve 206. The sleeve 206 is disposed in a housing
208 in the flow box 104. The sleeve 206 is a cylindrical object
with an outer diameter similar to an inner diameter of the
housing.
[0019] In the embodiment of FIG. 2, a first valve seat 202 is
optionally disposed in the first end 210 of the sleeve 206, and a
second valve seat 204 is optionally disposed in the second end 212
of the sleeve 206. The first valve seat 202 is disposed between the
first valve 201 and the first end 210 of the sleeve 206. The second
valve seat 204 is disposed between the second valve 200 and the
second end 212 of the sleeve 206. The valve seats 202 and 204 each
have a seating surface 203 that engages a seating surface 205 of
each valve 201 and 200.
[0020] The first end 210 of the sleeve 206 has a lip 214 that
extends radially inward from the first end 210. The second end 212
of the sleeve 206 has a lip 216 that extends radially outward from
the second end 212. Each valve seat 202 and 204 has a lip 215 that
extends radially outward and engages a portion of the sleeve 206 to
stabilize the valve seat. At the first end 210 of the sleeve 206,
the lip 215 of the first valve seat 202 engages the lip 214 at the
first end 210 of the sleeve 206. At the second end 212 of the
sleeve 206, the lip 215 of the second valve seat 204 engages
directly with the second end 212 of the sleeve 206. The first valve
201 thus operates inside the sleeve 206 while the second valve 200
operates outside, and adjacent to the sleeve 206.
[0021] The valve seats 202 and 204 are optional because the sleeve
206 may be configured with sealing surfaces to engage the sealing
surfaces 205 of the valves directly. For example, valve landings
(not shown in FIG. 2) may be shaped directly into the wall of the
sleeve 206 at appropriate locations to provide sealing surfaces to
engage the sealing surfaces 205 of the valves. Further description
of such optional sealing surfaces is provided below in connection
with FIG. 3.
[0022] The sleeve 206 has an opening 213 in registration with an
opening (not shown) in the flow box 104 to allow fluid
communication to the power adaptor 122 (FIG. 1). The opening 213
typically has an axis orthogonal to a general direction of fluid
flow through the valve cartridge 112.
[0023] Each of the first valve seat 202 and the second valve seat
204 has a first end 218 and a second end 220. In the embodiment of
FIG. 2, the first end 218 of each valve seat has a diameter greater
than a diameter at the second end 220. The lip 215 of each valve
seat has a planar surface 224 extending along a plane perpendicular
to an axis of the valve cartridge 112, which is also an axis of
movement of the valves 200 and 201, and the axis of general fluid
flow through the valve cartridge 112. Each valve 200 and 201 moves
along its axis, and the axis of the sleeve 206 substantially
corresponds with the axes of the valves 202 and 204.
[0024] Each valve seat 202 and 204 also has a tapered side 226 that
extends from the lip 215 at the first end 218 to the second end
220. The lip 215 protrudes radially outward from the tapered side
226 such that the planar surface 224 and the tapered side 226
define an angle. The tapered side 226 has a diameter that declines
monotonically from the first end 218 to the second end 220. The
decline may be linear, may include a linear section, or may be
non-linear. Each valve seat 202 and 204 remains substantially
concentric with the overall axis of the valve along its length.
[0025] The tapered side 226 of each valve seat 202 and 204 provides
additional stabilization of the valve seat, if desired. The lip 215
of the first valve seat 202 engages with the lip 214 of the sleeve
206 along the planar surface 224. Additionally, and optionally, the
tapered side 226 of the first valve seat 202 may engage with an
inner surface of the lip 214 at the first end 210. The lip 214 has
a tapered inner surface 228 that matches the tapered side 226 of
the first valve seat 202 and a planar surface 230 that matches the
planar surface 224 of the first valve seat 202. The tapered
surfaces of the first valve seat 202 and the lip 214 are optional
features. In alternate embodiments, each of the tapered side 226 of
the first valve seat 202 and the tapered inner surface 228 of the
lip 214 may be untapered, i.e. vertical in the view of FIG. 2.
Alternately, the tapered surfaces of the first valve seat 202 and
the lip 214 may be tapered in different ways or at different
angles, or one may be vertical while the other is tapered.
Additionally, the side 226 of the valve seat (tapered or untapered)
and the inner surface 228 of the lip 214 (tapered or untapered) may
define a gap, such that the valve seat 202 engages the lip 214 only
at the planar surface 224.
[0026] The second valve seat 204 engages directly with the second
end 212 of the sleeve 206. In the embodiment of FIG. 2, the second
valve seat 204 also optionally engages an inner wall 232 of the
sleeve 206 at the second end 212. The inner wall 232 is tapered to
match the tapered side 226 of the second valve seat 204. The second
end 212 of the sleeve 206 also has a planar surface 234 that
matches the planar surface 224 of the lip 215 of the second valve
seat 204.
[0027] As with the first valve seat 202, the side 226 of the second
valve seat 204, and the inner wall 232 of the sleeve 206, may
alternately be any combination of tapered and untapered, and may
define a gap such that the second valve seat 204 engages with the
second end 212 of the sleeve 206 only at the planar surface 224 of
the lip 215.
[0028] It should be noted that the lip 215 of the first valve seat
202 may have a radial extent different from the lip 215 of the
second valve seat 204. Likewise, the tapered side 226 of the first
valve seat 202 may have a different taper from the tapered side 226
of the second valve seat 204, which may differ in any or all of
linearity, non-linearity, and angle.
[0029] Each of the first and second valves 201 and 200 is biased
closed by a valve restraint 240. In FIG. 2, the valve restraints
240 are springs. The valve restraint 240 coupled to the first valve
201 is coupled between a rear 217 of the first valve 201 and a stem
242 of the second valve 200. The valve restraint 240 coupled
between the first and second valves 201 and 200 is disposed around
a rear stem 219 extending from the rear 217 of the first valve 201
and around the stem 242 of the second valve 200 which extends from
the front of the second valve 200 toward the first valve 201
through the interior of the sleeve 206. When the first valve 201
opens due to declining pressure between the first and second valves
201 and 200, the second valve 200 remains closed and provides a
biasing force through the valve restraint 240 between the first and
second valves 201 and 200 such that when pressure between the first
and second valves 201 and 200 equalizes, the biasing force urges
the first valve 201 to seat in the first end 210 of the sleeve 206,
stopping fluid flow into the valve cartridge 112 from the inlet
manifold 251.
[0030] The valve restraint 240 coupled to the second valve 200 is
coupled to the rear 217 of the second valve 200 around the rear
stem 219 of the second valve 200. The valve restraint 240 coupled
to the rear 217 of the second valve 200 may be coupled between the
rear 217 of the second valve 200 and a valve cap 244, which may be
attached to the sleeve 206. The valve cap 244 includes a collar 248
that removably engages with the sleeve 206 at the second end 212
thereof by any convenient means such as press fitting, snap
fitting, or threading (in the embodiment of FIG. 2 the collar 248
engages with the second end 212 of the sleeve 206 by a snap fit)
and a crown (not visible in the cross-sectional view of FIG. 2)
that extends from the collar 248 around the rear stem 219 of the
second valve 200 to back-stop the valve restraint 240 disposed
around the rear stem 219 of the second valve 200.
[0031] The valve restraint 240 coupled to the rear 217 of the
second valve 200 provides a biasing force to the second valve 200,
supported by the crown of the valve cap 244. When the second valve
200 opens due to increasing pressure between the first and second
valves 201 and 200, the valve restraint 240 coupled to the rear 217
of the second valve 200 compresses and the biasing force increases.
As the second valve 200 moves away from the first valve 201, the
valve restraint 240 coupled between the first and second valves 201
and 200 may lose contact with the second valve 200 at the stem 242.
As pressure between the first and second valves 201 and 200
equalizes, the biasing force on the second valve 200 urges the
second valve 200 to seat in the second end 212 of the sleeve 206
(i.e. in the second valve seat 204 in the embodiment of FIG. 2),
and the stem 242 moves back into contact with, or close proximity
to, the valve restraint 240 between the first and second valves 201
and 200.
[0032] The valve cartridge 112 is held in place inside the housing
208 by a cartridge restraint 246. The collar 248 of the valve cap
244 may have a landing surface 250 for the cartridge restraint 246
that faces away from the sleeve 206. Alternately, the cartridge
restraint 246 may contact the sleeve 206 directly at the planar
surface 234 or the lip 216. Seals 252 may be provided at the first
and second ends 210 and 212 of the sleeve 206 where the two ends of
the sleeve 206 contact the housing 208. Compression is maintained
on the seals 252 by action of the cartridge restraint 246, which is
compressed between the fluid end cap 108 (not shown in FIG. 2) and
the sleeve 206.
[0033] FIG. 3 is a cross-sectional view of the sleeve 206 of the
valve cartridge 112 of FIG. 2. The tapered inner wall 232 (which is
optional as described above) of the sleeve 206 has a first diameter
at a first end 302 of the tapered inner wall 232 and a second
diameter at a second end 304 of the tapered inner wall 232. The
first end 302 of the tapered inner wall 232 is at the second end
212 of the sleeve 206, and the second end 304 connects to a second
inner wall 306 of the sleeve 206. The second diameter is less than
the first diameter due to the taper of the tapered inner wall 232.
The second inner wall 306 has a diameter that may be the same as,
or different from, the second diameter, either larger or smaller.
In the embodiment of FIG. 3, the diameter of the second inner wall
306 is the same as the second diameter.
[0034] The opening 213 of the sleeve 206 is formed through the wall
of the sleeve 206, and generally has a diameter less than an outer
diameter of the sleeve 206. The diameter of the opening 213 may be
the same as, or different from, the diameter of the second inner
wall 306. In the embodiment of FIG. 3, the opening 213 has a
diameter that is greater than the diameter of the second inner wall
306 such that the second inner wall 306 connects to a curved inner
wall 308, which has a radius of curvature equal to the radius of
the opening 213. The curved inner wall 308 joins a fourth inner
wall 310 which, in the embodiment of FIG. 3, has a constant
diameter substantially equal to the diameter of the opening 213.
The fourth inner wall 310 extends from the point of joining with
the curved inner wall 308 to the lip 214 at the first end 210 of
the sleeve 206. Thus, proceeding from the second end 212 of the
sleeve 206 to the first end 210 of the sleeve 206 is the tapered
inner wall 232, then the second inner wall 306, then the curved
inner wall 308, then the fourth inner wall 310. It should be noted
that fourth inner wall 310 may have a diameter that is the same as,
or different from, the diameter of the opening 213, so long as the
fourth inner wall 310 has a length selected to avoid obstructing
the opening 213. Thus, the fourth inner wall 310 may have a
diameter greater than the diameter of the opening 213. Alternately,
the fourth inner wall 310 may have a diameter less than the
diameter of the opening 213 if the curved inner wall 308 is
extended around the periphery of the opening 213 to join the fourth
inner wall 310.
[0035] As noted above, the separate valve seats 202 and 204 of the
valve cartridge 112 are optional. Shown in phantom in FIG. 3 are
optional valve seats formed in the sleeve 206. A first valve seat
312 is shown at the first end 210 and a second valve seat 214 is
shown at the second end 212. The first valve seat 312 has a seating
surface 316 to engage the seating surface 205 of the first valve
201. The seating surface 316 is angled, or otherwise shaped, to
match the seating surface 205 of the first valve 201 to provide an
operative seal when the first valve 201 is closed. The second valve
seat 214 likewise has a seating surface 318 that is angled to match
the seating surface 205 of the second valve 200. In each case, the
sleeve 206 is shown with an interior wall 320 that is different
from the tapered inner wall 232 and the second inner wall 306. As
shown in phantom the alternative interior wall 320 of the sleeve
206 is has a diameter that is equal to a minimum diameter of the
seating surfaces 316 and 318. In the case of the seating surface
318, the interior wall 320 of the sleeve 206 is shown having a
constant diameter from the seating surface 318 to the opening 213.
For the seating surface 316, the interior wall 320 extending from
the seating surface 316 to the first end 210 Is shown with constant
diameter from the seating surface 316 to the first end 210.
Although such features (constant diameter interior wall) simplify
manufacture of the sleeve 206, the constant diameter of the
interior wall extending from the seating surfaces 316 and 318 is
optional. The interior wall 320 may be shaped in any convenient way
to promote flow of fluid through the valve cartridge 112, pressure
operation of the valves 200 and 201, or for any other reason.
[0036] The sleeve 206 may be made from any material with structural
strength to withstand operating pressures and forces experienced
inside the fluid end 100 and chemically resistant to fluids flowing
through the fluid end 100. In some cases, the sleeve 206 may be
made of a tough plastic such as polypropylene, polystyrene (for
example high impact polystyrene), polybenzimidazole, or hard
styrenic polymers such as acrylonitrile butadiene styrene
terpolymer. In other cases, the sleeve 206 may be made of any
appropriate metal. The various features of the sleeve 206 may be
accomplished by molding and/or by machining according to standard
practices known in the art.
[0037] FIG. 4A is a cross-sectional view of a fluid end assembly
400 according to another embodiment. FIG. 4B is a close-up view of
the valve cartridge of FIG. 4A. The flow box 104 is the same as in
FIG. 1, with the inlet 106, outlet 108, and outlet manifold 110.
Here, the inlet manifold is visible, labelled 402. In the example
of FIG. 4, the fluid end assembly 400 is shown with a cap 403 in
place covering the outlet manifold 110. An inner wall 401 separates
the inlet manifold 402 from the outlet manifold 110 and a plurality
of openings 405 provide fluid flow pathways from the inlet manifold
402 through the inner wall 401 into the outlet manifold 110.
[0038] Three valve cartridges 404 of a different design from the
valve cartridge 112 are disposed in the fluid end assembly 400. As
noted above, the fluid end assembly 400 can be configured with any
convenient number of valve cartridges 404 to match the number of
linear force members. Each valve cartridge 404 fits in a housing
407 formed in the inner wall 401. Each housing 407 is coaxial with
one of the openings 405.
[0039] Each valve cartridge 404 features a first valve 406 and a
second valve 408. The first and second valves 406 and 408 are
engaged in a telescoping relationship. The second valve 408 has a
hollow stem 410 with an inner diameter 412. The first valve 406
also has a stem 414, shown here as a solid stem, but which may also
be hollow. The stem 414 of the first valve 406 thus moves within
the stem 410 of the second valve 408. The first and second valves
406 and 408 have respective plug portions 416 and 418 coupled to
their respective stems 414 and 410. The stem 410 and the stem 414
may be sized with lengths such that an end 420 of the stem 410
contacts the plug portion 416 of the first valve 406 to define a
maximum travel of the stem 414 within the stem 410. A plurality of
openings 422, in this case horizontal (i.e. perpendicular to the
movement axis of the first and second valves 406 and 408), are
provided in the second valve 408 near where the stem 410 meets the
plug portion 418 of the second valve 408 to provide hydrostatic
balancing as the stem 414 moves within the stem 410. Here, there
are four openings 422, but any convenient number of openings 422
may be provided. For example one, two, or three openings 422 may be
provided, or more than four openings 422 may be provided.
Additionally, one, more than one, or all the openings may be angled
in any convenient manner, for example toward or away from the first
valve 406. The hollow stem 410 of the second valve 408 is bored
axially to a depth that provides a desired travel for the stem 414
within the stem 410.
[0040] The first and second valves 406 and 408 are housed in a cage
424. The cage has an upper portion 426 and a lower portion 428. The
lower portion 428 includes a first seat 430 for the first valve 406
and a second seat 432 for the second valve. A plurality of posts
434 connect the first seat 430 to the second seat 432 to provide
structural strength for the lower portion 428. The plug portion 416
of the first valve 406 travels within the lower portion 428 of the
cage 424, while the plug portion 418 of the second valve 408
travels within the upper portion 426 of the cage 424. The upper
portion 426 of the cage features a top plate 434 that provides
structural strength for the valve cartridge 404, and may, in some
cases, provide a contact surface for the cap 403. Here, a gap 435
is provided between the top plate 434 and the cap 403.
[0041] The cage 424 can be molded as one piece including the upper
portion 426 and the lower portion 428 in a single molded article.
Alternately, the upper and lower portions 426 and 428 can be
separately molded and then welded together. For example, the posts
of the upper portion can be welded to the second seat 432. The cage
424 can generally be made of structurally strong plastic or metal
selected based on loading, cycling, and chemistry of anticipated
service. The example plastics listed above in connection with the
sleeve of FIG. 3 can also be used for the cage 424.
[0042] The lower portion 428 of the cage 424 fits within the
housing 407. The first seat 430 contacts a floor 444 of the housing
407 such that the first seat 430 is adjacent to the opening 405.
The first seat 430 has an inner wall 429 with a dimension that is
substantially the same as a dimension of an inner wall 431 of the
opening 405. It should be noted, however, that flow characteristics
of the fluid end assembly 400 can be changed by using a valve
cartridge with a first seat that has an inner wall with dimension
different from that of the inner wall 431 of the opening 405. For
example, if the dimension of the inner wall of the first seat is
smaller than the dimension of the inner wall 431 of the opening
405, flow through the fluid end assembly 400 can be constrained.
Such flow characteristics can be changed by swapping a first valve
cartridge having a first flow rating with a second valve cartridge
having a second flow rating different from the first flow rating,
without changing any other pump hardware.
[0043] The housing 407 has a first portion 446 and a second portion
448. The first portion 446 extends from the floor 444 to the second
portion 448. The first portion 446 has an inner wall 447 with a
dimension larger than the dimension of the inner wall 431 of the
opening 405. The second portion 448 has an inner wall 449 with
dimension larger than the dimension of the inner wall 447 of the
first portion 446. As described above, the first seat 430 contacts
the floor 444 of the housing 407. The first seat 430 has an outer
wall 450 with a dimension that is smaller than the dimension of the
inner wall 447 of the first portion 446, so the first seat 430
contacts the housing 407 only at the floor 444 thereof. The second
seat 432 has an outer wall 452 with a dimension larger than the
dimension of the outer wall 450 of the first seat 430 and larger
than the inner diameter 447 of the first portion 446. The outer
diameter 452 is substantially the same as the inner diameter 449 of
the second portion 448 such that the second seat 432 contacts the
second portion 448 at a sidewall thereof. The first portion 446 and
the second portion 448 together define a shelf 454 that extends
from a side wall of the first portion 446, at the top end of the
first portion 446, to the side wall of the second portion 448, at
the bottom end of the second portion 448. The second seat 432 also
contacts the shelf 454, and thus provides a snug fit of the second
seat 432 within the second portion 448 of housing 407 at the shelf
454.
[0044] A first seal member 460 is disposed in a groove 462 along
the bottom surface of the lower portion 428, which contacts the
floor 444 of the housing 407, to provide a first seal between the
valve cartridge 404 and the inner wall 401. A second seal member
464 is provided in a groove 467 around the periphery of the second
seat 432, where the second seat 432 contacts the side wall of the
second portion
[0045] The second valve 408 has a rear stem 436 oriented toward the
top plate 434. The top plate 434 has an alignment bore 438 that
extends from an inner surface of the top plate 434 toward the plug
portion 418 of the second valve 408. The rear stem 436 is inserted
into the alignment bore 438 of the top plate 434, and travels
within the alignment bore 438 to maintain alignment of the first
and second valves 406 and 408. In this case, the second valve 408
can travel until the plug portion 418 of the second valve 408
contacts an end 440 of the alignment bore 438. At that time, the
rear stem 436 protrudes above the top plate 434 into the gap 435.
Length of the alignment bore 438 is selected to provide sufficient
travel for the second valve 408 based on flow characteristics
needed for the valve cartridge. Thickness of the top plate 434 can
be varied to optimize structural strength and cost. The top plate
434 is connected to the second seat 432 by a plurality of posts 442
that provide structural strength for the upper portion 426 while
allowing fluid flow through the upper portion 426 into the outlet
manifold 110.
[0046] While the foregoing is directed to embodiments of the
invention, other and further embodiments of the invention may be
devised without departing from the basic scope thereof.
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