Note: Descriptions are shown in the official language in which they were submitted.
213 5 613 ~ ~.j.~S93/02379~
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1
FLUID PRESSURE INTENSIFYING APPARATUS
FIELD OF THE INVENTION w
This invention relates to high pressure fluid intensifier
systems. More particularly, this invention relates to check
valve assemblies for controlling fluid flow into and out of
the high pressure intensifier chamber.
BACKGROUND OF THE INVENTION
In a typical high pressure fluid intensifier system,
hydraulic fluid acts on a reciprocating double-acting, low
pressure-high pressure piston assembly to compress water to
over several thousand psi. The piston assemblies of such
systems are exposed to hydraulic fluid pressures on the order
of 2,000 psi and to outlet water pressures on the order of 20-
60,000 psi. These. assemblies must be designed to withstand
tremendous pressure fluctuations while at the same time
maintain hydraulic fluid/water separation.
The inlet and outlet valve members of the pressurized
fluid check valve assembly and their valve seats are severely
stressed. Replacement of the valve members and their seats
periodically is difficult because of the attachment of the
various members making up the intensifie,~ pressure chambers
and piston assembly. Usually, the intensifier must be
completely dismantled.to reach and repair or replace such
internal elements.
In my U.S. Patent No., 4,818,194, I describe a check
valve assembly that is designed to be accessible for service
without dismantling the intensifier appurtenant thereto. In
this patent, the check valve assembly is so arranged that the
high. pressure water outlet portion is provided at the outer
end of the assembly adapter. In this design, removal of the
adapter exposes the high pressure valve element and its seat
for service or replacement. Also in this design, the inner
low pressure end of the check valve assembly, which requires
service less often, is accessible when the entire assembly is
removed from the intensifier. A check valve retainer ring
' secures the assembly to the intensifier, in this design, and
the ~tetainer ring is easily removed so that the check valve
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WO 94120754 ' PCTlUS93102379
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assembly can be removed without dismantling the intensifier.
When the various parts are serviced or replaced, it is a '
simple matter, in this design to re-install the check valve
assembly in full working condition, without having to be '
concerned about the relative alignment of the other components v,
that make up the complete intensifier system.
SUMMARY OF THE INVENTION
The check valve assembly of this_invention is designed
similarly to the assembly described in my U.S. Patent No.,
4,818,194. A similar valve body and check valve retainer ring
concept is employed to secure the check valve mechanism to the
intensifier. The operating components within the valve body,
however, are different. The internal valve mechanism provided
by the present invention comprises a high pressure ball poppet
sub-assembly for the outlet flow that is conveniently
accessible for service or replacement when the valve body
remains i:~stalled in the intensifier assembly. This ball
poppet configuration could also be a flat poppet type which
may be superior in some pressure ranges. A flat poppet and
seat open to permit inflow water in the high pressure barrel.
The inlet poppet is guided in such a way~as to insure nearly
perfect parallelism of the sealing surfaces at the instant of
contact. This is extremely important as contact of the poppet
on an edge,prior to flat contact causes heat, erosion, and
25' short life. The internal valve mechanism also is so
constructed that the cycling pressure on the higr. pressure
ball poppet sub-assembly during operation is contained within
a compressive stress field to reduce the possibility of
failure due to fatigue.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure d is a section through the right half of the
intensifier assembly illustrating the right hand check valve ,
in place;
Figure 2 is an enlarged cross section of the inlet/outlet
check valve assembly of this invention;
Figure 3 is a perspective view of the outlet valve ball
'poppet carrier;
CA 02135613 2003-12-17
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Figure 4 is a cross section illustrating the relative
positions of the outlet valve ball, the outlet valve ball
poppet carrier and its sleeve, and the outlet valve ball seat,
the view hereof of the outlet valve ball poppet carrier being
through lines 4-4 of Figure 3; and
Figure 5 is a section through the left end of the
intensifier assembly illustrating the left hand check valve in
place.
DETAILED DESCRIPTION OF THE INVENTION
l0 An intensifier arrangement utilizes hydraulic working
fluid (oil) to drive a high pressure-low pressure piston
assembly to produce a high pressure water flow. The
intensifier shown in Figures 1 and 5 is double-acting. In
comprises a housing to in the form of an elongated steel
cylinder. One half, the right half, is shown in Figure 1 and
the left end is shown in Figure 5. The left half is a
duplicate, a mirror image with the exception for the left hand
retainer ring, as will be described and explained hereinafter.
This intensifier assembly is described in greater detail in my
U.S. Patent No. 4,747,758.
Each end of the
housing mounts an end retainer ring, the right hand retainer
ring being designated 12 and the left hand retainer ring 12a,
the end of housing 10 being internally threaded to mate with
external threads on the retainer rings 12, 12a. Within
housing 10, a low pressure chamber 14 is provided by a steel
cylinder 16 fitted onto a cylindrical end cap 18 at each end
(the right hand cap being shown; the left hand end cap is an
opposite hand duplicate). All within housing 10, a right hand
and a left hand high pressure chamber are provided (the right
hand high pressure chamber 30 being shown in Figure 1 and the
left hand high pressure chamber 30a being shown in Figure 5),
each by an elongated steel barrel cylinder 22, 22a fitted at
its inner end into end cap 18 and at its outer end onto a
valve body 24, 24a of an inlet/outlet water check valve
assembly 25, 25a. Valve body 24, 24a is provided with a
machined external rim 2, 2a which is engaged by a
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WO 94/20?54 PCT/US93/023?9 ~ ~~;
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corresponding inner rim of retainer ring 12, 12a. A cylinder
sleeve or liner 20, 20a is confined within the high pressure
cylinder 22, 22a and defines the cylindrical periphery of the
high pressure chamber 30, 30a. End retainer ring 12, 12a,
acting through valve body 24, 24, centers the outer end of
cylinder 22, 22a, and consequently, the inner liner 30, 30a,
so that the cylinder rod 31, 31a will have an exactly axially-
aligned chamber 30, 30a within which to reciprocate.
Since the retainer ring 12a on the left hand side is
fixed, when snugged up to the housing 10, it establishes the
proper axial orientation of the high pressure module relative
to the housing 10. The right hand retainer ring 12 is snugged
up to the right hand end of the housing 10; then a second
preload ring 61 with six bolts hole 63, which match six
threaded holes 65 in the retainer ring 12, is screwed unto the
end of the retainer ring l2. The six bolts 59 are torqued
producing a force exerted on the flange of the right hand
check valve body 24, transmitted axially through the
components of the high pressure module, and seated'by the left
hand retainer ring 12a at the left end of the housing 10. The
torque value applied to each of the six p~eload bolts produces
a load greater than that force generated internally by the
pressurized water exerted on the area at the end of the high
pressure barrel. Hy this preload method, the components in
Z5 the stack-up of the high pressure module are forced to
maintain contact with each other during each complete cycle of
operation, thus in large part preventing gaps between the
contacting surfaces of,the high pressure components which
could allow extrusion of seal material and subsequent seal
~ breakdown and failure. The retainer ring 1:2a on the left hand
side is the same geometric configuration as the right had
retainer ring 12 but with a flange projection through which ,
f
the left hand check valve body 24a protrudes. The left hand
retainer ring 12a has a sufficiently small insider diameter to
provide a flat annular area which the shoulder of the left
hand check valve body 24a can contact and which can react to i
- the preload produced by the preload ring 61 on the right hand
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:. J 94/20754 . . PCT/US93/02379
side.
The outer surface of end cap 18 conforms to the inner
surface of housing cylinder 10, with a small allowance for a
slip-fit clearance. Tightening the end of preload ring 61
5 places the pressure chamber elements in longitudinal
compression and the housing cylinder 10 in longitudinal
tension. When one or both end retainers are removed, however,
these elements maybe removed from the housing in a very
expeditions manner. The low pressure and high pressure
cylinders, 16 and 22, 22a, are mounted in axial alignment with
the housing cylinder 10 by the end caps 18 and the retainer
rings at both ends. Because of the relative dimensions of the
elements thus far described, the pressure chamber elements are
confined against any lateral or longitudinal movement.
The low pressure-high pressure piston assembly comprises
a low pressure piston 26 and left and right hand high pressure
pistons 31a, 31. The low pressure piston is a cylindrical
disk contained with low pressure chamber 14. Its outer
surface conforms to the inner surface of low pressure cylinder
16, with a small allowance for a slip-fit clearance, and
mounts appropriate hydraulic pressure sgals 32 to seal one
side of low pressure chamber 14 from the other. The high
pressure pistons 31, 31a, are ground and polished carbide rods
connected to opposite faces of the low pressure piston 26 and
extended through the respective cylinder end block 18 into the
high pressure chamber sleeve 20, 20a.
Reciprocation of the high pressure piston is effect as a
consequence of hydraulic working fluid being pumped into low
pressure chamber 14 on one side of low pressure piston 26 or
the other. Each end cap 18 is ported as at 60 to provide for
hydraulic fluid flow into and out of low pressure~chamber 14.
An inlet tube 62 is screwed into port 60 for connection to a
hydraulic fluid supply. When hydraulic fluid is pumped
through port 60 into chamber 14, low pressure piston will be
driven leftward from the position shown, thus retracting the
right hand high pressure piston rod 31 and extending the left
hand high pressure piston rod 31a. Concurrently, hydraulic
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wo 94no~s4 213 5 613 PCTIUS93I02379 ~ 1
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fluid will be vented through the hydraulic fluid port in the
left hand cylinder block, and water in the left hand high
pressure chamber will be compressed and forcsd out through the
left hand valve body 24a. When low pressure piston 26 reaches '
the left end of low pressure chamber 14, hydraulic fluid flow
will be reversed and low pressure piston 26 will be driven ~ '
rightward. Hydraulic fluid will be vented through right hand
cylinder block prot 60 and water in high pressure chamber 30
will be compressed and forced out through valve body 24.
Now, with respect to the right hand check valve assembly
25 (the left hand check valve assembly being a duplicate and
represented by the same numerals with a lower case "a"
associated therewith, such as "25a" and so forth), the outer
end of high pressure cylinder 22, 22a fits over a pilot or
shoulder that protrudes from the check valve body 24. Valve
body 24 is machined to provide a stepped cylindrical pilot 3
for that purpose. A Delrin polycarbonate ring 5 is pressed
onto the outer shoulder of the pilot 3 at the inner side of
the valve body 24. The face of the ring 5 enters the high
pressure barrel 22 and, being softer, prevents damage to the
very critical surface finish of the inner bore of the high
pressure barrel 22. The end of the pilot is machined to
provide a smaller cylindrical end surface which is externally
threaded to accept a valve body nose 4 as a seat for a high
pressure static seal group 44. The stepped transition between
the high pressure cylinder-mounting pilot and the high
pressure seal seat afforded by nose 4 provides a metal back-up
for seal group 44. The nose 4 restrains the inner edges of
the static seal group, and houses the return spring 106 for
the low pressure poppet 100 and poppet guide 102.
As high pressure piston rod 31 is retracted from the
position shown, low pressure water is drawn into a high
pressure chamber 30 through inlet passages 50 in inlet/outlet
valve body 24. When piston rod 31 is driven back to the
position shown, water is compressed to a high pressure and
then forced out through outlet passage 54 in check valve
assembly 25. Water flow into and out of high pressure chamber
30 is controlled by water pressure-influenced poppet-type
outlet check and inlet valve subassemblies 52 and ~3.
Inlet/outlet check valve assembly 25 comprises valve body
24, low pressure water inlet manifold 51 communicating with
low pressure water inlet passages 50 through an annular water-
distributing interface 55 between the outer face of valued
body 24 and the inner face of manifold 51, outlet water poppet
subassembly 52, inlet water poppet subassembly 53, high
pressure outlet water line adapter 58 communicating with high
pressure water outlet passage 54, and manifold lock nut 59
sealing manifold 51 to the valve body 24. The outer end of
valve body 24 is externally threaded and manifold lock nut 59
is screwed thereon to water-tightly seal manifold 51 to the
outer face of the valve body. Low pressure water inlet line
56 is attached to manifold 51 and high pressure water outlet
line 57 is attached to adapter 58. The inner face of manifold
51 is counter bored to provide annulus 55 for distribution of
inlet water from inlet line 56 to inlet passages 50.
i
The check valve assembly, as shown in enlarged detail in
Figure 2, comprises an inlet disk poppet 100, an inlet poppet
guide tube 102 inserted into an axial bore 104 extending
axially through the valve body 24 as shown, inlet poppet
closing spring 106 and nose 4. Inlet water passages 50 are
bored through valve body 24 to open at the outer surface of
the protrusion, pilot 3, as shown. Inlet disk poppet 100 has
a planer inner surface that mates with the circular outer end
surface of pilot, or protrusion, 3 to seat thereagainst and
seal off the inlet water passages 50. Nose 4 is a metal end y
cap having a cylindrical inner diameter large enough to permit
inlet poppet 100 to reciprocate to and from contact with the
ce. The end of the nose cap is bored~to provide
pilot end fa
several apertures for passage of water into and out of the
nose 4. The outer end surface of inlet poppet 100 is
counterbored to receive a coil compression spring 106, and the
inner end of the nose cap is likewise counterbored to receive
the opposite end of spring 106. Spring 106 urges inlet poppet
against the end face of pilot 3 to seal off the inlet water
8
passage 50. Guide tube 10? is inserted into the valve body
outlet water passage 104 and extends through inlet poppet 100 '
and terminates in a hollow flange 108. Guide tube 102
protrudes from the end face of pilot 3 a sufficient distance '
that the inlet poppet can travel between the pilot end face
and the adjacent annular surface of the flange 108 to expose '
the inlet water gassages 50. When inlet water is to pass into
the intensifier high pressure chamber 30 for compression, the
force of the inlet water will act against the inner annular
surface of the inlet popper 100 and force it away from sealing
engagement with the end face of pilot 3 so that water can pass
from the inlet water passages 50, around poppet 100 and into
the chamber of nose 4 and out through the apertures 110 into
the end of the nose cap into the intensifier high pressure
chamber 30. During operation of the intensifier, the build-up
of water pressure in the compression cycle will cause the
inlet poppet 100 to closes against the end face of pilot 3
thereby sealing the water inlet passages 50 to prevent high
pressure water form entering the low pressure inlet water
.20 system. High pressure water will pass through the apertures
i of the nose 4 and through the hollow flare 108 and into the
guide tube 104 for passage through the valve body. When
intensifier operation is stopped, the force of compression
spring 106 will cause the inlet poppet to closes to prevent
inlet water from flowing back through the valve body.
The check valve assembly, as shown in enlarged detail in
Figure 2, and with certain elements further shown in Figures
3-4, comprises an outlet ball poppet 110, an outlet poppet
valve seat 112, an outlet valve seat retainer sleeve 114, an
~ outlet poppet ball retainer cage 116, and a ball return spring
118. The valve body 24 is machined to provide an axial '
P
cylindrical counterbore that terminates in a hemispherical . s
inner end as shown. The ball poppet valve seat 112 is v
configured with a hemispherical surface at one end to mate ,
i
with the hemispherical inner end of the valve body counter '
bore just mentioned. The edge of the opposite end of the ball
' valve seat 112 is chamfered 45°. The center of the flat
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surface insider the inner edge of the chamber has a
hemispherical seat for the ball poppet. in Figure 2, the
leftward end of the valve seat 112 is hemispherical and the
rightward end is flat with the chamfered edge. The outlet
ball 110 has a spherical configuration designed to seat within
and against the rightward hemispherical surface of the valve
seat. The ball valve seat 112 is bored to provide an axial
j passage 113 communicating with the axial byre 104 through the
c
valve body, bore 104 terminating at the axial base of the
valve body hemispherical inner end aforementioned. Valve seat
retainer sleeve 114 is a cylindrical sleeve inserted into the
valve body counterbore and chamfered to provide a 45° frusto-
conical inner edge that bears against the rightward chamfered
conical surface of the valve seat 112. Valve seat retainer
sleeve 114 is contacted by the inner end of the adapter 58 and
forced into engagement with the valve seat 112 so as to retain
the valve seat 112 firmly against the hemispherical end of the
valve body counterbore with its axial passage aligned with the
valve body axial bore 104. The inner edge of the frusto-
conical inner end of the valve sear retainer sleeve 114 is
coplaner and, consequently, when the retainer is forced
against the valve seat frusto-conical surface, any
misalignment of the valve seat with respect to the axis of the
valve body and its axial bore 104 will be corrected by causing
the valve seat 112 to rotate until seated accurately. Since
adapter 58 is threaded into the valve body, screwing the
adapter into the valve body will automatically force the valve
seat 112 to be properly seated in the correct axial attitude.
The outlet valve ball retainer cage 116 has a cylindrical
configuration with a diameter machined to provide a small
allowance between it and the inner surface of the retainer
sleeve 114 so that a sliding fit is achieved. The inner end
of the cage 116 is machined to provide a conical surface 116a
which captures the ball poppet and maintains alignment of the
ball poppet 110 with the spherical seat in the rightward end
of the seat. The retainer cage 116 is shorter than the
passage within which it sets so that a small gap exists
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wo 94n0754 _ 213 5 fi 13 ~/US93/02379 ~ y
between the inner end of adapter 58 and the rightward end of
the cage 116. Compression spring 118 fits into axial
counterbores in the adjacent ends of the adapter 58 aad the
cage 116 to urge the cage 116 leftward to force the ball
5 poppet 110 to seat into the recess provided therefor in the
rightward end of the valve seat 112. The retainer cage 116 is
provided with several longitudinal slots 116b in it s outer
surface to provide fluid passages between it and the valve
sear retainer sleeve 114, and the rightward end of the cage is
10 also slotted to provide radial cross-slots 116c connecting
with the longitudinal peripheral slots.
When high pressure water reaches a predetermined level,
as a result of the compression cycle of the intensifier
system, high pressure water flows into the nose cage 4,
through the apertures 110, through the hollow flange 108 and
the guide tube 102, axial bores 104 and 113, to force ball
poppet 110 away from its valve seat 112 (thereby forcing ball
cage 116 rightward until its rightward end contacts the inner
end of adapter 51~ so that the high pressure water can flow
around the ball poppet 110 to the longitudinal slots 116b in
the periphery of the cage 116, through these slots and through
the radial cross slots 116c in the end of the cage, and out
through the axial passage 54 in adapter 51. When the
intensifier compression cycle is completed, back pressure from
the water in line 57 will cause ball poppet 110 to re--seat in
the ball recess of valve seat 112 and seal off the high
pressure water path leftward of that point. when back
pressure from line 57 is insufficient to force the ball poppet
110 back onto its seat, as would be the case when the system
is shut off and the high pressure water line 57 is drained,
the force of compression spring 118 will re-seat the ball
poppet so that low pressure water will not flow from the inlet ,
line 58, through the valve body inlet passages 50 into the
nose 4 and then be detoured and flow back through the inlet ,
passages 102, 104, and 54 to outlet line 57.
Of the two poppet sealing surfaces, the sealing surfaces
associated with the ball outlet poppet 114 incur much more
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i sever stress. This stress is debilitating and can causes
premature failure of the valve seat 112, the ball poppet 110 '
or the retainer cage 1i6. This stress on the valve seat 112
f
is considerably minimized by the provision of the valve seat
retainer 114 being wedged against the valve seat when the
adapter 58 is screwed into position as aforementioned. This
relationship of the chamfered edge of the retainer 114 bearing
against the chamfered surface of the seat 112, creates a
compression stress field within the seat 112 which minimizes
the possibility of a fatigue failure within the seat. This is
so because the compression stress thus created will cause the
maximum value of the cyclic stress fluctuation, caused by
fluctuating water pressures, to remain below the endurance
limit of the material of the seat 112.
To summarize:
Incoming low pressure water enters the manifold 55,
r
passes through the angled passages 50 through the body 24,
fw unseating the low pressure poppet 100 against the spring force
of spring 106, passes through the annular area between the
inside bore of the nose 4 and the outside of the poppet 100,
and out through the holes in the end of~the nose into the high
pressure barrel chamber 30. The high pressure fluid in the
outlet passage 57 maintains sealing between the ball poppet
110 and the sealing seat 112 during charging of the high
pressure barrel chamber:
Upon reversal of the high pressure piston 31, increased
fluid pressure seats the low pressure poppet 100 against the
common surfaces of the body 24 and unseats the ball poppet 110
from its seat 112 against the decaying fluid system pressure
30~ and pumps the high pressure fluid past the ball 110, ball
carrier 116, spring 1i8, and through the outlet adapter 58.
Upon reversal of the high pressure piston 31 again, the
ball poppet 11,0 seats in its, spherical seat 112 and high
pressure water'at system pressuxe is prevented from back
flowing into the valve. Downstream of the adapter 58,
whatever use is made of the high pressure water will deplete
the flow and the system pressure downstream will gradually
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WO 94120?54 _ ~ ~ ~ ~ ~ ~ ~ ~ PCT/US93/023?9
12
decay. Thus, spring 118 acts through ball carrier 116 to keep
ball poppet 110 seated, while low pressure water is directed '
into the high pressure barrel chamber 30 as described above.
When the outlet valve mechanism requires servicing, the
adapter 58 is unscrewed and removed. The, the spring 118,
bald poppet retainer 116, ball poppet 110, valve seat retainer
sleeve 114, and the valve seat 112 may be removed and
polished, resurfaced or replaced, as may be required. These
high pressure outlet valve elements are the most likely to
require periodic maintenance. When reinserted, the
hemispherical surfaces of the valve seat cavity and the valve
seat itself facilitate the automatic alignment of the valve
seat 112 so that the valve seat passage 113 and the valve body
passage 104 are exactly aligned. When the valve seat retainer
'114 is positioned and the adapter 58 screwed back into
position, the valve seat 12 must align properly,
automatically, because the frusto-conical edge of the valve
seat retainer 114 will force realignment until it uniformly
contacts the chamfered surface of the valve seat 112.
If the inlet valve mechanism requires servicing, the
intensifier assembly end cap 12, 12a is screwed and removed,
after removing the six preload bolts 59. Then, the valve body
24, 24a can be removed and the nose 4 can be unscrewed to
expose the inlet valve elements.
While the preferred embodiment of the invention has been
described herein, variations in the design may be made. The
scope of the invention, therefore, is only to be limited by
the claims appended hereto.
The embodiments of the invention in which an exclusive
E 30 property is claimed are defined as follows:
