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Патент USA US3024743

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March 13, 1962
c. |_. ENGLISH
3,024,733
SUBSURF'ACE FLUID-OPERATED PUMP
Filed March 18, 1960
2 Sheets-Sheet l
74
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IN VEN TOR.
CHAQLes La LLA/@UGH
March 13, 1962
C. L. ENGUSH
3,024,733
SUBSURFACE FLUID-OPERATED PUMP
“Y „dv/M»
United States Patent O " ÍCC
1
3,024,733
Patented Mar. 13, 1962
2
on the main valve to hydraulically shift the main valve.
When a single pilot valve of this type is used, the pilot
3,024,733
SUBSURFACE FLUID-OPERATED PUMP
Charles L. English, Tulsa, Okla.
Filed Mar. 18, 1960, Ser. No. 15,946
valve is invariably subjected to varying Huid pressures,
as well as varying frictional forces, when the pump unit
is subjected to abnormal operations, such as in gassy well
conditions. These various unpredictable forces on the
pilot valve will frequently cause the pilot valve to pre
20 Claims. (Cl. 10B-_46)
This invention relates generally to improvements in
fluid-operated pump units such as are used in producing
maturely change position and provide a premature shift
oil wells, and more particularly, but not by way of limita
ing of the main valve, such that the piston assembly
tion, to an improved fluid motor.
ll) merely oscillates through an unduly short stroke length.
As it is well known in the oil producing industry, oil
wells which have ceased flowing naturally are frequently
The other basic type of valve mechanism is exempliñed
in my co~pending application entitled “Oil Well Pump,”
ñled October 9. 1959, Serial No. 845,571, now Patent No.
2,943,576. This latter type of Valve mechanism includes
produced by subsurface fluid-operated pump units. The
tluid-operated pump unit is supported in the lower por
tion of an oil well and is energized by directing high pres
only what may be considered a main valve which is phys
sure fluid, usually oil, from the surface downwardly
ically unseated at the opposite ends of the movement of
through the well bore to the engine or motor end of the
pump unit. The pump unit operates to force well fluids
the piston assembly. but includes choking elements on
the valve for controlling the application of fluid pressures
und exhausting power fluid upwardly through the well
bore to the surface. Generally speaking, subsurface fluid
operated pump units have performed satisfactorily and
to the valve after the valve is unseated for hydraulically
shifting the valve from one operating position to another.
Such a valve mechanism is simple in construction and has
been found exceptionally efñcient in many operating en
possess several distinct advantages over the more conven
tional sucker rod type pumps which are mechanically ac
tuated by a surface power unit and require a string of rods
vironments. However, the mechanical unseating of the
valve possesses some inherent disadvantages. Since the
amount of mechanical forces which can be applied to the
extending from the surface of the well downwardly to
the subsurface pump. However, prior subsurface fluid»
operated pumps have operated unsatisfactorily in some oil
wells, which has prevented such pumps from being what
valve is limited by the physical strength of the actuating
members for the valve. the force with which the main
valve may be held on its operating seats is also limited.
may be considered universally accepted. For example,
prior subsurface huid-operated pump units have frequently
operated unsatisfactorily in wells having a high gas-oil
Furthermore, the magnitude of the hydraulic forces im
posed on the valve after it is unseated are also related to
the force with which the valve can be held on either of
its seats. As a result, any foreign matter which may be
ratio. ln such well conditions, the motor and pump pis
tons have a tendency to move with excessive speeds, and
come trapped between cooperating surfaces of the valve
most prior pump units fail to make complete strokes in
and the piston assembly will tend to hold the valve in an
such gassy well conditions.
C3 Cil intermediate and inoperative position. Also, the forces
Most, if not all, present<day subsurface Huid-operated
applied on the valve limit the speed with which the valve
pumps include an engine or motor piston assembly hav
is shifted at the end of a stroke of the piston assembly,
ing a main valve therein which controls the flow of high
such that the unseating of the valve must take place a
pressure ñuid to either one or both ends of the motor
short time prior to the end of a stroke. Therefore, under
cylinder and opens an exhaust passageway from at least
unusual operating conditions, the pump sometimes fails to
one end of the motor cylinder when power oil is being
move through its maximum stroke length, which reduces
supplied to the opposite end of the motor cylinder. These
the overall efficiency of the pump unit.
main valves are of various designs, but are reciprocally
The present invention contemplates a novel pump unit
which may be utilized in substantially any pumping en
disposed in the piston assembly for a shifting movement
as the piston assembly reaches or approaches the opposite
ends of the motor cylinder. When the main valve is com
pletely shifted from one of its operating positions to an
other, the flow of power oil and exhausting power oil is
sure to the main valve at the end of one stroke of the
reversed to reverse the movement of the piston assembly.
lt will therefore be apparent that if the main valve is
shifted prior to the completion of a stroke of the piston
of lluid pressure to the main valve at the end of the other
stroke of the unit. Since each pilot valve has only one
vironment, The pump unit includes a novel valve assem
bly comprising ‘a main valve and two pilot valves. One
of the pilot valves controls the application of tluid pres
unit and the other pilot valve controls the application
assembly, the piston assembly will still be immediately
reversed.
operatingr position, the pilot valves may be easily retained
in their inoperative positions during the major portion of
On the other hand, if the main valve is not
shifted early enough, the piston assembly will tend to
the cycle of operation of the unit and will not be affected
by abnormal pressure conditions ín the motor or engine
end of the unit. Also, since the main valve is unseated
knock against the end of the motor cylinder and cause
damage to the intricate pump construction. lt may be
noted that if the main valve tends to shift prior to the
and shifted solely by the application of huid pressures
controlled by the pilot valves, the effective pressure areas
of the main valve may be of sufficient size to securely hold
the main valve in a desired operating position and to
completion of the strokes of the piston assembly, the pump
end of the device tends to “cavitate” in gassy wells, that
is. the pump plunger will merely reciprocate in a gaseous
medium and will not create suñîcient suction in the pump
cylinder to draw in oil from the well bore.
Basically, two types of valve mechanisms have been
used to shift the main valve as a piston assembly reaches
the end of its stroke, as well as hold the main valve in 65
the desired position during a stroke of the piston assembly.
In one type of valve mechanism, a single pilot valve ex
tends from one end of the piston assembly and is slid
ingly secured to one end of the motor cylinder, such that
the pilot valve is mechanically shifted as the piston assem
bly reaches the end of either of its strokes. The pilot
valve in turn controls the application of lluid pressures
assure that the main valve will be shifted from one
operating position to another. Therefore, the operation
of the valve mechanism will be substantially unaffected
either by foreign matter entering the unit, as by means of
dirty power oil, or by varying pressure conditions in the
motor end of the unit. ln a preferred construction, at
least one of the pilot valves is in the form of a ball type
valve which may be constructed of minimum size for
controlling the application of maximum fluid pressures on
70 the main valve and yet will have a minimum resistance
against unseating as the piston assembly reaches the end
of astroke.
3,024,733
3
4
An important object of this invention is to provide a
subsurface huid-operated pump unit which will operate
art. The standing valve assembly 34 comp-rises a tubular
body 38 having an upwardly facing valve seat 40 therein
efiiciently in substantially all environments.
to receive a valve member 42. The valve member 42 is
provided with a stem 44 slidingly positioned in a tubular
guide 46 to retain the valve member 42 concentric with
Another object of this invention is to provide a sub
surface ñuid~operated pump unit which will not be ren
dered inoperative by a normal amount of foreign matter
in the high pressure fluid used for operating the unit.
Another object of this invention is to provide a novel
valve mechanism for a lluid motor wherein the minimum
force is required for actuating the pilot valves of the
mechanism.
A further object of this invention is to provide a novel
valve mechanism for a lluid motor utilizing a main valve
which will be held on its operating seats or in its operat
ing positions with maximum forces and will be shifted
between its operating positions with the maximum forces.
but wherein the minimum physical forces are imposed
on the valve mechanism.
A more specific object of this invention is to provide
the valve seat 40. The upward, opening movement of
the valve member 42 is limited by a suitable perforated
stop 48. It will be apparent that the valve member 42
moves upwardly to `an open position when the pressure in
the lower end of the pump cylinder 28 is less than the
pressure below the tubular standing valve body 38, and
that the valve member 42 will move downwardly to a
closed position on the seat 40 when the pressure in the
lower end of the pump cylinder 28 is greater than the
pressure below the valve member. Suitable threads 50
may be provided in the lower end portion of the valve
body 38, if desired, for supporting a gas anchor (not
shown) on the lower end of the pump unit 10 in the usual
fashion.
a valve mechanism for a fluid motor utilizing two pilot
A tubular pump piston 52 is reciprocally disposed in
valves and wherein the pilot valves will not be inadvert
ently shifted or actuated by abnormal pressure conditions
the pump cylinder 28 and is provided with a plurality
of piston rings 54 around the outer periphery thereof
which slidingly and sealingly engage the inner periphery
of the pump cylinder 28 during reciprocation of the pump
piston. A seating member 56 is threadedly secured in
the lower end of the pump piston 52 and is provided
with an upwardly facing annular seating area 58 at the
in the motor.
A still further object `of this invention is to provide a
subsurface fluid-operated pump unit which is simple in
construction, may be economically manufactured, may
be easily repaired and which will have a long service life.
upper end thereof to receive a valve member 60. The
Other objects and advantages of the invention will be
valve member 60 is provided with a stem 62 extending
evident from the following detailed description, when
read in conjunction with the accompanying drawings 30 downwardly therefrom and slidingly received in a tubu
lar guide 64 formed in the valve seating member 56.
which illustrate my invention.
In the drawings:
It will therefore be apparent that the valve member 60
moves upwardly when the pressure below the piston 52
FIGURE lA is a vertical sectional view through the
is higher than the pressure above the piston 52, and
engine or motor end of a pump unit constructed in ac
cordance with this invention.
FIGURE 1B is a continuation of the pump unit from
the lower end of FIG. 1A and is a vertical sectional view
through the pump end of the unit.
FIGURE 2 is a vertical schematic sectional view
vice versa, such that the pump 14 is what is commonly
known in the art as a single-acting pump.
It may also
be noted that the upstroke of the pump piston 52 is the
working stroke.
A hollow connecting rod 66 is connected to the upper
through the engine end of the pump unit illustrating the 40 end of the pump piston S2 and extends vertically up
position of the valve mechanism at the end of the down
ward through the middle plug 26 into connection with
stroke of the unit.
the motor l2, as will be described. It should be noted
FIGURE 3 is a view similar to FIG. 2 illustrating the
here, however, that the lower end 68 of the hollow con
position of the valve mechanism at the beginning of the
necting rod 66 is in communication with the interior of
upstroke of the unit.
the piston S2 through a bore 70 to provide a continuous
FIGURE 4 is another view similar to FIG. 2 illustrat
passageway from the connecting rod 66 through the
ing the position of the valve mechanism during a normal
upper end portion of the piston 52 into the upper end
upstroke ofthe unit.
portion of the pump cylinder 28.
FIGURE 5 is still another view similar to FIG. 2 illus
trating the position of the valve mechanism at the end
of the upstroke of the pump unit.
Referring to the drawings in detail, and particularly
FIGS. 1A and IB, reference character 10 generally desig
Suitable packing 72 is retained in a bore 74 in the
central portion of the middle plug 26 to provide a seal
around the connecting rod 66. The packing 72 is held
in fluid-tight engagement with the outer periphery of
the connecting rod 66 and the walls of the bore 74 by
nates a pump unit constructed in accordance with this
a suitable retaining nut 76. An outlet 78 is formed
invention and which generally comprises a huid-operated 55 through one side of the middle plug 26 below the pack
motor 12 and a pump 14 connected to the lower end of
ing 72 and in communication with the upper end por
the tluid motor in tandem relation with the Huid motor.
tion of the pump cylinder 28. Therefore, all fluids
The motor 12 comprises a cylinder 16 having a cap or
pumped by the pump unit 14 will be discharged through
head 18 threadedly secured on the upper end 20 thereof
the outlet 78. The outlet 78 in turn communicates with
and having its lower end 22 threadedly secured in a 60 a suitable conduit (not shown) extending from the pump
counterborc 24 off a middle plug 26. The middle plug
unit 10 upwardly to the top of the Well bore in which
26 forms the lower head for the motor cylinder 16 and
the upper head for the pump cylinder 28. It will be ob
served in FIG. lB that the upper end 30 of the pump
cylinder 28 is threadedly secured in a counterbore 32
formed in the lower end of the middle plug 26.
A standing valve assembly, generally designated by ref
the pump unit is installed for recovery of the fluids
pumped by the pump 14.
An inlet 80 (FIG. 1A) is also formed through one
side of the middle plug 26, but is positioned above the
packing 72 to direct high pressure power ñuid into the
lower end of the motor cylinder 16 for operation of
the motor 12, as will be described. It will be under
erence character 34, is secured on the lower end 36 of
stood that the inlet 80 communicates with a suitable
the pump cylinder 28 to control the flow of fluid from a
well bore (not shown) into the lower end of the motor 70 conduit (not shown) extending from the top of the well
bore in which the pump unit is installed, such that high
cylinder 28 in a manner common to the art. In this con
pressure fluid may be pumped downwardly into the lower
nection it may also be noted that the pump unit 10 is of
end of the pump cylinder 16 for operation of the motor
a diametrical size for insertion in a well bore at the level
12.
of the well fluid in the well bore for pumping this well
A motor piston assembly 82 is reciprocally disposed
fluid to the top of the well in a manner common to the 75
3,024,733
in the motor cylinder 16 and includes a piston element
84 having a plurality of piston rings 86 secured around
the periphery thereof in sliding and sealing contact with
the inner periphery of the cylinder 16. A piston ex»
tension 88 is threadedly secured to the lower end of
the piston element 84 and is in turn threadedly secured
to the upper end 90 of the hollow connecting rod 66.
such that reciprocation of the motor piston assembly
82 will be transferred to the pump piston 52. It may
also be noted in this connection that since the connect
ing rod 66 extends from the lower end of the motor
piston assembly 82, the downwardly facing areas of the
assembly 82 are smaller than the upwardly facing areas
of the piston assembly, to provide what is commonly
known in the art as a differential area piston.
A main valve chamber 92 is provided in the central
portion of the piston element 84 and extends along the
longitudinal center of the piston element 84 to be par
6
The passageway 138 in turn communicates with the upper
end of the hollow connecting rod 66 through a suitable
chamber 140 to form what may be considered an exhaust
passageway which conducts spent operating or power
fluid from the upper end of the motor cylinder 16 down
wardly into the connecting rod 66. The uppcr port 136
extends through the spacer 106 and the wall of the piston
element 84 into communication with the Lipper end of
the motor cylinder 16.
An upwardly facing annular seating arca 142 is formed
10
at the upper end ofthe main valve 100 around a counter
bore formed at the upper end of the valve bore 124 to
mate with a downwardly facing seating area 146 formed
on the cap member 108 at the upper end of the piston
element 84. The seating arca 146 is formed around a
projection extending below the lower end of the cup mem
ber 10S into a counterbore 148 formed in the upper end
of the spacer 106. A plurality of ports 150 are formed
in the cap member 108 from the lower end thereof around
allel with the direction of movement of the piston as
sembly 82. A valve seating member 94 extends around 20 the seating area 146 to a common passageway 152 com»
a medial portion of the valve chamber 92 and is pro
municating with the upper end of the cap member 108
vided with an upwardly facing annular seating area 96
and the upper end portion of the motor cylinder 16. lt
to receive a mating seating area 98 of the main valve
will he apparent that when the main valve 100 is in the
100. The seating member 94 is provided with a suit
position shown in FIG. lA. the passageway 152 and
able sealing ring 102 around the periphery thereof and
is held in operating position against an upwardly facing
shoulder 104 in the piston element 84 by an insert 106
which is in turn held in the piston element by a cap
member 108 threadedly secured in the upper end of the
piston element.
~ ports 150 communicate with the counterbore 148, the
valve bore 124, and the port 122 to form what is called
herein the high pressure passageway, such that high pres
sure fluid may flow from the lower end portion of the
motor cylinder 16 through the piston assembly 82 into
30 the upper end of the motor cylinder. In this connection
The main valve 100 is an elongated member of a
it may also be noted that the low pressure or exhaust
size to provide a metal-to-metal seal with the walls of
the medial portion of the valve chamber 92 and having
sets of piston rings 110 and 112 on the lower and upper
passageway 138 is closed between the ports 134 and 136
by the cooperation of the valve seating areas 96 and 98.
such that fluid may not be exhausted from the upper end
ends thereof, respectively. The lower piston rings 110 35 portion of the motor cylinder 16 into the hollow connect~
are secured around the respective end of the valve 100
ing rod 66.
by suitable spacer rings 114 which are in turn held in
contact with one another and in Contact with a down
A ball type pilot valve 154 is positioned in a counter
bore 156 formed in the lower end of the cap member 108
wardly facing annular shoulder 116 by a suitable snap
concentrically inside of the seating area 146, The ball
ring 118. These lower piston rings 110 form an en 40 type valve 154 cooperates with a downwardly facing seat
larged head portion 119 which slidingly contacts the
ing area 158 formed between the counterbore 156 and a
walls of the lower, enlarged portion 120 of the valve
bypass port 160 which communicates with the passageway
chamber 92.
152. lt will therefore be apparent that the ball pilot valve
A port 122 is formed transversely through the piston
154 will normally be retained on the seat 158 by the
element 84 below the lower end of the main Valve 100 45 action of high pressure fluid in the upper end of the valve
in communication with the enlarged portion 120 of the
bore 124 acting through the counterbore 156. The ball
valve chamber 92 to form a portion of a high pressure
valve 154 is unseated by a rod 162 suitably secured to the
passageway through the piston assembly 82, as will be
upper cylinder head 118 when the piston assembly 82
more fully hereinafter set forth.
A bore 124 extends
reaches the end of its upstroke.
The rod 162 has a re
longitudinally through the main valve 100 to provide a 50 duced lower end portion 164 of a size to be received in the
continuation of the high pressure passageway. lt may
bypass port 160 to contact the ball valve 154 and physi
also be noted that a small port or aperture 126 is formed
transversely through the wall of the main valve 100
directly above the lower head portion 119 to provide
communication between the valve bore 124 and the en
larged portion 120 of the valve chamber 92, for pur
poses to be described.
cally unseat this ball valve. It may also be noted that a
suitable retainer or spider 166 is mounted in the counter
bore 156 below the ball valve 154 to prevent the ball valve
55 >154 from being completely removed from the counterbore
156 when unseated by the rod 162. The stop 166 is per
forated or otherwise suitably constructed so as not to inter
The upper piston rings 112 of the main valve 100
fere with the transfer of fluid pressure therethrough
are supported in mating grooves around an enlarged
against the ball valve 154.
head portion 128 of the valve 100 to slidingly contact 60
Another pilot valve 168 is slidingly disposed in a tubu
the walls of an upper enlarged portion 130 of the valve
lar insert 170 secured betweenthe piston element 84 and
chamber 92 formed by the spacer 106. lt will be ob
the piston extension 88 and extends through a bore 172 in
served that the downwardly facing seating area 98 of
the piston extension 88. The insert 170 is sealed in the
the main valve 100 is formed around the lower end por
lower end of the enlarged portion 120 of the valve chamtion of this head 128 to mate with the valve seat 94.
85 ber 92 and in the piston extension 88 by suitable sealing
The medial portion 132 of the main valve 100 between
rings 174 to prevent leakage from the lower end of the
the head 128 and the main body portion of the valve
valve chamber. The pilot valve 168 is an elongated
which is slidingly sealed in the valve chamber 92 is re
member having a cylindrical head 176 formed on the
duced in diameter to extend loosely through the valve seat
upper end thereof and continuously exposed to the pres
94. This reduced diameter portion 132 is provided for 70 sure of the fluid in the lower portion of the valve cham
the communication of ports 134 and 136 provided directly
ber 92A The head 176 is of a size to slidingly fit in the
below and above the valve seat 94 in one position of the
lower end of the main valve bore 124 to control the appli
valve 100, as will be described. The lower port 134 com
cation of fluid pressure to the main valve at the lower end
municates with a passageway 138 extending vertically
of the downstroke, as will be described. Also. a flange
through the piston element 84 and the piston extension 88. 75 178 extends outwardly around the pilot valve 168 directly
3,024,733
8
below the head porti-on 176 to limit the movement of
the pilot valve into the main valve, as will be described.
A compression spring 180 extends around the pilot valve
the valve bore 124 immediately above the pilot valve
cylindrical head 176. As a result, the cylindrical head
168 between the insert 170 and a nut 182 threaded onto
restrict the flow of high pressure lluid into the valve
bore 124. Since the piston assembly 82 is moving down
wardly at this time, the pressure of the fluid standing
in the valve bore 124, the upper end portion of the main
the lower end of the pilot valve, such that the spring 180
176 will be “sucked‘” into the valve bore 124 to further
constantly urges the pilot valve 168 downwardly to move
the cylindrical head portion 176 in a direction away from
the main valve 100.
The pilot valve 168 is actuated by a suitable harness 184
valve chamber 92 and in the upper end of the motor
cylinder 16 is reduced to a pressure below the pressure
when the piston assembly 82 reaches the lower end of its
of the power fluid. Thus, the force acting downwardly
downstroke.
on the upper end of the main valve 100 and the force
acting downwardly on the lower head portion 119 of the
main valve (by reason of the port 126) are reduced,
The harness 184 comprises a ring 186 ñt
ting loosely around the piston extension 88 arranged to
contact an upwardly facing shoulder 188 at the lower end
of the middle plug counterbore 24 when the piston as
sembly reaches the end of its downstroke. A bar 190
is secured to the upper end of the harness ring 186 by a
suitable screw 192 and extends inwardly through a mating
slot 194 in the piston extension 88 to contact the nut 182
on the lower end of the pilot valve 168. lt will be appar
ent that when the harness 184 contacts the upwardly facing
shoulder 188 at the lower end of the motor cylinder 16,
the pilot valve 168 will be moved upwardly relative to the
piston assembly upon any further downward movement of
the piston assembly. The harness 184 is normally in its
lower position resting at the lower end of the slot 194 by
the action of gravity and, as previously noted, the spring
180 normally retains the pilot valve 168 in its lowermost
position in contact with the harness 184 as illustrated in
FIG. 1A.
Operation
while the upwardly acting force imposed by the power
fluid on the lower head 119 of the main valve 100 is
continued. As a result, the net force acting on the main
valve 100 will be in an upward direction to shift the
main valve 100 off of the seat 96 and onto the seat 146,
as illustrated in FIG. 3.
ln analyzing the function of the valve mechanism at
the end of the downstroke, it will be apparent that the
pilot valve 168 is first moved by physical contact with
the harness 184, and then the upward movement of the
pilot valve 168 is continued by hydraulic forces. As a
result, the pilot valve 168 actually moves to a position
above the harness 184 when the cylindrical head portion
176 is fully inserted in the valve bore 124. It should
also be noted that under the dynamic conditions existing
during operation of the piston assembly 8’2, the lower
30 pilot valve 168 merely controls the application of fluid
pressures on the main valve 100 and provides a hydraulic
As previously indicated, high pressure power fluid,
which is normally in the form of clean oil, is continuously
fed through the inlet 80 into the lower end of the motor
shifting of the main valve. The hydraulic forces acting
on the main valve 100 are changed immediately upon
entry of the cylindrical head portion 176 into the lower
cylinder 16 to act on the downwardly facing areas of the 35 end of the valve bore 124 to initiate the shifting of the
main valve. The cylindrical head portion 176 will be
moved on into the valve bore 124 by hydraulic forces
until the flange 178 on the pilot valve 168 contacts the
lower end of the main valve. However, this physical con
ports 150 and passageway 152 to act on the upwardly
facing areas of the piston assembly 82. Since the upward 40 tact takes place after the hydraulic forces acting on the
valve 100 are changed and actually does not function to
ly facing areas of the piston assembly 82 provide a larger
shift the main valve. Since the pressure above the cylin»
effective area than the downwardly facing areas of the
drical head portion 176 is then less than the upwardly
piston assembly' (by reason of the connecting rod 66 ex
acting pressure forces on the pilot valve 168, the pilot
tending from the lower end of the piston assembly), the
net hydraulic force acting on the piston assembly 82 will 45 valve 168 will tend to move upwardly with the main valve
100 against the action of the spring 180. As a result,
be in a downward direction to produce a downstroke for
some portion of the cylindrical head 176 remains in the
the pump unit 10. During this downstroke it will also
valve bore 124 during the complete shifting of the main
be observed that the pilot valve 168 will be held in its
valve from the seat 96 to the seat 146, such that the net
lowermost position by the action of the spring 180 and
hydraulic force acting on the main valve 100 will con
by the action of gravity. The port 122 which provides
tinue to be in an upward direction while the main valve is
the application of fluid pressure across the upper end of
fully seated on the seat 146. The final position of the
the lower pilot valve 168 is of appreciable size and will
pilot valve 168 during a seating of the main valve 100 on
produce no appreciable pressure drop for high pressure
the seat 146 is illustrated in FIG. 3. As soon as the main
fluid flowing therethrough. Therefore, the fluid pressure
valve 100 is shifted to its upper position as shown in
forces acting on the pilot valve 168 will be balanced, re
FIG. 3, the pilot valve 168 is moved back downwardly
gardless of the speed of the downstroke or any other
by action of the spring 180 into contact with the harness
commonly encountered abnormal pump operation, such
184, as shown in FIG. 4.
that the pilot valve 168 will remain in the position
When the lower pilot valve 168 is completely removed
shown in FIG. 1A. The upper pilot valve 1541's retained
piston assembly 82. ln the position of the main valve
100 shown in FlG. 1A, this high pressure power fluid
also flows through the port 122, the valve bore 124, the
on its seat 158 by the action of high pressure fluid flow
from the valve bol‘e 124, the power 'fluid has access to the
ing through the valve bore 124 and through the upper
valve bore 124 to act in an upward direction on the
end of the valve chamber 92.
However, on the down
stroke of the pump unit, the power fluid flows around
the pilot valve 154 (through the ports 150) and it is
immaterial whether or not the pilot valve 154 is re
tained on its seat 158.
Near the end of the downstroke of the pump unit,
upper pilot valve 154 and positively close the bypass
passageway 160.
lt will be recalled that at this time
the pressure above the piston assembly 82 is less than
65 power fluid pressure and the pilot valve 154 will `be re
tained on its cooperating seat 158 by a pressure differ
ential acting across the area of the seat 158.
When the
main valve 100 is seated on the seat 146 and when the
the harness 184 contacts the upwardly facing shoulder
bypass passageway 160 is closed by the upper pilot
188 in the middle plug 26 (see FIG. 2) and moves the
lower pilot valve 168 upward relative to the piston assem- 70 valve 154, the hydraulic force acting downwardly on the
upper end of the main valve will be substantially less
bly S2. As soon as the cylindrical head portion 176 of
the pilot valve 168 first enters the lower end of the valve
bore 124, flow of the power fluid through the valve bore
124 is restricted and a substantial pressure drop occurs
between the lower cntl of thc main valve chamber 92 and
than the force acting upwardly across the lower end of
the main valve. Also, power fluid is communicated
through the port 126 across the upwardly facing area of
the lower main valve head 119, but this area is small
3,024,733
10
compared with the downwardly facing lower end of the
main valve, such that the main valve will be positively
inder 23 through the standing valve assembly 34 will
ing of the main valve 100, the lower end of the piston
the pilot valve 154 is mechanically actuated by the rod
extension 88 moves into a counterbore 200 formed in
162 to produce a net hydraulic force on the main valve
lûtl acting in a downward direction to move the main
occur. This slow reversal of the pump stroke greatly
held on the upper seat 146 during the upstroke of thc
facilitates the operation of the standing valve 42 and
pump unit.
minimizes the cutting out of the standing valve seat 40
As the main valve 100 is being shifted upwardly and
by the leakage of the dirty well ñuid therethrough.
L1
after the main valve is seated on the seat 146, the upward
ln analyzing the function of the Valve mechanism, it
flow of power ñuid through the valve bore 124 is dis
will be apparent that both of the pilot valves 154 and
continued and the exhaust passageway 138 is immediately
168 are mechanically actuated and then control the ap
opened to provide a net hydraulic force on the piston as
plication of fluid pressures on the main valve 1(10. The
sembly 82 in an upward direction, such that the move
lower pilot valve 168 is actuated at the end of the down
ment of the piston assembly 82 is reversed and the pump
stroke to produce a net hydraulic force on the main
unit moved on an upstroke. lt may also be noted that
valve 190 in an upward direction to shift the main valve
at the completion of the downstroke and during the shift
upwardly onto the seat 146. At the end of the upstroke`
the middle plug 26 to provide a dashpot action and fur
ther assure that the piston assembly 82 will not knock
against the middle plug 26 and cause damage to the pump
unit. The slow reversal provided by this dashpot action
and by fluid being fed into the lower end of the motor
cylinder 16 allows sutlicient time for the pump traveling
valve 60 to close, thus minimizing leakage through the
pump piston 52 and increasing the service life of the
traveling valve seat ‘58.
During the upstroke of the pump unit, as shown in
FIG. 4, ñuid in the upper end of the motor cylinder 16
is exhausted downwardly through the passageway 138,
as previously indicated, and this exhausting fluid enters
the hollow connecting rod 66. Therefore, the
power fluid will be co-mingled with the well
forced upwardly through the pump cylinder
action of the pump piston 52 and will be
exhausting
fluid being
28 by the
discharged
through the outlet 78 for conduction to the top of the
well.
As the piston assembly 82 reaches the end of the up
stroke, as illustrated in FIG. 5, the rod 162 is received
in the passageway 152 and the bypass 160 to Contact the
upper ball type pilot valve 154. As a result, the valve
valve downwardly onto the seating area 96. Since the
main valve 100 is both unseated and then shifted solely
by hydraulic forces, the pressure areas of the main valve
may be designed to provide substantial hydraulic forces
for unseating the valve, shifting the valve and holding
the valve on its respective seats. Furthermore, the pres
sure areas of the main valve 100, and the actual forces
applied on the main valve for the unseating, shifting and
holding operations are not limited by either the sizes or
strengths of the pilot valves. The upper pilot valve 154
and the actuating rod 162 may be of economical construc
tion, since the only force applied on the pilot valve 154
is that force necessary to overcome a pressure differential
acting across the area of the pilot valve seat 158. The
mechanical unseating of the ball valve 154 results in a
substantial hydraulic force benig applied to the main
valve 100. The lower pilot valve 168 is moved mechani
cally only against the action of the spring 1.80, such
that the harness 184 will have minimum strength require
ments. Here again, the mechanical force applied to the
lower pilot valve 168 is extremely small compared with
the resulting hydraulic forces imposed on the main valve
100 for the unseating, shifting and holding of the main
154 is removed from its seat 158 to provide communica
tion from the valve bore 124 through the bypass 160 to
the ports 150 and increase the hydraulic force acting in
valve.
a downward direction on the upper end of the main valve
pilot valves 154 and 168 not only provide an economical
100. This downwardly acting force, in combination with
the action of the power fluid across the upper end of the
lower main valve head 119, provides a net downwardly
acting force on the main valve 100 to shift the main valve
back downwardly onto the seat 96 in the position illus
trated in FIG. 1A. lt should also be noted that the up
wardly facing area of the upper end of the main valve
100 around the seating area 142 is substantially larger
than the cross sectional area of the pilot valve seat 158.
Therefore, the mechanical force applied on the ball
valve 154 by the rod 162 is substantially less than the
downwardly acting force obtained by the application of
the power fluid through the bypass passageway 160 and
ports 150 against the upper end of the main valve. Fur
thermore, the ball valve 154 and its cooperating seat 158
may be of minimum size to minimize the force required
to be applied by the rod 162 to unseat the valve` to in
turn minimize the strength of materials required in the
pump construction.
As soon as the main Valve 100 is shifted downwardly
onto the seating area 96, the exhaust passageway 138 is
closed and power fluid is admitted to the upper end of
the motor cylinder 16 through the valve bore 124, ports
150 and passageway 152 to again reverse the movement
of the piston assembly 82 and provide a downstroke of
The above-described functional requirements for the
construction having minimum strength requirements, but
also assure that the piston assembly 82 will complete
its up and down strokes under substantially all operating
conditions.
The appreciable hydraulic forces imposed
on the main valve 100 will minimize the possibility of
the main valve being stuck in an inoperative position by
the accumulation of foreign matter from dirty power
fluid in the valve chamber 92. Also, since substantial
hydraulic forces are imposed on the main valve by mini
mal physical actuation of the pilot valves 154 and 168, the
actuating mechanisms comprising the rod 162 and the
harness 134 may be designed to provide a shift of the
main valve 100 only when each stroke of the piston
assembly 82 is substantially complete. In other words,
the valve mechanism and the actuators 162 and 184 may
be designed to shift the main valve when the piston as
sembly 82 is within a few thousandths of an inch from
the respective end of the motor cylinder 16. The fast
response of the main valve 100 to the application of the
hydraulic forces provides an immediate control of the
flow of the power fluid to the piston assembly 82 to
reverse the piston assembly movements. As a result, the
present pump unit will be particularly effective under
abnormal operating conditions, such as when the pump
unit is used in gassy wells or is driven by dirty power
fluid, to provide a pump unit having universal utility.
the pump unit. lt may also be noted that since the rod
162 occupies an appreciable portion of the area of the
From the foregoing it will be apparent that the pres
passageway 152 at the end of the upstrok-e and the begin
70 ent invention provides a novel subsurface fluid-operated
ning of the downstroke, the movement of the piston as
pump unit which is simple in construction, may be eco
sembly 82 is slowly reversed and the standing valve 42
of the pump 14 will have sufficient time to close prior
to the initiation of the downstroke, such that a minimum
back-flow of well fluid downwardly from the pump cyl 75
nomically manufactured, may be easily repaired and
which will have a long service life.
The present pump
unit will have substantially more universal utility than
present-day subsurface fluid-operated pumps. The pump
3,024,733
12
unit will not tend to “cavitate” in gassy well conditions
and each stroke of the pump unit will be completed be~
fore the next stroke is undertaken to assure the maximum
efficiency in a pumping operation. Also, the reversals of
the pump unit will be retarded such that the valves in
the pump end of the unit will have the maximum service
life. The valve mechanism of the motor end of the
unit is simply constructed, will not be affected by ab
normal pumping conditions and may be economically con
structed.
Changes may be made in the combination and arrange
valve comprises an annular seating area arranged concen
trically around said ball valve seat to receive the respec
tive end of the main valve, and characterized further to
include a bypass passageway from said ball type valve seat
around said concentric main valve seat for directing high
pressure fluid against the respective end of the main valve
when the main valve is seated on said concentric seat and
said ball type valve is actuated.
5. A subsurface fluid-operated pump unit as defined
in claim 4 wherein the other of said pilot valves com
specification and shown in the drawings, it being under
stood that changes may be made in the precise embodi
ment disclosed herein without departing from the spirit
prises an elongated element reciprocally supported in the
motor piston member with one end thereof projecting
into the main valve chamber, said one end of said other
pilot valve being in the form of a cylindrical head of a
size to slidingly lit the adjacent end of the main valve,
and scope of the invention as defined in the following
and one of said actuating means comprises a harness car
ment of parts or elements as heretofore set forth in the
ried by the motor piston member in a position to contact
said other pilot valve and move said cylindrical head
into the adjacent end of the main valve and control the
l. A subsurface fluid-operated pump unit, comprising:
a motor cylinder member; a motor piston member re 20 application of fluid pressure on the main valve when the
motor piston member reaches one end of the motor
ciprocally disposed in the motor cylinder member and re
cylinder member.
sponsive to fluid pressures in the opposite ends of the
6. A subsurface fluid-operated pump unit, comprising:
motor cylinder member for reciprocation in the motor
a motor cylinder; a motor piston assembly reciprocally
cylinder member; a main valve chamber in one of said
members; a high pressure passageway intersecting the 25 disposed in the motor cylinder and having a large end and
a small end; a supply of high pressure power fluid; means
main valve chamber and communicating with at least one
providing constant communication between said supply
end of the motor cylinder member; an exhaust passageway
and the end of the motor cylinder associated with the
intersecting the main valve chamber and communicating
small end of the motor piston assembly to constantly ar»
with at least one end of the motor cylinder member;
valve seats in the main valve chamber in the high pres 30 ply power fluid against said small end and urge the motor
piston assembly in one direction in the motor cylinder; a
sure and exhaust passageways; a main valve disposed in
main valve chamber in the motor piston assembly; a first
the main valve chamber and being responsive to the appli
passageway intersecting the main valve chamber provid
cation of fluid pressures thereto for reciprocation in the
ing communication between said supply and the end of
main valve chamber to alternately seat on the valve seats
and control the flow of fluid to and from at least one 35 the motor cylinder associated with the large end of the
claims.
I claim:
end of the motor cylinder member; a pair of pilot valves
in the high pressure passageway for controlling the appli
motor piston assembly to direct power fluid against the
cation of high pressure fluid to the main valve for shifting
the main valve off of and on to said seats; separate
motor piston assembly in an opposite direction; an ex
haust passageway intersecting the main valve chamber and
communicating with the end of the motor cylinder as
actuating means at the opposite ends of one of said mem
bers arranged to actuate one of the pilot valves when the
motor piston member reaches one end of the motor
cylinder member and actuate the other pilot valve when
the motor piston member reaches the opposite end of the
motor cylinder member; a pump cylinder connected in
tandem relation to the motor cylinder member and having
an inlet and an outlet, and a pump piston reciprocally dis
posed in the pump cylinder and connected to the motor
piston member.
2 A subsurface fluid-operated pump unit as defined in
claim l wherein one of said pilot valves comprises a
large end of the rnc-tor piston 'assembly and urge the
sociated with the large end of the motor piston assembly
for exhausting power fluid from the end of the motor
cylinder associated by the large end of the motor piston
assembly and provide movement of the motor piston as
sembly in said one direction; a valve seat in the main
valve chamber in each of the first and exhaust passage
ways, said valve seats being positioned in spaced relation;
a main valve reciprocally disposed in the main valve
chamber for alternately closing said valve seats and con
trolling the flow of power fluid to and from the end of the
motor cylinder associated with the large end of the motor
piston assembly; a first pilot valve carried by the motor
piston assembly and cooperating with said first passage
way to control the ap-plication of power fluid pressure to
the main valve and hydraulically shift the main valve
ball type valve and cooperating seat with the seat facing
high pressure fluid in the high pressure passageway such
that the ball type valve is continuously urged onto the
seat by the high pressure fluid, one of said actuating means
from one of said seats to the other seat; a second pilot
comprises a rod positioned to knock said ball type valve
valve carried by the motor piston assembly and cooperat
off of its cooperating seat when the motor piston member
ing with said first passageway to control the application
reaches the respective end of the motor cylinder member,
of power fluid pressure to the main valve and hydrauli
and characterized further to include a bypass passageway
extending from said ball type valve seat to the main valve 60 cally shift the main valve from said other valve seat to
said one valve seat; means for actuating one of said pilot
chamber for applying high pressure fluid against the main
valves when the motor piston assembly reaches one end
valve when the ball type valve is removed from its seat.
of the motor cylinder; separate means for actuating the
3. A subsurface fluid-operated pump unit as defined in
other of said pilot valves when the motor piston assembly
claim l wherein said main and pilot valves are carried by
the motor piston member in alignment along the axis of 65 reaches the opposite end of the motor cylinder; a pump
cylinder connected in tandem relation to the motor cylin
movement of the motor piston member, and said main
der and having a fluid inlet and outlet; a pump piston as
valve is tubular in form with the bore therethrough form
sembly reciprocally disposed in the pump cylinder, and a
ing a portion of said high pressure passageway.
connecting rod secured to the pump piston assembly and
4. A subsurface fluid-operated pump unit as defined
the motor piston asssembly to reciprocate the pump piston
in claim 3 wherein the main valve chamber is elongated,
assembly simultaneously with the motor piston assembly.
said pilot valves are positioned at the opposite ends of
7. A subsurface fluid-operated pump unit as defined in
the main valve chamber, one of said pilot valves com»
claim 6 wherein the main valve chamber is an elongated
prises a ball valve seat facing the opposite end of the
chamber extending along the axis of movement of the
main valve chamber and a ball type valve cooperating
with said ball valve seat, one of the seats for the main 75 motor piston assembly, said main valve is tubular in form
3,024,733
13
14
and the bore therethrough forms a portion of Said first
passageway, and said pilot valves are positioned at the
opposite ends of the main valve chamber.
S. A subsurface fluid-operated pump unit as defined in
claim 7 wherein one of said pilot valves comprises a ball
valve seat facing the opposite end ofthe main valve cham
ber and a ball type valve cooperating with said seat, one
of said main valve seats comprises an annular seating
area positioned at the end of the main valve chamber
l2. A fluid motor as defined in claim 10 wherein said
main valve is tubular in form and the bore therethrough
forms a portion of the high pressure passageway, one of
said pilot valves includes a cylindrical head of a size to
slidingly fit in one end of the main valve, said last-men
tioned pilot valve being reciprocally supported in align
ment with and adjacent to one end of the main valve for
movement of said cylindrical head into the main valve
upon actuation thereof by one of said actuating means to
associated with the ball valve and arranged concentri
control the application of fluid pressure on the main valve
10
c'ally around said ball valve seat, said main valve having
and shift the main valve, and characterized further to in
a seating area around the inner periphery of the end
clude a spring anchored to said last-mentioned pilot valve
thereof associated with the ball type valve to mate with
urging said pilot valve in a direction away from the main
said annular seating area in one position of the main
valve.
valve, a bypass passageway extending from said ball valve
f3. A fluid motor as defined in claim 10 wherein said
seat, and said first passageway being extended from said 15 main and pilot valves are carried by the piston member in
bypass passageway around said annular seating area t0
alignment along the axis of movement of the piston mem.
apply high pressure fluid pressure on the end of the main
ber, and said main valve is tubular in form with the bore
valve when the main valve is seated on said annular seat~
therethrough forming a portion of said high pressure
ing area and said ball valve seat is open.
passageway.
9. A subsurface fluid-operated pump unit as defined in 20
14. A fluid motor as defined in claim 13 wherein the
claim 7 wherein one of' said pilot Valves comprises an
main valve chamber is elongated, said pilot valves are
elongated element reciprocally supported in the motor
positioned at the opposite ends of the main valve cham
piston `assembly in alignment with the main valve and with
ber, one of said pilot valves comprises a ball valve seat
the opposite ends thereof exposed to said high pressure
facing the opposite end of the main valve chamber and
fluid, one end of said elongated element being positioned
a ball type valve cooperating with said ball valve seat,
in the respective end of the main valve chamber, said one
one of the seats for the main valve comprises an annular
end of said elongated element being in the form of a
seating area arranged concentrically around said ball
cylindrical head of a size to slidingly fit in the respective
valve seat to receive a seating area formed on the respec
end of the main valve, and said actuating means associ
tive end of the main valve, said last-mentioned seating
ated with said elongated element comprises a harness car 30 area being formed around the inner periphery of the
ried by the motor piston assembly in a position to contact
main valve, and characterized further to include a bypass
one end of the motor cylinder when the motor piston as
passageway from said ball type valve seat around said
sembly reaches said end for contacting said elongated
concentric main valve seat for directing high pressure
element and moving said cylindrical head into the respec
fluid against the respective end of the main valve when
tive end of the main valve for controlling the application
the main valve is seated on said concentric seat and said
of fluid pressure on the main valve.
ball type valve is actuated.
l0. A reciprocating type fluid motor, comprising a
l5. A fluid motor as defined in claim 14 wherein the
cylinder member; a piston member reciprocally disposed
other of said pilot valves comprises an elongated element
in the cylinder member and responsive to fluid pressures
reciprocally supported in the piston member with one
in the opposite ends of the cylinder member for recipro 40 end thereof projecting into the main valve chamber,
cation in the cylinder member; a main valve chamber in
said one end of said other pilot valve being in the form
one of said members; a high pressure passageway inter
of a cylindrical head of a size to slidingly fit in the adja~
secting the main valve chamber and communicating with
cent end of the main valve, and one of said actuating
at least one end of the cylinder member; an exhaust pas 45 means comprises a harness carried by the piston member
sageway intersecting the main valve chamber and com
in a position to contact said other pilot valve and move
municating with at least one end of the cylinder member;
said cylindrical head into the adjacent end of the main
valve seats in the main valve chamber in the high pres~
valve and control the application of fluid pressure on the
sure and exhaust passageways; a main valve disposed in
main valve when the piston member reaches one end of
the main valve chamber and being responsive to the ap 50 the cylinder member.
plication of fluid pressure thereto for reciprocation in the
16. A reciprocating type fluid motor, comprising: a
main valve chamber to alternately seat on the valve seats
cylinder; a piston assembly reciprocally disposed in the
and control the flow of fluid to and from at least one end
cylinder and having a large end and a small end; a supply
of the cylinder member; a pair of pilot valves in the high
of high pressure power fluid; means providing constant
pressure passageway for controlling the application of 55 communication between Said supply and the end of the
high pressure fluid to the main valve for shifting the main
cylinder associated with the small end of the piston
valve off of and onto said seats; and separate actuating
assembly to constantly supply power fluid against said
means at the opposite ends of one of said members ar
small end and urge the piston assembly in one direction
ranged to actuate one of the pilot valves when the piston
in the cylinder; a main valve chamber in the piston
member reaches one end of the cylinder member and ac
assembly; a first passageway intersecting the main valve
tuate the other pilot valve when the piston member reaches 60 chamber providing communication between said supply
the opposite end of the cylinder member.
and the end of the cylinder associated with the larger
ll. A fluid motor as defined in claim 10 wherein one
end of the piston assembly to direct power fluid against
of said pilot valves comprises a ball type valve and coop
the large end of the piston assembly and urge the piston
erating seat with the seat facing high pressure fluid in the
assembly in an opposite direction; an exhaust passageway
65
high pressure passageway such that the ball type valve is
intersecting the main valve chamber and communicating
with the end of the cylinder associated with the large
end of the piston assembly for exhausting power fluid
to knock the ball type pilot valve ofi of its cooperating
from the end of the cylinder associated with the large
seat when the piston member reaches the respective end
70 end of the piston assembly and provide movement of the
of the cylinder member, and characterized further to in
piston assembly in said one direction; a valve seat in the
continuously urged onto the seat by high pressure fluid,
one of said actuating means comprises a rod positioned
clude a bypass passageway extending from said ball type
valve seat to the main valve chamber for applying high
pressure fluid against the main valve when the ball type
valve is removed from its seat.
75
main valve chamber in each of the first and exhaust
passageways, said valve seats being positioned in spaced
relation; a main valve reciprocally disposed in the main
valve chamber for alternately closing said valve seats and
3,024,733
15
controlling the flow of power fluid to and from the end
of the cylinder associated with the large end of the
piston assembly; a ñrst pilot valve carried by the piston
assembly and cooperating with said first passageway to
control the application of power fiuid pressure to the
main valve and hydraulically shift the main valve from
one of said seats to the other seat; a second pilot valve
carried by the piston assembly and cooperating with said
16
being extended from bypass passageway around said
annular seating area to apply high pressure fluid pressure
on the respective end of the main valve when the main
valve is seated on said annular seating area and said ball
valve seat is open.
i9. A fluid motor as defined in claim 18 wherein said
actuating means associated with said ball type valve
comprises a rod secured to the respective end of the
cylinder and being of a size to be received in said first
first passageway to control the application of power iiuid
pressure to the main valve and hydraulically shift the 10 passageway when the piston assembly reaches the respec
tive end of the cylinder for unseating said ball type valve
main valve from said other valve seat to said one valve
from its cooperating seat.
seat, means for actuating one of said pilot valves when
20. A fluid motor as defined in claim 17 wherein one
the piston assembly reaches one end of the cylinder, and
of said pilot valves comprises an elongated element recip
separate means for actuating the other of said pilot valves
when the piston assembly reaches the opposite end of the 15 rocally Supported in the piston assembly in alignment
with the main valve and with the opposite ends thereof
cylinder.
exposed to said high pressure ñuld, one end of said elon
17. A ñuid motor as defined in claim i6 wherein said
gated element being positioned in the respective end of
main valve chamber is an elongated chamber extending
the main valve chamber, said one end of said elongated
along the axis of movement of the piston assembly, said
main valve is tubular in form and the bore therethrough 20 element being in the form of a cylindrical head of a size
to slidingly fit in the respective end of the main valve`
forms a portion of said first passageway, and said pilot
and Said actuating means associated with said elongated
valves are positioned at the opposite ends of the main
element comprising a harness carried by the piston assem
valve chamber.
18. A ñuid motor as defined in claim 17 wherein one
bly in a position to contact one end of the cylinder when
of said pilot valves comprises a ball valve seat facing 25 the piston assembly reaches said end for contacting said
elongated element and moving said cylindrical head into
the opposite end of the main valve chamber and a ball
the respective end of the main valve for controlling the
valve cooperating with said seat, one of said main valve
application of ñuid pressure on the main valve.
seats comprises an annular seating area positioned at the
end of the main valve chamber associated with the ball
References Cited in the file of this patent
valve and arranged concentrically around said ball valve 30
UNITED STATES PATENTS
seat, said main valve having a seating area around the
2,183,538
Butler ______________ __ Dec. 19, i939
inner periphery of the end thereof facing the ball type
valve to mate with said annular seating area in one
position of the main valve. a bypass passageway extend
ing from said ball valve seat, and said first passageway
2,580,657
2,746,431
2,821,141
Coberly ______________ __ Jan. l, 1952
Tebbetts ____________ __ May 22, 1956
Sargent _____________ __ Jan. 28, 1958
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