U.S. patent number 3,707,161 [Application Number 05/074,621] was granted by the patent office on 1972-12-26 for variable choke valve.
Invention is credited to Douglas W. Crawford.
United States Patent |
3,707,161 |
Crawford |
December 26, 1972 |
VARIABLE CHOKE VALVE
Abstract
A valve of the type having a rotatable closure member with a
flow passage which may be moved into and out of communication with
flow passages in the valve housing to respectively permit and
terminate flow through the housing is provided with removable
housing segments whereby direct access to the passage in the
closure member is possible through the housing wall when the
closure member is rotated out of communication with the housing
flow passage. The closure member passage is adapted to carry
removable inserts to permit variation in flow passage or choke
size. Exchange of inserts is made possible even while the valved
fluid is under pressure. In a modified form, a mechanism is
provided for variation of choke size in the closure member without
the need for removal of a portion of the housing wall to permit
adjustment of choke size in the closure member while fluid is
flowing through the valve. The mechanism is removable from the
valve housing when the valve is in the off position.
Inventors: |
Crawford; Douglas W. (Houston,
TX) |
Family
ID: |
22120594 |
Appl.
No.: |
05/074,621 |
Filed: |
September 23, 1970 |
Current U.S.
Class: |
137/269;
137/614.17 |
Current CPC
Class: |
F16K
5/0605 (20130101); Y10T 137/5109 (20150401); Y10T
137/8803 (20150401) |
Current International
Class: |
F16K
5/06 (20060101); F16k 047/10 () |
Field of
Search: |
;137/269,329.2,329.3,614.17 ;251/309,312,316,304 ;138/44 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
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13,516 |
|
Nov 1885 |
|
GB |
|
772,759 |
|
May 1934 |
|
FR |
|
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Miller; Robert J.
Claims
What is claimed is:
1. A valve choke assembly comprising:
a. housing means having connection means for connecting said
housing means into a fluid flow conducting means;
b. valving means included within said housing means for regulating
the flow of a fluid through said housing means;
c. closure means included within said valving means;
d. fluid flow passage means included in said closure means with
said closure means being rotatable within said housing means to
open or close said passage means with respect to said conducting
means for regulating fluid flow through said housing means;
e. control means for rotating said closure means with respect to
said housing means;
f. choke adjustment means extending through said housing means for
changing the dimensions of said flow passage means;
g. movable valve stem means included in said choke adjustment means
and extending through said housing means substantially coaxially
with the axis of rotation of said closure means; and
h. dual closure elements included in said choke adjustment means
and movable relative to each other and to said flow passage means
upon manipulation of said stem means, said dual closure elements
including two adjacent apertured plates threadedly connected with
said valve stem means whereby rotation of said valve stem means
moves said plates toward or away from each other to vary the
coincident aperture area between said plates to thereby vary the
dimensions of said passage means.
2. A valve choke assembly comprising:
a. housing means having connection means for connecting said
housing means to a fluid flow conducting means;
b. valving means included within said housing means for regulating
flow of fluid through said housing means;
c. closure means included within said valving means;
d. fluid flow passage means included in said closure means with
said closure means being movable within said housing means to open
or close said passage means with respect to said conducting means
for regulating fluid flow through said housing means;
e. control means for moving said closure means with respect to said
housing means;
f. externally operable choke adjustment stem means extending
through said housing means and connecting with removable flow
passage defining means for externally effecting a change in the
dimensions of said flow passage means;
g. removable housing wall means for removing said removable flow
passage defining means from said stem means and said housing means
when said closure means is moved to the position closing said
passage means; and
h. means cooperating with said closure means for preventing flow of
fluids through said conducting means while said removable housing
wall means are removed.
3. A valve choke assembly as defined in claim 2 wherein said
closure means is rotatable within said housing means to open or
close said passage means and said choke adjustment means includes
movable valve stem means extending through said housing means
substantially coaxially with the axis of rotation of said closure
means.
4. A valve choke assembly as defined in claim 3 wherein said choke
adjustment means further includes dual closure elements movable
relative to each other and to said flow passage means upon
manipulation of said valve stem means.
5. A valve choke assembly as defined in claim 2 wherein said
closure means includes ball valve closure means.
6. A valve choke assembly as defined in claim 2 wherein said
removable wall means intersects the longitudinal axis of said flow
passage means when said closure means is moved to a position which
closes said passage means with respect to said conducting
means.
7. A valve choke assembly comprising:
a. housing means having connection means for connecting said
housing means to a fluid flow conducting means;
b. valving means included within said housing means for regulating
flow of fluid through said housing means;
c. closure means included within said valving means;
d. fluid flow passage means included in said closure means with
said closure means being movable within said housing means to open
or close said passage means with respect to said conducting means
for regulating fluid flow through said housing means;
e. control means for moving said closure means with respect to said
housing means;
f. choke adjustment means extending through said housing means and
connecting with removable flow passage defining means for
externally effecting a change in the dimensions of said flow
passage means;
g. removable housing wall means for removing said removable flow
passage defining means from said housing means when said closure
means is moved to the position closing said passage means; and
h. plural means in said choke adjustment means movable relative to
each other and to said flow passage means for varying the
dimensions of said flow passage means about the central
longitudinal axis of said passage means whereby said central
longitudinal axis of said passage means remains substantially
coaxial with the opening in said flow passage means as the
dimensions of said flow passage means are varied by said choke
adjustment means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to valves for regulating the flow of
fluids, including liquids and gases, through a flow conductor. More
specifically, the present invention relates to a new and improved
valve mechanism specifically adapted for use with valves of the
type wherein flow passages in the closure member may be rotated
into or out of communication with the flow passages in the valve
housing to permit, terminate or regulate fluid flow through the
valve. In a specific application, the variable choke valve of the
present invention is employed to regulate or restrict fluid flow
through a flow conductor.
2. Brief Description of the Prior Art
It is often necessary, for a variety of reasons, to change the flow
passage or choke size in a valving means. When such change is
required in conventional flow lines, it may be necessary to
terminate flow through the line, remove the valve from its
operational position in the flow conductor and replace it with a
valve having the desired choke size. In the alternative, it is also
conventional to employ upstream and downstream valves which are
both closed to permit an intermediate choke housing to be
disassembled and equipped with a new choke body to provide the
desired flow passage.
In an attempt to overcome the expense associated with a multiple
valve assembly and the lost time associated with replacement of a
single valve, the prior art dealing with orifice controls and
metering systems has employed a single valve which may be moved to
the off position to permit replacement of a plate having the
desired orifice size. In this device, the valve is turned to the
off position and a bottom housing plate is removed to permit
removal of the orifice plate and the insertion of a specially
apertured orifice plate. While offering many advantages over the
conventional approaches to changing orifice size, the prior art
valve is objectionable to the extent that removal of the bottom
housing plate is difficult and time consuming, the plate is often
inaccessible or difficult to reach because of its location at the
bottom of the housing, the bottom positioning of the plate prevents
the easy use of valve extension or control members at that
position, it is difficult to properly align and seal the orifice
plate within the valve closure member, and relatively numerous and
expensive components are required to hold the orifice plate within
the closure member without vibration, leakage or misalignment.
SUMMARY OF THE INVENTION
In the preferred form of the present invention, the valve includes
a removable housing section which may be disengaged from the main
housing body to permit access to the flow passage in the rotatable
closure member of the valve. While the prior art metering valve
described previously provides indirect access to the closure member
flow passage through the bottom of the valve housing, the present
invention provides direct access to the closure member through the
side of the valve. When the closure member is rotated to its closed
position, the closure member flow passage is out of communication
with the housing flow passage so that the sealing functions of the
valve may be effected even with the closure member passage exposed
during removal of the side housing plate.
Choke inserts with different size flow passages or choke openings
may be positioned within the flow passage of the closure member to
effect a desired change in choke size. The inserts are rigidly
secured and sealed within the closure member flow passage to ensure
proper orifice alignment and to prevent undesirable vibrations or
leakage. The inserts themselves may be equipped with wear resistant
liners to extend the life of the insert and to reduce valve
maintenance.
More than one removable side housing plate may be employed to
provide internal access to valves of the present invention. There
is also disclosed a means for venting high pressure fluids trapped
between the closure member and the valve housing to reduce any
difficulty in removing the side plate and to prevent sudden high
pressure release upon removal of a side housing plate.
In a modified form of the invention, choke adjustment means are
provided for continuous variation of choke size without the need
for removal of the housing wall or the requirement for the changing
of a choke insert. In this latter form, the valve includes the
primary, conventional means for rotating the closure member between
open and closed positions and also includes a choke size adjustment
means extending through the housing coaxially with the axis of
rotation of the closure member to provide continuous choke size
adjustment while fluid flow is maintained through the valve. Where
the choke adjustment extends through the bottom of the valve, the
entire adjustment mechanism may be removed from the valve when the
closure member has been rotated to off position to permit
replacement or repair of the adjustment mechanism.
In one form of the choke adjustment means, a plate is moved
relative to the flow passage in the closure means to provide
continuous variation in the dimensions of the valve aperture. In
another form of the variable choke adjustment means, dual closure
elements are movable relative to each other and to the flow passage
in the closure means to vary the dimensions of the valve aperture
uniformly about the central longitudinal axis of the flow passage.
The latter modification is particularly well suited for
applications where turbulence is to be minimized or where precise
regulation is desired. In both of the latter modified forms, the
adjustable valve stem for the choke adjustment means extends
coaxially with the axis of rotation of the rotatable closure member
which permits rotation of the ball by means of the primary control
mechanism and adjustment of the choke size by the choke adjustment
means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical elevation, in section, illustrating a
rotatable ball valve of the present invention;
FIG. 2 is a view taken along the line 2--2 of FIG. 1, partially
broken away;
FIG. 3 is a partial vertical section of a modified form of a ball
valve of the present invention with a continuously variable choke
adjustment means;
FIG. 4 is a partial view taken along the line 4--4 of FIG. 3
showing the flow passage choke in full open position;
FIG. 5 is a view similar to FIG. 4 showing the flow passage choke
partially closed;
FIG. 6 is a partial vertical section illustrating a third
modification of the present invention having dual closure elements
movable relative to each other;
FIG. 7 is a view similar to FIG. 6 illustrating the flow passage
choke partially closed;
FIG. 8 is a view taken along the line 8--8 of FIG. 7;
FIG. 9 is a perspective view, partially broken away, illustrating a
plug valve of the present invention; and
FIG. 10 illustrates a valve of the present invention equipped with
a self-controlled operator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, one form of the valve of the present
invention is indicated generally at 10. The valve 10 includes a
main housing body assembly 11 within which is disposed a ball valve
closure member 12. The closure member is connected to a valve stem
13 which in turn is secured to a handle 14 and both are used to
rotate the closure member in a conventional manner between open and
closed positions or any intermediate position.
With reference jointly to FIGS. 1 and 2, it may be seen that a
plurality of removable housing wall plates 15, 16 and 17 are
removably secured to the bottom and sides, respectively of the main
housing 11. O-ring seals 15a, 16a and 17a are positioned between
the removable wall plates and the main valve housing to provide a
leakproof engagement. As illustrated, each of the removable housing
wall means 15 through 17 is threadedly secured to the main housing
11. The housing 11 also includes upstream and downstream connectors
11a and 11b which may be employed in conventional manner to connect
the valve 10 into a fluid flow conducting line (not
illustrated).
Annular upstream and downstream seal assemblies 18 and 19,
respectively, are positioned between the main housing 11 and the
connectors 11a and 11b in the manner illustrated to provide
continuous sealing engagement with the ball closure member 12. The
assemblies 18 and 19 include annular O-ring seals 18a and 19a,
respectively, annular sliding seals 18b and 19b, respectively, and
spring biasing means 18c and 19c, respectively. The O-ring seals
provide sealing between the connectors and the seal assemblies, the
sliding seals provide the necessary seal between the ball closure
member and the seal assemblies and the spring bias means urge the
sliding seal into continuous engagement with the ball closure
member 12.
The upstream and downstream connecting means 11a and 11b are
secured to the housing 11 by means of bolts 11a' and 11b' ,
respectively. O-ring seals 11a" and 11b" provide leakproof
engagement between the connecting means and the housing. Sealing of
the valve 10 is completed by O-rings 13a and 13b which are
positioned about a valve stem bonnet 13'.
From an inspection of FIGS 1 and 2, it may be seen that the closure
member 12 is mounted for rotation in upper and lower mounting
sleeves 13" and 15' , respectively. The ball valve closure member
12 includes a fluid flow passage means indicated generally at 20.
When the closure means 12 is in the position illustrated in FIG. 1,
it will be apparent that the fluid flow passage means 20 is aligned
with the housing flow passages in the connecting means 11a and 11b
to permit flow through the valve 10. When the handle 14 is rotated
90.degree. from the position illustrated in FIG. 1, the passage 20
is positioned at right angles to the housing flow passages which
permits the sealing assemblies 18 and 19 to cooperate with the
solid portions of the closure member 12 in terminating fluid flow
through the valve.
With reference to FIG. 2, it will be appreciated that with the
valve in the closed position, the wall plate means 16 or 17 may be
removed to permit direct access to the ball closure passage 20.
Where high pressure fluids are contained within the valve, a relief
valve 17' may be opened to slowly bleed off any entrapped pressure,
thereby permitting the side walls to be removed.
The ball closure member 12 is equipped with a removable choke body
insert 21 which is threadedly engaged within the valve flow passage
20. An annular O-ring seal is positioned between the insert 21 and
the ball closure member to prevent bypass of fluid around the
central choke opening of the insert. A removable sleeve 23 formed
of a very hard, wear resistant material is press fitted within the
central choke opening of the insert 21. An internally developed
shoulder 21' formed at the rear of the insert 21 retains the sleeve
23 in proper position within the insert. The upstream end of the
insert 21 is provided with lateral slots 21" with which the insert
may be engaged by a suitable tool permitting it to be rotated into
and out of engagement with the ball closure member.
By means of the illustrated construction of the valve of the
present invention, it will be apparent that the valve closure
member 12 may be rotated to off position to terminate flow through
the valve 10. When in this position, the side plate 16 or 17 may be
removed to expose the slots 21" of the choke insert 21. The insert
may be removed through the opening provided by the removal of the
side wall plate and replaced with an insert body having the desired
choke dimensions. The wall plate may thereafter be reattached to
the housing and the valve rotated back into open position to
reinitiate flow through the valve. Thus, it will readily be
appreciated that removal of a side wall plate in the valve of the
present invention provides direct communication between the
exterior of the valve and the flow passage in the closure member.
By this means, aperture dimensions may be easily and quickly
changed in any desired manner. In addition, the positive seating of
the insert within the ball closure member ensures proper alignment
of the choke with the flow passage in the valve and prevents
undesirable vibration, leakage or misalignment.
A modified form of the present invention is indicated generally at
110 in FIG. 3. The valve 110 is similar to the valve 10 and the
various valve components have been designated by reference
characters which are higher by 100 than the reference character for
the same or similar components illustrated in FIGS. 1 and 2. The
primary distinction between the valve 10 and the valve 110 is the
inclusion in the latter of a choke adjustment means indicated
generally at 130 in FIG. 3. The adjustment means 130 is formed by a
laterally movable plate 131 which is adapted to be moved upon
rotation of an adjustment valve stem 132 to advance laterally
across the face of a choke plate 133 to vary the effective flow
area of an aperture 133a. Threads 132a formed at one end of the
valve stem 132 are adapted to engage and mate with threads formed
in the choke plate 131 whereby rotation of the valve stem provides
the desired movement of the adjustable plate. The valve stem
extends through an assembly bushing 150 which is threadedly mounted
in the base plate 115. The lower exposed end of the valve stem 132
is provided with a suitable means such as the rectangular head 132b
by which the valve stem may be secured for rotation by a suitable
mechanism or handle (not illustrated). A radially developed flange
132c extends about the valve stem 132 and is seated against a
bearing surface 115 on the bushing 150. O-ring seals 134, 135 and
131 ensure leakproof engagement between the rotatable ball closure
member 112, valve stem 132, aperture plate 133, and assembly
bushing 150, respectively.
In operation, the valve stem 132 may be rotated causing the movable
plate 131 to advance upwardly and partially cover the aperture
opening 133a to reduce the effective flow passage through the
valve. FIG. 5 of the drawings illustrates the plate 131 adjusted to
provide partial opening through the choke opening. Operation of the
choke adjustment means 130 is permitted even while the flow passage
120 is aligned with the flow passages in the valve housing to
permit continuous regulation of fluid flow through the valve.
It will be appreciated that the coaxial mounting of the valve stem
132 with the axis of rotation of the ball closure member 112
permits a double acting valve function in that the closure member
112 may be rotated by the primary control secured to the valve stem
113 while also permitting variation in the choke size of the ball
member by rotation of the stem 132. When it is desired to remove
the choke mechanism 130 for any reason, the valve closure member
112 may be rotated 90.degree. from the position illustrated in FIG.
3, the side housing plates (not illustrated) along the housing wall
similar to those illustrated in FIGS. 1 and 2 may be removed, and
the valve stem 132 may be rotated to completely disengage the plate
131 so that it may be removed through the side wall opening. The
bushing 150 may then be disengaged from the housing 111 to permit
withdrawal of the valve stem, and the choke plate 133 may
thereafter be removed through one of the side wall openings. It
will, of course, be understood that all of the foregoing procedures
may be undertaken while the valve closure member 112 is functioning
to form a seal against fluid flow through the flow conductor within
which the valve 110 is connected.
With reference to FIGS. 6, 7 and 8, a third modification of the
present invention is indicated generally at 210. The valve 210 is
similar to the valve 110 and components have been designated by
reference characters which are 100 higher than those employed in
identifying the corresponding components of valve 110.
The adjustable choke means of the valve 210 is indicated generally
at 230 and includes first and second adjacent aperture plates 231
and 240, respectively. The plates are provided with apertures 231a
and 240a. Left hand threads 232a' engage the aperture plate 240
while right hand threads 232a" are secured to the movable plate
231. The illustrated connection between the valve stem 232 and the
plates 231 and 240 causes the plates to move away from each other
as illustrated in FIGS. 7 and 8 upon rotation of the valve stem.
The resulting relative movement between the two apertured plates
and the fixed plates 233 maintains a uniform aperture area which is
evenly distributed about the central longitudinal axis of the flow
passage 220. As with the valve 110, the valve 210 may be adjusted
to change the effective choke size of the valve during conditions
of fluid flow.
When removal or replacement of the orifice adjustment means 220 is
desired, the ball closure member 212 may be rotated to its closed
position and the assembly bushing in the bottom housing plate, (not
illustrated) may be removed to permit the entire assembly to be
withdrawn from the valve. The fixed plate 233 may then be removed
from the ball closure member 212 by removal of the side housing
wall plate in the manner described with reference to valve 110.
FIG. 9 of the drawings illustrates a plug valve indicated generally
at 310 which includes the teachings of the present invention. The
valve includes a rotatable, frustroconical closure member 312 set
within a main valve housing assembly 311. The main housing is
provided with one or more removable side wall sections such as the
section 316 which is threadedly engaged to the main housing body. A
lower, removable housing section 315 is also provided at the base
of the housing. As with the valves previously described, the valve
310 includes an upstream housing section 311a and a downstream
section 311b. The valve closure member 312 includes a valve stem
313 secured to a master handle 314 which may be employed to rotate
the flow passage 320 between closed position and the full opened
position illustrated in FIG. 9. A removable choke insert body 321
is threadedly engaged within the passage 320 and may be removed
from the passage when the closure member 312 is rotated to the off
position in the manner previously described with reference to the
valve 10. A lateral slot 321" permits the use of a tool to assist
in rotating the insert 321 and a hard, sleeve insert 323 is
positioned within the central flow passage of the insert for the
same purpose as described previously with reference to the valve of
FIG. 1.
It will be appreciated that the operation of the valve 310 is
similar to that previously described with reference to the valve
10. It should also be noted that if desired, the plug valve of FIG.
9 may be modified to include choke adjustment means such as those
previously described with reference to the valves 110 and 210.
FIG. 10 of the drawings illustrates a valve of the present
invention indicated generally at 410 which has been equipped with a
choke adjustment means such as that illustrated with reference to
valves 110 and 210. The valve 410 is positioned in a flow conduit C
to regulate flow of a fluid medium through the conduit. The choke
adjustment mechanism of the valve 410 is secured to an operator
indicated generally at 450. The operator is provided with a
suitable drive means such as an electric motor which is supplied
through a source of external electrical power through input lines
451. The operator 450 is equipped with a conventional sensor or
regulator device 452 which is adapted to detect pressure or flow or
other conditions of the fluid flowing through the valve 410. An
appropriate control signal is conveyed from the regulator 452 to a
drive mechanism 454 to rotate the valve stem in the choke
adjustment means to appropriately increase or decrease the
effective size of the choke opening.
By means such as that illustrated in FIG. 10, it will be
appreciated that the valve of the present invention may be easily
modified for continuous regulation of flow in a remotely located
conductor. In general, the valves described herein are susceptible
of use in any location requiring regulation of a flowing fluid. A
specific example is the regulation of injection or input gas into
an oil well during a gas lift operation. The valves of the present
invention are capable of effectively and efficiently regulating the
quantity of fluid moving past a point in such systems to provide a
desired production rate in the well.
The foregoing disclosure and description of the invention is
illustrative and explanatory thereof, and various changes in the
size, shape and materials as well as in the details of the
illustrated construction may be made within the scope of the
appended claims without departing from the spirit of the
invention.
* * * * *