CA1069018A - Quick disengaging valve actuator - Google Patents
Quick disengaging valve actuatorInfo
- Publication number
- CA1069018A CA1069018A CA292,137A CA292137A CA1069018A CA 1069018 A CA1069018 A CA 1069018A CA 292137 A CA292137 A CA 292137A CA 1069018 A CA1069018 A CA 1069018A
- Authority
- CA
- Canada
- Prior art keywords
- fluid
- shaft
- housing
- operative
- actuator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
TITLE QUICK DISENGAGING VALVE ACTUATOR
ABSTRACT OF THE INVENTION
An actuator is provided which is respondable to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator comprises a housing having a cylin-drical bore defined therethrough. A shaft is carried in the hous-ing and is engagable with the operative means. Piston means are carried by one of the shaft and the housing and are sealingly slidable along the other of the shaft and the housing and longi-tudinally movable within the cylindrical bore. Fluid chamber means are companionly associated with the piston for yielding a differential force across the piston means upon variation of fluid control pressure within the actuator. The shaft is selectively shiftable longitudinally in a first direction to move the opera-tive means to one of open and closed positions by variation in fluid control pressure, and is shiftable to a second direction to move the operative means to the other of the open and closed positions upon subsequent variation in fluid control pressure. One of the shaft and operative means has slotted means thereon for transverse receipt of a companion engagement means on the other of the shaft and the operative means whereby the operative means and the shaft are thereafter in substantial longitudinal engagement. The shaft and the operative means are disengageable by relative transverse shifting of the shaft and the operative means to remove the actuator from the valve.
ABSTRACT OF THE INVENTION
An actuator is provided which is respondable to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator comprises a housing having a cylin-drical bore defined therethrough. A shaft is carried in the hous-ing and is engagable with the operative means. Piston means are carried by one of the shaft and the housing and are sealingly slidable along the other of the shaft and the housing and longi-tudinally movable within the cylindrical bore. Fluid chamber means are companionly associated with the piston for yielding a differential force across the piston means upon variation of fluid control pressure within the actuator. The shaft is selectively shiftable longitudinally in a first direction to move the opera-tive means to one of open and closed positions by variation in fluid control pressure, and is shiftable to a second direction to move the operative means to the other of the open and closed positions upon subsequent variation in fluid control pressure. One of the shaft and operative means has slotted means thereon for transverse receipt of a companion engagement means on the other of the shaft and the operative means whereby the operative means and the shaft are thereafter in substantial longitudinal engagement. The shaft and the operative means are disengageable by relative transverse shifting of the shaft and the operative means to remove the actuator from the valve.
Description
~0690~8 .~ : . ' ' BACE~GROUNI) OF THE INVENTION
1. FIELD OF THE INVENTION: The present invention relates .
to a fluid operable valve actuator having means thereon for quickly disengaging the actuator from the valve body.
1. FIELD OF THE INVENTION: The present invention relates .
to a fluid operable valve actuator having means thereon for quickly disengaging the actuator from the valve body.
2. DESCRIPTION OF THE_PRIOR ART: Actuators are utilized to manipulate a valve mechanism within a flow line into open and/or closed position in response to control pressure variation.
Normally, these actuators comprise a shaft and a fluid activated mechanism in association therewith whieh, upon activation thereof ;~
lo by increase in control line pressure, causes longitudinal move- -ment of the shaft to shift the valve in relation to its seat.
Venting of control line pressure will cause a subsequent and `
~ ~ second longitudinal shiftlng of the shaft and the valve head to ,~ a second position. Such aalve systems zre frequently utilized in safety systems used in conjunction with the drilling, comple-tion and production of offshore, as well as inland, oil and gas wells. Additionally, such components are utilized in natural gas transmission lines, and the like.
During the completion, testing and/or wor~over of a sub-` 20 terranean well, it may be necessar~ to run equipment such as a ;` `
perforating gun, or the lIke, on a wire or other line into the well when the well is under pressure. This is achieved by inserting the equipment lnto a l~ength of production tubing above ; .
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the christmas tree, the length of tubing being commonly referred to as a 1l lubricator". The lubricator is isolated from the , portion of the well therebelow by a valvc or a series of readily accessible hand manipulated valves. In view of the fact that . .
the lubricator assembly must contain the well pressure while the equipment is inserted therethrough for subsequent utilization in the well, it is necess-ary to control the well pressure below the , lubricator assembly during this procedure. To contain the well, in the event of failure of the components of the lubricator, a safety valve mechanism is positioned below the lubricator. This valve should be "fail safe" and should be activatable remotely or automatically upon loss of control.
When a gate valve mechanism is utilized below the lubricator, the valve actuator should be of such design and construction that, upon longitudinal shifting of the stem therein, the gate is permitted to completely close ~ith sufficient force such that a wire line carrying downhole tools may be sheared by the gate ~ upon longitudinal shifting of the shaft within the actuator.
J~'` Upon detection of pressure leaks within the lubricator, or when control of the well is lost and it begins to prematurely flo~J, the actuator should have sufficient force to cause the wire line ; to be sheared when the gate is closed in order to assure that ~ . , , the gate is sealingly interfaced onto its seat to prevent flo~
there;through. The force which shears the wire line penetrating through the gate opening should be independent of the well pressure within the valve body.
Normally, valve actuators depend upon pressure within the :
valve body operably associated with a compressed spring asse~bly to shift the bonnet stem longitùdinally in order to permit the valve to close. The spring assembly within the actuator is present only for minor frlction forces, and fail safe gate valve ~ ' , .
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actuators he~etofore made commercially available do not have su~icient force to shear a wire line during the valve closing sequence, in the absence of well pressure in the valve body.
Standard fail safe gate valve actuators are not afforded ; sufficient force to shear wire inserted through the valve due to physical and technological limitations and sizing requirements for the valves and their associated operating components. A
double acting actuator with pressure operable upon either side of a piston element could be utilized in conjunction with spring force to cause manlpulation of a shaft within the actuator to, in turn, cause sufficient force to be exerted on the shaft such that longitudinal movement of the shaft shears the wire line inserted through the valve body. It should be noted that this double acting actuator design is not fail safe, because loss of control pressure will not assure closing of the valve head onto its seat. This piston arrangement would require an e~ternal charging force, such as a~nitrogen accumulator. Consequently, a - stock of nitrogen bottles would be required at the well or other commercial site. The nitrogen charged accumulator would force control fluid out of one of the piston chambers, whereby the valve head is shlfted to the closed position. Thus, it is clear - -that longitudinal movement of the stem when control pressure is ,~ vented off to close the valve would require two control lines, the first line being in association with a supply port and one - piston chamber, and a second control line in a second or boost port communicating with a second or boost piston chamber. In view o~ the fact that the~actuator design must be "fail safe", that is, it must assure closure of the valve when control line pressure is intentionally or unintentionally`bled off, the incorporation of two control lines into the design of the actuator -~renders the design doubly susceptible to failure by leaks and/or 5'breaks in the lines.
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~ s an alternative design, a concentric accumulator e~.tcr-iorly sur~ounding the actuator could be utilized as an integral part of the actuator. This design would require the ucilization of nitrogen bottles in a bank for continuous charging of the accumulator. Additionally, the t~o control lines would, of nec-essity, still be required to maintain nitrogen charges. Use of plural lines would, in turn, continue to double e~pose the ap-paratus to the likelihood of nîtrogen leaks which are extremely difficult to detect and seal.
lo In the past, when it has been found necessary to repair the valve mechanism or the actuator itself on location, consider-able do~n time has been required during the dismanteling of the actuator from the valve bonnet stem in order to have access to the valve or actuator components. The down time has neces-sitated shut in of a flowing well or isolation o~ the valve mechanism from the flor~ stream of a transmission line, which, : in turn, has an adverse economic impact because of the cost of lost rig time, lost production, and the like. ~Ioreover, many prior art actuators are designed such that in the event of onsite failure of the attached valve mechanism or the actuator, the actuator must be almost completely disassembled in order to remove or replace the actuator or repair the valve. For e~ample, t~e prior art has taught use of an actuator valve assembly wherein the actuator is affi~ed onto the valve body by means of bolts inserted through the lower housing and into companion bores in the upper face of the valve housing. ~lso, the prior art typically provldes for connection of the actuator shaft to the valve head by means of a shoulder on the actuator shaft insertible within a companion slot in the valve head, all within the valve body, the actuator shaft and bonnet stelll being one continuous piece. Variations of prior art actuators incl~lde those generally as above desc~ bed a~d lncludlng an actuator . . .
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: expander ~hich funccions to adaptably mount an actuator onto ~he valve body. The present invencion overcomes this deiclenc~ by providing means for quickly engaging and disengaging the ac~u-ator with ~espect to the valve body and within the approximate total length of the actuator.
The present invention overco~es many or the disadvantages :.
found in prior art commercially available actuators by providing an actuator having an internal cylindrical accumulator with .: ~
, sufficient volume such that the fluid therein may be compressed :.
- 10 with sufficient force to assure that the shaft is longitudinally shifted to shear a wire line inserted ~hrough the valve body during~ the valve closing sequence. The accumulator requires no : .
. incremental or continuous charging with secondary sources, sucX
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as nitrogen; hence, problems associated wi.th secondary source leakage are eliminated. Additi.onally, in the preferred form, : the present invention necessitates usage of only one control : :.
line, this advantageous feature being attributable to usage of a " . .
.. check valve within a conduit or passageway e~tending between the .
. ~ control line and the accu~ulator chamber and being within the .
actuator itselE. Moreover, the check valve mechanism permi-~s . continuous charging of the accumulator chamber so that when A~ supply pressure is vented of, presswre within the accumulator chamber is trapped and compressed fluid therein will drive the piston and its assoclated shaEt in a longitudinal direction to shift the gate or other valve ~ember, for e~ample, to isolate ~ the fluid flow within the valve body. In the present invention, ; in the event of leakage oE 0-rings or other sealing elements, the accumulator chamber will continue to be charged ~Jith fluid . through the c:ont-rol line which will result in a "fail safe"
; 30 actuator which does not require usage of secondary fluid sources, . . . .
: such as nitrogen bottles or nltrogen caps on the accumulator to : drive the fluid under the piston and up~lzrdly to shiEt the va].ve.
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( ~0690~L8 The presen~ actuator has a physical design advantage in that it can be manufactured substantially shorter lengthwise :.. .
than actuators desi~ned to operate within and at similar pres-sure environments, but responsive to compressibility of spring~
elements. Although the diameter of the present actuator is somewhat larger than comparative-sized actuators operative at the same control pressure, the present invention now contains approximately ten ti~es the closing force of spring-fed ~ct~aators.
For example, a 5,000 pound closing force can be obtained using ; 10 the contlnuously fed accumulator chamber of the present astua~or.
- To obtain such a cLosing force in a spring-fed prior art actuator, ' ten concentricly mounted S00 pound force springs would have to be utilized. This, in turn, would require an actuator having a housing approximately two times the diameter of the housing of the actuator of the present invention. Additionally, such a spring-fed actuator would be considerably longer (length~ise) than the present actuator due to space requirements for the action of the spring. Moreover, the absence of a spring element in the present actuator renders it less susceptible to mechanical ~; 20 failure because the risk of spring failure or breakage due to corrosion and/or metal fatigue is eliminated.
The present actuator utilizes a plurality o~ pressure chamber areas which permits continuous charging of ~he accumulator because of the variance in the areas of each of the chambers, whereby ~orces applied through the chambers are selectively pressurable. Thus, by having independent control of each of the chamber areas, fluid media, control pressure, and operating forces can be independently controlled. This design will result in reduced loads being applied to the bonnet stem.
Another advantage of the present actuator is that the shearing of wire line inserted through the valve is no~ a function ~)691)~3 of well pressure through the valve body itself, and there is sufficient pressure acting upon the piston and sha~t elements to sufficiently shear a wire line extending through the valve, thus permitting a complete fluid seal bet~een the valve head and its seat, upon closing of the valve.
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SU~ARY OF THE INVENTION
The present invention comprises an actuator which is respond-able, preferably, to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator has a housing which defines a cylindrical bore therethrough. A
shaft is carried within the housing and is engagable with the operative means,in a preferred form. Means defining first and ; second effective pis~on areas are carried by one of the shaft and the housing and are sealingly slidable along the other of the shaft and the housing and longitudinally movable within the cylindrical bore. The apparatus provides first and second fluid chambers whlch are companionly associated with the means defining first and second effective piston areas within the bore for yielding a differential force across the means derining the first and second effective piston areas upon variation of fluid control pressure within the actuator. The apparatus has a continuously chargeable fluid accumulator means in fluid communi-cation with said second fluid chamber ~or the storage of energy defined preferably by control fluid which is compressible therein.
A fluid passage means for transmitting fluid under pressure is provided to said first fluid chamber and to the accumulator means. A valve means i5 movable bet~een open and closed positions and communicates bet~een the accumulator means and the fluid - passage means to permit fluid control pressure charging of the accumulator chamber when in said open position and preventing discharge of fluid pressure within the accumulator cham~er when ~. , , ~` ` ( ~.
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the valve is in the closed position, the valve being responsive .~ to pressure differential between the accumulator chamber and the fluid passage means, the shaft being selectively shiftable longitudinally in a first direction to move the operative means :~ .
to one of open and closed positions, preferably, by increase in ~ fluid control pressure, the shat being selectively shiftable .~`` longitudinally in a second direction to move the operative m~ans . to the other o~ open and closed positions, pre~erably, upon subsequent decrease in fluid control pressure and release of energy stored within the accumulator.
. The present invention also provies, independently of the : utilization of plural piston means and/or the fluid accumulator, .: means.for readily and quickly engaging and disengaging the ` actuator with respect to the valve body without t~e require~ent of disassembly of the actuator. Moreover, the engagement means are operative to assure that the valve head is in closed position with respect to its seat during removal of the actuator from the valve body. The engagement means also permit affixation onto .~ and removal of the valve body of the actuator within the approx-:: 20 imate total length of the actuator such that the actuator is very ; ..;:
. easily affixed to or removed from valve mechanisms in close , proximity eo well heads and the like.
: The apparatus of the present invention is utilized in a : preferred form with a continuously chargeable fluid accumulator : means in fluid.communication with a second fluid chamber for the storage of energy defined~preferably by control fIui.d which is . compressible therein.
:.~ BRIEF DESCRIPTION OF THE DP~INGS
Fig. 1 is a longitudinal schematic and sectional. vie~ of the ; 30 actuator of the present invention incorpora.ted.onto an ol~erative - . - 9 -.
, means, or bonnet assembly, o~ a gate valve which, in turn, ~ . .
forms a parc of a lubricator assembly, with a wire~ line being inserted through the gate valve, the gate o~ the valve being sho~n in open position.
Fig. 2 is a view similar to that shown in Fig. l, wi~h Lhc gate of the valve being shown in closed position an~ the wire line completely sheared.
Fig. 3 is a longitudinal sectional drawing of the actuator sho~m in Figs~ l and 2, the position of the respective components of the actuator being as is illustrated in Fig. l.
Fig. 4 is a partial longitudinal sectional dra~Jing of the `' actuator in position durin~ ~emoval ~rom the valve body, -'~Ji Lh its bolts securin~ the actuator housing to the valve body belng removed to permit the housing to be pumped up to permit relative transverse shifting o~ the shaft and the bonnet LO completely dis-engage the actuator from the valve body.
Fig. 5 is a detailed vle~7 of the shaft and bonnet in completel disengaged position.
Fig. 6 is a view of an alternative design illustratinO the slotted means on the val~e bonnet and the conmpanion engagement ring on the shaft of the actuator.
DESC~IPTI0N OF THE PREFERRED E~IB0DI~IE~TTS
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The actuator A basica~lly is comprised of a shaft 1, an inner housing 2 longitudinally e~ctending e~teriorly oE the sha~t 1, and an accumulator housing 3 defined exteriorly from the inner housing 2 In Figs. 1 and 2, the actuator .~ is shown in engagement onto a valve body C by means of a bonnet assembly B.
The shaft 1 is a longitudinally e~tending elongated member having c!xteriorly and circumferentially mounted thereon upper and 10~7er piston head members 4 and 5. The upper piston head 4 has defined thereon an elastomeric exteriorl~; protruding T-seal element ~7hich slides ~longitudinally along a smooth wall 8~ of the inner cylinder 30 when the sha~t ~ is manipulated The seal element 6 provides a d~ynamic seal between ~he piston heacl _ and .
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~06~C1 11 3 the inner cylinder 30 and defines the lower end of an upper piston chamber 8. An interiorly protruding beveled shoulder 10 on the inner cylinder 30 defines ~he down stop for downward travel of the upper piston head 4.
The lower piston head 5 carries exteriorly thereon a T-scal element 7 of substan~ially thc same construction as T-seal 6, the T-seal 7 being permitted to travel longitudinally along the smooth wall llA of the inner cylinder 30 and forming a dynamic seal therebetween and thereby defining the lower end of the lower piston chamber 11.
The upper piston head 4 is the lower end of an upper piston chamber 8 interiorly defined ~ithin the inner cylinder 30 by means of the smooth wall 8A. The upper piston chamber 8 is terminated by means of dynamic T-seal 9 carried within and pro-truding outwardly from a shaft guide 15, the T-seal 9 preventing fluid communication between the shaft 1 and the shaft guide 15 while the shaft 1 is longitudinally stabilized as ~ell as when the.shaft 1 is shifted to open or close the gate valve described below.
The lower piston head S defines the lower end of a second or lower piston chamber 11 defined thereabove and extending interiorly of the inner cylinder 30 along the smooth ~all llA
thereof. T-seals 6 and 7 define the upper and lo~ermost ends, respectively, of the lower chamber 11, while T-seals 9 and 6 def.ine the upper and lower ends, respectively, of the upper piston chamber 8.
Immediate the top end 13 of the shaft 1 is a plastic wiper seal 12 which wipes contaminants off the shaft 1 as the shaft 1 is longitudinally manipulated within the inner housing 2 and the T-seal 9. A "T" shaped slot 14 is defined at the lor~ermost end of the shaft 1 for receipt of a companion bonnet stem B-l in the bonnet assembly B. .
10~9()~13 i` .
The inner housing 2 of the actuator`_ is comprised of a longitudinally e~tending shaft gui.de 15, an inner cyLinder . member 30 immediately therebelo~, an upper cap 20 i~lmediate and affixed to shaft guide _5, and a bonnet attachment 36 define~
exteriorly around the lo~ermost portion of the inner cylinder 30. The shaf L guide 15 is elongatedly defined around the exterior of the shaft 1 and has thread members 16 for affixation onto the actuator A of accessory components, such as heat-sensitive lock open elements, and the like. Additionally, the threads 16 serve to receive a protector element (not shown) which is threadedly secured thereon to position the shaft 1 within the actuator A
: during shipment and on-site asse~bly to the bonnet and valve, the protec~or and its companion washer.being rotatably removable by hand from the threads 16 and the actuator A prior to initial operation of the actuator A. The shaft guide 15 also houses the wiper ring 12 and the T-seal 9, and is secured by threads 19 to .. the cap member 20 exteriorly thereof, an O-ring 17 circumfer-entially extending around the shaft guide 15 within its companion bore 18 preventing fluid communication between the shaft guide . 20 15 and the cap 20.
- In order to assure elimination o relative rotational move-ment between the members 15 and 20, a pin 29 is longitudinally extended therebetween. The cap member 20 has at its upper end a supply port 22 for receipt of a control line 23 sealingly.en-gagable therewithin and in com~unication with a control panel (not shown) containing supply of fluid under pressure~ The j supply port 22 is immediately co~llunicable at all times with a ;; . .
i . longitudinally ex~endi.ng passageway 21A defined within the cap -., ~ .. 20, the passageway 21A terminating.at its lower end at a chcck 30 valve 24, the passagcw~y 21A being intersected at a point de-fined as the beginning of a latitudinal passageway ~lB e~tcnding :
~069()~8 laterally of the passage~ay 21A within thè cap 20 for ~luid co~nunication between the upper piston chamber 8 and the passage-way 21A.
The check valve 24 comprises a lower plug element 24A
threadedly securable within the cap 20 and having therein a . longitudinally extending passageway 24B, the plug element 24A
: providing on its upper end a seat for the receipt of the lower end of a compressible spring element 25. The spring element 25 normally urges a companion spherical ball element ?6 at the top thereof onto its seat 27 at the lower end of the passageway 21A.
However, fluid under pressure within the passageway 21~ is permitted to travel e~teriorly around the ball 26 within the : check valve 24 and thence through the passageway 24B when the ball 26 is urged off ics seat 27 at such time as the compressi~e force contained within the spring 25 is overcome by the higher control fluid pressure transmitted within the passageway 21A.
Extending below the:shaft guide 15 and secured to the lower portion of the cap member 20 by means of threads 31 is the inne~
cylinder 30 which has a circumrerentially extending elastomeric seal element 32 defined within its bore 33 for prevention o fluid communication betwe.en the cylinder 30 and the cap 20. The upper portion o~ the inner cylinder 30 has a smooth interior wall 8A which defines a travelway for the T-seal 6 carried on ..
the piston head 4 upon longitudinal shifting of the shaft 1, as described below. Additionally, the inner cylinde~ 30 comp-~ises the beveled shoulder 10 for definition of the do~n stop for the piston head 4 and the shaft 1. The inner cylinder 30 has, . ;~
- immediately below the shoulder 10, a latitudinally define~ boost - port 34 to permit continuous fluid transmission and communication between the lower or boost.chamber 11 below the lower or piston head 4 and the accumulator chamber 48. The inner cylinder ,~.'.
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- . , i 30 also has a smooth wall llA which is a companion wall to smooth wall 8A ~or travel thereon of the T-seal 7 carried on the , ' -- , .
;' lo~er boost piston head 5 when the shaft 1 is longitudinally manipulated. The inner cylinder 30 also contains at its 10~7er-;-- most end a longitudinally extending outwardly protruding shouldcr " ` member 30A which, when the inner cylinder 30 is affixed to the '; bonnet attachment 36 therebelow by means of threads 351 serves `,'i to carry load thereon and through the inner housing 2. A set , screw 39 serves to further secure the bonnet attachment 36 to :
-';' 10 the inner'cylinder 30 during on-site assembly of the actuator A
with the bonnet and valve members.
~ The bonnet attachmenc 36 is a cylindrical member having `~ defined therethrough a series of circular bores 36A for receipt .... ~ .
of thr,eaded bolt members B7 of the bonnet assembly B when the , actuator A is affixed to the bonnet B.
i~, The accumulator housing 3 is comprised of an elongated ',~;, cylindrical body 3A which is affixed at its upper and lower ends by upper and lower plates 40 and 49, respectively. The upper ~'~ plate 40 is affixed to the body 3A by means,of threads 43, with ' 20 a circumferentially extending 0-ring 41 within its bore 42 on ,'~ the c2p 20 preventing fluid communication between -~he cap 20 and ' ~,' the upper plate 40, while 0-ring 44 de~ined within a circumfer- '`
f`'", entially extending bore 45 prevents fluid communication between ~; the upper'plate 40 and the body 3A. The upper plate 40 has ;~
'' defined there-in a port 46 at the upper end of a longitudinally , extending passageway 46A. The port 46 receives a valve 47 which is in normally closed posltion. The valve 47 is manipulated to ,' open position subsequent Eo operation of the actuator A in the ,~ event and at such time that it lS desired to permanently or ', 30 temporarily remove the actuator ~ from the bonnet B in order to ., .
"~ relieve residual pressure within the chamber 48 and remove ' residual fluid therefrom.
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The lo~er plate 49 i5 a companion plate to the upper plate 40 and is secured to the body 3A b~ means of threads 50. An 0-ring element 53 circumferentially carried within a bore 54 defined on the bonnet attachment 36 prevents fluid communication between the bonnet attachment 36 and thc lower p:l.ate 49, while a companion elastomeric 0-ring element 51 within its bole 52 .
prevents fluid communication between the lower plate 49 and the body 3A.
A passageway 56A longitudinal.ly extending through the lower plate 49 terminates within an area derining a por~ 56 within the lower plate 49 and receives a check valve 58 on a fluid line 57 - which may be in fluid communication with a pressurized fluid :~ source utilized as a second or back-up means for continuously or ;.......... .
incrementally charging the accumulator housing 3, with the valve 58 in closed position assuring "fail safe" operation of the apparatus A. Additionally, the line 57 and valve 58 may be disconnected from the back-up accumulator charging means and the port sealingly plugged. A thermal relief valve 60 is sealingly engaged within a relief port 61 defined through the lower plaLe 49. This valve 60 permits automatic pressure relief do~n to normal control le~.7el in the event that the actuator A is e~posed to increased temperature environrnents to prevent overpressurization.
Thus, as above described, the accumulator housing 3 and its .
assoclated parts define a chamber 48 within the actuator ~, this chamber being referred to as the "accumulator" for the actuator A.
The actuator A is affi~ed to a bonnet assembly ~ and,.in .
turn, to a gate or other valve mechanism C by means of the threaded bolts B7 being inserted through the bores 36A of the bonnet attachment 36 and the T-slot 14 being engagably secured to the bonnet head B2 on the upper end of a longitudinally . ' :
' ~L~69(~18 e~tending bonnet stem Bl carried within the housing b~se ~L or the bonnet assembly B. The threaded bolcs B7 secure the bonr.ec attachment 36 to the outer housing BG of the bonneL assembly 3, with ~he housing B6 being secured by threads B5 to the housing base B4. The bonnet assembly B and, in t~lrn, the actua~or ~., are secured to the uppermost end of the gate valve C by means of nut and bolt assembly B3 e~tending through the housing base B4 and through the uppermost end of the valve seat S of the gate valve C. A pluralit~ of 0-rings B9 in a seal asse~bly housing B10 are defined in grooveways Bll to prevent fluid communication between the base B4 and the housing B10. Similarly designed --0-rings B12 are carried within grooveways B13 to prevent fluid communication bet~7een the housing B10 and the bonne~ stem Bl.
The housing B6 is threade;dly secured to the housing base B'~.
As seen in Fig. 5, the bonnet stem Bl has pro-vided at the upper-most end thereof a recessed ringhead B2, the outer diamete- of which is somewhat less than the inner diameter of the T-slot 14 !` . -- .
on the actuator ste~ 1 The T-slot 1~ is defined at one end by . a U-shaped outwardly prorruding shoulder B21 which is desiGned for slidable engagement of the end 14l of the ring B2, when the ring B2 is transversely shifted through the T-slot 14, ei~her during engagement of disengagement of the actuator shaft 1 to the bonnet stem Bl. The usa~e of the T-slot permits the bonnet stem -Bl to be transversely inserted within, but not completely- through, the actuator shaft ~I such that disengagement and engagement thereof may be conducted transversely without requirement or : longitudinal movement of the bonnet stem Bl and/or the actuator shart 1. ~ig. 6 is an alternative embodiment depicting the ring B2 on the actuator shaft 1 and the T-slot 14 defined on the bonnet stem Bl.
r ~ 6~ L8 The gate valve C basically is comp~ised of a valve s~eat S
. which has defined longitudinally therethrough the gaLe ~ carried : by the bonnet stem Bl. As shown in Fig. l, the gate G is in its : upper and opened position with wire line W extendIng therethrou~h and through the gate valve C.
OPERA ION
To install the actuator A onto a valve body C, such as '' shown in the Figs., the actuator shaft 1 should be s.roked to the down position, as shown in Fig~ 1, either manually or b~
control line pressure being applied through passage~,ays 21~
and 21B and within the chamber 8. Thereafter, the actuator A
is lowered over the bonnet stem Bl. When the ring B2 is in .~ substantial alignment ~ith the T-slot 1~ and the.shoulder B2 '~ the actuator shaft 1 and the bonnet stem Bl are trarsversely moved such that the ring B2 slides through the T-slot 14 i .
with the end 141 of the ring B2 sliding alorlg the'shoulder :''': ' ~....................................................................... .
:. B21 of the T-slot 14 until further transverse movement is ~ ~
prevented and the bonnet~stem Bl and the actuator shaft 1 are in '~
;~: substantial lonOitudinal:alignment, as sho~v-n in Fig. 4. There-after, pressure actinV within chamber 8 and on plston 4 is bled '~
` off to permit the housing 3 to move longitudinally ~o~v-n~.. ardly ; with respect to the bonnet assembly B. Thereafter, the bolts .' B7 may be affixed through the bores 36A to secure the actuator'A .'.' - to the bonnet assembly B. Thereafter, the bolts B7 may be affixed .'.:~; to the gate valve C by means of bolt B3. Alternatively, the ~ bonnet assembly _ may first be a'ffi~ed to the valve C, and, there-after, the bonnet stem Bl and actuator shaft 1 affi~ed as above described. ~ ~
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To remove the ac~uator A from the gate valve C and ~he bonnet assembly B, pressure within the control line 23 is per-mi~tcd to be bled o~f to permit closure of the ~a~e with resp~ctto thc valve sea~ S. The uppe~.lost end of thc~ ac~uator sha~t 1 will rise to the position as sho~m in Fig. 2. Therea~ter, the ;- bolts B7 within their respective bores 36A may be easily removed.
,. Thereafter, pressure is applied through the control line 23 and passageways 21A and 21B to exert pressure within chamber 8 on . piston 4. Because the actuator A has been disengaged from the bonnet assembly B at the bonnet attachment 36 which, in turn, is secured to the housing 3 of the actuator A, the.housing 3 will - be caused to shift longitudinally upwardly wlth respect to the ~= actuator shaft 1 which still îs affixed to the bonnet stem Bl . of t~e bonnec assembly B. Thereafter, the bonnet stem Bl may . be disengaged from the actuator shaft 1 b~J moving one of the .: shaft 1 and the stem Bl transversely to permit the stem Bl to become disengaged from the shaft 1 and out of the T-slot 14.
, The actuator A then is completely free of the bonnet assembly B
- and the valve C and can be removed for repair of the actuator A
or the valve C. :
When the actuator is affi~ed to the bonnet assembly B, in ' order to place the gate in the down or open position, the .-control line 23 is affix2d within the supply port 22 of the cap20 on the actuator A and is, in turn, placed in fluid communi-cation with the control panel for transmission of hydraulic or o~her pressurized fluid therethrough to the actuator A.
The flui~ passes within control line 23 through the cap 20 wi.thln the passageway 21~ and concurrently is trans-mitted through passageway 21B into the upper piston chamber 8 and, whcn pressure is increased with the line 23, s . resistance afforded by the compression in sprin~ 25 is 6g()18 overcome by a slight but negligible pressure increase such that the ball 26 will be removed and sealingl~ disengaged from its seat 27~ thus permitting fluid transmission through the check valve 24, and the passage 24B to the accumulator chamber 48.
Concurrently with the fillir~g of the accumulator chamber 48, the pressure within the chzmber defined by dynamic T-seals 6 and 9 e~erts a force upon the piston head 4 greater than the opposing force contained within the chamher 11 between the seals 6 and 7 such that the shaft 1 is urged downwardly because oE chamber area differential until the gate G o the gate valve C is completely opened.
.: :
,~ As fluid is permitted to build up within the upper piston chamber 8, fluid also is transmitted through the check valve 24 ;~
- and is contained within the accumulator chamber 48. Additionally, , since the accumulator chamber 48 always is in fluid communication ; with the lower chamber 11 by means of the boost port 34, pressure ; and fluid are always permltted to enter the lower chamber 11. -~Since the check valve 24 is one-way acting, that is, it permits fluid within passageway 21A to travel therethrough and into the 20 accumulator chamber 48, but prevents fluid within ~he chamber 48 from passing out of the chamber 48 and into the passageway 21A, the accumulator chamber 48 is fluid tight, and lower longitudinal travel o the piston head 4 will permit contraction o the lower chamber 11 area, with 1uid being transmitted out of the lower chamber 11 through the boost port 34 and within the accumulator ` chamber 48 whereby the fluid is compressed.
,~ - It should be noted that the 0-rings in association with the accumulator chamber ~8 prevent fluid leakage. Additionally, it ~-also should be noted that vcrlves 58 and 47A are closed.
~hen it is desired~to close the gate G of the gate valve C, fluid within the control line ~3 will be bled oE~. ~s a resul~, ~ .
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( 106~18 pressure within the upper piston chamber 8 and the passageway , 21A will be reduced below the amount neces.sar~ to posltion the shaft 1 downwarclly and maintain the gate G in open position.
Ho~ever, it should be emphasized tha~ pressure within the accumu-lator chamL)er 48 is not reduccd, bled o~f or lost inasmuch as the ball 2fj is sealingly engaged on lts seat 27 by the compressive force afforded by the spring 25 in the check valve 24. Thus~
~: the pressure within the accumulator chamber 48 will be at least equal to the initial high pressure carried to the actuator A
;~ 10 within the control line 23, the passager.~ay 21A and the upper ~ piston chamber 8. Upon reduction of pressure within the upper -:: piston chamber 8, the pressure within chambers 11 and 48 acting on the piston head 4 will permit the shaft 1 to be urged longi-tudinally upwardly with a force determined by accumulator pres-sure and the area defined within chamber 11. Thus~ pressure is .:
'.; permitted to be bullt up within the accumulator chamber 48 such .. :
~that the venting of control pressure within the control line 23 ~:~ : will enable the compressive fluid force contained within the accumulator chamber 48 to act as a compressed "spring", thus urging the shaft 1 longitudinally upwardly with suEficient force that the wire line 1~ carried through and within th~ valve seat S
within a lubricator as`sembly (not sho~n) will be completely sheared.
In order to reactivate the actuator A af~er shearing of the wire line W, pressure within the control line 23 is increased ~:
and the procedure as above described is repeated. ..
The desired compressive force to be charged within the ~: accumulator chamber 48 is preselectable,.with parameters being : dependent upon the ~olume oE- the accumulator, the area of the upper and lower piston chambers 8 and 11, the pressure ~ithin the control line 23, the compressive force e~ertcd by the spring .
: ~ -20-, 9~
25, and the compressi~ility o~ the selec~ed hydraulic or ~neu~atic control fluid.
Even though the accumulator chamber 48 and .he lower cha~ber 11 are initially filled, they can be continuousl~ and incre~ent~lly recharged in the event that O-rings and/or valves leak. Thus, it can be clearly seen that the acc~nulator chamber 48 is a continuously charged one, assuring a fl~ed pressurized force for selectively acting upon the lower end of the piston head 4 and, , . :
in turn, urging the shaft 1 to an upward position to shear the wire W and close the gate.
As an alternative source of shirting the sha't 1 longitu-dinally up~ardly, a nitrogen or other fluid source may be arfixed to the line 57, with the valve 58 being manipulated ~o "open"
positlon. Thus, the nitrogen may be charged into the cha~ber 48 and the lo~er chamber 11 for activation upon the lower end of the piston head 4 to urge the shaf, 1 in an upwardly posltion to shift the gate to completely closed position while still assuring fail safe operation of the valve C.
~ Although the invention has been described in te~s of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that ~he invention is not necessariLy limited thereto, since alternative embodi.ments and operating techniques will become apparent to those skilled in the art in vie~ of the disclosure. Acco~d-ingl~ modifications are contemplated which can be made ~ithout departing from the spirit of the described invention.
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Normally, these actuators comprise a shaft and a fluid activated mechanism in association therewith whieh, upon activation thereof ;~
lo by increase in control line pressure, causes longitudinal move- -ment of the shaft to shift the valve in relation to its seat.
Venting of control line pressure will cause a subsequent and `
~ ~ second longitudinal shiftlng of the shaft and the valve head to ,~ a second position. Such aalve systems zre frequently utilized in safety systems used in conjunction with the drilling, comple-tion and production of offshore, as well as inland, oil and gas wells. Additionally, such components are utilized in natural gas transmission lines, and the like.
During the completion, testing and/or wor~over of a sub-` 20 terranean well, it may be necessar~ to run equipment such as a ;` `
perforating gun, or the lIke, on a wire or other line into the well when the well is under pressure. This is achieved by inserting the equipment lnto a l~ength of production tubing above ; .
`~ -2-.
~\
the christmas tree, the length of tubing being commonly referred to as a 1l lubricator". The lubricator is isolated from the , portion of the well therebelow by a valvc or a series of readily accessible hand manipulated valves. In view of the fact that . .
the lubricator assembly must contain the well pressure while the equipment is inserted therethrough for subsequent utilization in the well, it is necess-ary to control the well pressure below the , lubricator assembly during this procedure. To contain the well, in the event of failure of the components of the lubricator, a safety valve mechanism is positioned below the lubricator. This valve should be "fail safe" and should be activatable remotely or automatically upon loss of control.
When a gate valve mechanism is utilized below the lubricator, the valve actuator should be of such design and construction that, upon longitudinal shifting of the stem therein, the gate is permitted to completely close ~ith sufficient force such that a wire line carrying downhole tools may be sheared by the gate ~ upon longitudinal shifting of the shaft within the actuator.
J~'` Upon detection of pressure leaks within the lubricator, or when control of the well is lost and it begins to prematurely flo~J, the actuator should have sufficient force to cause the wire line ; to be sheared when the gate is closed in order to assure that ~ . , , the gate is sealingly interfaced onto its seat to prevent flo~
there;through. The force which shears the wire line penetrating through the gate opening should be independent of the well pressure within the valve body.
Normally, valve actuators depend upon pressure within the :
valve body operably associated with a compressed spring asse~bly to shift the bonnet stem longitùdinally in order to permit the valve to close. The spring assembly within the actuator is present only for minor frlction forces, and fail safe gate valve ~ ' , .
(.
:~ ~069()18 . . . :
actuators he~etofore made commercially available do not have su~icient force to shear a wire line during the valve closing sequence, in the absence of well pressure in the valve body.
Standard fail safe gate valve actuators are not afforded ; sufficient force to shear wire inserted through the valve due to physical and technological limitations and sizing requirements for the valves and their associated operating components. A
double acting actuator with pressure operable upon either side of a piston element could be utilized in conjunction with spring force to cause manlpulation of a shaft within the actuator to, in turn, cause sufficient force to be exerted on the shaft such that longitudinal movement of the shaft shears the wire line inserted through the valve body. It should be noted that this double acting actuator design is not fail safe, because loss of control pressure will not assure closing of the valve head onto its seat. This piston arrangement would require an e~ternal charging force, such as a~nitrogen accumulator. Consequently, a - stock of nitrogen bottles would be required at the well or other commercial site. The nitrogen charged accumulator would force control fluid out of one of the piston chambers, whereby the valve head is shlfted to the closed position. Thus, it is clear - -that longitudinal movement of the stem when control pressure is ,~ vented off to close the valve would require two control lines, the first line being in association with a supply port and one - piston chamber, and a second control line in a second or boost port communicating with a second or boost piston chamber. In view o~ the fact that the~actuator design must be "fail safe", that is, it must assure closure of the valve when control line pressure is intentionally or unintentionally`bled off, the incorporation of two control lines into the design of the actuator -~renders the design doubly susceptible to failure by leaks and/or 5'breaks in the lines.
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( ~6~ai~ , :.-.
~ s an alternative design, a concentric accumulator e~.tcr-iorly sur~ounding the actuator could be utilized as an integral part of the actuator. This design would require the ucilization of nitrogen bottles in a bank for continuous charging of the accumulator. Additionally, the t~o control lines would, of nec-essity, still be required to maintain nitrogen charges. Use of plural lines would, in turn, continue to double e~pose the ap-paratus to the likelihood of nîtrogen leaks which are extremely difficult to detect and seal.
lo In the past, when it has been found necessary to repair the valve mechanism or the actuator itself on location, consider-able do~n time has been required during the dismanteling of the actuator from the valve bonnet stem in order to have access to the valve or actuator components. The down time has neces-sitated shut in of a flowing well or isolation o~ the valve mechanism from the flor~ stream of a transmission line, which, : in turn, has an adverse economic impact because of the cost of lost rig time, lost production, and the like. ~Ioreover, many prior art actuators are designed such that in the event of onsite failure of the attached valve mechanism or the actuator, the actuator must be almost completely disassembled in order to remove or replace the actuator or repair the valve. For e~ample, t~e prior art has taught use of an actuator valve assembly wherein the actuator is affi~ed onto the valve body by means of bolts inserted through the lower housing and into companion bores in the upper face of the valve housing. ~lso, the prior art typically provldes for connection of the actuator shaft to the valve head by means of a shoulder on the actuator shaft insertible within a companion slot in the valve head, all within the valve body, the actuator shaft and bonnet stelll being one continuous piece. Variations of prior art actuators incl~lde those generally as above desc~ bed a~d lncludlng an actuator . . .
~' ( 10~
: expander ~hich funccions to adaptably mount an actuator onto ~he valve body. The present invencion overcomes this deiclenc~ by providing means for quickly engaging and disengaging the ac~u-ator with ~espect to the valve body and within the approximate total length of the actuator.
The present invention overco~es many or the disadvantages :.
found in prior art commercially available actuators by providing an actuator having an internal cylindrical accumulator with .: ~
, sufficient volume such that the fluid therein may be compressed :.
- 10 with sufficient force to assure that the shaft is longitudinally shifted to shear a wire line inserted ~hrough the valve body during~ the valve closing sequence. The accumulator requires no : .
. incremental or continuous charging with secondary sources, sucX
., .
as nitrogen; hence, problems associated wi.th secondary source leakage are eliminated. Additi.onally, in the preferred form, : the present invention necessitates usage of only one control : :.
line, this advantageous feature being attributable to usage of a " . .
.. check valve within a conduit or passageway e~tending between the .
. ~ control line and the accu~ulator chamber and being within the .
actuator itselE. Moreover, the check valve mechanism permi-~s . continuous charging of the accumulator chamber so that when A~ supply pressure is vented of, presswre within the accumulator chamber is trapped and compressed fluid therein will drive the piston and its assoclated shaEt in a longitudinal direction to shift the gate or other valve ~ember, for e~ample, to isolate ~ the fluid flow within the valve body. In the present invention, ; in the event of leakage oE 0-rings or other sealing elements, the accumulator chamber will continue to be charged ~Jith fluid . through the c:ont-rol line which will result in a "fail safe"
; 30 actuator which does not require usage of secondary fluid sources, . . . .
: such as nitrogen bottles or nltrogen caps on the accumulator to : drive the fluid under the piston and up~lzrdly to shiEt the va].ve.
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( ~0690~L8 The presen~ actuator has a physical design advantage in that it can be manufactured substantially shorter lengthwise :.. .
than actuators desi~ned to operate within and at similar pres-sure environments, but responsive to compressibility of spring~
elements. Although the diameter of the present actuator is somewhat larger than comparative-sized actuators operative at the same control pressure, the present invention now contains approximately ten ti~es the closing force of spring-fed ~ct~aators.
For example, a 5,000 pound closing force can be obtained using ; 10 the contlnuously fed accumulator chamber of the present astua~or.
- To obtain such a cLosing force in a spring-fed prior art actuator, ' ten concentricly mounted S00 pound force springs would have to be utilized. This, in turn, would require an actuator having a housing approximately two times the diameter of the housing of the actuator of the present invention. Additionally, such a spring-fed actuator would be considerably longer (length~ise) than the present actuator due to space requirements for the action of the spring. Moreover, the absence of a spring element in the present actuator renders it less susceptible to mechanical ~; 20 failure because the risk of spring failure or breakage due to corrosion and/or metal fatigue is eliminated.
The present actuator utilizes a plurality o~ pressure chamber areas which permits continuous charging of ~he accumulator because of the variance in the areas of each of the chambers, whereby ~orces applied through the chambers are selectively pressurable. Thus, by having independent control of each of the chamber areas, fluid media, control pressure, and operating forces can be independently controlled. This design will result in reduced loads being applied to the bonnet stem.
Another advantage of the present actuator is that the shearing of wire line inserted through the valve is no~ a function ~)691)~3 of well pressure through the valve body itself, and there is sufficient pressure acting upon the piston and sha~t elements to sufficiently shear a wire line extending through the valve, thus permitting a complete fluid seal bet~een the valve head and its seat, upon closing of the valve.
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SU~ARY OF THE INVENTION
The present invention comprises an actuator which is respond-able, preferably, to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator has a housing which defines a cylindrical bore therethrough. A
shaft is carried within the housing and is engagable with the operative means,in a preferred form. Means defining first and ; second effective pis~on areas are carried by one of the shaft and the housing and are sealingly slidable along the other of the shaft and the housing and longitudinally movable within the cylindrical bore. The apparatus provides first and second fluid chambers whlch are companionly associated with the means defining first and second effective piston areas within the bore for yielding a differential force across the means derining the first and second effective piston areas upon variation of fluid control pressure within the actuator. The apparatus has a continuously chargeable fluid accumulator means in fluid communi-cation with said second fluid chamber ~or the storage of energy defined preferably by control fluid which is compressible therein.
A fluid passage means for transmitting fluid under pressure is provided to said first fluid chamber and to the accumulator means. A valve means i5 movable bet~een open and closed positions and communicates bet~een the accumulator means and the fluid - passage means to permit fluid control pressure charging of the accumulator chamber when in said open position and preventing discharge of fluid pressure within the accumulator cham~er when ~. , , ~` ` ( ~.
: 1~690~1 3 . . .~
the valve is in the closed position, the valve being responsive .~ to pressure differential between the accumulator chamber and the fluid passage means, the shaft being selectively shiftable longitudinally in a first direction to move the operative means :~ .
to one of open and closed positions, preferably, by increase in ~ fluid control pressure, the shat being selectively shiftable .~`` longitudinally in a second direction to move the operative m~ans . to the other o~ open and closed positions, pre~erably, upon subsequent decrease in fluid control pressure and release of energy stored within the accumulator.
. The present invention also provies, independently of the : utilization of plural piston means and/or the fluid accumulator, .: means.for readily and quickly engaging and disengaging the ` actuator with respect to the valve body without t~e require~ent of disassembly of the actuator. Moreover, the engagement means are operative to assure that the valve head is in closed position with respect to its seat during removal of the actuator from the valve body. The engagement means also permit affixation onto .~ and removal of the valve body of the actuator within the approx-:: 20 imate total length of the actuator such that the actuator is very ; ..;:
. easily affixed to or removed from valve mechanisms in close , proximity eo well heads and the like.
: The apparatus of the present invention is utilized in a : preferred form with a continuously chargeable fluid accumulator : means in fluid.communication with a second fluid chamber for the storage of energy defined~preferably by control fIui.d which is . compressible therein.
:.~ BRIEF DESCRIPTION OF THE DP~INGS
Fig. 1 is a longitudinal schematic and sectional. vie~ of the ; 30 actuator of the present invention incorpora.ted.onto an ol~erative - . - 9 -.
, means, or bonnet assembly, o~ a gate valve which, in turn, ~ . .
forms a parc of a lubricator assembly, with a wire~ line being inserted through the gate valve, the gate o~ the valve being sho~n in open position.
Fig. 2 is a view similar to that shown in Fig. l, wi~h Lhc gate of the valve being shown in closed position an~ the wire line completely sheared.
Fig. 3 is a longitudinal sectional drawing of the actuator sho~m in Figs~ l and 2, the position of the respective components of the actuator being as is illustrated in Fig. l.
Fig. 4 is a partial longitudinal sectional dra~Jing of the `' actuator in position durin~ ~emoval ~rom the valve body, -'~Ji Lh its bolts securin~ the actuator housing to the valve body belng removed to permit the housing to be pumped up to permit relative transverse shifting o~ the shaft and the bonnet LO completely dis-engage the actuator from the valve body.
Fig. 5 is a detailed vle~7 of the shaft and bonnet in completel disengaged position.
Fig. 6 is a view of an alternative design illustratinO the slotted means on the val~e bonnet and the conmpanion engagement ring on the shaft of the actuator.
DESC~IPTI0N OF THE PREFERRED E~IB0DI~IE~TTS
j: , --_ ............ . .. _ . .
The actuator A basica~lly is comprised of a shaft 1, an inner housing 2 longitudinally e~ctending e~teriorly oE the sha~t 1, and an accumulator housing 3 defined exteriorly from the inner housing 2 In Figs. 1 and 2, the actuator .~ is shown in engagement onto a valve body C by means of a bonnet assembly B.
The shaft 1 is a longitudinally e~tending elongated member having c!xteriorly and circumferentially mounted thereon upper and 10~7er piston head members 4 and 5. The upper piston head 4 has defined thereon an elastomeric exteriorl~; protruding T-seal element ~7hich slides ~longitudinally along a smooth wall 8~ of the inner cylinder 30 when the sha~t ~ is manipulated The seal element 6 provides a d~ynamic seal between ~he piston heacl _ and .
:.
~06~C1 11 3 the inner cylinder 30 and defines the lower end of an upper piston chamber 8. An interiorly protruding beveled shoulder 10 on the inner cylinder 30 defines ~he down stop for downward travel of the upper piston head 4.
The lower piston head 5 carries exteriorly thereon a T-scal element 7 of substan~ially thc same construction as T-seal 6, the T-seal 7 being permitted to travel longitudinally along the smooth wall llA of the inner cylinder 30 and forming a dynamic seal therebetween and thereby defining the lower end of the lower piston chamber 11.
The upper piston head 4 is the lower end of an upper piston chamber 8 interiorly defined ~ithin the inner cylinder 30 by means of the smooth wall 8A. The upper piston chamber 8 is terminated by means of dynamic T-seal 9 carried within and pro-truding outwardly from a shaft guide 15, the T-seal 9 preventing fluid communication between the shaft 1 and the shaft guide 15 while the shaft 1 is longitudinally stabilized as ~ell as when the.shaft 1 is shifted to open or close the gate valve described below.
The lower piston head S defines the lower end of a second or lower piston chamber 11 defined thereabove and extending interiorly of the inner cylinder 30 along the smooth ~all llA
thereof. T-seals 6 and 7 define the upper and lo~ermost ends, respectively, of the lower chamber 11, while T-seals 9 and 6 def.ine the upper and lower ends, respectively, of the upper piston chamber 8.
Immediate the top end 13 of the shaft 1 is a plastic wiper seal 12 which wipes contaminants off the shaft 1 as the shaft 1 is longitudinally manipulated within the inner housing 2 and the T-seal 9. A "T" shaped slot 14 is defined at the lor~ermost end of the shaft 1 for receipt of a companion bonnet stem B-l in the bonnet assembly B. .
10~9()~13 i` .
The inner housing 2 of the actuator`_ is comprised of a longitudinally e~tending shaft gui.de 15, an inner cyLinder . member 30 immediately therebelo~, an upper cap 20 i~lmediate and affixed to shaft guide _5, and a bonnet attachment 36 define~
exteriorly around the lo~ermost portion of the inner cylinder 30. The shaf L guide 15 is elongatedly defined around the exterior of the shaft 1 and has thread members 16 for affixation onto the actuator A of accessory components, such as heat-sensitive lock open elements, and the like. Additionally, the threads 16 serve to receive a protector element (not shown) which is threadedly secured thereon to position the shaft 1 within the actuator A
: during shipment and on-site asse~bly to the bonnet and valve, the protec~or and its companion washer.being rotatably removable by hand from the threads 16 and the actuator A prior to initial operation of the actuator A. The shaft guide 15 also houses the wiper ring 12 and the T-seal 9, and is secured by threads 19 to .. the cap member 20 exteriorly thereof, an O-ring 17 circumfer-entially extending around the shaft guide 15 within its companion bore 18 preventing fluid communication between the shaft guide . 20 15 and the cap 20.
- In order to assure elimination o relative rotational move-ment between the members 15 and 20, a pin 29 is longitudinally extended therebetween. The cap member 20 has at its upper end a supply port 22 for receipt of a control line 23 sealingly.en-gagable therewithin and in com~unication with a control panel (not shown) containing supply of fluid under pressure~ The j supply port 22 is immediately co~llunicable at all times with a ;; . .
i . longitudinally ex~endi.ng passageway 21A defined within the cap -., ~ .. 20, the passageway 21A terminating.at its lower end at a chcck 30 valve 24, the passagcw~y 21A being intersected at a point de-fined as the beginning of a latitudinal passageway ~lB e~tcnding :
~069()~8 laterally of the passage~ay 21A within thè cap 20 for ~luid co~nunication between the upper piston chamber 8 and the passage-way 21A.
The check valve 24 comprises a lower plug element 24A
threadedly securable within the cap 20 and having therein a . longitudinally extending passageway 24B, the plug element 24A
: providing on its upper end a seat for the receipt of the lower end of a compressible spring element 25. The spring element 25 normally urges a companion spherical ball element ?6 at the top thereof onto its seat 27 at the lower end of the passageway 21A.
However, fluid under pressure within the passageway 21~ is permitted to travel e~teriorly around the ball 26 within the : check valve 24 and thence through the passageway 24B when the ball 26 is urged off ics seat 27 at such time as the compressi~e force contained within the spring 25 is overcome by the higher control fluid pressure transmitted within the passageway 21A.
Extending below the:shaft guide 15 and secured to the lower portion of the cap member 20 by means of threads 31 is the inne~
cylinder 30 which has a circumrerentially extending elastomeric seal element 32 defined within its bore 33 for prevention o fluid communication betwe.en the cylinder 30 and the cap 20. The upper portion o~ the inner cylinder 30 has a smooth interior wall 8A which defines a travelway for the T-seal 6 carried on ..
the piston head 4 upon longitudinal shifting of the shaft 1, as described below. Additionally, the inner cylinde~ 30 comp-~ises the beveled shoulder 10 for definition of the do~n stop for the piston head 4 and the shaft 1. The inner cylinder 30 has, . ;~
- immediately below the shoulder 10, a latitudinally define~ boost - port 34 to permit continuous fluid transmission and communication between the lower or boost.chamber 11 below the lower or piston head 4 and the accumulator chamber 48. The inner cylinder ,~.'.
(~ ~
~;169Ul~
- . , i 30 also has a smooth wall llA which is a companion wall to smooth wall 8A ~or travel thereon of the T-seal 7 carried on the , ' -- , .
;' lo~er boost piston head 5 when the shaft 1 is longitudinally manipulated. The inner cylinder 30 also contains at its 10~7er-;-- most end a longitudinally extending outwardly protruding shouldcr " ` member 30A which, when the inner cylinder 30 is affixed to the '; bonnet attachment 36 therebelow by means of threads 351 serves `,'i to carry load thereon and through the inner housing 2. A set , screw 39 serves to further secure the bonnet attachment 36 to :
-';' 10 the inner'cylinder 30 during on-site assembly of the actuator A
with the bonnet and valve members.
~ The bonnet attachmenc 36 is a cylindrical member having `~ defined therethrough a series of circular bores 36A for receipt .... ~ .
of thr,eaded bolt members B7 of the bonnet assembly B when the , actuator A is affixed to the bonnet B.
i~, The accumulator housing 3 is comprised of an elongated ',~;, cylindrical body 3A which is affixed at its upper and lower ends by upper and lower plates 40 and 49, respectively. The upper ~'~ plate 40 is affixed to the body 3A by means,of threads 43, with ' 20 a circumferentially extending 0-ring 41 within its bore 42 on ,'~ the c2p 20 preventing fluid communication between -~he cap 20 and ' ~,' the upper plate 40, while 0-ring 44 de~ined within a circumfer- '`
f`'", entially extending bore 45 prevents fluid communication between ~; the upper'plate 40 and the body 3A. The upper plate 40 has ;~
'' defined there-in a port 46 at the upper end of a longitudinally , extending passageway 46A. The port 46 receives a valve 47 which is in normally closed posltion. The valve 47 is manipulated to ,' open position subsequent Eo operation of the actuator A in the ,~ event and at such time that it lS desired to permanently or ', 30 temporarily remove the actuator ~ from the bonnet B in order to ., .
"~ relieve residual pressure within the chamber 48 and remove ' residual fluid therefrom.
, .. . .
- 106g~
The lo~er plate 49 i5 a companion plate to the upper plate 40 and is secured to the body 3A b~ means of threads 50. An 0-ring element 53 circumferentially carried within a bore 54 defined on the bonnet attachment 36 prevents fluid communication between the bonnet attachment 36 and thc lower p:l.ate 49, while a companion elastomeric 0-ring element 51 within its bole 52 .
prevents fluid communication between the lower plate 49 and the body 3A.
A passageway 56A longitudinal.ly extending through the lower plate 49 terminates within an area derining a por~ 56 within the lower plate 49 and receives a check valve 58 on a fluid line 57 - which may be in fluid communication with a pressurized fluid :~ source utilized as a second or back-up means for continuously or ;.......... .
incrementally charging the accumulator housing 3, with the valve 58 in closed position assuring "fail safe" operation of the apparatus A. Additionally, the line 57 and valve 58 may be disconnected from the back-up accumulator charging means and the port sealingly plugged. A thermal relief valve 60 is sealingly engaged within a relief port 61 defined through the lower plaLe 49. This valve 60 permits automatic pressure relief do~n to normal control le~.7el in the event that the actuator A is e~posed to increased temperature environrnents to prevent overpressurization.
Thus, as above described, the accumulator housing 3 and its .
assoclated parts define a chamber 48 within the actuator ~, this chamber being referred to as the "accumulator" for the actuator A.
The actuator A is affi~ed to a bonnet assembly ~ and,.in .
turn, to a gate or other valve mechanism C by means of the threaded bolts B7 being inserted through the bores 36A of the bonnet attachment 36 and the T-slot 14 being engagably secured to the bonnet head B2 on the upper end of a longitudinally . ' :
' ~L~69(~18 e~tending bonnet stem Bl carried within the housing b~se ~L or the bonnet assembly B. The threaded bolcs B7 secure the bonr.ec attachment 36 to the outer housing BG of the bonneL assembly 3, with ~he housing B6 being secured by threads B5 to the housing base B4. The bonnet assembly B and, in t~lrn, the actua~or ~., are secured to the uppermost end of the gate valve C by means of nut and bolt assembly B3 e~tending through the housing base B4 and through the uppermost end of the valve seat S of the gate valve C. A pluralit~ of 0-rings B9 in a seal asse~bly housing B10 are defined in grooveways Bll to prevent fluid communication between the base B4 and the housing B10. Similarly designed --0-rings B12 are carried within grooveways B13 to prevent fluid communication bet~7een the housing B10 and the bonne~ stem Bl.
The housing B6 is threade;dly secured to the housing base B'~.
As seen in Fig. 5, the bonnet stem Bl has pro-vided at the upper-most end thereof a recessed ringhead B2, the outer diamete- of which is somewhat less than the inner diameter of the T-slot 14 !` . -- .
on the actuator ste~ 1 The T-slot 1~ is defined at one end by . a U-shaped outwardly prorruding shoulder B21 which is desiGned for slidable engagement of the end 14l of the ring B2, when the ring B2 is transversely shifted through the T-slot 14, ei~her during engagement of disengagement of the actuator shaft 1 to the bonnet stem Bl. The usa~e of the T-slot permits the bonnet stem -Bl to be transversely inserted within, but not completely- through, the actuator shaft ~I such that disengagement and engagement thereof may be conducted transversely without requirement or : longitudinal movement of the bonnet stem Bl and/or the actuator shart 1. ~ig. 6 is an alternative embodiment depicting the ring B2 on the actuator shaft 1 and the T-slot 14 defined on the bonnet stem Bl.
r ~ 6~ L8 The gate valve C basically is comp~ised of a valve s~eat S
. which has defined longitudinally therethrough the gaLe ~ carried : by the bonnet stem Bl. As shown in Fig. l, the gate G is in its : upper and opened position with wire line W extendIng therethrou~h and through the gate valve C.
OPERA ION
To install the actuator A onto a valve body C, such as '' shown in the Figs., the actuator shaft 1 should be s.roked to the down position, as shown in Fig~ 1, either manually or b~
control line pressure being applied through passage~,ays 21~
and 21B and within the chamber 8. Thereafter, the actuator A
is lowered over the bonnet stem Bl. When the ring B2 is in .~ substantial alignment ~ith the T-slot 1~ and the.shoulder B2 '~ the actuator shaft 1 and the bonnet stem Bl are trarsversely moved such that the ring B2 slides through the T-slot 14 i .
with the end 141 of the ring B2 sliding alorlg the'shoulder :''': ' ~....................................................................... .
:. B21 of the T-slot 14 until further transverse movement is ~ ~
prevented and the bonnet~stem Bl and the actuator shaft 1 are in '~
;~: substantial lonOitudinal:alignment, as sho~v-n in Fig. 4. There-after, pressure actinV within chamber 8 and on plston 4 is bled '~
` off to permit the housing 3 to move longitudinally ~o~v-n~.. ardly ; with respect to the bonnet assembly B. Thereafter, the bolts .' B7 may be affixed through the bores 36A to secure the actuator'A .'.' - to the bonnet assembly B. Thereafter, the bolts B7 may be affixed .'.:~; to the gate valve C by means of bolt B3. Alternatively, the ~ bonnet assembly _ may first be a'ffi~ed to the valve C, and, there-after, the bonnet stem Bl and actuator shaft 1 affi~ed as above described. ~ ~
-17- ' ' ~' ' ' '.
, '' " ~ ( ~,06~
.
:`
To remove the ac~uator A from the gate valve C and ~he bonnet assembly B, pressure within the control line 23 is per-mi~tcd to be bled o~f to permit closure of the ~a~e with resp~ctto thc valve sea~ S. The uppe~.lost end of thc~ ac~uator sha~t 1 will rise to the position as sho~m in Fig. 2. Therea~ter, the ;- bolts B7 within their respective bores 36A may be easily removed.
,. Thereafter, pressure is applied through the control line 23 and passageways 21A and 21B to exert pressure within chamber 8 on . piston 4. Because the actuator A has been disengaged from the bonnet assembly B at the bonnet attachment 36 which, in turn, is secured to the housing 3 of the actuator A, the.housing 3 will - be caused to shift longitudinally upwardly wlth respect to the ~= actuator shaft 1 which still îs affixed to the bonnet stem Bl . of t~e bonnec assembly B. Thereafter, the bonnet stem Bl may . be disengaged from the actuator shaft 1 b~J moving one of the .: shaft 1 and the stem Bl transversely to permit the stem Bl to become disengaged from the shaft 1 and out of the T-slot 14.
, The actuator A then is completely free of the bonnet assembly B
- and the valve C and can be removed for repair of the actuator A
or the valve C. :
When the actuator is affi~ed to the bonnet assembly B, in ' order to place the gate in the down or open position, the .-control line 23 is affix2d within the supply port 22 of the cap20 on the actuator A and is, in turn, placed in fluid communi-cation with the control panel for transmission of hydraulic or o~her pressurized fluid therethrough to the actuator A.
The flui~ passes within control line 23 through the cap 20 wi.thln the passageway 21~ and concurrently is trans-mitted through passageway 21B into the upper piston chamber 8 and, whcn pressure is increased with the line 23, s . resistance afforded by the compression in sprin~ 25 is 6g()18 overcome by a slight but negligible pressure increase such that the ball 26 will be removed and sealingl~ disengaged from its seat 27~ thus permitting fluid transmission through the check valve 24, and the passage 24B to the accumulator chamber 48.
Concurrently with the fillir~g of the accumulator chamber 48, the pressure within the chzmber defined by dynamic T-seals 6 and 9 e~erts a force upon the piston head 4 greater than the opposing force contained within the chamher 11 between the seals 6 and 7 such that the shaft 1 is urged downwardly because oE chamber area differential until the gate G o the gate valve C is completely opened.
.: :
,~ As fluid is permitted to build up within the upper piston chamber 8, fluid also is transmitted through the check valve 24 ;~
- and is contained within the accumulator chamber 48. Additionally, , since the accumulator chamber 48 always is in fluid communication ; with the lower chamber 11 by means of the boost port 34, pressure ; and fluid are always permltted to enter the lower chamber 11. -~Since the check valve 24 is one-way acting, that is, it permits fluid within passageway 21A to travel therethrough and into the 20 accumulator chamber 48, but prevents fluid within ~he chamber 48 from passing out of the chamber 48 and into the passageway 21A, the accumulator chamber 48 is fluid tight, and lower longitudinal travel o the piston head 4 will permit contraction o the lower chamber 11 area, with 1uid being transmitted out of the lower chamber 11 through the boost port 34 and within the accumulator ` chamber 48 whereby the fluid is compressed.
,~ - It should be noted that the 0-rings in association with the accumulator chamber ~8 prevent fluid leakage. Additionally, it ~-also should be noted that vcrlves 58 and 47A are closed.
~hen it is desired~to close the gate G of the gate valve C, fluid within the control line ~3 will be bled oE~. ~s a resul~, ~ .
.
. .
( 106~18 pressure within the upper piston chamber 8 and the passageway , 21A will be reduced below the amount neces.sar~ to posltion the shaft 1 downwarclly and maintain the gate G in open position.
Ho~ever, it should be emphasized tha~ pressure within the accumu-lator chamL)er 48 is not reduccd, bled o~f or lost inasmuch as the ball 2fj is sealingly engaged on lts seat 27 by the compressive force afforded by the spring 25 in the check valve 24. Thus~
~: the pressure within the accumulator chamber 48 will be at least equal to the initial high pressure carried to the actuator A
;~ 10 within the control line 23, the passager.~ay 21A and the upper ~ piston chamber 8. Upon reduction of pressure within the upper -:: piston chamber 8, the pressure within chambers 11 and 48 acting on the piston head 4 will permit the shaft 1 to be urged longi-tudinally upwardly with a force determined by accumulator pres-sure and the area defined within chamber 11. Thus~ pressure is .:
'.; permitted to be bullt up within the accumulator chamber 48 such .. :
~that the venting of control pressure within the control line 23 ~:~ : will enable the compressive fluid force contained within the accumulator chamber 48 to act as a compressed "spring", thus urging the shaft 1 longitudinally upwardly with suEficient force that the wire line 1~ carried through and within th~ valve seat S
within a lubricator as`sembly (not sho~n) will be completely sheared.
In order to reactivate the actuator A af~er shearing of the wire line W, pressure within the control line 23 is increased ~:
and the procedure as above described is repeated. ..
The desired compressive force to be charged within the ~: accumulator chamber 48 is preselectable,.with parameters being : dependent upon the ~olume oE- the accumulator, the area of the upper and lower piston chambers 8 and 11, the pressure ~ithin the control line 23, the compressive force e~ertcd by the spring .
: ~ -20-, 9~
25, and the compressi~ility o~ the selec~ed hydraulic or ~neu~atic control fluid.
Even though the accumulator chamber 48 and .he lower cha~ber 11 are initially filled, they can be continuousl~ and incre~ent~lly recharged in the event that O-rings and/or valves leak. Thus, it can be clearly seen that the acc~nulator chamber 48 is a continuously charged one, assuring a fl~ed pressurized force for selectively acting upon the lower end of the piston head 4 and, , . :
in turn, urging the shaft 1 to an upward position to shear the wire W and close the gate.
As an alternative source of shirting the sha't 1 longitu-dinally up~ardly, a nitrogen or other fluid source may be arfixed to the line 57, with the valve 58 being manipulated ~o "open"
positlon. Thus, the nitrogen may be charged into the cha~ber 48 and the lo~er chamber 11 for activation upon the lower end of the piston head 4 to urge the shaf, 1 in an upwardly posltion to shift the gate to completely closed position while still assuring fail safe operation of the valve C.
~ Although the invention has been described in te~s of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that ~he invention is not necessariLy limited thereto, since alternative embodi.ments and operating techniques will become apparent to those skilled in the art in vie~ of the disclosure. Acco~d-ingl~ modifications are contemplated which can be made ~ithout departing from the spirit of the described invention.
. :
.
` .
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position comprising: a housing defining a cylindrical bore therethrough; a shaft carried in said housing and engagable with said operative means; piston means carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; and fluid chamber means companionly associated with said piston means yielding a differential force across said piston means upon variation of fluid control pressure within said actuator, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions by a variation of fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other or said open and closed positions upon subsequent variation of fluid control pressure, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
2. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position: a housing defining a cylindrical bore therethrough; a shaft carried in said housing; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore yielding a differential force across said means defining said first and second effective piston areas upon increase of fluid control pressure within said actuator; continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber for storage of energy defined by fluid compressible therein; fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means; valve means movable between open and closed positions and communicating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differ-ential between said accumulator chamber and said fluid passage means, one of said housing and said shaft being engagable with said operative means, one of said housing and said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions by in-crease in fluid control pressure, one of said housing and said shaft means being selectively shiftable longitudinally in a second direction to move said operative means to the other of open and closed positions upon subsequent decrease in fluid control pressure and release of energy stored within said accumulator, one of said shaft and said housing having slotted means thereon for transverse receipt of a companion engagement means on said operative means, whereby said operative means and one of said shaft and said housing may be placed in substantial longitudinal engagement.
3. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position: a housing defining a cylindrical bore therethrough; a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore yielding a differential force across said means defining said first and second effective piston areas upon increase of fluid control pres-sure within said actuator; continuously chargeable fluid accumu-lator means in fluid communication with said second fluid chamber for storage of energy defined by control fluid compressible therein;
fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means; valve means movable between open and closed positions and communicating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differential between said accumulator chamber and said fluid passage means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions by increase in fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of open and closed positions upon subsequent decrease in fluid control pressure and release of energy defined by control fluid compressed and stored within said accumulator, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft thereafter may be placed in substantial longitudinal engagement.
fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means; valve means movable between open and closed positions and communicating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differential between said accumulator chamber and said fluid passage means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions by increase in fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of open and closed positions upon subsequent decrease in fluid control pressure and release of energy defined by control fluid compressed and stored within said accumulator, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft thereafter may be placed in substantial longitudinal engagement.
4. The apparatus of Claim 2 wherein the continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber is defined exteriorly of said housing and within said actuator.
5. The apparatus of Claim 2 wherein the continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber is exterior of said actuator.
6. The apparatus of Claim 2 additionally comprising second fluid transmission means communicating to said continuously chargeable fluid accumulator means for storage of energy defined by second fluid carried within said transmission means and com-pressible in said accumulator means.
7. The apparatus of Claim 2 wherein the fluid passage means transmits a liquid under pressure to said first chamber and to said accumulator means.
8. The apparatus of Claim 2 wherein said fluid passage means transmits a gas under pressure to said first fluid chamber and to said accumulator means.
9. The apparatus of Claim 2, said continuously chargeable fluid accumulator means receivable of at least one of liquid and gas fluid medium.
10. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position: a housing defining a cylindrical bore therethrough;
a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore; continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber for storage of energy defined by fluid com-pressible therein; fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means;
valve means movable between open and closed positions and communi-cating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differ-ential between said accumulator chamber and said fluid passage means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions when pressure within said first and second fluid chambers is substantially equal, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of open and closed positions upon decrease of pressure within one of said first and second fluid chambers and release of energy stored within said accumulator, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore; continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber for storage of energy defined by fluid com-pressible therein; fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means;
valve means movable between open and closed positions and communi-cating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differ-ential between said accumulator chamber and said fluid passage means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions when pressure within said first and second fluid chambers is substantially equal, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of open and closed positions upon decrease of pressure within one of said first and second fluid chambers and release of energy stored within said accumulator, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
11. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position: a housing defining a cylindrical bore therethrough;
a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore yielding a differential force across said means defining said first and second effective piston areas upon increase of fluid control pressure within said actuator, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions when pressure within said first and second fluid chambers is substan-tially equal, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed positions when pressure defined by fluid within one of said first and second fluid chambers is greater than pressure defined by fluid within the other of said first and second fluid chambers, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means defining said first and second effective piston areas within said bore yielding a differential force across said means defining said first and second effective piston areas upon increase of fluid control pressure within said actuator, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions when pressure within said first and second fluid chambers is substan-tially equal, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed positions when pressure defined by fluid within one of said first and second fluid chambers is greater than pressure defined by fluid within the other of said first and second fluid chambers, one of said shaft and said operative means having slotted means thereon for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
12. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position, said actuator comprising: a housing defining a cylin-drical bore therethrough; a shaft carried in said housing and engagable with said operative means; piston means carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; fluid chamber means companionly associated with said piston means yeilding a differential force across said piston means upon variation of fluid control pressure with said actuator, said shaft being selectively shiftable longi-tudinally in a first direction to move said operative means to one of open and closed positions by increase in fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed positions upon subsequent decrease in fluid control pressure, the improvement comprising: and slotted means on one of said shaft and said operative means for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
13. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position, said actuator comprising: a housing defining a cylin-drical bore therethrough; a shaft carried in said housing and engagable with said operative means; piston means carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; fluid chamber means companionly associated with said piston means yeilding a differential force across said piston means upon variation of fluid control pressure with said actuator, said shaft being selectively shiftable longi-tudinally in a first direction to move said operative means to one of open and closed positions by increase in fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed positions upon subsequent decrease in fluid control pressure, the improvement comprising: slotted means on one of said shaft and said operative means for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement;
and affixation means through said housing for engagement of said housing immediate said valve.
and affixation means through said housing for engagement of said housing immediate said valve.
14. In an actuator respondable to control fluid pressure for moving an operative means of a valve between open and closed position: a housing defining a cylindrical bore therethrough; a shaft carried in said housing and engagable with said operative means; means defining first and second effective piston areas carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore; first and second fluid chambers companionly associated with said means de-fining said first and second effective piston areas within said bore yielding a differential force across said means defining first and second effective piston areas upon increase of fluid control pressure within said actuator; continuously chargeable fluid accumulator means in fluid communication with said second fluid chamber for storage of energy defined by fluid compressible therein; fluid passage means for transmitting fluid under pressure to said first fluid chamber and to said accumulator means; valve means movable between open and closed positions and communicating between said accumulator means and said fluid passage means to permit fluid control pressure charging of said accumulator chamber when in said open position and preventing discharge of fluid pressure within said accumulator chamber when in said closed position, said valve means being responsive to pressure differ-ential between said accumulator chamber and said fluid passage means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed positions by increase in fluid control pressure, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed positions upon subsequent decrease in fluid control pressure and release of energy stored within said accumulator;
and slotted means on one of said shaft and said operative means for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
and slotted means on one of said shaft and said operative means for transverse receipt of a companion engagement means on the other of said operative means and said shaft, whereby said operative means and said shaft may be placed in substantial longitudinal engagement.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US77737377A | 1977-03-14 | 1977-03-14 | |
| US05/801,507 US4135547A (en) | 1977-03-14 | 1977-05-31 | Quick disengaging valve actuator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1069018A true CA1069018A (en) | 1980-01-01 |
Family
ID=27119308
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA292,137A Expired CA1069018A (en) | 1977-03-14 | 1977-12-01 | Quick disengaging valve actuator |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1069018A (en) |
-
1977
- 1977-12-01 CA CA292,137A patent/CA1069018A/en not_active Expired
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |