CA1139189A - Hydraulically operated actuator - Google Patents
Hydraulically operated actuatorInfo
- Publication number
- CA1139189A CA1139189A CA000345581A CA345581A CA1139189A CA 1139189 A CA1139189 A CA 1139189A CA 000345581 A CA000345581 A CA 000345581A CA 345581 A CA345581 A CA 345581A CA 1139189 A CA1139189 A CA 1139189A
- Authority
- CA
- Canada
- Prior art keywords
- piston
- actuator
- seal
- metal
- seal ring
- 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
Links
- 229910052751 metal Inorganic materials 0.000 claims abstract description 84
- 239000002184 metal Substances 0.000 claims abstract description 84
- 239000012530 fluid Substances 0.000 claims abstract description 53
- 229920001971 elastomer Polymers 0.000 claims abstract description 10
- 239000000806 elastomer Substances 0.000 claims abstract description 10
- 238000007789 sealing Methods 0.000 claims description 25
- 230000006835 compression Effects 0.000 claims description 11
- 238000007906 compression Methods 0.000 claims description 11
- 238000004891 communication Methods 0.000 claims 17
- 230000006854 communication Effects 0.000 claims 17
- 230000003068 static effect Effects 0.000 abstract description 13
- 230000000694 effects Effects 0.000 abstract description 6
- 125000006850 spacer group Chemical group 0.000 description 11
- 229910000831 Steel Inorganic materials 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000000717 retained effect Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 244000309464 bull Species 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 210000002445 nipple Anatomy 0.000 description 2
- 235000012976 tarts Nutrition 0.000 description 2
- 238000013022 venting Methods 0.000 description 2
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- 241000243251 Hydra Species 0.000 description 1
- 229910001182 Mo alloy Inorganic materials 0.000 description 1
- 101100504379 Mus musculus Gfral gene Proteins 0.000 description 1
- 208000036366 Sensation of pressure Diseases 0.000 description 1
- WAIPAZQMEIHHTJ-UHFFFAOYSA-N [Cr].[Co] Chemical compound [Cr].[Co] WAIPAZQMEIHHTJ-UHFFFAOYSA-N 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- OGSYQYXYGXIQFH-UHFFFAOYSA-N chromium molybdenum nickel Chemical compound [Cr].[Ni].[Mo] OGSYQYXYGXIQFH-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 229910000701 elgiloys (Co-Cr-Ni Alloy) Inorganic materials 0.000 description 1
- 229910001119 inconels 625 Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- QRXWMOHMRWLFEY-UHFFFAOYSA-N isoniazide Chemical compound NNC(=O)C1=CC=NC=C1 QRXWMOHMRWLFEY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 230000036316 preload Effects 0.000 description 1
- 235000002020 sage Nutrition 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/46—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings
- F16J15/48—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings influenced by the pressure within the member to be sealed
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/16—Control means therefor being outside the borehole
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
- E21B2200/04—Ball valves
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Architecture (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mechanical Engineering (AREA)
- Actuator (AREA)
- Sealing Devices (AREA)
Abstract
APPLICATION FOR UNITED STATES PATENT
HYDRAULICALLY OPERATED ACTUATOR
ABSTRACT OF THE DISCLOSURE
A hydraulically operated actuator employs multiple metal-to-metal static seals to isolate the hy-draulic fluid and to isolate the actuator from surrounding contaminating (ambient) fluids. A housing contains at least two linearly spaced apart chambers. A piston recip-rocates from a retracted position to an extended position (power stroke) and from the extended position to the re-tracted position (return stroke) in one of the chambers (hydraulic chamber). The hydraulic chamber is separated by the piston into two sections, one of which contains high pressure hydraulic fluid and the other of which con-tains low pressure hydraulic fluid. A first static metal seal ring unit is designed to seal first at the comple-tion of the power stroke of the piston to isolate the low pressure hydraulic fluid section from external con-taminating fluids which may be at a higher pressure. A
second static metal seal ring unit is designed to seal at the completion of the return stroke of the piston also to isolate the low pressure section from external contami-nating fluids. Power for the return stroke is primarily supplied by springs, with biasing pressure from the ex-ternal environment providing a lesser contribution. A
third static metal seal ring unit may be employed to ob-tain a simultaneous seal with the first metal seal ring unit to isolate the high pressure section from the low pressure section at the completion of the power stroke of the piston. Alternatively, an elastomer or a knife-edge metal-to-metal type static seal may be substituted for the third metal seal ring unit. Deformable means positioned adjacent the first metal seal ring unit ensures that the third metal seal ring unit effects a seal once the first metal seal ring unit effects its seal. The actuator may be employed to operate a subsurface safety valve used to control flow of fluids through a well tubing and may be located external of the well tubing with the piston being linked to a valve operator. Means may be provided to compensate for any differences in travel between the pis-ton and valve operator.
HYDRAULICALLY OPERATED ACTUATOR
ABSTRACT OF THE DISCLOSURE
A hydraulically operated actuator employs multiple metal-to-metal static seals to isolate the hy-draulic fluid and to isolate the actuator from surrounding contaminating (ambient) fluids. A housing contains at least two linearly spaced apart chambers. A piston recip-rocates from a retracted position to an extended position (power stroke) and from the extended position to the re-tracted position (return stroke) in one of the chambers (hydraulic chamber). The hydraulic chamber is separated by the piston into two sections, one of which contains high pressure hydraulic fluid and the other of which con-tains low pressure hydraulic fluid. A first static metal seal ring unit is designed to seal first at the comple-tion of the power stroke of the piston to isolate the low pressure hydraulic fluid section from external con-taminating fluids which may be at a higher pressure. A
second static metal seal ring unit is designed to seal at the completion of the return stroke of the piston also to isolate the low pressure section from external contami-nating fluids. Power for the return stroke is primarily supplied by springs, with biasing pressure from the ex-ternal environment providing a lesser contribution. A
third static metal seal ring unit may be employed to ob-tain a simultaneous seal with the first metal seal ring unit to isolate the high pressure section from the low pressure section at the completion of the power stroke of the piston. Alternatively, an elastomer or a knife-edge metal-to-metal type static seal may be substituted for the third metal seal ring unit. Deformable means positioned adjacent the first metal seal ring unit ensures that the third metal seal ring unit effects a seal once the first metal seal ring unit effects its seal. The actuator may be employed to operate a subsurface safety valve used to control flow of fluids through a well tubing and may be located external of the well tubing with the piston being linked to a valve operator. Means may be provided to compensate for any differences in travel between the pis-ton and valve operator.
Description
~3.~
2 Field of the Invention
3 The present inven~ion concerns hydraulically
4 operated actuators which use ~ul~iple metal~to-metal static seals and, more particularly, such actuators em-6 ployed as external operators for subsea valves.
7 D_~cription of the P_ior Art 8 Conventional elastomer type seals have been used 9 heretof~re on hydraulically operated type actuators to pre-lQ vent contamination of the po~er fluid in subsea and/or well 11 environments. Those environments are corrosive and degrad-12 ing to most elastomeric ~resilient) materials and, conse-13 quently, such seals are of questionable reliability. The 14 metal-to-metal static seals of the present invention have greater reliability than the elastomer seals~ The metals 16 (alloys) which ~orm the metallic static seals are much less 17 susceptible to deterioration and failure from chemical at-18 tack and high temperatures than elastomer compounds cur-19 rently being used for actuator seals. Further, the actua~or-safety valve design of the present invention 21 is more reliable than known conventional actuator safety 22 valve designs and achieves full through-bore capability re-23 quired for wire line and pump-down tool work. Also, metal-24 to-metal seals are not contained in such conventional de-signs. In addition, conventional downhole safety valves 26 are subject to seal leakage due to transfer of loads 27 through the hydraulic components whereas in the present 28 invention, axial loads in the ~ubing string do not affect 29 operation of the hydraulic system.
SUMMARY ~F T~ I~VENTION
31 In accordance with the ~eachings of the invention, 32 an improved hydraulically operated ac~uator for use subsea ~ 3 - ~
.~ 3~
1 and/or in wells for producing oil and~or gas includes a 2 housing containing at least two linearly spaced apart 3 chambers. I~ one Df the chambers - a hydraulic chamber - a 4 piston reciprocates f~om ~ retracted position to an extended ~ position in a power stroke and from the extended position 6 to the retracted position in a return stroke. The piston 7 sepaxates the hydraulic chamber into high and low pressure 8 sections. A first metal seal ring unit effects a seal only 9 at the completion of the power stroke of ~he piston to isolate the ~ow pressure section from external ambient 11 fluids which may be at a higher pressure. A second metal 12 seal ring unit effects a seal only at the completion of the 13 return stroke of the piston to isolate ~he low pressure 14 section from such external ambient fluids. The force needed to energize the second metal seal ring unit is sup-16 plied by return springs, with pressure from the surrounding 17 (contaminating fluid) environment contributing some biasing 18 force when ambient pressure is higher than the pressure of 19 the power fluid. Means are provided in the housing on opposite sides of the piston for supplying operating or 21 power fluid to and for exhausting fluid from the hydraulic 22 chamber when the piston reciprocates in its power and re-23 turn strokes. A third metal seal ring unit, which, al-~4 ternatively, may be a knife-edqe type metal-to-metal seal or a resilient type seal, is provided to isolate the high 26 pressure section from the low pressure section of the hy-27 draulic chamber at the completion of the power stroke of 28 the piston. To ensure that the third metal seal ring 29 unit effects a se~l afterthe first seal means effects its seal, deformable travel compensation means is positioned 31 adj acent the first metal seal ring unit. A further 32 feature of the invention is employing the actuar-~r to r. ~
1 operate a s~bsurface safety ~alve used to control flow of 2 fluids through a well tubing and locating the actuator ex-3 terna7 ~f the w~1~ tu~ing. ~eans are provided to compen 4 sate for difex~nces in trav~l between the piston and a
7 D_~cription of the P_ior Art 8 Conventional elastomer type seals have been used 9 heretof~re on hydraulically operated type actuators to pre-lQ vent contamination of the po~er fluid in subsea and/or well 11 environments. Those environments are corrosive and degrad-12 ing to most elastomeric ~resilient) materials and, conse-13 quently, such seals are of questionable reliability. The 14 metal-to-metal static seals of the present invention have greater reliability than the elastomer seals~ The metals 16 (alloys) which ~orm the metallic static seals are much less 17 susceptible to deterioration and failure from chemical at-18 tack and high temperatures than elastomer compounds cur-19 rently being used for actuator seals. Further, the actua~or-safety valve design of the present invention 21 is more reliable than known conventional actuator safety 22 valve designs and achieves full through-bore capability re-23 quired for wire line and pump-down tool work. Also, metal-24 to-metal seals are not contained in such conventional de-signs. In addition, conventional downhole safety valves 26 are subject to seal leakage due to transfer of loads 27 through the hydraulic components whereas in the present 28 invention, axial loads in the ~ubing string do not affect 29 operation of the hydraulic system.
SUMMARY ~F T~ I~VENTION
31 In accordance with the ~eachings of the invention, 32 an improved hydraulically operated ac~uator for use subsea ~ 3 - ~
.~ 3~
1 and/or in wells for producing oil and~or gas includes a 2 housing containing at least two linearly spaced apart 3 chambers. I~ one Df the chambers - a hydraulic chamber - a 4 piston reciprocates f~om ~ retracted position to an extended ~ position in a power stroke and from the extended position 6 to the retracted position in a return stroke. The piston 7 sepaxates the hydraulic chamber into high and low pressure 8 sections. A first metal seal ring unit effects a seal only 9 at the completion of the power stroke of ~he piston to isolate the ~ow pressure section from external ambient 11 fluids which may be at a higher pressure. A second metal 12 seal ring unit effects a seal only at the completion of the 13 return stroke of the piston to isolate ~he low pressure 14 section from such external ambient fluids. The force needed to energize the second metal seal ring unit is sup-16 plied by return springs, with pressure from the surrounding 17 (contaminating fluid) environment contributing some biasing 18 force when ambient pressure is higher than the pressure of 19 the power fluid. Means are provided in the housing on opposite sides of the piston for supplying operating or 21 power fluid to and for exhausting fluid from the hydraulic 22 chamber when the piston reciprocates in its power and re-23 turn strokes. A third metal seal ring unit, which, al-~4 ternatively, may be a knife-edqe type metal-to-metal seal or a resilient type seal, is provided to isolate the high 26 pressure section from the low pressure section of the hy-27 draulic chamber at the completion of the power stroke of 28 the piston. To ensure that the third metal seal ring 29 unit effects a se~l afterthe first seal means effects its seal, deformable travel compensation means is positioned 31 adj acent the first metal seal ring unit. A further 32 feature of the invention is employing the actuar-~r to r. ~
1 operate a s~bsurface safety ~alve used to control flow of 2 fluids through a well tubing and locating the actuator ex-3 terna7 ~f the w~1~ tu~ing. ~eans are provided to compen 4 sate for difex~nces in trav~l between the piston and a
5 valve operator in opening and maintaining open the valve.
6 The compensating means may be arranged on the linkage be-
7 tween the piston and the valve operator or on the valve
8 operator.
9 BRIEF DESCRIPTION OF THE DRAWINGS
.
~igs. lA and lB are vertical views of the actuator 11 of the invention, partly in section, illustrating the com-12 ponents thereof at the ~tart of the power stroke of the 13 piston;
14 Figs. 2A and 2B are ~ertical ~iews ~f the actuator of the invention~ partly in section, illustrating the com-16 ponents thereof at the completion of the power stroke of 17 the piston;
18 Fig. 3 is a vertical, partly sec~ional, view il-19 lustrating a portion of the actuator apparatus of Fig. lA
in greater detail;
21 Fig. 4 is a vertical view, partly in section, 22 illustrating another portion of the actuator apparatus of 23 Fig. lA in greater detail;
24 Fig. 5 is an enlarged view of a portion of the apparatus shown in Fig. lA;
26 Fig. 6 is an enlarged view of a portion of the 27 apparatus shown in Fig. 5;
28 Fig. 7 is a vertical, partly sectional, view of 29 the actuator of the invention connected to a ball type sub-surface ~afety val~e used in well operations with the 31 safety valve in its open position;
1 Fig. 8 is a similar view of a portion of the 2 actuator and subsurface safety valve illustrated in Fig. 7 3 wi~h ~he safety v~lve in it~ closed position;
4 Fig. 9 is a more detailed v:iew ~f the connection between the actu~or and safety valve of Figs. 7 and 8;
6 Fig. 10 is a vertical, partly sectional, view of 7 the actuator of the invention connec~ed to a ga~e valve;
8 Fig. 11 is a view of the actuator of the inven-9 tion connected t~ a ball valve which requires rotat:ion to operate;
11 Figs. 12 and 13 are vertical, partly sectional, 12 views of the actuator of the invention connected to a flap-13 per type safet~ ~alve us~d in well operations in its open 14 and closed positlons, respactively;
Fig. 14 is a view taken along line 14-14 of Fig.
16 12;
17 Fig. lS is a view taken along line 15-lS of Fig.
18 12;
19 Fig. 16 is another vertical, partly sectional view of the flapper typ~ subsurface safety valve of Figs.
21 12 and 13 showing the flapper valve closed and the load 22 limiter spring compressed;
23 Figs. 17 and 18 are ver~ical views, partly in 24 section, of another e~bodiment of the actuator of the in-vention illustrating the components thereof at the begin-26 ning and at ~he oompletion of the power s~roke, respec-27 tively;
28 Fig. 19 is a view of still another embodiment of 29 the actuator of the invention illustrating the u~e of a re~ilient type sta~ic ~eal for sealing off the pistGn;
31 Fi~. 20 is a vertical, partly sectional, view of 32 a modified valve shroud;
1 Fig. 21 is a ~ertical, partly sectional, view o 2 a modified return spring arrangement.
3 ~ig. 22 is a ~e~tical, partly sectional view, of 4 a modified val~e ~hroud; and Fig. 23 is a ~ertical, part:ly sectional, ~iew of 6 another modification o the va~ve shroud.
7 DESCRIPTION Q~ THE PREFERRED EMBODIMENTS
, . .,.
8 Referring to Figs. lA, lB, 2A and 2B there is 9 shown a hydraulically ~perated actuator, generally desig-nated 10, for use in operating valves and ~he like, partic-11 ularly in subsea and/or well environments.
12 The actuator includes a housing 11 having a 13 closed upper end 12 ~nd containing threP chambers, upper 14 chamber 13, middle (hydraulic) chamber 14 and lower chamber 15. An upper piston rod 16 reciprocates in ch~bexs 13 and 16 14 through a bushing 17 formed in a nipple 18 ~part of 17 housing 11). The upper end of piston rod 16 contains a 18 wrench backup head 20 and a threaded portion 21 on which 19 is threaded a pre-load nut 22 provided with an interior vertical keyway 23. Threaded portion 21 is provided with 21 an exterior vertical keyway 25. A wedge~shaped key ~4 22 positioned in keyway 23 and keyway 25 prevents rotation of 23 nut 22 on piston rod 16. A return compression spring, 24 designated 26, surrounds piston rod 16 between nut 22 and nipple lB and includes two coiled springs 26a and 26b 26 separated by a spacer ring 27. Chamber 13 contains hy-27 draulic fluid indicated by numeral 28.
28 Hydxaulic chamber 14 has a large diameter por-~9 tion 50 in which a pi~ton 30, connected to piston rod lfi, reciproca~es in power and return strokes and upper and 31 l~weT smaller diameter portions 51 and 52, respectively.
32 Chamber 14 contains hydraulic power fluid which is ¢~
1 introduced from a hydraulic power fluid sys~em, which may be 2 a closed system, into a high pressure section of chamber 14 3 above pist~n 3~ thro~gh an inlet 55 formed in housing 18 4 and exhaus~s from a ~ow pre~sure section of chamber 14 be-low piston 30 through an exit opening 56. High pressure 6 fluid is introduced into chamber 14 above piston 30 to 7 drive piston 30 downwardly in i~s power stroke. The posi-8 tion of piston 30 a~d the other components connected to it 9 are shown in Figs. lA and lB at the start or beginning of the power stroke (or completion of the return stroke) of 11 the piston. The position of piston 30 and the other com-12 ponents connected to it are shown in ~igs. 2~ and 2B at the 13 completion of the power stroke of piston 30. Piston 30 i5 14 provided with a metal piston ring 31 which serves as a dy-namic seal for the power fluid. A lower piston rod 33, 16 slightly less in diameter than the diameter of portion 52, 17 is formed on the lower end of piston 30. Piston rod 33 may 18 be a separate component connected to piston 30 or it may 19 be made integral with piston 30, as shown. A metal seal ring unit 32 surrounds and is retained on piston rod 33 21 against the underside of piston 30 by a snap ring 34. A
22 connector rod 36 is connected to the lower end of piston 23 rod 33 or it may be an integral part of piston rod 33. A
24 metal seal ring unit 35 is arranged on the upper end of connector rod 36. A crushable keeper ring 37 is also ar-26 ranged on oonnector rod 36 below seal ring unit 35. Keeper 27 ring 37 and seal ring unit 35 are maintained on connector 28 rod 36 by a snap ring 38. Connector rod 36 extends ~hrough 29 a wall member 39 containing a press fit slee~e bushing 39a and into lower chamber 15. The lower end of connector rod 31 36 is pro~ided with an enlarged cylindrical portion 40 32 which is of slightly less diameter than the diameter of ,3~
1 chamber 15. A metal seal ring unit 42 is a~ranged on con-2 nectox rod 36 above cylindrical portion 40. Seal ring 3 unit 42 i5 main~ained in position ~y a snap ring 43. ~n 4 actuator rod 4~ is connected to the lower end of connector rod portion 40 and extends through an opening in the lower 6 end 45 of housing 11. A unidirectional resilient seal 41 7 on that lower end seals off the space between housina 11 8 and actuator rod 44 in that opening. Seal 41 permits fluid 9 to exit at venting port 46 if the volume change in chamber 15 is significant during energization of the metal seal 11 ring unit 35. A 1ower flange 47 on housing 11 contains 12 bolt holes 47a for fastening ~he actuator ~o equipment to 13 be opexated and a venting port 46 is provided in the hous-14 ing between seal 41 and flange 47.
Referring now to Figs. 3, 4, 5 and 6 in which 16 the actuator components are shown in grea~er detail, a by-17 pass 60 is formed in piston 30 and fluidly communicates 18 chamber 14 above and below piston ring 31. Bypass 60 is 19 provided with a threaded portion 60a for locating a threaded orifice member (not shown) for controlling the rate of up-21 ward movement (return stroke) of piston 30. The ori~ice 22 size is small enough so that sufficient differential pres-23 sure can be developed across piston 30 to permit the power 24 stroke of the actuator. Metal seal ring unit 32 includes two chamfered spacer rings 32a and 32b between which are 26 positioned two frusto conical me~al seal rings 32c. The 27 seal rings are similar in shape to Bellville springs.
28 Such metal rings, because of their resilient character-29 istics, can be seated and unseated with a high degree of reliability and yet permit loading forces to be developed.
l 31 The materials fo~ming the metal rings may suitably be ~,~ ., ~
32 nickel-chromium-molybdenum alloys such as Inconel 625 and ~r~
_ g _ ~ ~3~
`-` 1 Hastelloy C or cobalt-nickel-chromium-molybd2num alloys 2 such as MP 35 N an~ Elgiloy. The Yealing principle is 3 based on changiny o~ the outer and inner diameters of the 4 F,eal ~ings as they are ~lattened under loading. In un-5 loaded position as shown in Fig. 3 the outer edges or 6 pexipheries of rings 32c are aligned or nearly aligned 7 with the outer peripheries of spacer rings 32a and 32b.
8 When loaded, as shown in Fig. 4, seal rings 32c are com-9 pressed ~o seal against the bore wall of the portion 50 of chamber 14 and against the outer periphery of piston rod 11 33.
12 Metal seal ring unit 35 is similar to m~tal seal 13 ring unit 32 and is provided with chamfered spacer rings 14 35a and 35b between which are positioned two frusto conical metal seal rings 35c. As shown in Fig. 3, in unloaded 16 position the outer edges or peripheries of rinys 35c are 17 aligned or approximately aligned with ~he outer peripheries 18 of spacer rings 35a and 35b and when loaded seal rin~s 35c 19 are compressed to ~eal against the bore wall of the portion 52 of chamber 14 and against ~he outer periphery of con-21 nector rod 36, as shown in F'ig. 4.
22 As shown in Fig. 1, length Dl is slightly greater 23 than length D2. Dl represents the downward travel (power 24 stroke of piston 30) of seal unit 32 un~il its lower end engages the lower end wall, shoulder 50a, of chamber 50.
26 Similarly, D2 represents the downward travel of the crush-27 able keeper ring 37 until its lower end engages, the lower 28 end wall, 52a, of chamber ~2. It i5 desirable to have 29 both sea~ ring units 32 and 3~ seal off at the same time.
As shown in Fig. 4, keeper ring 37 has deformed slightly to 31 ensure precise spacing for seal ring units 32 and 35 when 32 in their seali~g positions. Keeper ring 37 deforms, if at 1 sll, only on ~ompletion of the initial power stroke of 2 pis~n 30 and, thereafter, retain~ its plastically deformed 3 ~hape. Such deform~ty ~nsures pxecise spacing for the 4 metal seal ring units 32 and 35 in ~he sealing position.
ln Figs. 5 and 6 me~al seal ring unit 42 is shown 6 in sea}ing position against the wall of chamher 15 and con-7 nector rod 36. Seal ring unit 42 is also similar to seal 8 ring units 32 and 35 in that frusto conical metal seal 9 rings 42c are p~itioned between chamfered spacer rings 42a and 42b. Metal rings 42c seal on the inner wall of 11 chamber 15 when piston 30 is at the end of its return 12 stroke (ox at the start of its power stroke). Seal ring 13 unit 42 is energized in its sealing position by return 14 spring 26 in chamber 13 and ambient fluid pressure that may act on the area o~ actuator rod 44. At the completion 16 of the power stroke, seal units 32 and 35 are in sealing 17 position as shown in Fig. 4 and seal unit 42 in non-sealing 18 position. As shown, the inwardly directed taper of frusto 19 conical metal rings 32c, 35c or 42c are in the direction of the movement of the rings which causes release of the 21 seal. The apices of the conically shaped metal rings 32c, 22 35c or 42c are in the direction of their mo~ement which 23 causes release of the seal. In this manner a more eE-24 ficient release of the seal rings is achieved and jamming of the seal rings against the chamber wall on which the 26 seal rings seal is prevented.
27 In Fig. 7, actuator 10 is shown mounted by bolts 28 48 on a safety val~e housing 8Q which is connected into a 29 well pipe string 81. A ~luid supply conduit 82 connects a closed hydra~lic power system fluid supply to opening 31 55 in actuator 10 and exhaust conduit 83 connects port 56 32 of actuator 10 into the closed hydraulic system. Actuator 1 rod 44 is connected to a drive rod 84 through linkage 85.
2 Rod 8~ is connected to a rack B6 which engages a pinion 3 gear ~7 axranged in a c~amber 91 of housing 80. Pinion 4 gear B7 is oonnected to a ~all valve 88 which is mounted for rotation in valve housing 80. The rack and pinion 6 arrang~ment may be suitably lubri~ated by oil or other lu~
7 bricant 92 contained in chamber 91. An adjustable stop 8 member, indicated at ~3, is connected ~o the lower end o~
9 rack 86 and extends through the lower end of chamber 91 of housing 80. The stop member 93 limits the downward travel 11 of the rack when opening ball valve 88. This permits the 12 ball valve to assume its full open position as shown in 13 Fi~, 7. The ~ull open position is desired when producing 14 or circulating fluids and when running downhole tools through the safety valve to perform operations in the well 16 bore below the safety valve.
17 Fig. 8 shows ball valve 88 in closed position.
18 In that position of the valvP, piston 30 of actuator 1~ is 19 in its retracted position. ~eal ring unit 42 is energized 20~ at this time.
21 As shown in Fig. 9 a compression spring 94 is 22 positioned in a chamber 95 in linkage 85. Spring 94 23 functions as a load limiter to allow the piston to stroke 24 fully, and the metal rings to obtain a seal, in the event the valve is stuck in the closed position (pressure trapped 26 below the ball). Spring 94 also permits overtravel of 27 actuator rod 44 so that the ball valve may be moved to its 28 full open position and thereafter allow sealing movement 29 of metal seal ring units 32 and 35. This assures full seating o~ the mRta~ seals when the valve is in its closed 31 positionO Thus, it allows further stroke of rod 44 after 32 rack 86 abuts stop 93.
~l3~
1 Fig. 10 illustrates the use of actuator 10 with a gate-type valve 96 positioned in a valve housing 97 which 3 may be i~2~ted in a flow line, not shown.
4 Fig. 11 illu~t~ates the use of actuator 10, which is mounted as at 98 ~n a flow line 99, with a xotatable 6 ball valve or stopcock type valve 100. Actuator rod 44 is 7 connected to suitable linkage 101 for causing rotation of 8 the ball valve.
9 ~e~esring tv ~igs. 12 through 16, ac~uator 10 is connected to a shroud 110 which is welded to (or made inte-11 gral with) a housing 111 through which a 10w tube 112 ex-12 tends. Actuator rod 44 extends through the upper end of 13 shroud 110 and is sealed by a resilient bidirectional type 14 seal 113 and is bolted to a clevis 11~ within shroud 110.
The lower end of shroud 110 is closed by a bull plug 115 16 which permits access to the interior of the shroud so that 17 the clevis can be installed on the clevis ring 120 surround-18 ing flow tube 112. Shroud 110 is also provided with access 19 openings 121 which are shown plugged. Above clevis ring 120 a retainer ring 125 is attached to and surrounds flow 21 tube 112. A wiper ring 126 and a slotted wear ring (or 22 bearing) 127 are positioned on the interior wall of housing 23 111. An adjustable retainer 128 is arranged on threads 24 129 on flow tube 112. A load limiter spring 130 is posi-tioned between clevis ring 120 and the adjustable retainer 26 128. A wiper ring 135a and slotted wear ring (ox bearing) 27 135b are located in the lower end of housing 111. Differ-28 ential pressure will not be buil~ up across either of the 29 wiper or wear rings, so that frictional drag on the flow tube 112 is minimized~ The well bore fluid is isolated 31 ~rom the surrounding environment by resilient seal 113. A
32 ~pring-biased flappçr val~e 136 is ~ecured to ~:he lower end ~ 13 -1 of housing 111 to close off the pa~sage through which flow 2 tube 11 ? extends.
3 Load lim~tes spring 130 may be loaded to, for ex-4 ampl~, ab~ut 50D p~unds 50 that under ~ormal operation on 5 opening of ~lapper valve 136 flow tube 112 is moved down by 6 actuator rod 44 without further comprlession of spring 130 7 as illustrated in Fig. 13. However, if flapper valve 136 8 will not open because of high well pr~essure below it or for 9 other ~actors actua~or rod 44 will complete its fu:Ll stroke and compress the load limiter spring 130 as illustra~ed in 11 Fig. 16. Permitting full stroke of the actuator rod 44 12 prevents damage to the equipment, as for example, breaking 13 of cle~is 11~. As seen moxe clearly in Fig. 15 the sides 14 forming the opening between the valva body and the shroud, lS indicated at 139, serve as a retainer guide for clevis 114.
16 Bull plug llS is contoured to streamline the shroud for 17 running into the well pipe. Access openings 121 permit 18 bolting of clevis 114 to clevis ring 120.
19 Another embodiment of the invention is illustrated in Figs. 17 and 18. As shown in those figures an actuator 21 includes a housing 140 having three chambers as in the em-22 bodiments of the invention described heretofore, only two 23 of which, a hydraulic chamber 141 and a lower chamber 142, 24 aTe shown. An upper piston rod 146 reciprocates in chamber 141. Hydraulic chamber 141 contains a piston 150 connected 26 to the lower end of upper piston rod 146 and to a lower 27 piston rod 147. Piston 150 includes a bypass 151 which 28 fluidly communicates chamber 147 abo~e and below a piston 29 ring 152 and is provided with ~ threaded portion 151a for locating a thIeaded ~rifice member (not shown~ for control-31 ling the rate of upward movement lreturn stroke) of piston 32 150. A crushable keeper ring 115 is arranged about a 1 connector sod 156 which is connected to piston rod 147~
2 Keeper ring 155 is attached to ~he lower end of rod 147 by 3 bc)lts 1~7~ Cr~nnector rod lSfi ex~ends through a wall member 4 160 which contains 2 metal seal ring unit 161, a press fit ~leeve bushing 162 below metal ~eal ring unit 161 and a 6 second metal seal ring unit 163 below sleeve 162. Seal ring 7 unit 161 is retained in the recess in wall member 160 by a 8 snap ring 165 and seal ring unit 163 is retained in its re-9 cess in wall member 150 by a snap ring 166. The actuator rod 170 is connected to a ~houlder coupling 171 through 11 which a fluid by-pass 172 is fo~med. Piston 15Q contains a 12 metallic knife-edge seal 153, which, a~ shown in Fig. 18, 13 forms a static metal-to-metal seal with a ~houldex 154 formed 14 in the inner wall of housing 140. Static seal 153 is an annular member being tapered in cxoss-section, as shown, and 16 having a deformable reduced contact area or aage. At the 17 end of the power ætroke of piston 150 the edge contacts and 18 seals on shoulder seat 154. Under the compressi~e force of 19 piston 150 the edge yields or plastically deforms to con-form to seat 154 to achieve intimate contact and a seal.
21 Piston 150 is preferably constructed of a soft malleable 22 steel such as an annealed American Iron and Steel ~nstitute 23 (AISI) 1015 steel with a hardness in the range of 120 24 Brinell Hardness Number (BHN). The cylinder and static seat 154 are constructed of a harder steel such as AISI
26 4130 with a hardness in the range of 235 BHN. Preferably, 27 the seal e~ge is blunted to prevent failure of the steel 28 seal. The reduced area (edge) of the seal also facilitates 29 cutting t~rough any particles or debris which may be in the fluid in the piston chamber and adhere to s~at 154.
31 As shown in Fig. 17, s~al ring unit 161 does not 32 seal on connector rod shaft 156 but metal seal ring unit 1 163 seals on connector rod shaft 156 in ~he position of 2 piston 150 at the beginning or ~tart o~ the power stroke 3 th~eof. ~æal ~ing unit 163 isolates chamber 141 from 4 cham~er 142 ~n~ prevents c~ntaminating fluid in chamber 142 ~ from entering chamber 141. At the completion of the power 6 stroke of the piston, seal 153 seals off on surface 154 to 7 isolate the high and low pressure fluids on each side o 8 piston 15~ from each other and seal ring unit 161 seals on 9 connector rod 156. In that position seal ring unit 163 does not seal. However, contaminating fluid is prevented 11 from mixing with the l~w pressure fluid in chamber 141 by 12 seal ring unit 161.
13 Referring to Fig. 19, instead of the metal static 14 seal 153-154, a resilient type seal 153a may be arranged on a piston 150a to seal off on a seating surface 154a formed 16 on the inner wall of a housing 140a.
17 A modification of the seal for sealing off the 18 actuator rod is illustrated in ~ig. 2~. Actuator 10 is con-19 nected to a shroud 110' which is connected to housing 111 - 20 through which a flow tube ex~ends (not shown). An actuator 21 rod 44' extends through the upper end o~ shroud 110' and is 22 sealed by a resilient seal 113' and by a metal seal ring 23 unit 175 arranged in a recess 176 formed in the upper end of 24 shroud 110'. Metal seal ring unit 175 is similar to the earlier described metal seal ring units and includes an 26 upper spacer ring 191, seal rings 192 and a lower spacer 27 ring 193 ha~ing an enlarged diameter portion 194. A deform-28 able keeper slee~e 195 abuts against the enlarged portion 2g 194 of spacer sleeve 193 and is secured to rod 44' by a lock screw lg6. An adjustable retainer ring 178 is threaded to 31 the inner wall of recess 176 for engaging the enlarged . 3~ pcrtion 194 of spac2r ring 193 to retain m~tal seal ring a~
1 unit 175 and limit downward movement of that unit when rod 2 44' and keeper slee~e 195 move downward ~rom their upper 3 most positions, as sh~wn. In that position of rod 44' the 4 ~alve is closed.
Reerring to ~ig. 21, there is shown a modified 6 return spring axrangement in which a tension spring is used 7 instead of a compression sping. The lower end of tension 8 ~pring 187 is connected to piston 150' by a celvis con-9 nector 186 and threaded spring plug 185. The upp~r end of the spring is threaded to a second spring plug 188 provided 11 with an upwardly extending threaded rod 189 which extends 12 through a plate 190 fixed in the bore of the hous.ing 11'.
13 A threaded nut 191 allows tension adjustment of ~he spring 14 187.
The valve shroud shown in Fig. 2~ illustrates a 16 metal sealing unit 175' which seals in the lowermost posi 17 tion of rod 44'' in which position the valve is open. The 18 val~e shroud of Fig. 23 illustrates the use of two metal 19 seal units, one of which seals in the lowermost position of 20~ rod 44''' (valve open) as in Fig. 22 and the other of which 21 seals in the uppermost position of rod 44''' (valve closed) 22 as in ~ig. 2~. The components of Fig. 22 include a shroud 23 110'l, rod 44 " connected to cle~is 114, a recess 176' form-24 ed in shroud 110 which contains an adjustable retainer ring 178', metal ring seal unit 175' which includes a lower spac-26 er ring 191', an upper spacer ring 193' having an enlarged 27 upper portion 1~4', and seal rings 192' positioned between 28 spacer rings 191' and 193'. A deformable keeper ring 195' 29 is secured to rod 44lt ~y a lock screw 196'. An annular shoulder 1~7 is formed on rod 44'' and abuts against keeper 31 rincJ 195'. A resilient seal 113'' seals about rod 44'' in 32 t~.~ bore belcsw recess 176'.
1 The val~e shroud 110''' shown in Fig. ~3 includes 2 both the seal ring unit 175' of Fig. 22 and the seal ring 3 unit 175 ~ Fig~ 2~. In this position of rod 44''' seal ring 4 unit 17~ is in the unsealed position, i.e, rod 44''' has completed its do~m stroke and in that po~ition ~eal ring 6 unit 175' is in sealing positi~n. The components which are 7 the same as the components of ~igs. 20 and ~2 have been 8 given the same designation in Fig. 23. A resilient seal 9 113''' seals ~b~u~ the rod 44''' in the bore between re-cesses 176 and 176'.
11 As mentioned heretofore, seal reliabilit:y of the 12 metal-to~metal static seals described above is superior to 13 conventional elastomer or resilient type seals. Therefore, 14 the possibility of the hydraulic power fluid system used to operate the actuator being contaminated hy sea water or by 16 production well fluids is minimized. With respect to use 17 of the actua~or of the invention as an external operator 18 for a subsurface sa~ety valve, the actuator provides iso-19 lation of the hydraulic power fluid system from the pro-20~ duction well fluid. In addition, the safety valve design 21 is greatly simplified and provides for full, through-bore 22 capability which is required for wire-line and p~np-down 23 tool work. Also, axial loads in the tubing strin~ in which 24 the safety valve is located do not affect operation of the hydraulic system whereas concentric operator type safety 26 valves are subject to seal leakage caused by distortion 27 which results from the transfer of axial loads in the tubing 28 string through the hydraulic components. The metal-to-metal 29 seals are pressure energizing in that an increase is pres-sure causes a higher contact load at the seal surfaces.
31 The actuator is compatible for use with a flapper valve, 32 ball valve or other type valves operable by an actuator.
3-a~
1 Changes and modifications may be made in the il-2 lustrative embodiments of the invention shown and/or de-3 scri~ed herein with~t. ~epar~ing from the ~cope of the in-4 vention as defined in the appended claims.
.
~igs. lA and lB are vertical views of the actuator 11 of the invention, partly in section, illustrating the com-12 ponents thereof at the ~tart of the power stroke of the 13 piston;
14 Figs. 2A and 2B are ~ertical ~iews ~f the actuator of the invention~ partly in section, illustrating the com-16 ponents thereof at the completion of the power stroke of 17 the piston;
18 Fig. 3 is a vertical, partly sec~ional, view il-19 lustrating a portion of the actuator apparatus of Fig. lA
in greater detail;
21 Fig. 4 is a vertical view, partly in section, 22 illustrating another portion of the actuator apparatus of 23 Fig. lA in greater detail;
24 Fig. 5 is an enlarged view of a portion of the apparatus shown in Fig. lA;
26 Fig. 6 is an enlarged view of a portion of the 27 apparatus shown in Fig. 5;
28 Fig. 7 is a vertical, partly sectional, view of 29 the actuator of the invention connected to a ball type sub-surface ~afety val~e used in well operations with the 31 safety valve in its open position;
1 Fig. 8 is a similar view of a portion of the 2 actuator and subsurface safety valve illustrated in Fig. 7 3 wi~h ~he safety v~lve in it~ closed position;
4 Fig. 9 is a more detailed v:iew ~f the connection between the actu~or and safety valve of Figs. 7 and 8;
6 Fig. 10 is a vertical, partly sectional, view of 7 the actuator of the invention connec~ed to a ga~e valve;
8 Fig. 11 is a view of the actuator of the inven-9 tion connected t~ a ball valve which requires rotat:ion to operate;
11 Figs. 12 and 13 are vertical, partly sectional, 12 views of the actuator of the invention connected to a flap-13 per type safet~ ~alve us~d in well operations in its open 14 and closed positlons, respactively;
Fig. 14 is a view taken along line 14-14 of Fig.
16 12;
17 Fig. lS is a view taken along line 15-lS of Fig.
18 12;
19 Fig. 16 is another vertical, partly sectional view of the flapper typ~ subsurface safety valve of Figs.
21 12 and 13 showing the flapper valve closed and the load 22 limiter spring compressed;
23 Figs. 17 and 18 are ver~ical views, partly in 24 section, of another e~bodiment of the actuator of the in-vention illustrating the components thereof at the begin-26 ning and at ~he oompletion of the power s~roke, respec-27 tively;
28 Fig. 19 is a view of still another embodiment of 29 the actuator of the invention illustrating the u~e of a re~ilient type sta~ic ~eal for sealing off the pistGn;
31 Fi~. 20 is a vertical, partly sectional, view of 32 a modified valve shroud;
1 Fig. 21 is a ~ertical, partly sectional, view o 2 a modified return spring arrangement.
3 ~ig. 22 is a ~e~tical, partly sectional view, of 4 a modified val~e ~hroud; and Fig. 23 is a ~ertical, part:ly sectional, ~iew of 6 another modification o the va~ve shroud.
7 DESCRIPTION Q~ THE PREFERRED EMBODIMENTS
, . .,.
8 Referring to Figs. lA, lB, 2A and 2B there is 9 shown a hydraulically ~perated actuator, generally desig-nated 10, for use in operating valves and ~he like, partic-11 ularly in subsea and/or well environments.
12 The actuator includes a housing 11 having a 13 closed upper end 12 ~nd containing threP chambers, upper 14 chamber 13, middle (hydraulic) chamber 14 and lower chamber 15. An upper piston rod 16 reciprocates in ch~bexs 13 and 16 14 through a bushing 17 formed in a nipple 18 ~part of 17 housing 11). The upper end of piston rod 16 contains a 18 wrench backup head 20 and a threaded portion 21 on which 19 is threaded a pre-load nut 22 provided with an interior vertical keyway 23. Threaded portion 21 is provided with 21 an exterior vertical keyway 25. A wedge~shaped key ~4 22 positioned in keyway 23 and keyway 25 prevents rotation of 23 nut 22 on piston rod 16. A return compression spring, 24 designated 26, surrounds piston rod 16 between nut 22 and nipple lB and includes two coiled springs 26a and 26b 26 separated by a spacer ring 27. Chamber 13 contains hy-27 draulic fluid indicated by numeral 28.
28 Hydxaulic chamber 14 has a large diameter por-~9 tion 50 in which a pi~ton 30, connected to piston rod lfi, reciproca~es in power and return strokes and upper and 31 l~weT smaller diameter portions 51 and 52, respectively.
32 Chamber 14 contains hydraulic power fluid which is ¢~
1 introduced from a hydraulic power fluid sys~em, which may be 2 a closed system, into a high pressure section of chamber 14 3 above pist~n 3~ thro~gh an inlet 55 formed in housing 18 4 and exhaus~s from a ~ow pre~sure section of chamber 14 be-low piston 30 through an exit opening 56. High pressure 6 fluid is introduced into chamber 14 above piston 30 to 7 drive piston 30 downwardly in i~s power stroke. The posi-8 tion of piston 30 a~d the other components connected to it 9 are shown in Figs. lA and lB at the start or beginning of the power stroke (or completion of the return stroke) of 11 the piston. The position of piston 30 and the other com-12 ponents connected to it are shown in ~igs. 2~ and 2B at the 13 completion of the power stroke of piston 30. Piston 30 i5 14 provided with a metal piston ring 31 which serves as a dy-namic seal for the power fluid. A lower piston rod 33, 16 slightly less in diameter than the diameter of portion 52, 17 is formed on the lower end of piston 30. Piston rod 33 may 18 be a separate component connected to piston 30 or it may 19 be made integral with piston 30, as shown. A metal seal ring unit 32 surrounds and is retained on piston rod 33 21 against the underside of piston 30 by a snap ring 34. A
22 connector rod 36 is connected to the lower end of piston 23 rod 33 or it may be an integral part of piston rod 33. A
24 metal seal ring unit 35 is arranged on the upper end of connector rod 36. A crushable keeper ring 37 is also ar-26 ranged on oonnector rod 36 below seal ring unit 35. Keeper 27 ring 37 and seal ring unit 35 are maintained on connector 28 rod 36 by a snap ring 38. Connector rod 36 extends ~hrough 29 a wall member 39 containing a press fit slee~e bushing 39a and into lower chamber 15. The lower end of connector rod 31 36 is pro~ided with an enlarged cylindrical portion 40 32 which is of slightly less diameter than the diameter of ,3~
1 chamber 15. A metal seal ring unit 42 is a~ranged on con-2 nectox rod 36 above cylindrical portion 40. Seal ring 3 unit 42 i5 main~ained in position ~y a snap ring 43. ~n 4 actuator rod 4~ is connected to the lower end of connector rod portion 40 and extends through an opening in the lower 6 end 45 of housing 11. A unidirectional resilient seal 41 7 on that lower end seals off the space between housina 11 8 and actuator rod 44 in that opening. Seal 41 permits fluid 9 to exit at venting port 46 if the volume change in chamber 15 is significant during energization of the metal seal 11 ring unit 35. A 1ower flange 47 on housing 11 contains 12 bolt holes 47a for fastening ~he actuator ~o equipment to 13 be opexated and a venting port 46 is provided in the hous-14 ing between seal 41 and flange 47.
Referring now to Figs. 3, 4, 5 and 6 in which 16 the actuator components are shown in grea~er detail, a by-17 pass 60 is formed in piston 30 and fluidly communicates 18 chamber 14 above and below piston ring 31. Bypass 60 is 19 provided with a threaded portion 60a for locating a threaded orifice member (not shown) for controlling the rate of up-21 ward movement (return stroke) of piston 30. The ori~ice 22 size is small enough so that sufficient differential pres-23 sure can be developed across piston 30 to permit the power 24 stroke of the actuator. Metal seal ring unit 32 includes two chamfered spacer rings 32a and 32b between which are 26 positioned two frusto conical me~al seal rings 32c. The 27 seal rings are similar in shape to Bellville springs.
28 Such metal rings, because of their resilient character-29 istics, can be seated and unseated with a high degree of reliability and yet permit loading forces to be developed.
l 31 The materials fo~ming the metal rings may suitably be ~,~ ., ~
32 nickel-chromium-molybdenum alloys such as Inconel 625 and ~r~
_ g _ ~ ~3~
`-` 1 Hastelloy C or cobalt-nickel-chromium-molybd2num alloys 2 such as MP 35 N an~ Elgiloy. The Yealing principle is 3 based on changiny o~ the outer and inner diameters of the 4 F,eal ~ings as they are ~lattened under loading. In un-5 loaded position as shown in Fig. 3 the outer edges or 6 pexipheries of rings 32c are aligned or nearly aligned 7 with the outer peripheries of spacer rings 32a and 32b.
8 When loaded, as shown in Fig. 4, seal rings 32c are com-9 pressed ~o seal against the bore wall of the portion 50 of chamber 14 and against the outer periphery of piston rod 11 33.
12 Metal seal ring unit 35 is similar to m~tal seal 13 ring unit 32 and is provided with chamfered spacer rings 14 35a and 35b between which are positioned two frusto conical metal seal rings 35c. As shown in Fig. 3, in unloaded 16 position the outer edges or peripheries of rinys 35c are 17 aligned or approximately aligned with ~he outer peripheries 18 of spacer rings 35a and 35b and when loaded seal rin~s 35c 19 are compressed to ~eal against the bore wall of the portion 52 of chamber 14 and against ~he outer periphery of con-21 nector rod 36, as shown in F'ig. 4.
22 As shown in Fig. 1, length Dl is slightly greater 23 than length D2. Dl represents the downward travel (power 24 stroke of piston 30) of seal unit 32 un~il its lower end engages the lower end wall, shoulder 50a, of chamber 50.
26 Similarly, D2 represents the downward travel of the crush-27 able keeper ring 37 until its lower end engages, the lower 28 end wall, 52a, of chamber ~2. It i5 desirable to have 29 both sea~ ring units 32 and 3~ seal off at the same time.
As shown in Fig. 4, keeper ring 37 has deformed slightly to 31 ensure precise spacing for seal ring units 32 and 35 when 32 in their seali~g positions. Keeper ring 37 deforms, if at 1 sll, only on ~ompletion of the initial power stroke of 2 pis~n 30 and, thereafter, retain~ its plastically deformed 3 ~hape. Such deform~ty ~nsures pxecise spacing for the 4 metal seal ring units 32 and 35 in ~he sealing position.
ln Figs. 5 and 6 me~al seal ring unit 42 is shown 6 in sea}ing position against the wall of chamher 15 and con-7 nector rod 36. Seal ring unit 42 is also similar to seal 8 ring units 32 and 35 in that frusto conical metal seal 9 rings 42c are p~itioned between chamfered spacer rings 42a and 42b. Metal rings 42c seal on the inner wall of 11 chamber 15 when piston 30 is at the end of its return 12 stroke (ox at the start of its power stroke). Seal ring 13 unit 42 is energized in its sealing position by return 14 spring 26 in chamber 13 and ambient fluid pressure that may act on the area o~ actuator rod 44. At the completion 16 of the power stroke, seal units 32 and 35 are in sealing 17 position as shown in Fig. 4 and seal unit 42 in non-sealing 18 position. As shown, the inwardly directed taper of frusto 19 conical metal rings 32c, 35c or 42c are in the direction of the movement of the rings which causes release of the 21 seal. The apices of the conically shaped metal rings 32c, 22 35c or 42c are in the direction of their mo~ement which 23 causes release of the seal. In this manner a more eE-24 ficient release of the seal rings is achieved and jamming of the seal rings against the chamber wall on which the 26 seal rings seal is prevented.
27 In Fig. 7, actuator 10 is shown mounted by bolts 28 48 on a safety val~e housing 8Q which is connected into a 29 well pipe string 81. A ~luid supply conduit 82 connects a closed hydra~lic power system fluid supply to opening 31 55 in actuator 10 and exhaust conduit 83 connects port 56 32 of actuator 10 into the closed hydraulic system. Actuator 1 rod 44 is connected to a drive rod 84 through linkage 85.
2 Rod 8~ is connected to a rack B6 which engages a pinion 3 gear ~7 axranged in a c~amber 91 of housing 80. Pinion 4 gear B7 is oonnected to a ~all valve 88 which is mounted for rotation in valve housing 80. The rack and pinion 6 arrang~ment may be suitably lubri~ated by oil or other lu~
7 bricant 92 contained in chamber 91. An adjustable stop 8 member, indicated at ~3, is connected ~o the lower end o~
9 rack 86 and extends through the lower end of chamber 91 of housing 80. The stop member 93 limits the downward travel 11 of the rack when opening ball valve 88. This permits the 12 ball valve to assume its full open position as shown in 13 Fi~, 7. The ~ull open position is desired when producing 14 or circulating fluids and when running downhole tools through the safety valve to perform operations in the well 16 bore below the safety valve.
17 Fig. 8 shows ball valve 88 in closed position.
18 In that position of the valvP, piston 30 of actuator 1~ is 19 in its retracted position. ~eal ring unit 42 is energized 20~ at this time.
21 As shown in Fig. 9 a compression spring 94 is 22 positioned in a chamber 95 in linkage 85. Spring 94 23 functions as a load limiter to allow the piston to stroke 24 fully, and the metal rings to obtain a seal, in the event the valve is stuck in the closed position (pressure trapped 26 below the ball). Spring 94 also permits overtravel of 27 actuator rod 44 so that the ball valve may be moved to its 28 full open position and thereafter allow sealing movement 29 of metal seal ring units 32 and 35. This assures full seating o~ the mRta~ seals when the valve is in its closed 31 positionO Thus, it allows further stroke of rod 44 after 32 rack 86 abuts stop 93.
~l3~
1 Fig. 10 illustrates the use of actuator 10 with a gate-type valve 96 positioned in a valve housing 97 which 3 may be i~2~ted in a flow line, not shown.
4 Fig. 11 illu~t~ates the use of actuator 10, which is mounted as at 98 ~n a flow line 99, with a xotatable 6 ball valve or stopcock type valve 100. Actuator rod 44 is 7 connected to suitable linkage 101 for causing rotation of 8 the ball valve.
9 ~e~esring tv ~igs. 12 through 16, ac~uator 10 is connected to a shroud 110 which is welded to (or made inte-11 gral with) a housing 111 through which a 10w tube 112 ex-12 tends. Actuator rod 44 extends through the upper end of 13 shroud 110 and is sealed by a resilient bidirectional type 14 seal 113 and is bolted to a clevis 11~ within shroud 110.
The lower end of shroud 110 is closed by a bull plug 115 16 which permits access to the interior of the shroud so that 17 the clevis can be installed on the clevis ring 120 surround-18 ing flow tube 112. Shroud 110 is also provided with access 19 openings 121 which are shown plugged. Above clevis ring 120 a retainer ring 125 is attached to and surrounds flow 21 tube 112. A wiper ring 126 and a slotted wear ring (or 22 bearing) 127 are positioned on the interior wall of housing 23 111. An adjustable retainer 128 is arranged on threads 24 129 on flow tube 112. A load limiter spring 130 is posi-tioned between clevis ring 120 and the adjustable retainer 26 128. A wiper ring 135a and slotted wear ring (ox bearing) 27 135b are located in the lower end of housing 111. Differ-28 ential pressure will not be buil~ up across either of the 29 wiper or wear rings, so that frictional drag on the flow tube 112 is minimized~ The well bore fluid is isolated 31 ~rom the surrounding environment by resilient seal 113. A
32 ~pring-biased flappçr val~e 136 is ~ecured to ~:he lower end ~ 13 -1 of housing 111 to close off the pa~sage through which flow 2 tube 11 ? extends.
3 Load lim~tes spring 130 may be loaded to, for ex-4 ampl~, ab~ut 50D p~unds 50 that under ~ormal operation on 5 opening of ~lapper valve 136 flow tube 112 is moved down by 6 actuator rod 44 without further comprlession of spring 130 7 as illustrated in Fig. 13. However, if flapper valve 136 8 will not open because of high well pr~essure below it or for 9 other ~actors actua~or rod 44 will complete its fu:Ll stroke and compress the load limiter spring 130 as illustra~ed in 11 Fig. 16. Permitting full stroke of the actuator rod 44 12 prevents damage to the equipment, as for example, breaking 13 of cle~is 11~. As seen moxe clearly in Fig. 15 the sides 14 forming the opening between the valva body and the shroud, lS indicated at 139, serve as a retainer guide for clevis 114.
16 Bull plug llS is contoured to streamline the shroud for 17 running into the well pipe. Access openings 121 permit 18 bolting of clevis 114 to clevis ring 120.
19 Another embodiment of the invention is illustrated in Figs. 17 and 18. As shown in those figures an actuator 21 includes a housing 140 having three chambers as in the em-22 bodiments of the invention described heretofore, only two 23 of which, a hydraulic chamber 141 and a lower chamber 142, 24 aTe shown. An upper piston rod 146 reciprocates in chamber 141. Hydraulic chamber 141 contains a piston 150 connected 26 to the lower end of upper piston rod 146 and to a lower 27 piston rod 147. Piston 150 includes a bypass 151 which 28 fluidly communicates chamber 147 abo~e and below a piston 29 ring 152 and is provided with ~ threaded portion 151a for locating a thIeaded ~rifice member (not shown~ for control-31 ling the rate of upward movement lreturn stroke) of piston 32 150. A crushable keeper ring 115 is arranged about a 1 connector sod 156 which is connected to piston rod 147~
2 Keeper ring 155 is attached to ~he lower end of rod 147 by 3 bc)lts 1~7~ Cr~nnector rod lSfi ex~ends through a wall member 4 160 which contains 2 metal seal ring unit 161, a press fit ~leeve bushing 162 below metal ~eal ring unit 161 and a 6 second metal seal ring unit 163 below sleeve 162. Seal ring 7 unit 161 is retained in the recess in wall member 160 by a 8 snap ring 165 and seal ring unit 163 is retained in its re-9 cess in wall member 150 by a snap ring 166. The actuator rod 170 is connected to a ~houlder coupling 171 through 11 which a fluid by-pass 172 is fo~med. Piston 15Q contains a 12 metallic knife-edge seal 153, which, a~ shown in Fig. 18, 13 forms a static metal-to-metal seal with a ~houldex 154 formed 14 in the inner wall of housing 140. Static seal 153 is an annular member being tapered in cxoss-section, as shown, and 16 having a deformable reduced contact area or aage. At the 17 end of the power ætroke of piston 150 the edge contacts and 18 seals on shoulder seat 154. Under the compressi~e force of 19 piston 150 the edge yields or plastically deforms to con-form to seat 154 to achieve intimate contact and a seal.
21 Piston 150 is preferably constructed of a soft malleable 22 steel such as an annealed American Iron and Steel ~nstitute 23 (AISI) 1015 steel with a hardness in the range of 120 24 Brinell Hardness Number (BHN). The cylinder and static seat 154 are constructed of a harder steel such as AISI
26 4130 with a hardness in the range of 235 BHN. Preferably, 27 the seal e~ge is blunted to prevent failure of the steel 28 seal. The reduced area (edge) of the seal also facilitates 29 cutting t~rough any particles or debris which may be in the fluid in the piston chamber and adhere to s~at 154.
31 As shown in Fig. 17, s~al ring unit 161 does not 32 seal on connector rod shaft 156 but metal seal ring unit 1 163 seals on connector rod shaft 156 in ~he position of 2 piston 150 at the beginning or ~tart o~ the power stroke 3 th~eof. ~æal ~ing unit 163 isolates chamber 141 from 4 cham~er 142 ~n~ prevents c~ntaminating fluid in chamber 142 ~ from entering chamber 141. At the completion of the power 6 stroke of the piston, seal 153 seals off on surface 154 to 7 isolate the high and low pressure fluids on each side o 8 piston 15~ from each other and seal ring unit 161 seals on 9 connector rod 156. In that position seal ring unit 163 does not seal. However, contaminating fluid is prevented 11 from mixing with the l~w pressure fluid in chamber 141 by 12 seal ring unit 161.
13 Referring to Fig. 19, instead of the metal static 14 seal 153-154, a resilient type seal 153a may be arranged on a piston 150a to seal off on a seating surface 154a formed 16 on the inner wall of a housing 140a.
17 A modification of the seal for sealing off the 18 actuator rod is illustrated in ~ig. 2~. Actuator 10 is con-19 nected to a shroud 110' which is connected to housing 111 - 20 through which a flow tube ex~ends (not shown). An actuator 21 rod 44' extends through the upper end o~ shroud 110' and is 22 sealed by a resilient seal 113' and by a metal seal ring 23 unit 175 arranged in a recess 176 formed in the upper end of 24 shroud 110'. Metal seal ring unit 175 is similar to the earlier described metal seal ring units and includes an 26 upper spacer ring 191, seal rings 192 and a lower spacer 27 ring 193 ha~ing an enlarged diameter portion 194. A deform-28 able keeper slee~e 195 abuts against the enlarged portion 2g 194 of spacer sleeve 193 and is secured to rod 44' by a lock screw lg6. An adjustable retainer ring 178 is threaded to 31 the inner wall of recess 176 for engaging the enlarged . 3~ pcrtion 194 of spac2r ring 193 to retain m~tal seal ring a~
1 unit 175 and limit downward movement of that unit when rod 2 44' and keeper slee~e 195 move downward ~rom their upper 3 most positions, as sh~wn. In that position of rod 44' the 4 ~alve is closed.
Reerring to ~ig. 21, there is shown a modified 6 return spring axrangement in which a tension spring is used 7 instead of a compression sping. The lower end of tension 8 ~pring 187 is connected to piston 150' by a celvis con-9 nector 186 and threaded spring plug 185. The upp~r end of the spring is threaded to a second spring plug 188 provided 11 with an upwardly extending threaded rod 189 which extends 12 through a plate 190 fixed in the bore of the hous.ing 11'.
13 A threaded nut 191 allows tension adjustment of ~he spring 14 187.
The valve shroud shown in Fig. 2~ illustrates a 16 metal sealing unit 175' which seals in the lowermost posi 17 tion of rod 44'' in which position the valve is open. The 18 val~e shroud of Fig. 23 illustrates the use of two metal 19 seal units, one of which seals in the lowermost position of 20~ rod 44''' (valve open) as in Fig. 22 and the other of which 21 seals in the uppermost position of rod 44''' (valve closed) 22 as in ~ig. 2~. The components of Fig. 22 include a shroud 23 110'l, rod 44 " connected to cle~is 114, a recess 176' form-24 ed in shroud 110 which contains an adjustable retainer ring 178', metal ring seal unit 175' which includes a lower spac-26 er ring 191', an upper spacer ring 193' having an enlarged 27 upper portion 1~4', and seal rings 192' positioned between 28 spacer rings 191' and 193'. A deformable keeper ring 195' 29 is secured to rod 44lt ~y a lock screw 196'. An annular shoulder 1~7 is formed on rod 44'' and abuts against keeper 31 rincJ 195'. A resilient seal 113'' seals about rod 44'' in 32 t~.~ bore belcsw recess 176'.
1 The val~e shroud 110''' shown in Fig. ~3 includes 2 both the seal ring unit 175' of Fig. 22 and the seal ring 3 unit 175 ~ Fig~ 2~. In this position of rod 44''' seal ring 4 unit 17~ is in the unsealed position, i.e, rod 44''' has completed its do~m stroke and in that po~ition ~eal ring 6 unit 175' is in sealing positi~n. The components which are 7 the same as the components of ~igs. 20 and ~2 have been 8 given the same designation in Fig. 23. A resilient seal 9 113''' seals ~b~u~ the rod 44''' in the bore between re-cesses 176 and 176'.
11 As mentioned heretofore, seal reliabilit:y of the 12 metal-to~metal static seals described above is superior to 13 conventional elastomer or resilient type seals. Therefore, 14 the possibility of the hydraulic power fluid system used to operate the actuator being contaminated hy sea water or by 16 production well fluids is minimized. With respect to use 17 of the actua~or of the invention as an external operator 18 for a subsurface sa~ety valve, the actuator provides iso-19 lation of the hydraulic power fluid system from the pro-20~ duction well fluid. In addition, the safety valve design 21 is greatly simplified and provides for full, through-bore 22 capability which is required for wire-line and p~np-down 23 tool work. Also, axial loads in the tubing strin~ in which 24 the safety valve is located do not affect operation of the hydraulic system whereas concentric operator type safety 26 valves are subject to seal leakage caused by distortion 27 which results from the transfer of axial loads in the tubing 28 string through the hydraulic components. The metal-to-metal 29 seals are pressure energizing in that an increase is pres-sure causes a higher contact load at the seal surfaces.
31 The actuator is compatible for use with a flapper valve, 32 ball valve or other type valves operable by an actuator.
3-a~
1 Changes and modifications may be made in the il-2 lustrative embodiments of the invention shown and/or de-3 scri~ed herein with~t. ~epar~ing from the ~cope of the in-4 vention as defined in the appended claims.
Claims (37)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An actuator comprising:
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged for reciprocation in one of said chambers in a power stroke and in a return stroke;
reciprocative means connected to said piston for movement therewith and extending from said one chamber into said other chamber;
an annular space formed between said reciproca-tive means and the inner wall of said housing; and metal seal ring means operable to seal upon com-pression sealing off fluid communication between said cham-bers only at the completion of the power stroke and at the completion of the return stroke of said piston, said metal seal ring means comprising two metal seal ring units, one of said seal ring units being resiliently compressed to close off said annular space and seal off fluid com-munication between said chambers at the completion of the power stroke of said piston and the other of said metal seal ring units being resiliently compressed to close off said annular space and seal off fluid communication between said chambers at the completion of the return stroke of said piston.
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged for reciprocation in one of said chambers in a power stroke and in a return stroke;
reciprocative means connected to said piston for movement therewith and extending from said one chamber into said other chamber;
an annular space formed between said reciproca-tive means and the inner wall of said housing; and metal seal ring means operable to seal upon com-pression sealing off fluid communication between said cham-bers only at the completion of the power stroke and at the completion of the return stroke of said piston, said metal seal ring means comprising two metal seal ring units, one of said seal ring units being resiliently compressed to close off said annular space and seal off fluid com-munication between said chambers at the completion of the power stroke of said piston and the other of said metal seal ring units being resiliently compressed to close off said annular space and seal off fluid communication between said chambers at the completion of the return stroke of said piston.
2. The actuator as recited in claim 1 in which said one chamber is formed in two parts; and including seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston.
3. The actuator as recited in claim 2 including deform-able means arranged on said reciprocative means and capable of deforming to allow simultaneous seals to be obtained by said seal means and by said one metal seal ring unit at the comple-tion of the power stroke of said piston.
4. The actuator as recited in claims 2 or 3 in which said seal means comprises a third metal seal ring unit.
5. The actuator as recited in claims 2 or 3 in which said seal means comprises an elastomer type seal.
6. The actuator as recited in claims 2 or 3 in which said seal means comprises a metal-to-metal knife-edge type seal.
7. The actuator as recited in claim 1 in which said seal ring units are stationary and are positioned on said inner wall o F said housing.
8. The actuator as recited in claim 1 in which said seal ring units are arranged on said reciprocative means and movable therewith.
9. An actuator comprising:
a housing, said housing containing linearly spaced-apart first, second and third chambers;
said first chamber being formed in two parts, one part having a larger cross-sectional area than the other part;
a piston arranged in said one part to reciprocate from one position to another position in a power stroke and from the other position to said one position in a return stroke;
a first piston rod attached to and movable with said piston;
a first metal seal ring unit sealing off fluid communication between said first and second chambers only at the end of the power stroke of said piston;
a connector rod connected to and movable with said piston rod and extending into said second chamber;
a second metal seal ring unit sealing off fluid communication between said first and second chambers only at the completion of the return stroke of` said piston;
seal means for sealing off fluid communication between said parts of said first chamber only at the end of the power stroke of said piston;
an actuator rod connected to said connector rod;
a second piston rod attached to said piston and extending into said third chamber; and biasing means arranged in said third chamber for urging said piston to said one position thereof.
a housing, said housing containing linearly spaced-apart first, second and third chambers;
said first chamber being formed in two parts, one part having a larger cross-sectional area than the other part;
a piston arranged in said one part to reciprocate from one position to another position in a power stroke and from the other position to said one position in a return stroke;
a first piston rod attached to and movable with said piston;
a first metal seal ring unit sealing off fluid communication between said first and second chambers only at the end of the power stroke of said piston;
a connector rod connected to and movable with said piston rod and extending into said second chamber;
a second metal seal ring unit sealing off fluid communication between said first and second chambers only at the completion of the return stroke of` said piston;
seal means for sealing off fluid communication between said parts of said first chamber only at the end of the power stroke of said piston;
an actuator rod connected to said connector rod;
a second piston rod attached to said piston and extending into said third chamber; and biasing means arranged in said third chamber for urging said piston to said one position thereof.
10. The actuator as recited in claim 9 in which said seal ring units are stationary and are positioned on an inner wall of said housing.
11. The actuator as recited in claim 9 in which said seal ring units are arranged on said connector rod and movable there-with.
12. The actuator as recited in claims 10 or 11 in which said seal means comprises a third metal seal ring unit.
13. The actuator as recited in claims 10 or 11 in which said seal means comprises an elastomer type seal.
14. The actuator as recited in claims 10 or 11 in which said seal means comprises a metal-to-metal knife-edge type seal.
15. The actuator as recited in claim 9 in which said biasing means comprises compression spring means.
16. The actuator as recited in claim 9 in which said biasing means comprises tension spring means.
17. The actuator as recited in claim 9 including deform-able means arranged on said connector rod and capable of deform-ing to allow simultaneous seals to be obtained by said seal means and by said first metal seal ring unit at the completion of the power stroke of said piston.
18. An actuator comprising:
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged in one of said chambers for reciprocation from one position to another position in a power stroke and from the other position to the one po-sition in a return stroke;
a piston rod attached to said piston and movable in said one chamber therewith;
a first metal seal ring unit connected to said piston rod for movement therewith and for sealing off fluid communication between said chambers at the completion of the power stroke of said piston;
a connector rod connected to said piston rod and extending into said other chamber;
a second metal seal ring unit connected to said connector rod for movement therewith in said other chamber and for sealing off fluid communication between said cham-bers at the completion of the return stroke of said piston;
an actuator rod connected to said connector rod; and biasing means in said housing for urging said piston to said one position thereof.
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged in one of said chambers for reciprocation from one position to another position in a power stroke and from the other position to the one po-sition in a return stroke;
a piston rod attached to said piston and movable in said one chamber therewith;
a first metal seal ring unit connected to said piston rod for movement therewith and for sealing off fluid communication between said chambers at the completion of the power stroke of said piston;
a connector rod connected to said piston rod and extending into said other chamber;
a second metal seal ring unit connected to said connector rod for movement therewith in said other chamber and for sealing off fluid communication between said cham-bers at the completion of the return stroke of said piston;
an actuator rod connected to said connector rod; and biasing means in said housing for urging said piston to said one position thereof.
19. The actuator as recited in claim 18 in which said biasing means comprises compression spring means.
20. The actuator as recited in claim 18 in which said biasing means comprises tension spring means.
21. The actuator as recited in claim 18 in which said one chamber is formed in two parts; and including seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston.
22. The actuator as recited in claim 21 in which said metal seal ring units are stationary and are positioned in said inner wall of said housing.
23. The actuator as recited in claim 21 in which said seal ring units are arranged on said connector rod and movable therewith.
24, The actuator as recited in claim 21 including deformable means arranged on said connector rod and capable of deforming to allow simultaneous seals to be obtained by said seal means and said first metal seal ring unit at the completion of the power stroke of said piston.
25. The actuator as recited in claim 21 in which said seal means comprises a third metal seal ring unit.
26. The actuator as recited in claim 21 in which said seal means comprises an elastomer type seal.
27. The actuator as recited in claim 21 in which said seal means comprises a metal-to-metal knife-edge type seal.
28. An actuator comprising:
a housing, said housing containing at least one chamber;
a piston arranged in said chamber for reciproca-tion from one position to another position in a power stroke and from the other position to the one position in a return stroke;
a piston rod attached to said piston and movable in said chamber therewith;
said chamber being formed in two parts;
seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston;
an annular space between said piston rod and the inner wall of said housing;
a metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the power stroke of said piston to close off said annular space; and deformable means arranged on said piston rod and capable of deforming to allow simultaneous seals to be obtained by said seal means and by said one metal seal ring unit at the completion of the power stroke of said piston.
a housing, said housing containing at least one chamber;
a piston arranged in said chamber for reciproca-tion from one position to another position in a power stroke and from the other position to the one position in a return stroke;
a piston rod attached to said piston and movable in said chamber therewith;
said chamber being formed in two parts;
seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston;
an annular space between said piston rod and the inner wall of said housing;
a metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the power stroke of said piston to close off said annular space; and deformable means arranged on said piston rod and capable of deforming to allow simultaneous seals to be obtained by said seal means and by said one metal seal ring unit at the completion of the power stroke of said piston.
29. The actuator as recited in claim 28 in which said seal means comprises another metal seal ring unit.
30. The actuator as recited in claim 28 in which seal means comprises an elastomer type seal.
31. The actuator as recited in claim 28 in which said seal means comprises a metal-to-metal knife-edge type seal.
32. An actuator comprising:
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged for reciprocation in one of said chambers in a power stroke and in a return stroke;
said chamber being formed in two parts;
seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston;
reciprocative means connected to said piston for movement therewith and extending from said one chamber into said other chamber;
32. An actuator comprising:
a housing having an inner wall and containing at least two linearly spaced-apart chambers;
a piston arranged for reciprocation in one of said chambers in a power stroke and in a return stroke;
said chamber being formed in two parts;
seal means for sealing off fluid communication between said parts only at the end of the power stroke of said piston;
reciprocative means connected to said piston for movement therewith and extending from said one chamber into said other chamber;
claim 32 cont'd a first annular space formed between said reci-procative means and the inner wall of said housing;
an actuator means connected to said reciproca-tive means and movable in said other chamber and extending from said housing;
a first metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the power stroke of said piston to close off said first annular space;
a second metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the return stroke of said piston to close off said first annular space;
a second annular space formed between said actuator rod and the inner wall of said housing;
a third metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the return stroke of said piston to close off said second annular space;
first deformable means arranges on said recipro-cative means and capable of deforming to allow simultaneous seals to be obtained by said seal means and by said one metal seal ring unit at the completion of the power stroke of said piston; and second deformable means arranged on said actuator rod and capable of deforming to allow simultaneous seals to be obtained by said second metal seal ring unit and by said third metal seal ring unit at the completion of the return stroke of said piston.
an actuator means connected to said reciproca-tive means and movable in said other chamber and extending from said housing;
a first metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the power stroke of said piston to close off said first annular space;
a second metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the return stroke of said piston to close off said first annular space;
a second annular space formed between said actuator rod and the inner wall of said housing;
a third metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the return stroke of said piston to close off said second annular space;
first deformable means arranges on said recipro-cative means and capable of deforming to allow simultaneous seals to be obtained by said seal means and by said one metal seal ring unit at the completion of the power stroke of said piston; and second deformable means arranged on said actuator rod and capable of deforming to allow simultaneous seals to be obtained by said second metal seal ring unit and by said third metal seal ring unit at the completion of the return stroke of said piston.
33. The actuator as recited in claim 32 in which said seal means comprises another metal seal ring unit.
34. The actuator as recited in claim 32 in which said seal means comprises an elastomer type seal.
35. The actuator as recited in claim 32 in which said seal means comprises a metal-to-metal knife-edge type seal.
36. The actuator as recited in claim 32 including a fourth metal seal ring unit operable to seal upon compression sealing off fluid communication only at the completion of the power stroke of said piston to close off said second annular space.
37. The actuator as recited in claim 32 or 36 including another seal means for sealing off said second annular space.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US1394179A | 1979-02-22 | 1979-02-22 | |
| US013,941 | 1993-02-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1139189A true CA1139189A (en) | 1983-01-11 |
Family
ID=21762620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000345581A Expired CA1139189A (en) | 1979-02-22 | 1980-02-13 | Hydraulically operated actuator |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1139189A (en) |
| GB (1) | GB2043780B (en) |
| MX (1) | MX150727A (en) |
| NO (1) | NO800471L (en) |
| SG (1) | SG59784G (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107461174B (en) * | 2017-09-26 | 2023-07-21 | 西南石油大学 | Underground safety valve |
-
1980
- 1980-02-13 CA CA000345581A patent/CA1139189A/en not_active Expired
- 1980-02-21 NO NO800471A patent/NO800471L/en unknown
- 1980-02-22 GB GB8006106A patent/GB2043780B/en not_active Expired
- 1980-02-22 MX MX181299A patent/MX150727A/en unknown
-
1984
- 1984-08-24 SG SG597/84A patent/SG59784G/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| MX150727A (en) | 1984-07-06 |
| GB2043780B (en) | 1983-04-20 |
| SG59784G (en) | 1985-04-26 |
| NO800471L (en) | 1980-08-25 |
| GB2043780A (en) | 1980-10-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |