CA1051482A - Coupling apparatus - Google Patents

Abstract

NEW AND IMPROVED COUPLING APPARATUS

Abstract of the Disclosure For use in connecting first and second pipes, an apparatus which incorporates an external sleeve adapted to be abutted against a flange and positioned about a first pipe and enclosing oppositely facing sets of tapered slips.
The slips incorporate serrations to enable them to grip the first pipe. An encircling cavity receives fluid under high pressure and hydraulically forces the two sets of slips to an actuated position, firmly gripping the first pipe. This provides a good mechanical connection of the connector to the first pipe. The second pipe is preferably connected to the flange. A separate set of fluid seals prevent leakage.
They are actuated by means of a second set of pistons which hydraulically force the seal members with adequate pressure to cause them to seal the connection of the first and second pipes. The coupling apparatus has a separate mechanical coupling and an isolated seal mechanism which are separately actuated.

Description

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NEW AND IMPROVED COUPLING APPA~TUS
, _ A~stract of the Disclosure For use in connecting first and second pipes, an apparatus wh~ch incorporates an external sleeve adapted to be abutted against a flange and positioned about a first pipe and enclosing oppositely facing sets of tapered slips.
The slips incorporate serrations to enable them to grip the first pipe. An encircling cavity receives fluid under high pressure and hydraulically forces the two sets of slips to an actuated position, fir~ly gripping the first pipe. This provides a good mechanical connection of the connector to the first pipe. The second pipe is preferably connected to the flange. A separate set of fluid seals prevent leakage.
They are actuated by means of a second set of pistons which hydraulically force the seal members with adequate pressure to cause them to seal the connection of the first and second pipes. The coupl~ng apparatus has a separate mechanical coupling and an i~olated seal mechanism which are separately actuated.

! Back round of the Di~closure g In installation of gatherlng lines at sea which extend from submerged well head production equlpment to a collection facility, it i9 necessary to install couplings.

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Often the collection pipe is welded in strings on the surface and coated with concrete weight material to cause it to sink. The surface welded connections cannot be used for thle entirety of the length of the line from origin to destination, and it is necessary to install a coupling which is attached mechanically. It is the ~ort of coupling which can be installed normally only once, and its correct installation is necessary initially. The coupling must be fluid tight and not require service or checking after installation.
The pxesent invention is a coupling which ha~
the~e virtue~. It ~s a single coupling which isolates the mechanical coupling of pipe from fluid coup}ing. It , incorporate~ a mechanical coupling which Sears up under loading placea on ~t, and has a separate fluid seal coupling which ~s not lnflicted with the qubstantial mechanical load carried by the mechanical coupling. The coupling apparatus finds applicat$on at other locations such as on land.

Summa of the Disclosure ry The present invention cooperates with first and ~econd pipes to connect them. It includes a tubular sleeve which encircles the first pipe. The tubular sleeve captures on its interior two sets of latching mechanisms which work against ona another~ Each set includes a taper, a serrated lO~ Z
set of slips, and a piston which force~ the slip against the taper, thereby causing the slips to grip and engage the first pipe which is on the interior. ~ydraulic ~luid is introduced between the piston~ under pressure to force them apart. After the pistons move apart, they are held in position by a ratchet mechanism connected between the two pistons. The tubular ~leeve connects to a flange plate which bolts to an enlarged housing attached to the end of the second pipe. The enlarged housing receives a set of ~eal members on its lnterior asainst the exterior of the first pipe which is telescoped into the housing. A 1uid connection through the houslng lntroduces fluid against a piston arrangement which pressurize~ the ~eal, thereby forc$ng th~m into sealing engagement with the interior of the houslng and the exterior o~ the ~ir~t pipe.

Description of the Drawing~
Fig. 1 is a sectional view of the coupling of the present invention disclosing separate mechanical couplings and ~eal members and means for actuating them and a novel means for retaining the engaged position; and, Fig. 2 ~s an enlarged sectional view showing details of a ratchet means which holds the mechanical coupling in th~ engaged position.

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D~scription of the Preferred ~mbodiment In Fig. 1, the coupling 10 cooperates with a first pipe 12 and a second pipe 14. The pipes 12 and 14 are equal preferably in di~neter, though this is not mandaiory. The S coupling 10 of the present invention contemplates the attachment of an enlarged housing 16 to the pipe 14 by means of welding or integral manufacture. The enlarged housing has an internal diameter and length to receive the first pipe 12 and the sealing apparatus of the coupling 10. The enlarged housing extends to a flange plate 18 which is abutted against a similar flange plate 20, and the ~wo are joined by nuts and bolts threaded through bolt holes on a common circle in the two flange plates 18 and 20.
Alternatively, an encircling clam~ can be used to fasten the flange plates together. The flange plate 20 is connected to a tubular sleeve 22 which is concentrically located around the first plpe 12. The space inside the tubular sleeve generally receive~ that portion of the equipment which provides the mechanical connection of the two pipes. By contrast, the cavity in3ide the housing 16 receives the seal portion.
The equipment is assembled in the manner shown in Fig. 1 and the mechanical coupling is made first by ~(~5i~8Z
application of extremely high fluid pressure thereto. After it has been made fast, the seal apparatu~ in the housing 16 is then actuated to sealing engagement and made fast. This will be explained in deta11. The tubular sleeve 22 is threaded at 23 to engage a hollow member 24 which serves as a taper. The member 24 has a ~loping ~nternal face.. The tapered body 24 fits about the pipe 12 but it is not necessary that ~t form a leak-proof connection therewith or even contact the pipe surface. The tapered body 24 works again~t a tapered ~lip 25 which i8 ormed of cyl~ndrical stock. The 51ip 25 has a set of serrations or thrsaas on its inner face against the pipe. They are normally spaced slightly about the pipe in the disas~embled state. The tapered slip 25 has an external tapered face ex~ending along its exter~or which ha~ an angle matching that of th~ tapered face on ~he body 24. In the relaxed condition of Fig. 1, the two faces match and contact along their ength. The tapered slip 25 incorporates an abutting end face 26. Force applied to the face 26 forces the ~lip 25 against the tapered body 24 and deflect~ ~t inwardly. The sl~p 25 has at lea~t two and as many as nece~sary 810t8 cut therein from each end ana interleaved to permlt lt to deflect inwardly more read1ly as $t i5 pushed to the left as viewed in Fig.
1~ The slots accomodate shrinkage of the encircling tubular body as it 18 radially loaded. When it i8 forc~d to the ~05~L48Z
left, the thread~ or serrations on its inter~ or faCQ com~
.Lnto contact with the first pipe 12 and grip it irm1y.
A ~l~dable piston 28 abuts the face 26 of the slip 25. The p~ston 28 1~ concentrically arranged around the 'pipe 12 and bears again~t the en~ face 26. The piston ~nc~rporates a seal member 30 which prevents lea~age of pressure flu~d therepast. The piston bears against the face 26 and i~ sized to fit snuggly ~n the tubular sleeve 22. It i~ not necessary that it contact the pipe. The piston 28 incorporates a shoulder 3~ and has an extended body portion 34 wh~ch ~ of reduced d~ameter. This defines an external step fully encirallng the pi~on 28 to ena~le a second pi~ton to be 81~ dably posit~oned against the ~houlder 3~ and telesaope~ around the relatively narrow neck portion 34.
lS The nec~ port~on 34 term~natQs ln a set of elongate f~ngers 36. Th~ flngers 36 def~ne a set of collet finger~ separated I ~y ln~ividual lengthwise grooves 40. The grooves 40 ¦ separate the ~lngers, and the finger~ are thus able ~o I Aeflect ~nwardly and outwardly ln response to lateral 1 20 loading. ~he fingers 36 support f~ nger tip~ 3B which have a ` ~et o thraaas cut ln ~he~r exterior face. Treat~ng all the : fingers collectively, the finger tlp~ 38 are collect~vely machined with a set of threads better illu~trated at 44 ln th~ low~r half of F~g. 1. The thread3 44 ~erve as a ratchet m~chan~sm whlch will be mor~ fuliy de~cribed.

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A secona piston 48 has an elongate tubular portion 50 whlch abuts the shoulder 32 of ~he f~rst pi~ton 28. The tubular portion extends over the neck portion 34 of th~
firQt piston. The second piston i~ provided with a ~eal means 52 whiah engages the surrounding tubular sleeve 22. A
sscond seal member 54 $~ located on the interior of the tubular portion 50 ana seals against the narrow neck portion 34 of the first pi~ton 28. The interior surface of the narrow neck portion 50 i5 threaded for about one-half of lt~
length at ~a. The thread 58 engages the thread 44 at the collet f~nger tip~ 38. The threads ~8 pref~rably are cut to def~ne a ratchet mechan~m. They are cut w~th one angled face and a ~ran~verse face. The tran~verse face 1OOkB
towar~ the flr~t plst~n 28. The threads ~4 and 58 define a 1 15 loc~$ng thread~d arrangement. The pls~on 28 i8 f hydraullcally forced away from the p~ston 58, ¢aus$ng the aollet finger~ 36 to ratchet as they are forced axially away from the max$mum penetration in~o the ~econd piston, without rotation. ~owever, they cannot ratchet to enable movement ln the oppos~e d~rect~on~ Maximum penetration on rethreading ~ achieved only by rotat~on. Thi~ i~
CO~V~niQnt at ~he time of a~sembly.
The pi3~0ns are able to be forced apart by the introduction of hydraul~c flu~d through a fltting 60. Ater they have been forced apart, they ar8 held apart by the .

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ratchet mecllani~m. The ratche~ mechanism malntains i~9 position indefinitely.
The first piston 2~ sets a first slip 25. The sec~nd piston 48 works against a second slip 62. The slip 62 is constructed identically to the slip 25. It is pr~vided with a facing transverse shoulder which contacts the second piston. It has a tapered outer surface and an axlally formed central passage with threads ~ormed therein to enable it to grip the plpe 12. ~he tapered slip 62 is telescoped into a tapered body 64. The tapered body is captured lnside ~he tubular 31eeve 22 and abuts the flange plate 20. It ~s fixed in position and is not movable. Th~
51ip 62 iS moved by forcing it to the interior of the tapered body 64. The slip 62 also has set~ of interleave~
ax~al ~lot~ to enable contract~on toward the pipe 12.
The housing 16 receiveR that port~on o~ the equipment which provldes the fluid seal. ~he mechanical connection ls achleved to the left of the flange plates 18 and 20~ On the rlght slae of the flange plates is a spacer meMber 66. A stacX of 8eAl~ is shown at 68. Another ~pacer, a lantern ring, ~ 8 shown at 70. An additional set of seals 72 ~8 included. ~he seals can be che~ron ~eal~ or a~y other su1table form of seal. The ~eals are brought ~nto contaat with the lnner faae of the hous~ng 16 and the external face of the p~pe 12. The 8eal8 are compres~ed into ~05~Z
sealing contact by a piston 74. The piston 74 incorporates a seal ring 76 on it~ exterior to prevent leakage therepast.
For reduction of cost in manufacturing, the piston 74 i8 preferably ldentical to the first piston 28 previously ~ r~bed. The pin~ton 74 does not ordinarily carry the ~ inflicted on the piston 28. A second piston 78 is preferably s~milar or identical to the second piston 48 pre'.r' ou81y described. The ~irst and second pistons 74 and 78 incorporate outwardly faclng seal rings to prevent leaXage therepast~ The ~econd piston 78 extend~ over a relatively narrow neck port~on on the first piston and the two are appropriately sealed. The second piston has a set of nternal threads which are engaged by a set of collet fingQr3. Thi~ enables ~he pistons 74 and 78 to be forced apaxt hy~raulcally a~d maintaln their po~ltlon after relief of hydraulic pressure. Fig~ 1 further discloses a thre~ded fi~ting 80 ad~acent the ~pacer 70 and in the midst of all of the seals. A hydraulic fitting 82 open~ into the space between the first and ~econd pistons~ There i~ a small enclrcling volume ~etween the first and ~econd pistons in communlcation with the port 82 to enable flu~d pressure to be ~ntro~uced~ The plstonfi 74 and 78 are held apart ~y a ratchet mechan~m ~milar to the one previou~ly aescr~bed.
For operat~on, the hou~lng 16 i~ attached to the cond pipe 14 by welding or ~ntegral manufacture. The :.
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fluid pressure seal apparatu~ is posit~oned ~n the housing 16. The tubular sleeve 22 and all of the apparatus on its ~nterlor i~ telescoped over the end of the first pipe 1~.
The first pipe 12 is stabbed ~nto the housing 16 and abutted`
against the far end of the housing. The flange plate 20 i~
moved against the flange plate 18 and the two flanges are made fast with appropriate nuts and bolts, or a flange clamp. It is preferable to lock the mechanical anchor f~rst. ~ydraulic fluid is introduced through the fitting 60 at extremely high pressures. There ~ a ~mall cylindrical vol~me to receiv~ hydraulic fluid betwoen ~he first and second piston~. It is introduced into thi-~ spaae. As the pres~ure ig increa~ed, the fir~t and second pistons are forced apart as illustrated ln F1~. 2. As th~y move apart, they forae ~he tapered slips 25 and 62 away from one another and against the surrounding tapered bod~e~ 24 and Ç4, respeoti~ely. This mo~ement of the tapered slips forces them into firm binding grip aroun~ the first pip~ 12, thereby secur$ng the apparatu~ to the first p~pe. When an ade~uate gri~ i achieved, it can then be rele~sed~ A~ the p~3ton~ move apart, the collet finger~ 36 aro pulled from th~ thread~ 5B on th~ interior of the ~econd pis~on. A~ t~e ~irs~ pis~on mov~s ~o the left, the collet fingers 36 ride o~er ~he cre~t of ~he threads 58. As th~ fingers 36 ride ~Yer th~ ~hreads, th~y ~o~e to the left untll the Beparation ~05148Z
of the two pistons is completed. When the fluid pressure is removed, there will be a tendancy of the collet flngers to slide back to the right. This i~ accomodated only slightly as the external threads 44 mesh with the internal threads 58. The threads permit only ~light movement back to the right, and this movement ~s limited onto that required to enable the collet finger~ to deflect outwardly and achieYe complete facial contact with the threads 58.
~ne fitting 60 can conveniently be closed over with a cap to seal hydraullc fluid in the equ~pment.
~ydraulic oil wh~ch will be protective to the parts of the equipment i~ preferably use~. ~f the apparatus is placed under water for a long lnterval, water might intrude along the surface of the plpe 12, but it cannot ordinarily come in~o contact w~th the machined faces of the piston~. ThQ
cap on the fittiny 60 can be removed mu¢h later and additional pre~sure fluid applied to the apparatus D
Th~ mechanical connective means ha~ ~een described. Fluld pressure 18 appl~ed to ths f~tt~nq 82 to perfect the leak-pr~of seal. Fluid ~s introduced ~etwesn th~ first and ~econd p~ ston~ 74 an~ 78. Adequate pre~ur~
for operat~ng th~ ~eals ~8 a~d 72 is introduced~
~xces~ively ~arge press~re is not normally required. Ater adequate pres~ur~ i8 attain~d~ the ~eal~ are compresssd and move radially ~nwardly snd outwardly to pe~fect 6e~1ing ~OS1~8Z

ca,ntact with the concentrically arranged tubular members about the seal. The fitting 80 permit~ auxillary acce~s to the seals. The fitting i~ preferably capped after a seal has been consummated. A small line connected to the fitting 80 collects any leakage. The piston 78 cannot ~ove to the right, 80 movement is by the first piston to th~ left.
The pipe 12 is ~tabbed in~o the seals 68 and 72 where its penetration i8 limited by an end abutting shou~der. However, it is not necessary for the pip~ 12 to penetrate to the shoulder, or for the shoulder to be incorporated ~n the housing 16. The pipe 14 conveniently connects to a flange tnot shown~ or other down~tream equipment. The seal section of apparatus to the right of the flange 18 can be removed and reused. Subsequent reuse requires d$sassembly of the nest of ~eal members and rethread~ng of the ratchet mechanism between the pistons 74 and 78 to the lllustrated position ~f Fi~. 1.
Th~ foregoing i9 dir~cted to a descript~on and installatlon of the present invention. Many alterations and variat~ons can be incorporated without departing from the scope of the present invention.

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Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pipe coupling device for leak-proof connection of two pipes comprising a tubular sleeve adapted to be telescoped about a first pipe which extends into said sleeve;
an expandable pipe gripping means within said sleeve for selectively gripping the first pipe therein;
a housing which is connected to said sleeve and receives the first pipe therein, said housing incorporating an opening adapted to be connected into a second pipe and which pipe is to be connected to the first pipe;
an encircling fluid seal means within said housing having an outer surface which seals against said housing and an inner surface which seals against the outer surface of the first pipe on its insertion into said seal means;
first means for actuating said gripping means to grip the first pipe to hold said sleeve relative to the pipe; and wherein said pipe gripping means and said first means include a pair of fluid actuated movable pistons;
a chamber means for said pistons which is adapted to receive fluid under pressure to force said pistons apart;
a pair of oppositely facing slips and co-acting tapered surfaces for wedging said slips toward the first pipe to grip and hold the first pipe, said slips working against each other to hold said tubular sleeve relative to the first pipe; and, means for securing and holding said pistons apart after movement; and, second means for actuating said fluid seal means to sealing operation.

2. The apparatus of Claim 1 wherein said seal means includes a plurality of circular seal members within said housing and a slidable piston abutting said seal members, and said second means incorporates means for securing and holding said piston after movement to the position achieved on pressurizing said seal members.

3. The apparatus of Claim 2 wherein said last named means includes a ratchet mechanism engaging a mating set of shoulders to lock thereagainst.

4. The apparatus of Claim 3 wherein said ratchet mechanism includes at least a pair of resiliently deflectable fingers having an exposed face formed into a plurality of threads cut therein, and said mating shoulders are a set of threads formed on a tubular member.

5. The apparatus of Claim 4 wherein said fingers are a set of collet fingers movable with said piston along said tubular member.

6. A pipe coupling device for leak-proof connection of two pipes comprising a tubular sleeve adapted to be telescoped about a first pipe which extends into said sleeve;
an expandable pipe gripping means within said sleeve for selectively gripping the first pipe therein;
a housing which is connected to said sleeve and receives the first pipe therein, said housing incorporating an opening adapted to be connected into a second pipe and which pipe is to be connected to the first pipe;
an encircling fluid seal means within said housing having an outer surface which seals against said housing and an inner surface which seals against the outer surface of the first pipe on its insertion into said seal means;
first means for actuating said gripping means to grip the first pipe to hold said sleeve relative to the pipe;

and, second means for actuating said fluid seal means to sealing operation;
said tubular sleeve enclosing first and second oppositely facing, axially dis-placed tapered surfaces;
first and second radially contractable slips operatively engaged with said tapered surfaces, each having an internal cylindrical surface facing the first pipe on insertion thereinto;
first and second pistons;
chamber means for receiving said first and second pistons, said pistons being deployed such that said pistons, on introduction of fluid under pressure, said slips against said tapered surfaces to cause said slips to contract and grip the pipe to hold it securely relative to said housing;
a set of deflectable fingers carried on one of said pistons;
a set of threads on the other of said pistons, said fingers being provided with a ratcheting means thereon and contacted with said threads wherein said threads permit movement of said pistons in a direction to contract said slips and lock with said ratcheting means to prevent move-ment in the opposite direction.

7. A pipe coupling device for leak-proof connection of two pipes comprising a tubular sleeve adapted to be telescoped about a first pipe which extends into said sleeve;
an expandable pipe gripping means within said sleeve for selectively gripping the first pipe therein;
a housing which is connected to said sleeve and receives the first pipe therein, said housing incorporating an opening adapted to be connected into a second pipe and which pipe is to be connected to the first pipe;

an encircling fluid seal means within said housing having an outer surface which seals against said housing and an inner surface which seals against the outer surface of the first pipe on its insertion into said seal means;
first means for actuating said gripping means to grip the first pipe to hold said sleeve relative to the pipe; and;
second means for actuating said fluid seal means to sealing operation;
wherein said housing encloses a plurality of seal elements having an outer surface and an inner surface, which elements seal on axial pressure thereon;
a shoulder abutting said seal elements;
a circular piston abutting said seal elements;
chamber means in said housing for slidably receiv-ing said piston and for receiving a fluid under pressure to force said piston against said seal elements to expand them into sealing contact with the wall of said housing and the first pipe inserted therein; and, ratchet means cooperative with said piston for holding its position after movement in said chamber means to continue the force against said seal elements.

8. A pipe coupling device for leak-proof connection of two pipes comprising a tubular sleeve adapted to be telescoped about a first pipe which extends into said sleeve;
an expandable pipe gripping means within said sleeve for selectively gripping the first pipe therein;
a housing which is connected to said sleeve and receives the first pipe therein, said housing incorporating an opening adapted to be connected into a second pipe and which pipe is to be connected to the first pipe;

encircling fluid seal means within said housing having a sealing surface expandable into a sealing contact with the first pipe positioned therein and said housing, said seal means preventing leakage therepast;
said seal means being positioned relative to said sleeve and said housing to seal leakage from the first and second pipes;
first means for actuating said seal means to sealing operation;
second means independent of said first means for actuating said gripping means to grip the first pipe to secure it in axial relationship and wherein said pipe gripping means and said second means include a pair of fluid actuated movable pistons;
a chamber means for said pistons which is adapted to receive fluid under pressure to force said pistons apart;
a pair of oppositely facing slips and co-acting tapered surfaces for wedging said slips toward the first pipe to grip and hold the first pipe, said slips working against each other to hold said tubular sleeve relative to the first pipe;
lock means for securing said pipe gripping means in the expanded condition after operation of said second means.

9. A pipe couling device for leakproof connection of two pipes, comprising:
an elongate tubular sleeve means adapted to be telescoped about a first pipe which extends into said sleeve;
an expandable pipe gripping means within said sleeve means for selectively gripping the first pipe therein;
said sleeve means further incorporating an end located opening for connection with a second pipe to be placed in fluid communication with the first pipe;

an encircling fluid seal means within said sleeve means having an inner surface which seals against the outer surface of the first pipe after positioning within said sleeve means and which seal means is supported within said sleeve means;
first means for actuating said gripping means to grip the pipe in said sleeve means; and second means for actuating said fluid seal means to seal about the pipe in said sleeve means.