AU725395B2

AU725395B2 - Method and device for connecting a flexible pipe

Info

Publication number: AU725395B2
Application number: AU47093/97A
Authority: AU
Inventors: Anh Tuan Do; Joel Le Nouveau
Original assignee: Coflexip SA
Current assignee: Technip Energies France SAS
Priority date: 1996-10-16
Filing date: 1997-10-13
Publication date: 2000-10-12
Anticipated expiration: 2017-10-13
Also published as: AU4709397A; ZA979260B; FR2754585B1; WO1998016774A1; CA2268985A1; FR2754585A1; EP0932788A1

Description

-1- Method and device for connecting a flexible pipe The present invention relates to a method and a device for connecting an end fitting onto one end of a flexible pipe, and more particularly a flexible pipe which is exposed to high mechanical and thermal stresses when it is transporting a fluid such as gas or crude.

Various connection devices, denoted most generally in their entirety by the term end fitting, have been proposed over several decades.

In a simplified version, a flexible pipe includes, from the inside to the outside, at least one tightness internal sheath, a pressure vault consisting of armouring, and a tightness external sheath.

An end fitting commonly used includes a certain number of components which are connected and interact with each other, and in particular a hollow internal end component whose terminal face butts against the impermeable 15 internal sheath of the flexible pipe, a special component which is placed under, and is connected to, the pressure tube, and an external retention and pinching sleeve or cap which is placed on the outside of the flexible pipe, over an axial length, in order to surround, on the one hand, the region which joins the terminal faces of the internal component and the impermeable internal sheath and, on the other hand, a part of the flexible pipe. Means are also provided for fixing the external sleeve. However, fitting such an end fitting requires partial stripping of the end of the pipe to be connected and moving the armouring of the pressure tube apart so as to insert the special component, without which it would be impossible to insert anything into the end of the flexible pipe.

Another type of end fitting, also developed by the Applicant, requires in the same way as above prior preparation of the end of the flexible pipe to be connected so as to be able to fit an internal component in the pipe.

FR-A-2,728,049 and FR-A-2,728,051 relate to a connection device for plastic pipes, which consists of a pinching sleeve, internally threaded and capable of being screwed onto reverse-handed threads provided on each of the ends of the pipes to be connected. A seal is interposed between the terminal faces of the pipes and is housed in a central groove made in the sleeve.

This type of end fitting can only be used if the ends of the pipes are threaded since the connection is essentially made by screwing. In the case of pipes xN 5' which do not have threads on the external protective sheath, it is essential, V PA 0 -2beforehand, to give the said pipes appropriate threads, something which is not easy when the connection has to be made at the place of operation; in addition, this type of connection requires a special tool.

FR-A-2,729,206 relates to a method for making a connection between a rigid tubular piece and the end of a flexible pipe. The tubular piece must have two parts separated by a collar provided with a circumferential groove, one of the parts having circumferential slots into which a layer of thermoplastic enters. A metal sleeve, one end of which is taken out and turned over into the groove and the other end of which is turned over radially towards the inside beyond the end of the tubular piece, is mounted so as to retain the connection. The connection method consists in inserting heating means into the flexible pipe, so as to deform the latter, flaring it out before inserting the tubular piece, then in heating the tubular piece while at the same time compressing the metal sleeve so as to melt the thermoplastic and to pinch the tubular piece and the flexible pipe in their 15 joining position. Over and above the fact that the pipes capable of being connected to the tubular piece must be sufficiently flexible in order to be able to be deformed by heating and to allow the insertion of the tubular piece, it should be noted that the recommended connection further requires either special :i components, such as the tubular piece (with circumferential groove and slots), or a prior preparation. Finally, and above all, such a connection device cannot be used for flexible pipes which carry a fluid under high pressure, for example of about bar and higher, and which develop high stresses, such as the end force which is o the tensile force exerted on the end fitting-pipe connection, the end force possibly being about 10 tonnes.

25 US-A-2,262,228 discloses a method of fitting an end fitting onto quite a flexible and deformable plastic hose so that its end can be forcibly inserted into the end fitting with a large reduction in its outside diameter; this operation is followed by a new compression of the thickness of the pipe by expanding a central sleeve. The pipe is then compressed and pinched, but not otherwise deformed. Such a method cannot be applied to the pipes to which the invention relates, which are too rigid to be inserted in this manner into an end fitting having an inside diameter which is much less than the outside diameter of the pipe.

US-A-4,653,779 teaches a method of fitting an end fitting in which an external sleeve provided with internal rings compresses and deforms the pipe as far as its reinforcement plies. However, in this method, the internal passage of the p:\AOPERRSH\47093-97 spe 220.do-9 Augusl 2000 -3pipe has a diameter which varies greatly in the region of the end fitting, so that the flow may be disturbed.

Document US-A-2,146,756 relates to a permanent end fitting for a nonreinforced hose.

According to the present invention, there is provided an end fitting for connecting one end of a flexible pipe comprising at least one internal sheath having a diameter DI, an armour and an external protective sheath having a diameter Do, said end fitting including a tubular part composed of a rear part and a tube having teeth on its external side and a sleeve having corrugations, said tube and said sleeve being designed to undergo deformation in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube, wherein the tube has, before deformation, a portion with an external diameter DCEO equal to or slightly greater than the diameter D, and an internal diameter Dclo less than said diameter DI, said sleeve having before deformation an internal diameter DMo greater than the external diameter Do and greater than or equal to the new diameter DI after tube-expansion of the portion of pipe which surrounds the tube and being capable of withstanding a drawing operation that gives thereto after deformation a diameter D 2 less than D 1 and the tube has a thickness permitting both its being tube-expanded and its resistance to compression during the drawing operation of the sleeve.

20 Further according to the present invention, there is provided an end fitting :for connecting one end of a flexible pipe comprising at least one internal sheath having a diameter DI, an armour and an external protective sheath having a diameter Do, said fitting including a tubular part composed of a rear part and a tube having teeth on its external side and a sleeve having corrugations, said tube and said sleeve being designed for undergoing deformation in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube, wherein the tube has after deformation a portion with a external diameter DCE1 greater than the diameter DI and an internal diameter Dci equal to said diameter D, or substantially equal thereto plus or minus about the tube-expansion of the tube enlarges the portion of the pipe which surrounds the tube from an external diameter Do to a new external diameter D 1 the enlarged portion of the pipe is i connected to the remaining portion of the pipe by a dogleg, the dogleg, the pipe and the P:\OPER\RSH\47093-97 spe 220.do~-9 August, 2000 -4enlarged portion having substantially the same thickness, and the sleeve has after deformation an internal diameter D 2 less than said new diameter D 1 Advantageously, the sleeve is under a radial tensile stress.

Advantageously, the tube is under a radial compressive stress.

Advantageously, the sleeve and the tube are squeezed together through the said end of the flexible pipe, with a degree of squeezing of between 15% and Advantageously, the squeezing causes the corrugations of the sleeve to penetrate into the external sheath and causes the teeth of the tube to penetrate into the internal sheath.

According to another aspect of the invention, there is provided a method for connecting an end fitting to one end of a flexible pipe comprising at least one internal sheath having a diameter DI, an armour and an external protective sheath having a diameter Do, said fitting including a tubular portion composed of a rear part and a tube having teeth S'on its external side and a sleeve having corrugations, said method comprising inserting the 15 tube into the end of the pipe over a predetermined length L, deforming said tube and said sleeve in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube by means of a mandrel placed beforehand in the flexible pipe, wherein tube-expansion of the tube enlarges the portion of the pipe which surrounds the tube from an external diameter Do to a new external diameter D 1 said 20 method further comprising moving the sleeve in order to bring it over the length of tube inserted, and, after the tube-expansion, drawing the sleeve and the corresponding portion of pipe in a drawing device in which said sleeve is radially squeezed at the same time as said pipe portion within the sleeve, the enlarged portion of the pipe being connected to the remaining portion of the pipe by a dogleg, said dogleg, the pipe and the enlarged portion having substantially the same thickness.

Advantageously, the sleeve and the pipe portion are squeezed to a predetermined degree of squeezing.

Advantageously, the degree of squeezing is between 15 and

ILL

A)0 ~i P:\OPR\RSH47093-97 pn 220.dA-7 August 2000 -4A- Preferred embodiments of the present invention seek to remedy the drawbacks discussed previously and to provide a connection device which can be used in any type of pipe to be connected, as long as the end of the pipe is capable of being tube expanded in diameter.

The diametral tube-expansion to which reference is made herein is the operation by which at least the end of a pipe is expanded over a certain length, in order to allow introduction of one component of a piece, in this case the tube of a joining end fitting.

When reference is made to the drawing operation, this means that the piece to be drawn is subjected to squeezing by a radial compression, leading to a reduction in the external diameter.

When reference is made to the operation of hooping, this means that a mechanical connection is made between two components by means of pressure exerted on one or both of the components.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a diagrammatic view, in longitudinal section, of the pipe to be *•o S: connected; Figure 2 shows the sleeve fitted around the pipe of Figure 1; 20 Figure 3 shows the tube fitted into the pipe of Figure 2; 0..0 Figure 4 shows the result of the diametral expansion of the pipe of Figure 3; Figure 5 shows the sleeve fitted around the diametrally expanded part of the pipe of Figure 4; Figure 5A shows an enlargement of the section of the pipe of Figure Figure 6 shows the pipe of Figure 5 after die-drawing; Figure 6A shows an enlargement of the section of the pipe of Figure 6; Figure 7 is a partial sectional view of the connection end fitting; and Figures 8 to 10 are views, in partial elevation, of the apparatus used to carry out the various steps in connecting the end fitting onto a flexible pipe.

The pipe 2 to be connected (Figure 1) has an inside diameter Dx and an outside diameter Do. Its thickness is e, and consists of at least one internal sheath, s15 layersof armouring and an external sheath.

Passed around the pipe 2 is a sleeve 23 (Figure the inside diameter DM0 (taken level with the teeth 28) of which is at least equal to the outside diameter D 1 of the pipe after diametral tube-expansion (Figure 4).

A tube 7, of inside diameter Dclo and outside diameter DCEO equal to or slightly greater than the inside diameter D 1 of the pipe, is inserted into the end of the pipe 2 over a length L which is preferably greater that the width of the sleeve 23 (Figure 3).

S In order to aid its penetration into the pipe 2, the tube 7 preferably terminates in a tapered shape 20 (shown here in simplified form, but more precisely in Figure The outer surface of the tube 7 has corrugations or indentations, not shown in this figure. After inserting the tube 7 into the pipe 2, the outside diameter Do of the latter is not significantly modified.

The tube 7 (at least its end) is forcibly enlarged (Figure by means of a tube-expansion mandrel, which is not shown, so that its new internal diameter Dcil is equal to or very close to the diameter Di of the undeformed pipe 2, its outside diameter becoming DCE1. The outermost part 2' of the pipe is therefore enlarged in order to take on an internal diameter equal to DCE1 and a new external diameter D 1 The additional degree of expansion, by tube-expansion, [(D 1 Do)/Do], is greater than 1% and preferably greater than or equal to 3%.

-6- During this widening by tube-expansion, a dog-leg 2a is formed between the widened part 2' and the non-widened part; the thickness e of the pipe is not very appreciably different between the part 2' and the part 2, and the dogleg 2a itself has this thickness. In other words, the slight reduction in thickness results only from the perimeter of the pipe being increased but not from the thickness of the pipe being compressed.

Next (Figure the sleeve 23, which was in readiness, is moved so that it surrounds the tube expanded part this being possible because of the sufficient diameter DM0 of the sleeve 23. Alternatively, it would have been conceivable, depending on the tool chosen, to place the sleeve immediately around the part 2'.

The pipe has, in this region the shape which may be seen in Figure namely that the inner sheath 3 and outer sheath 5 and the armouring ply 4 are appreciably deformed (apart from their widening as a result of the tube- 15 expansion). There was, approximately, merely a displacement of material, but no .compression.

By means of a drawing operation (Figure the diameter of the sleeve 23 is reduced, resulting in its internal diameter (and the outside diameter of the S.:i part adopting a value D 2 which is less than D 1 and less than DM0. During this 20 operation, the tube 7 is designed to withstand the drawing and its new inside ooo° diameter DcI2 is very slightly different from D 1 Optionally, the tube-expansion tool may be kept in the tube 7 in order to prevent it from collapsing during the drawing. It is also possible to pass the tube-expansion tool back in if the diameter DC12 was too small.

25 During the drawing operation, it should be noted that the dog-leg 2a remains, even if it is slightly reduced.

As shown in Figure 6A, the pipe 2' deforms locally under the effect of the penetration of the teeth 28 of the sleeve 23 (and additionally of the reliefs 34 on the tube 7, the function of which is essentially to prevent the pipe from slipping) so that the armouring ply 4 is corrugated.

A more detailed description will now be given of a particular application which is that of connecting an end fitting 1 onto a flexible pipe 2 through which a pressurized fluid, for example a gas or crude, flows. The flexible pipe 2 generally includes, from the inside out, at least one impermeable internal sheath 3, of a given internal diameter DI, one or more armouring plies 4 wound -7around the impermeable internal sheath 3, which is made of a material identical to or different from that of an external protective sheath 5 placed around the armouring 4. The structure of such a pipe is well known to experts and will not be described in detail. Nevertheless, the application relates more particularly to a pipe in which the armouring plies 4 each consist of a winding of "Kevlar" tapes.

which form the subject of Documents WO 97/13091 and WO 97/12753 in the name of the Applicant.

The end fitting 1 includes, on the one hand, a tubular part comprising in particular the tube 7 intended to be inserted into the end 14 of the pipe 2 and, on the other hand, the sleeve or cap 23 placed around the end of the pipe 2 to be connected (Figure 7).

The tubular part includes a rear part 6 and a distal part or tube 7 proper. The rear part 6 is fixed and centred by a centring ring 9 in a traction fixture 8 integrally fastened to a thrust or traction member 10 which can move on a frame 11 of the drawing rig 12 (Figure Mounted in the tube 7 is a tubeexpansion rod 13 which is integrally fastened to the traction fixture 8. The o flexible pipe 2 is held in place in a support denoted in its entirety by the reference and including, in particular, a support plate 16, a spacer 17 and a clamping collar 18. In a first step, the tube 7 of the tubular portion is inserted into the end o••o 14 of the pipe 2 so as to enlarge (very slightly) the said end 14 over a predetermined length L, for example 250 mm, such a deformation in fact being *9o* 0 *very limited (if not, a considerable force would be necessary to thrust the tube 7 into the pipe The end 14 of the pipe 2, as shown in Figure 1, may have a chamfer 14a to make it easier to insert the tip of the tube 7 into the said end 14.

This insertion is carried out without any prior preparation of the pipe 2, i.e.

S°without separating and/or removing part of the constituent components of the structure of the pipe 2. This insertion is carried out by means of the tube 7, which is also thick enough to withstand the residual stresses resulting from the drawing.

Tests carried out have shown that a thickness of 5 mm of the tube 7 was perfectly acceptable for a flexible pipe having an inside diameter equal to three inches. The tube 7 includes a thick cylindrical part 19 which is extended towards the front by a tapered tip 20. The dotted line 21 is an imaginary line which divides the thickness of the tube 7 into two regions, the upper region approximately 3 mm in thickness Ocorresponding to the diametral expansion and the lower region corresponding to that which will be hooped subsequently so as to ensure that the -8inside diameter DC 1 2 of the tube 7 is, after hooping, equal to the inside diameter DI of the pipe 2.

In the second phase, shown in Figure 9, the tube is unfastened from the traction fixture 8 in order to be moved forward and integrally fastened to the support 15 by means of bolts 22. In this forward position of the tube 7 and of the pipe 2, the sleeve or cap 23 fitted beforehand on the pipe 2 is positioned opposite the tube 7, which sleeve or cap, referring to Figure 7, includes a region 24 raised up with respect to the main body 25, the difference in thickness in the cap being portrayed by an imaginary dotted line 26. Provided on the lower face 27 of the cap 23 are corrugations in the form of separate rings 28 which.

during the subsequent squeezing, have to penetrate into the external sheath 5. An end part 29 of the cap rests on a flat 30 made on the rear part 6 of the tubular part.

The rings 28 are made over a predetermined length of the sleeve, which is at least 1 equal to the internal diameter DI of the pipe and more particularly equal to 15 approximately 250 mn, and they are spaced apart with a pitch of at least 4 mm.

The height of each ring is approximately 8 nim so that the rings can penetrate into the external sheath 5 and, during the subsequent drawing, cause the anrmouring wires to become corrugated.

When the cap 23 is fitted, a mandrel 33, positioned beforehand in the pipe, is moved so as to force it into the tube 7. Such an insertion of the mandrel 33 deforms the tube 7 of the tubular part until the sections of the said tube 7 and of the pipe 2 are aligned, that is to say that there is continuity between the pipe 2 and the tube 7 since the diameters DI and Dcli are equal. This is the •tube-expansion operation.

On its external face, the tube 7 has teeth 34, which differ in structure from the rings 28, a few of which have been shown in Figure 7. The function of the teeth 34 is to provide hooping between the tube 7 and the facing internal sheath 3 as well as hooping between the tube 7 and the armouring 4. After hooping, the end of the pipe lies in a confined space, which makes it possible to limit the creep over time of the internal sheath 3 and consequently to ensure that there is a lasting seal at the end of the pipe. In an illustrative embodiment, the pitch between the teeth is about one millimetre and the height of each tooth is about 0.5 mm.

In a following step, the end fitting-pipe assembly is retracted towards 0- the rear position on the frame 11 and a die 31 with its die-holder 32 is fitted into 9 the die-drawing rig 12. Having done this, the above assembly is moved through the die 31, this die-drawing operation having the effect of pinching the cap 23 onto the external sheath 5 and of completing the hooping of the tube 7 onto the internal sheath 3 and the armouring 4 of the pipe 2, so that, on leaving the die 31, the diameters Di and Dc12 are equal, thereby ensuring continuity between the connected components and avoiding any obstacle for flow of the fluid.

The tests carried out have shown that a thickness of 5 mm for the tube 7 was sufficient to withstand the traction, during insertion, of the diametral expansion and the residual compression effect after the drawing, for the pipe's internal diameter in question.

With regard to the degree of squeezing, it has been determined empirically that this was between 15 and 20% and more particularly about 16.5%, i.e. approximately 2 to 3 times the conventional pinching employed in the prior art.

15 The degree of squeezing is defined by the ratio of the difference between the thickness of the free pipe and the thickness of the flared end of the pipe to the thickness of the free pipe.

Likewise, the die-drawing length is related to the internal diameter DI of the pipe and depends essentially on the end force which is known in principle, on the coefficients of internal friction of the structure of the pipe (about 0.2) and on the nature of materials used for making the pipe (the impermeable sheaths and armouring) as well as on the material from which the cap is made. The tests have S: shown that this drawing length is at least approximately 3 times the internal diameter D 1 of the pipe.

25 On leaving the die, the cap 23 is under a radial tensile stress and the tube 7 is under a radial compressive stress, the stress state (T of the cap and of the cannula being able to be expressed by the relationship: a Ethermoplastic x degree of pinch in which Ethermoplastic is the Young's modulus of the external thermoplastic sheath of the pipe.

It should be noted that the die-drawing action makes it possible, furthermore, to ensure keying of the armouring 4 because of the rings 28 of the cap 23 which, by compressing the external sheath 5 of the pipe 2 non-uniformly, armouring 4, combined with compression between the two, external and internal, thermoplastic sheaths of the pipe 2.

In summary, the method for connecting an end fitting onto a flexible pipe consists in: a) inserting a mandrel 33, the diameter of which is equal to the internal diameter D, of the pipe, into an end 14 of the flexible pipe 2; b) placing a sleeve or cap 23 around the pipe 2; c) introducing the tube 7 of the tubular portion of the end fitting, the nominal internal diameter Dclo of which is less than the internal diameter D 1 of the pipe and the external diameter DCEO of which is slightly greater than or equal to the internal diameter D, of the flexible pipe 2, into the end 14; d) continuing the said insertion over a defined length of pipe L, optionally with a slight flaring of the said end 14 along the said length; e) moving the cap 23 in order to bring it over or opposite the tube 7 of the tubular part; :t t: f) moving the mandrel 33, inserted beforehand, in order to bring it into the tube 7 of the tubular part, thereby causing, by tube-expansion, radial deformation of the said tube 7 until the nominal diameter Dclo becomes Dcli, S:i° equal to the internal diameter D, of the unexpanded pipe, this tube-expansion operation ensuring hooping between the tube 7 and the internal sheath 3 and therefore sealing between the end fitting and the flexible pipe; and ooo* g) drawing the cap 23 and the corresponding pipe end 14 so as to reduce the outside diameter of the said cap and to compress that pipe portion lying between the cap and the distal part with a defined degree of pinch.

As was seen earlier, step e) could come before step f).

Finally, it should be noted that the effects of the hooping and the drawing are long-lasting. This is because relaxation of the plastics will tend to cancel out the initial stresses imposed by the hooping and drawing. The fact that the pipe is a reinforced pipe considerably increases the relaxation times of the layers of the thermoplastic sheaths; in addition, after drawing, the end of the pipe thus compressed between the cannula and the sleeve is, after compression, in a confined space which has the effect of making the relaxation times of the thermoplastic sheaths virtually infinite and therefore of virtually eliminating the phenomena of creep. Permanent sealing and bonding of the pipe to the end fitting are thus obtained.

PR\OPER\RSH O7093-97 spc 220.doc-7 AuguL 2000 Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

o *0 000* *0*0 0 0

Claims

1. An end fitting for connecting one end of a flexible pipe comprising at least one internal sheath having a diameter DI, an armour and an external protective sheath having a diameter Do, said end fitting including a tubular part composed of a rear part and a tube having teeth on its external side and a sleeve having corrugations, said tube and said sleeve being designed to undergo deformation in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube, wherein the tube has, before deformation, a portion with an external diameter DCEO equal to or slightly greater than the diameter D 1 and an internal diameter Dclo less than said diameter DI, said sleeve having before deformation an internal diameter DMo greater than the external diameter Do and greater than or equal to the new diameter DI after tube-expansion of the portion of pipe which surrounds the tube and being capable of withstanding a drawing operation that gives thereto after deformation a diameter D 2 less than D and the tube has a 15 thickness permitting both its being tube-expanded and its resistance to compression during the drawing operation of the sleeve. l An end fitting for connecting one end of a flexible pipe comprising at least one internal sheath having a diameter D I an armour and an external protective sheath having a 20 diameter Do, said fitting including a tubular part composed of a rear part and a tube having t teeth on its external side and a sleeve having corrugations, said tube and said sleeve being designed for undergoing deformation in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube, wherein the tube has after deformation a portion with a external diameter DCE1 greater than the diameter DI and an internal diameter Dcii equal to said diameter D 1 or substantially equal thereto plus or minus about the tube-expansion of the tube enlarges the portion of the pipe which surrounds the tube from an external diameter Do to a new external diameter D 1 the enlarged portion of the pipe is connected to the remaining portion of the pipe by a dogleg, the dogleg, the pipe and the enlarged portion having substantially the same thickness, and m .the sleeve has after deformation an internal diameter D 2 less than said new diameter D 1 P:kOPER\RSH\47093-97 spe 220.doc.7 AugLL, 2000 -12-

3. An end fitting according to claim 1 or claim 2, wherein the tube has a tapered portion.

4. A method for connecting an end fitting to one end of a flexible pipe comprising at least one internal sheath having a diameter DI, an armour and an external protective sheath having a diameter Do, said fitting including a tubular portion composed of a rear part and a tube having teeth on its external side and a sleeve having corrugations, said method comprising inserting the tube into the end of the pipe over a predetermined length L, deforming said tube and said sleeve in order to pinch therebetween the end of the flexible pipe, said deformation comprising at least tube-expansion of the tube by means of a mandrel placed beforehand in the flexible pipe, wherein tube-expansion of the tube enlarges the portion of the pipe which surrounds the tube from an external diameter Do to a -o•new external diameter D 1 said method further comprising moving the sleeve in order to *fee V bring it over the length of tube inserted, and, after the tube-expansion, drawing the sleeve o•8 15 and the corresponding portion of pipe in a drawing device in which said sleeve is radially squeezed at the same time as said pipe portion within the sleeve, the enlarged portion of the pipe being connected to the remaining portion of the pipe by a dogleg, said dogleg, the pipe and the enlarged portion having substantially the same thickness. some 20 5. A method according to claim 4, wherein during the drawing operation, the tube is maintained by the tube-expanding mandrel. 0*00

6. A method according to claim 4 or claim 5, wherein the squeezing ratio of the pipe after tube-expanding and drawing is between 15% and

7. A method according to any one of claims 4 to 6, wherein the step of moving the sleeve is performed after the tube-expanding step.

8. An end fitting substantially as hereinbefore described with reference to the accompanying drawings. PA\OPER\RSH47093-97 Spe 22f0d 9 Augu 200 -13-

9. A method for connecting an end fitting to an end of a flexible pipe, substantially as hereinbefore described with reference to the accompanying drawings. DATED this 8th day of August, 2000 COFLEXIP By its Patent Attorneys: DAVIES COLLISON CAVE o b .P<