WO2015007854A1

WO2015007854A1 - Connection end piece of a flexible pipe, and associated flexible pipe

Info

Publication number: WO2015007854A1
Application number: PCT/EP2014/065413
Authority: WO
Inventors: Guillaume CHAUDET; Jean-Christophe BOURGET
Original assignee: Technip France
Priority date: 2013-07-18
Filing date: 2014-07-17
Publication date: 2015-01-22
Also published as: EP3022477A1; FR3008764A1; CN105492816B; CN105492816A; FR3008764B1

Abstract

The invention relates to a pipe comprising at least one tubular sleeve (20) and at least one layer (24, 25) of traction shielding arranged outside the tubular sleeve (20). Said shielding layer (24, 25) comprises a plurality of filiform shielding elements (29), and the end piece (14) comprises a plurality of end sections (34) of each shielding element (29), an end collar (50), and a cover (51) fixed to the end collar (50), the end collar (50) and the cover (51) defining between them a chamber (52) for receiving the end section and at least one anchoring support (62, 64) for each shielding layer (24, 25), which is mounted in a fixed manner according to an axis (A-A') of the pipe in relation to the end collar (50) and/or in relation to the cover (51). Each end section (34) is anchored to the anchoring support (62, 64) by a pivoting connection or a ball-and-socket connection.

Description

Connection end of a flexible pipe, and associated flexible pipe

The present invention relates to a connecting end of a flexible fluid transport pipe, the flexible pipe comprising at least one tubular sheath and at least one layer of tensile armor disposed externally with respect to the tubular sheath, the layer of armor comprising a plurality of threadlike armor elements, the tip comprising:

a plurality of end sections of each armor element,

- An end vault and a hood fixed on the end vault, the end vault and the cap delimiting between them a receiving chamber of the end section;

at least one anchoring support for each armor layer, fixedly mounted along an axis of the pipe with respect to the end vault and / or with respect to the hood.

The pipe is in particular an unbonded flexible pipe for the transport of hydrocarbons through an expanse of water, such as an ocean, a sea, a lake or a river.

Such a flexible pipe is for example made according to the normative documents API 17J (Specification for Unbounded Flexible Pipe) and API RP 17B (Recommended Practice for Flexible Pipe) established by the American Petroleum Institute.

The pipe is generally formed of a set of concentric and superimposed layers. It is considered as "unbound" in the sense of the present invention since at least one of the layers of the pipe is able to move longitudinally relative to the adjacent layers during bending of the pipe. In particular, an unbonded pipe is a pipe devoid of binding materials connecting layers forming the pipe.

The pipe is generally disposed across a body of water, between a bottom assembly for collecting the fluid operated in the bottom of the body of water and a set of floating or stationary surface for collecting and distributing the fluid. The surface assembly may be a semi-submersible platform, an FPSO or other floating assembly.

In some cases, for the operation of fluids in deep water, the flexible pipe has a length greater than 800 m. The ends of the pipe have tips for connection to the bottom assembly, the connection to the surface assembly and the intermediate connections.

These pipes undergo very high forces in axial tension, especially when the body of water in which is arranged the pipe is very deep. In this case, the upper end connecting the pipe to the entire surface must take a very important axial tension, which can reach several hundred tons. These forces are transmitted to the tip through the layers of tensile armor extending along the pipe.

The axial tension has not only a high average value, but also permanent variations as a function of the vertical movements of the surface assembly and the pipe, under the effect of the agitation of the body of water caused by the swell or waves.

The axial tension variations can reach several tens of tons and be repeated continuously during the service life of the pipe. In 20 years, the number of cycles can reach more than 20 million.

It is therefore necessary to ensure a particularly strong attachment between the layers of tensile armor and the body of the tip.

For this purpose, in known tips, the anchoring of the armor is generally provided by the friction between the armor son and the epoxy resin cast in the chamber defined by the arch and the hood.

Moreover, the capstan effect linked to the helical trajectory of the armor wires also contributes to the anchoring of the armor, this effect being able to be increased by modifying the diameter of the helix described by the wires in the endpiece by relative to the diameter of this helix in current length, for example by progressively increasing this diameter by following on an ascending cone, then decreasing it along a descending cone.

In addition, deformations in the form of a hook, or wave or twist can be formed at the end of each armor wire to be engaged in the epoxy resin, to achieve a mechanical blocking against the applied voltage. These deformations initiate the effort necessary to implement the capstan effect.

Sometimes, over time, the anchoring of the tensile armor becomes defective in fatigue.

In particular, this failure appears at the level of wave-shaped deformations, where the wires forming the armor have been strongly deformed.

To overcome this problem, WO 2004/051 131 discloses a tip of the aforementioned type, wherein the armor wires deviate helically from the axis of the pipe to fit into a higher diameter end support to the diameter of the envelope defined by the armor wires in the current length of the pipe.

The end of each tack wire is further inserted into an inclined groove defined on the support and is secured in the groove by introducing a wedge through the wire to locally increase its diameter. A resin is then poured into the groove to completely immobilize the end of the wire, avoiding any degree of freedom.

Such a tip is not entirely satisfactory. Attaching the armor wire by inserting a wedge into its thickness, and total immobilization of the end of the wire is likely to create fatigue failures at the front end of each wire.

The failure is likely to also appear in the rear part, at the level of the armor detachment zone relative to the diameter of the current length, this part being more fragile during assembly due to a folding of the armor, necessary at the installation of the mouthpiece.

An object of the invention is therefore to obtain a tip of a flexible pipe having an effective axial tension recovery, in which the risk of fatigue failure, especially in the end sections of the armor is greatly reduced, and which nevertheless remains simple to assemble.

For this purpose, the invention relates to a tip of the aforementioned type, characterized in that each end portion is anchored to the anchoring support by a pivot connection or a ball joint.

The tip according to the invention may comprise one or more of the following characteristics, taken separately or in any technically possible combination:

the end sections of the armor elements of each armor layer define a cylindrical envelope of substantially constant diameter along the entire length of the end piece;

the receiving chamber is devoid of filling material embedding the end sections;

the anchoring support comprises, for each end section, a connecting member projecting radially, the end section being mounted on the connecting member;

- The anchoring support comprises a circumferential flange, and at least one yoke projecting axially from the circumferential flange, each connecting member being mounted on the yoke;

- The anchoring support comprises a first inner yoke and a second outer yoke disposed around the first inner yoke, each connecting member being mounted on the first inner yoke and the second outer yoke;

each end section comprises an elongate portion and a hooking piece transversely attached to the elongated portion, the attachment piece being engaged on the connecting member;

- The attachment part comprises a base fixed on the elongate portion and a head projecting axially beyond the free end of the elongated portion; - The maximum width of the attachment piece, taken perpendicular to an axis of the elongated portion, is less than or equal to the maximum width of the elongated portion along the length of the elongate portion receiving the attachment piece;

- The elongate portion is flattened, the elongated portion having a first face, and a second face opposite to the first face, the attachment part being attached to the first face, without being reported on the second face;

- The connecting member and / or the attachment piece comprises a pin;

- The connecting member and / or the attachment part comprises a ball joint;

- It comprises an embodiment of a sealing around the tubular sheath, axially offset to the front of the or each anchoring support;

it comprises a plurality of end sections of the armor elements of a first armor layer defining a first cylindrical envelope of substantially constant diameter over the entire length of the endpiece and a plurality of end sections of the elements. armoring a second layer of armor defining a second cylindrical envelope of substantially constant diameter over the entire length of the tip and of diameter greater than the diameter of the first cylindrical envelope, and the tip comprises a first support of anchoring the first layer of armor, fixedly mounted along an axis of the pipe with respect to the end vault and / or with respect to the hood, each end section of an armor element of the first layer of armor armor being anchored to the first anchoring support by a pivot or ball joint,

the tip comprising a second anchoring support of the second layer of armor, fixedly mounted along an axis of the pipe relative to the end vault and / or relative to the hood, each end portion of a armor member of the second layer of armor being anchored to the second anchor support by a pivot connection or ball joint.

The invention also relates to a flexible fluid transport pipe, characterized in that it comprises:

a tubular sheath;

at least one tensile armor layer disposed externally with respect to the tubular sheath, the traction armor layer comprising a plurality of filiform armor elements,

- A tip as described above, mounted at the end of the tubular sheath.

The pipe according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination: each layer of armor defines, in the central section adjacent to the end piece, an intermediate cylindrical envelope of substantially constant diameter, the end sections of the armor elements of each armor layer defining a cylindrical envelope of substantially equal diameter; to the diameter of the intermediate cylindrical envelope, over the entire length of the tip.

The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended drawings, in which:

- Figure 1 is a partially cut away perspective view of a first flexible pipe according to the invention;

- Figure 2 is a partially cut away perspective view of a tip of the flexible pipe of Figure 1;

- Figure 3 is a partial perspective view of the attachment of an end section of a weave element in the tip of Figure 2;

- Figure 4 is a perspective view of three quarters face of the end of a weave element in the tip of Figure 2;

- Figure 5 is a view similar to Figure 3 of the nozzle of a second flexible pipe according to the invention;

- Figure 6 is a view similar to Figure 4 of the end of a weave element in the tip of a third flexible pipe according to the invention.

In all that follows, the terms "outside" and "inside" generally mean radially with respect to an axis AA 'of the pipe, the term "outside" meaning relatively more radially distant from the axis. AA 'and the term "inner" extending as relatively closer radially to the axis AA' of the pipe.

The terms "forward" and "rear" are axially related to an AA 'axis of the line, with the word "before" meaning relatively farther from the middle of the line and closer to one of its extremities, the term "rear" meaning relatively closer to the middle of the pipe and further away from one of its ends. The middle of the pipe is the point of the pipe situated equidistant from the two extremities of the latter.

A first flexible pipe 10 according to the invention is partially illustrated by FIG.

The flexible pipe 10 comprises a central section 12 illustrated in part in FIG. It comprises, at each of the axial ends of the central section 12, a end tip 14 (not visible in Figure 1), the relevant parts are shown in Figure 2.

Referring to Figure 1, the pipe 10 defines a central passage 16 for circulation of a fluid, preferably a petroleum fluid. The central passage 16 extends along an axis A-A 'between the upstream end and the downstream end of the pipe 10. It opens through the endpieces 14.

The flexible pipe 10 is intended to be disposed through a body of water (not shown) in a fluid operating installation, in particular hydrocarbons.

The body of water is, for example, a sea, a lake or an ocean. The depth of the water extent to the right of the fluid operating installation is for example between 500 m and 3000 m.

The fluid operating installation comprises a particularly floating surface assembly and a bottom assembly (not shown) which are generally connected to each other by the flexible pipe 10.

The flexible pipe 10 is preferably an "unbonded" pipe (referred to as "unbonded").

At least two adjacent layers of the flexible pipe 10 are free to move longitudinally with respect to each other during bending of the pipe.

Advantageously, all the layers of the flexible pipe are free to move relative to each other. Such conduct is for example described in the normative documents published by the American Petroleum Institute (API), API 17J, and API RP17B.

As illustrated in Figure 1, the pipe 10 defines a plurality of concentric layers around the axis A-A ', which extend continuously along the central section 12 to the ends 14 at the ends of the pipe.

According to the invention, the pipe 10 comprises at least a first tubular sheath 20 based on polymeric material advantageously constituting a pressure sheath.

The pipe 10 further comprises at least one layer of tensile armor 24, 25 arranged externally with respect to the first sheath 20.

Advantageously, and according to the desired use, the pipe 10 further comprises an internal carcass 26 disposed inside the pressure sheath 20, a pressure vault 28 interposed between the pressure sheath 20 and the layer or layers of pressure. traction armors 24, 25 and an outer sheath 30 for protecting the pipe 10.

In known manner, the pressure sheath 20 is intended to seal the fluid transported in the passage 16. It is formed of polymer material, for example based on a polyolefin such as polyethylene, based on a polyamide such as PA1 1 or PA12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

The thickness of the pressure sheath 20 is for example between 5 mm and 20 mm.

The carcass 26, when present, is formed for example of a profiled metal strip, wound in a spiral. The turns of the strip are advantageously stapled to each other, which makes it possible to take up the radial forces of crushing.

In this example, the carcass 26 is disposed inside the pressure sheath

20. Driving is then referred to as "rough bore" because of the geometry of the carcass 26

Alternatively (not shown), the flexible pipe 10 is devoid of internal carcass 26, it is then designated by the term "smooth bore".

The helical winding of the profiled metal strip forming the carcass 26 is short pitch, that is to say it has a helix angle of absolute value close to 90 °, typically between 75 ° and 90 °.

In this example, the pressure vault 28 is intended to take up the forces related to the pressure prevailing inside the pressure sheath 20. It is for example formed of a metallic profiled wire surrounded in a helix around the sheath 20 The profiled wire generally has a complex geometry, especially in the form of Z, T, U, K, X or I.

The pressure vault 28 is helically wound in a short pitch around the pressure sheath 20, that is to say with a helix angle of absolute value close to 90 °, typically between 75 ⁰ and 90 ⁰ .

The flexible pipe 10 according to the invention comprises at least one armor layer 24, 25 formed of a helical winding of at least one elongate armor element 29.

In the example shown in FIG. 1, the flexible pipe 10 comprises a plurality of armor layers 24, 25, in particular an inner armor layer 24, applied to the pressure vault 28 (or to the sheath 20 when the vault 28 is absent) and an outer armor layer 25 around which outer sheath 30 is disposed.

Each layer of armor 24, 25 comprises longitudinal armor elements 29 wound with a long pitch around the axis A-A 'of the pipe.

By "wound with a long pitch" is meant that the absolute value of the helix angle is less than 60 °, and is typically between 25 ° and 55 °. The armor elements 29 of a first layer 24 are generally wound at an opposite angle to the armor elements 29 of a second layer 25. Thus, if the winding angle of the armor elements 29 of the first layer 24 is equal to + a, a being between 25 ° and 55 °, the angle of winding armor elements 29 of the second layer of armor 25 disposed in contact with the first layer of armor 24 is for example equal to - a °.

The armor elements 29 are for example formed by metal wires, especially steel wires, or by ribbons made of composite material, for example carbon fiber-reinforced tapes.

As will be seen below, the armor elements 29 each have an end portion 34 inserted into the endpiece 14. The end portion 34 extends to a free end disposed in the endpiece 14. It advantageously has a helical or pseudo-helical trajectory of axis AA 'in the tip 14.

As illustrated in FIG. 4, each end section 34 comprises an elongated reinforcing portion 35, and an attachment piece 36 attached transversely to the elongated portion 35.

In the example shown in Figure 4, the elongate portion 35 extends over the entire length of the armor member 29. It has a substantially flattened shape. It defines an outer face 37, on which is attached the hooking piece 36, and an inner face 38 opposite to the outer face 37.

The attachment piece 36 is fixed on the elongated portion 35, without drilling the elongate portion 35, for example by welding, brazing, crimping or gluing.

The attachment piece 36 extends along the axis BB 'of the elongate portion 35. It has a maximum width, taken perpendicularly to this axis B-B', advantageously less than or equal to the width of the elongate portion 35.

However, in the case where the side clearances between the end sections 34 of the armor elements 29 are large, it is possible that the maximum width of the attachment piece is greater than that of the elongated portion 35.

The attachment piece 36 has a base 39 applied transversely to the elongated portion 35 and a hooking head 40 protruding longitudinally beyond the end of the elongated portion 35.

The base 39 has a maximum height, taken from the outer face 37, perpendicular to the axis B-B ', greater than the thickness of the base 39.

The height of the base 39 decreases from the head 40 to the front, to the rear.

The attachment head 40 extends parallel to and away from the axis B-B '. It defines, with the base 39, a notch 41 for wedging the end section 34. It internally defines a transverse passage 42 radial insertion of a fastener, as will be seen below.

With reference to FIG. 1, the outer sheath 30 is intended to prevent the permeation of fluid from outside the flexible pipe 10 inwards. It is advantageously made of a polymer material, in particular based on a polyolefin, such as polyethylene, based on a polyamide, such as PA1 1 or PA12, or based on a fluorinated polymer such as polyfluoride. vinylidene (PVDF).

The thickness of the outer sheath 30 is for example between 5 mm and 15 mm.

As illustrated in FIG. 2, each endpiece 14 has an end vault

50 and an outer connecting cover 51 projecting axially rearwards from the roof 50. The cover 51 delimits, with the end vault 50, a chamber 52 for receiving the end sections 34 of the elements. armor 29.

The tip 14 further comprises a front assembly 54 sealing around the tubular sheath 20, partially visible in Figure 2, and a rear assembly 56 sealing around the outer sheath 30.

According to the invention, the tip 14 further comprises, for each armor layer 24, 25, a support 62, 64 for anchoring each end section 34 of the armor elements 29 of the layer 24, 25 , able to anchor each end section 34 with at least one degree of freedom in rotation about a radial axis CC.

The tip 14 is advantageously free of solid filler filling the chamber 52. In this way, the end sections 34 are free to move laterally at the rear portion of the tip 14, reducing the constraints they must endure when the pipe 10 is subjected to strong variations in tension and / or curvature.

In this example, the end vault 50 is intended to connect the pipe 10 to another connection end 14 or to terminal equipment, advantageously via an end flange (not shown).

The end vault 50 has a central bore intended to receive the end of the first sheath 20 and to allow the flow of the fluid flowing through the central passage 16 towards the outside of the pipe 10.

The cover 51 has a tubular peripheral wall 70 extending around the axis A-A '. The peripheral wall 70 has a leading edge 71 fixed to the end vault 50, radially spaced from the armor layers 24, 25 and a rear edge 72 extending axially rearward beyond the arch. 50 end. The cover 51 delimits the chamber 52 radially outwardly. A rear face 73 of the end vault 50 axially defines the chamber 52 forwards.

The front sealing assembly 54 is advantageously located at the front of the endpiece 14, in contact with the roof 50. In the embodiment of FIG. 2, the front sealing assembly 54 is axially offset towards the front relative to each anchoring support 62, 64.

In known manner, it comprises a crimping front ring (not visible) intended to engage the pressure sheath 20, and a clamping collar 76.

In the example shown in FIG. 1, in which the pipe 10 comprises a pressure vault 28, the front assembly 54 further comprises an intermediate stop ring (not visible) of the pressure vault 28. The intermediate ring stop is interposed between the crimping front ring and the clamping collar 76

The rear sealing assembly 56 is disposed at the rear of the nozzle 14. It comprises at least one crimping rear ring 80 crimping the outer sheath 30, and a rear clamping collar 82 for clamping the fixed rear ring 80. on the cover 51, advantageously at the rear edge 72 of the peripheral wall 70.

In the example shown in FIG. 2, in which the flexible pipe 10 comprises an inner armor layer 24 and an outer armor layer 25, the tip 14 comprises a front support 62 for anchoring the end sections. 34 of the inner armor layer 24 and a rear support 64 for anchoring the end sections 34 of the outer armor layer 25, axially offset relative to the front support 62.

Each anchoring support 62, 64 is fixed axially relative to the cover 51 and with respect to the arch 50, at least from the front to the rear, for example by cooperation with a circumferential stop 88 defined by the cover 51.

With reference to FIGS. 2 and 3, each anchoring support 62, 64 comprises a circumferential flange 90, a peripheral yoke 92 protruding with respect to the circumferential flange 90, and a plurality of radial fixing members 94, fixedly mounted on the circumferential flange 90, along the axis AA 'on the yoke 92.

Each flange 90 extends around the axis A-A '. It delimits an internal lumen 96 for passage of the first sheath 20 and the pressure vault 28, when it is present.

A rear face 98 of the flange 90 is keyed against the stop 88 formed in the cover 51 to fix the anchoring support 62, 64 in translation backwards along the axis A-A '. The peripheral cap 92 protrudes rearwardly from the flange 90, advantageously around the inner lumen 96. It defines an external shoulder 100 for wedging each end section 34.

As will be seen below, the external shoulder 100 is configured to hold each end section 34 mounted on the anchoring support 62, 64 on a cylindrical envelope of substantially constant diameter over the entire length of the nozzle 14.

By "substantially constant diameter", it is advantageously meant that the trajectory of each end section 34 within the tip 14 is between two cylinders of diameter 24, 25 respectively equal to 0.9 x D and 1.2 x D, D being the average diameter of the armor layer 24, 25 corresponding to the end section 34 in current length, that is to say in the central section 12 of the pipe, outside the tip 14.

Preferably, the trajectory of each end section 34 within the end piece 14 is between two cylinders of diameter 24, 25 respectively equal to D and 1, 15 × D, D being the average diameter of the coating layer. armor 24, 25 corresponding to the end portion 34 in current length.

Advantageously, the distance separating each end section 34 from the axis A-A 'remains constant or increases monotonically between the rear part of the endpiece 10 and the attachment part 36, remaining between the two cylinders. defined above.

The support 62, 64 comprises, for each end section 34 anchored to the support 62, 64, a fixing member 94 corresponding to the end portion 34. Thus, the number of fixing members 94 advantageously corresponds to the number of end sections 34 anchored to the support 62, 64.

Each fastener 94 is mounted on the yoke 92. In the example shown in Figure 3, each fastener 94 passes through the yoke 92 and protrudes on either side thereof.

Each fastener 94 extends substantially radially with respect to the axis A-A 'of the pipe 10.

The circumferential spacing between two adjacent fasteners 94 is greater than the maximum width of each head 40 of a fastener 36, and is advantageously greater than the width of the elongate portion 35 of the end portion 34.

As can be seen in FIG. 3, each attachment piece 36 of an end section 34 is engaged on a fixing member 94. In particular, the fixing member 94 is received in the transverse passage 42 formed through the head 40. The head 40 bears on the shoulder 100. The shoulder 100 is received in the notch 41.

In the example shown in FIG. 3, each attachment piece 36 is mounted free to rotate about the radial axis C-C defined by the fixing member 94.

Thus, when the end section 34 is anchored on the anchoring support 62, 64, it is free to pivot about at least one radial axis C-C in the chamber 52.

This makes it possible to take up the tension applied by the armor elements 29, without creating a recess at the end portions 34 in the anchoring zone. The fatigue life of the tip 14 is improved.

In addition, each fastener 94 being associated with a single end section 34, the positioning of the end sections 34 of the armor elements 39 is perfectly organized in the anchoring zone.

According to this organization, for each armor layer 24, 25, the end sections 34 of the armor elements 29 are helically arranged parallel to each other, substantially at the same pitch and the same diameter of the helix as the one they occupy in the central section 12 of the pipe 10.

Thus, the end sections 34 define a cylindrical envelope of substantially constant diameter over the entire length of the endpiece 14.

For each layer of armor 24, 25, the diameter of this cylindrical envelope is substantially identical to the diameter of the intermediate cylindrical envelope defined by the armor elements 29 in the central section 12 of the pipe 10.

By "substantially identical" is advantageously meant that the difference between the mean diameter of the cylindrical envelope defined by the end sections 34 and the diameter of the intermediate cylindrical envelope is less than 15% of the average diameter of the envelope cylindrical defined by the end sections 34.

In this way, the risk of winding and / or unwinding of the armor elements 29 is limited during a large voltage variation, since no cone is present in the tip to increase or decrease the diameter of the the envelope defined by the end sections 34.

The armor elements 29, and their end portions 34 are therefore preserved in their initial state, without geometric modification, and therefore without changing their state of stress.

The folding / unfolding of the armor elements 29 is therefore no longer necessary, a simple lifting of the armor elements 29 being necessary to introduce the anchoring support 62, 64. Furthermore, since the anchoring is effected by the cooperation between the attachment pieces 36 and the fixing members 94 on each anchoring support 62, 64, it is no longer necessary to form hooks, twists or ripples on the end sections 34, which improves the fatigue resistance of the tip 14.

At the location of the rear clamping member, the armor elements 29 of the armor layers 24, 25 are wound helically with the same radius of helix as they have at the central section 12.

The assembly of the tip 14 according to the invention is carried out as follows.

Initially, the various layers of the pipe 10 are cut to the right length to reveal, on the roof 28, a free end section 34 of each armor element 29 of the armor layers 24, 25.

Each free end section 34 is free from radial deformation, in particular wave-shaped deformation or hook deformation.

Then, the various parts forming the rear sealing assembly 56 are introduced around the outer sheath 30.

Each end portion 34 is then provided with a hooking piece 36, which is attached on its elongate portion 35 at its free end 34, by welding, brazing, gluing or crimping.

Then, each anchoring support 62, 64 is engaged around the first sheath 20.

In the example shown in FIG. 2, the assembly formed by the circumferential flange 90 and the yoke 92 of the rear support 64 is first introduced around the end sections 34 of the inner armor layer 24.

Then, the end sections 34 of the outer armor layer 25 are slightly raised away from the axis A-A ', advantageously without folding them backwards, to introduce the yoke 92 under the heads 40 end sections 34.

Then, for each end section 34, the fixing member 94 is introduced through the transverse passage 42 formed in the attachment piece 36, and through the yoke 92.

Each end section 34 is then fixed axially on the anchor support

64, with a degree of freedom in rotation about a radial axis C-C.

Then, the assembly formed by the circumferential flange 90 and the yoke 92 of the front support 62 is introduced around the first sheath 20 and the pressure vault 28 when it is present. The end sections 34 of the inner armor layer 24 are slightly raised away from the axis A-A ', advantageously without folding them backwards, to introduce the yoke 92 under the heads 40 of the sections end 34.

The fixing operations of each member 94 described above are then repeated for the end sections 34 of the inner armor layer 24.

Then, the parts of the seal assembly 54, the roof 50 and the outer connecting cover 51 are put in place, in order to wedge each anchoring support 62, 64 in translation along the axis A- AT'.

Advantageously, no filler material is introduced into the chamber 52. The assembly time of the nozzle 14 is reduced.

In operation, when the endpiece 14 is connected to another endpiece or to a surface assembly, the axial tension transmitted by the armor layers 24, 25 resulting from the weight of the pipe 10 is taken up by the sections 34, then by the anchoring supports 62, 64 by the cooperation between the fasteners 94 and the attachment pieces 36 allowing a degree of freedom in rotation about a radial axis CC.

The anchoring achieved is very effective, with a small anchoring length, reduced to the longitudinal dimensions of the supports 62, 64 and that of the attachment pieces 36.

The tip 14 of a second flexible pipe 120 according to the invention is illustrated in FIG.

Unlike the tip 14 illustrated in Figure 3, the tip 14 described in this figure comprises an additional peripheral yoke 122 disposed outside the peripheral yoke 92.

The yokes 92, 122 define between them an intermediate annular space 124 for introducing the fastening pieces 36.

Each fixing member 94 is introduced successively through the additional peripheral screed 122, the transverse passage 42 of the attachment piece 36, and the peripheral cap 92.

Such a structure makes it possible to accommodate even higher voltages by limiting the shear stresses at the level of each fastener 94.

In a variant, shown in FIG. 6, a ball joint is created between each end section 34 and the anchoring support 62, 64.

For this purpose, each head 40 is provided with a ball joint 130 intended to engage a fastener 94.

Compared to a pivot system, the presence of a ball joint connection between each end section 34 and the anchor support 62, 64 allows tile variations in the anchoring zone. The end sections 34 of the armor elements 29 introduced into the end piece 14 are therefore free to occupy a configuration as close as possible to that of the current lengths of the armor elements 29 present in the central section 12.

Only the axial displacement of the armor elements 29 is blocked. The assembly between each attachment piece 36 and the elongated portion 35 is also more efficient in fatigue, since it will be subjected to alternating pure voltage.

In another variant, a flexible filler material is disposed in the chamber 52, advantageously to protect the end portions 34 from corrosion.

The filling material allows displacements of the end sections 34 rotated about each axis C-C in the anchoring zone.

This filling material is for example a flexible polyurethane introduced in liquid form into the chamber 52, and solidifying in situ.

In another variant, each anchoring support 62, 64 is directly screwed onto the end vault 50.

Claims

1. - Tip (14) for connecting a flexible pipe (10) for conveying fluid, the flexible pipe (10) comprising at least one tubular sheath (20) and at least one layer (24, 25) of tensile armor disposed externally with respect to the tubular sheath (20), the armor layer (24, 25) comprising a plurality of filamentary armor elements (29), the tip (14) comprising:

a plurality of end sections (34) of each armor element (29),

- an end vault (50) and a cover (51) fixed on the end vault (50), the end vault (50) and the cover (51) delimiting between them a receiving chamber (52) end section;

at least one anchoring support (62, 64) of each armor layer (24, 25) fixedly mounted along an axis (Α-Α ') of the pipe (10) with respect to the end vault (50) and / or relative to the hood (51),

characterized in that each end portion (34) is anchored to the anchor support (62, 64) by a pivot connection or a ball joint.

2. - nozzle (14) according to claim 1, characterized in that the end sections (34) of the armor elements (29) of each layer of armor (24, 25) define a cylindrical envelope of substantially constant over the entire length of the tip (14),

3. - Tip (14) according to any one of claims 1 or 2, characterized in that the receiving chamber (52) is free of filler material embedding the end portions (34).

4. - nozzle (14) according to any one of the preceding claims, characterized in that the anchoring support (62, 64) comprises, for each end section (34), a connecting member (94) in radial projection, the end section (34) being mounted on the connecting member (94).

5. - nozzle (14) according to claim 4, characterized in that the anchoring support (62, 64) comprises a circumferential flange (90), and at least one yoke (92) projecting axially from the flange. circumferential (90), each connecting member (94) being mounted on the yoke (92).

6. - End piece (14) according to claim 4 or 5, characterized in that the anchoring support (62, 64) comprises a first inner yoke (92) and a second outer yoke (122) disposed around the first yoke internal member (92), each connecting member (94) being mounted on the first inner clevis (92) and on the second outer clevis (122).

7. - nozzle (14) according to any one of claims 4 to 6, characterized in that each end section (34) comprises an elongated portion (35) and a hooking part (36) reported transversely on the elongate portion (35), the attachment piece (36) being engaged on the connecting member (94).

8. - Tip (14) according to claim 7, characterized in that the attachment piece (36) comprises a base (39) fixed on the elongate portion (35) and a head (40) projecting axially beyond the free end of the elongate portion (35).

9. - End piece (14) according to any one of claims 7 to 8, characterized in that the maximum width of the attachment piece (36), taken perpendicularly to an axis (Β-Β ') of the elongated portion (35), is less than or equal to the maximum width of the elongate portion (35) along the length of the elongated portion (35) receiving the attachment piece (36).

10. - Tip (14) according to any one of claims 7 to 9, characterized in that the elongated portion (35) is flattened, the elongate portion (35) having a first face (37), and a second face ( 38) opposite the first face (37), the attachment piece (36) being attached to the first face (37), without being reported on the second face (38).

1 1. - End piece (14) according to any one of claims 4 to 10, characterized in that the connecting member (94) and / or the attachment piece (36) comprises a pin.

12. - tip (14) according to any one of claims 4 to 10, characterized in that the connecting member (94) and / or the attachment piece (36) comprises a ball joint (130).

13. - Tip (14) according to any one of the preceding claims, characterized in that it comprises a set (54) for producing a seal around the tubular sheath (20) offset axially in front of the or each anchor support (62, 64).

14. - Tip (14) according to any one of the preceding claims, characterized in that it comprises a plurality of end sections (34) of the armor elements (29) of a first layer of armor ( 24) defining a first cylindrical shell of substantially constant diameter along the entire length of the bit (14) and a plurality of end sections (34) of the armor members (29) of a second layer of armor ( 25) defining a second cylindrical envelope of substantially constant diameter over the entire length of the tip (14) and of diameter greater than the diameter of the first cylindrical envelope,

and in that the tip (14) comprises a first anchoring support (62) of the first layer of armor (24), fixedly mounted along an axis (Α-Α ') of the pipe (10) by to the end vault (50) and / or to the hood (51), each end portion (34) of an armor member (29) of the first armor layer being anchored to the first anchoring support (62) by a pivot connection or a ball joint,

the tip comprising a second anchoring support (64) of the second layer of armor (25) fixedly mounted along an axis (Α-Α ') of the pipe (10) with respect to the end vault ( 50) and / or with respect to the cover (51), each end section (34) of a weave element (29) of the second armor layer (25) being anchored to the second anchoring support (64) by a pivot connection or ball joint.

15. - Flexible pipe (10; 120; 130) fluid transport, characterized in that it comprises:

a tubular sheath (20);

at least one tensile armor layer (24, 25) disposed externally with respect to the tubular sheath (20), the traction armor layer (24, 25) comprising a plurality of armor elements (29); ) filiform,

- A tip (14) according to any one of the preceding claims, mounted at the end of the tubular sheath (20).

16. - pipe according to claim 15, characterized in that each layer of armor (24, 25) defines, in the central section (12) adjacent to the tip (14) an intermediate cylindrical envelope of substantially constant diameter, the end sections (34) of the armor elements (29) of each layer of armor (24, 25) defining a cylindrical envelope of diameter substantially equal to the diameter of the intermediate cylindrical envelope, over the entire length of the mouthpiece (14).