END PIECE OF A HOSE FOR TRANSPORTING FLUID, HOSE AND ASSOCIATED METHOD

Description

[0001] The present invention relates to a flexible fluid transport hose fitting according to the preamble of claim 1. EP3040593 describes a fitting of the aforementioned type. WO2019105926 and US6923477 describe other types of fittings.

[0002] The pipeline is in particular a flexible, unbonded pipeline intended for the transport of hydrocarbons across a body of water, such as an ocean, sea, lake or river.

[0003] Such flexible driving is for example carried out in accordance with the normative documents API 17J, 4th edition May 2014 and API RP 17B, 5th edition - May 2014 established by the American Petroleum Institute.

[0004] The pipe is generally formed from a series of concentric and superimposed layers. It is considered "unbonded" within the meaning of the present invention when at least one of the pipe layers is capable of moving longitudinally relative to the adjacent layers during pipe bending. In particular, an unbonded pipe is a pipe lacking bonding materials connecting the layers forming the pipe.

[0005] The pipeline is typically laid across a body of water, between a bottom assembly, designed to collect the extracted fluid from the bottom of the body of water, and a floating surface assembly designed to collect and distribute the fluid. The surface assembly can be a semi-submersible platform, an FPSO, or another floating assembly.

[0006] In a known manner, the pipe includes a polymer pressure sheath, intended to contain the fluid carried by the pipe, possibly an intermediate sheath, and an external sheath intended to protect the pipe externally.

[0007] The ends of the pipe have fittings for connection to the bottom assembly and the surface assembly.

[0008] The end region of each sheath is received in a pipe fitting, and is fitted in a watertight manner in the fitting.

[0009] To this end, a known solution for making a watertight connection is to crimp a metal ring around the outer face of the sheath so that the ring partially penetrates the thickness of the sheath wall.

[0010] The crimped ring is generally shaped like a hollow cone surrounding the sleeve, with this cone positioned coaxially with the sleeve. During crimping, a conical bearing surface machined into the body of the ferrule is pushed axially around this cone, this conical bearing surface also being coaxial with the sleeve to be crimped and with the cone.

[0011] During this crimping process, the cone is compressed radially relative to the sheath axis, its diameter decreases, and it undergoes plastic deformation as it partially penetrates the sheath. This crimping operation simultaneously ensures a metal-to-polymer seal between the cone and the sheath, and a metal-to-metal seal between the cone and the nozzle body.

[0012] This solution withstands very high internal pressures (over 1000 bar) across a wide temperature range (up to 130°C and above). It performs particularly well when the pressure inside the sleeve is greater than the pressure outside, as this pressure difference tends to increase the sleeve diameter. This, in turn, increases the contact pressure between the sleeve and the crimping ring, as well as between the crimping ring and the fitting body, thus strengthening the seal of the assembly.

[0013] In the case of a pressure sleeve, the internal pressure is generally much higher than the external pressure, which strengthens the seal, but the pressure gradient can sometimes be reversed, for example during a production shutdown followed by decompression.

[0014] When the pressure gradient is reversed, the opposite effect to that described above occurs. The contact pressures between the crimping ring and the sleeve are reduced, and the seal of the assembly is diminished. This can generate micro-leaks in certain cases.

[0015] In the case of the outer sheath, the problem is more critical because the pressure gradient is often constantly reversed, especially when the fitting is submerged at great depths. In this case, the hydrostatic pressure applied against the outer face of the outer sheath is significantly greater than the pressure within the pipe wall acting against the inner face of the outer sheath.

[0016] To overcome these problems, it is known for example from WO2019 / 137591 to add a sealing ring in addition to the crimped polymer ring between the end cap and the sheath whose sealing must be achieved.

[0017] In some cases, the annular joint may include an external radial reinforcement region located radially outside an elastomeric ring.

[0018] Such a solution is not entirely satisfactory. In certain circumstances, the contact pressure applied to the polymer sheath is not sufficient to maintain a seal. Furthermore, the solution presented in the aforementioned document applies only to the pressure sheath and is not necessarily suitable for intermediate or external sheaths that may be present within the flexible hose.

[0019] An object of the invention is therefore to provide a flexible fluid transport pipe fitting, in which the sealing is improved between a polymer sheath and the arch of the fitting, regardless of the differential pressure conditions applied to the pipe, and regardless of the type of sheath around which the sealing is achieved in the fitting.

[0020] For this purpose, the invention relates to a flexible fluid transport conduit tip according to claim 1.

[0021] The nozzle according to the invention may include one or more of the features of claims 2 to 12.

[0022] The invention also relates to a flexible conduit according to claim 13.

[0023] The invention also relates to a method of mounting a flexible pipe fitting according to claim 14 or 15.

[0024] The invention will be better understood upon reading the following description, given solely by way of example, and made with reference to the attached drawings, in which: [ Fig 1 ] There figure 1 is a partially exploded perspective view of a first flexible conduit according to the invention; [ Fig 2 ] There figure 2 is a cross-sectional view along a median axial plane of the relevant parts of the flexible hose end of the figure 1 illustrating an annular seal applied to the pressure sheath; [ Fig 3 ] There figure 3 is a view analogous to the figure 2 , in the case of an annular seal applied to an external sheath; [ Fig 4 ] There figure 4 is a view analogous to the figure 2 , in the case of an annular seal applied to an intermediate sheath; [ Fig 5 ] There figure 5 illustrates the operating principle of the annular joint of the figures 2 à 4 ; Fig 6 ] There figure 6 illustrates a variant of an annular seal that can be implemented in a nozzle according to the invention.

[0025] Throughout the following, the terms "outside" and "inside" are generally understood radially with respect to an AA' axis of the pipe, the term "outside" being understood as relatively further radially from the AA' axis and the term "inside" being understood as relatively closer radially to the AA' axis of the pipe.

[0026] The terms "front" and "rear" are understood axially with respect to an axis AA' of the pipe, the term "front" being understood as being relatively farther from the midpoint of the pipe and closer to one of its ends, the term "rear" being understood as being relatively closer to the midpoint of the pipe and farther from one of its ends. The midpoint of the pipe is the point on the pipe located equidistant from its two ends.

[0027] A first flexible conduit 10 according to the invention is partially illustrated by the figures 1 à 3 .

[0028] The flexible conduit 10 includes a central section 12, partly illustrated on the figure 1 It comprises, at each of the axial ends of the central section 12, an end fitting 14 (not visible on the Figure 1 ) whose relevant parts are represented on the figures 2 And 3 .

[0029] With reference to the figure 1 The conduit 10 defines a central passage 16 for the circulation of a fluid, advantageously a petroleum fluid. The central passage 16 extends along a central axis A-A', between the upstream and downstream ends of the conduit 10. It opens through the end fittings 14.

[0030] The flexible pipe 10 is intended to be laid across a body of water (not shown) in a fluid handling facility, particularly for hydrocarbons.

[0031] The body of water is, for example, a sea, a lake, or an ocean. The depth of the body of water at the location of the fluid processing facility is, for example, between 500 m and 3000 m.

[0032] The fluid handling installation comprises a surface assembly, including a floating assembly, and a bottom assembly (not shown), which are generally connected to each other by the flexible pipe 10.

[0033] Flexible driving 10 is preferably "unbonded" driving (designated by the English term "unbonded").

[0034] At least two adjacent layers of the flexible pipe 10 are free to move longitudinally relative to each other during pipe bending. Advantageously, all layers of the flexible pipe are free to move relative to each other. Such a pipe is described, for example, in the standards documents published by the American Petroleum Institute (API), API 17J, 4th edition - May 2014 and API RP 17B, 5th edition - May 2014.

[0035] As illustrated by the figure 1 , the conduit 10 delimits a plurality of concentric layers around the axis A-A', which extend continuously along the central section 12 to the end fittings 14 located at the ends of the conduit.

[0036] According to the invention, the conduit 10 comprises at least a first polymer sheath advantageously constituting a pressure sheath 20.

[0037] The conduit 10 also includes layers of tensile armor 24, 25 arranged externally with respect to the pressure sheath 20.

[0038] Advantageously, and depending on the desired use, the pipe 10 further comprises an inner carcass 26 arranged inside the pressure sheath 20, a pressure arch 28 interposed between the pressure sheath 20, possibly a fret, the layer or layers of tensile armor 24, 25 and an outer sheath 30, intended for the protection of the pipe 10.

[0039] As is known, the pressure sheath 20 is intended to hermetically contain 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 PA11 or PA12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0040] Alternatively, the tubular sheath 20 is formed from a high-performance polymer such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), PAI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCPs (liquid crystal polymers), PPA (polyphthalamide) and / or mixtures thereof, or in a mixture with PTFE (polytetrafluoroethylene) or PFPE (perfluoropolyether).

[0041] The thickness of the pressure sheath 20 is, for example, between 5 mm and 20 mm.

[0042] As seen on the figure 2 , the pressure sheath 20 has an end region 27 disposed in the nozzle 14.

[0043] The frame 26, when present, is formed, for example, of a profiled metal strip, wound in a spiral. The turns of the strip are advantageously stapled together, which makes it possible to absorb radial crushing forces.

[0044] In this example, the carcass 26 is arranged inside the pressure sheath 20. The flexible pipe 10 is then designated by the English term "rough bore" because of the geometry of the carcass 26.

[0045] As an alternative (not shown), the flexible pipe 10 is devoid of an internal casing 26, it is then designated by the English term "smooth bore".

[0046] The helical winding of the profiled metal strip forming the carcass 26 has a short pitch, that is to say it has a helix angle around the axis AA' of the pipe with an absolute value close to 90°, typically between 75° and 90°.

[0047] In this example, the pressure arch 28 is designed to resist the radial forces related to the pressure inside the pressure duct 20. It is, for example, formed from a profiled metal wire wound helically around the duct 20. The profiled wire generally has a complex geometry, notably in the shape of a Z, T, U, K, X, or I, which allows the turns of the pressure arch 28 to be interlocked. Interlocking the turns of the pressure arch 28 makes it possible to control the spacing between adjacent turns in order, in particular, to prevent creep of the pressure duct 20 through the pressure arch 28 under the effect of the pressure inside the pipe 10.

[0048] The pressure vault 28 is wound in a short-pitch helix around the pressure sheath 20, i.e. with a helix angle around the axis AA' of the pipe of absolute value close to 90°, typically between 75° and 90°.

[0049] Possibly, a fret not shown on the figure 1 surrounds the pressure arch 28. The fret is also intended to take up the radial forces related to the pressure, in addition to the pressure arch 28. The fret is for example formed of a metal wire of substantially rectangular cross section wound in a short-pitch helix around the pressure arch sheath 28. The turns of the fret are not stapled together.

[0050] The flexible conduit 10 according to the invention comprises at least one layer of armor 24, 25 formed from a helical winding of at least one elongated armor element 29.

[0051] In the example shown on the figure 1 , the flexible conduit 10 comprises a plurality of armor layers 24, 25, including a first internal armor layer 24, applied to the pressure arch 28 (or to the sheath 20 when the arch 28 is absent) and a second external armor layer 25 around which the outer sheath 30 is arranged.

[0052] Each layer of armor 24, 25 has longitudinal armor elements 29 wrapped at long pitch around the AA' axis of the conduit.

[0053] By "long pitch winding", we mean that the absolute value of the helix angle is less than 60°, and is typically between 25° and 55°.

[0054] 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 + α, α being between 25° and 55°, the winding angle of the armor elements 29 of the second layer of armor 25 arranged in contact with the first layer of armor 24 is for example - α, with α between 25° and 55°.

[0055] The armor elements 29 are for example formed by metal wires, or by composite ribbons, in particular composite ribbons reinforced by carbon fibers.

[0056] As seen on the figure 2 , the armor elements 29 each have an end section 32 introduced into the tip 14. The end section 32 extends to a free end disposed in the tip 14. It advantageously has a helical or pseudo-helical trajectory with axis AA' in the tip 14.

[0057] The flexible conduit 10 advantageously includes wear-resistant layers interposed on the one hand between the pressure arch 28 and the first layer of internal reinforcement 24, and on the other hand between the two layers of reinforcement 24, 25.

[0058] Each anti-wear layer is formed by helically winding a polymer strip typically between 2 mm and 4 mm thick. The function of each anti-wear layer is to reduce friction between the metal wires or wear between the composite strips between which it is sandwiched.

[0059] The outer sheath 30 is intended to form a liquid-tight barrier from the outside of the flexible pipe to the inside. It is advantageously made of polymer material, in particular based on a polyolefin, such as polyethylene, based on a polyamide, such as PA11 or PA12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0060] Alternatively, the outer sheath 30 is formed from a high-performance polymer such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), PAI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCPs (liquid crystal polymers), PPA (polyphthalamide) and / or mixtures thereof, or in a mixture with PTFE (polytetrafluoroethylene) or PFPE (perfluoropolyether).

[0061] The thickness of the outer sheath 30 is, for example, between 5 mm and 15 mm.

[0062] As illustrated by the figure 2 Each end piece 14 comprises, in addition to the end region 27 of the pressure sheath 20 and the end sections 32 of the armor elements 29, an end arch 50 and an external connecting hood 51 projecting axially rearward from the end arch 50. The hood 51 delimits, with the end arch 50, a chamber 52 for receiving the end sections 32 of the armor elements 29.

[0063] The nozzle 14 also includes a front sealing assembly 54 around the pressure sheath 20, and a rear sealing assembly 56 around the outer sheath 30 (visible only the figure 3 (which will be described below).

[0064] In this example, the tip 14 also includes a solid filler material 58, such as a thermosetting polymer resin of the epoxy or araldite type. The solid filler material is arranged in the chamber 52 around the end sections 32.

[0065] In this example, the end arch 50 is intended to connect the pipe 10 to another connection fitting 14 or to terminal equipment, advantageously via an end flange (not shown).

[0066] The end arch 50 has a central bore 62 intended to receive the end region 27 of the pressure sheath 20 and to allow the flow of the fluid circulating through the central passage 16 to the outside of the conduit 10.

[0067] In the example of the figure 2 , the end arch 50 internally defines a rear face 64 delimiting a convergent surface 66 for support for a crimping ring.

[0068] The hood 51 has a tubular peripheral wall 70 extending around the axis A-A'. The peripheral wall 70 has a front edge (not visible) fixed to the end arch 50, radially offset from the armor layers 24, 25, and a rear edge 74 (visible only on the figure 3 ) extending axially backwards beyond the end vault 50.

[0069] The hood 51 delimits the chamber 52 radially outwards.

[0070] The front sealing assembly 54 is advantageously located at the front of the end cap 14, in contact with the end arch 50, being axially offset forward relative to the rear sealing assembly 56.

[0071] It includes a front crimping ring 76, intended to engage with the pressure sheath 20, and a front clamping flange 78 for the front crimping ring 76.

[0072] In the example shown on the figure 2 , in which the conduit 10 includes a pressure arch 28, the front sealing assembly 54 further includes a flange 80 for stopping the pressure arch 28 and advantageously a spacer 79.

[0073] According to the invention, the front sealing assembly 54 further comprises an activatable annular sealing seal 81, disposed to rest on the pressure sheath 20, the annular seal 81 being received in an annular housing 82 of the nozzle 14.

[0074] The front clamping flange 78 is designed to be screwed onto the rear face 64 of the end arch 50.

[0075] The front crimping ring 76 is adapted to be moved forward along the axis AA' by sliding on the convergent surface 66, being pushed forward by the front clamping flange 78, when mounted on the end arch 50. The front crimping ring 76 has a front bulge 84 adapted to be driven radially into the pressure sleeve 20 by wedge effect when the front crimping ring 76 is moved on the convergent surface 66.

[0076] As seen on the figures 2 And 5 The housing 82 is defined at the front by an annular shoulder formed in the flange 78, opposite the end region 27 of the pressure sleeve 20 located in the fitting. The shoulder defines a transverse surface 90 for activating the annular seal 81, located in front of the annular seal 81, and an inner circumferential face 91 extending around and opposite the sleeve 20.

[0077] The housing 82 is closed at the rear by a transverse thrust surface 92 defined at the front of the spacer 79. Thus, the transverse thrust surface 92 is able to be brought close to the transverse activation surface 90 to compress the annular joint 81. The spacer 79 here forms an additional part for activating the compression of the annular joint 81, attached to the end arch 50.

[0078] With reference to the figure 5 , the end arch 50 and the front flange 78 advantageously define at least one channel 94 for transmitting external pressure to the flexible conduit 10 towards the housing 82.

[0079] The channel 94 opens on one side, through the transverse activation surface 90, and on the other side, into the chamber 52. Thus, the external pressure which may be applied in the chamber 52 is able to be transmitted to the intermediate space located between the transverse activation surface 90 and the annular seal 81 through the channel 94.

[0080] As illustrated by the figures 2 And 5The activatable annular seal 81 comprises a deformable central region 100, intended to be interposed in a watertight manner between the sheath 20 and the inner face 91 delimiting the housing 82, a first rigidified front peripheral region 102, disposed on one side of the central region 100 and a second rigidified rear peripheral region 104, disposed on the other side of the central region 100. The first peripheral region 102 and the second peripheral region 104 are movable towards each other to compress the central region 100 and cause the radial expansion of the central region 100 towards the sheath 20.

[0081] The central region 100 is preferably formed of a deformable material, such as an elastomer. The elastomer is for example a fluoroelastomer, such as fluorocarbon (FKM) made from vinylidene fluoride (VDF or VF2) chosen for example from a copolymer of hexafluoropolyropylene (HFP) and VF2, a terpolymer of tetrafluoroethylene (or "TFE"), HFP, and VF2, a terpolymer of TFE, perfluoromethyl vinyl ether (or "PMVE") and VF2), a terpolymer of TFE, propylene and VF2 or a pentapolymer of TFE, HFP, ethylene, PMVE and VF2.

[0082] Alternatively, the fluoroelastomer is a perfluoroelastomer (FFKM), for example, a terpolymer of TFE, PMVE, and a third monomer that enables crosslinking. As another alternative, the fluoroelastomer is a fluorosilicone (FVMQ) or a propylene tetrafluoroethylene (FEPM) copolymer.

[0083] As an alternative or in addition, the central region 100 is made of a nitrile rubber, in particular a butadiene acrylonitrile copolymer (NBR) and / or a hydrogenated butadiene acrylonitrile copolymer (HNBR).

[0084] In this example, the central region 100 has a trapezoidal cross-section tapering from the outside in between the inner face 91 of the housing 82 and the pressure duct 20, the cross-section being taken in each median axial plane passing through the axis A-A'.

[0085] With reference to the figure 5 , the central region 100 comprises a first inclined front surface 106, a second inclined rear surface 108, and an outer circumferential surface 110 connecting the first inclined surfaces 106 and 108.

[0086] It also includes an internal 112 point, designed to be applied to the 20 sheath.

[0087] The first surface 106 is inclined backwards, moving from front to back. It converges towards the inner point 112. The second inclined surface 108 is inclined forwards, moving from back to front. It also converges towards the point 112.

[0088] Thus, the width of the central region 100, taken along the axis AA' at the level of the inner tip 112 is less than the width of the central region 100, taken along the axis AA' at the level of the outer circumferential surface 110.

[0089] Preferably, the hardness of the material forming the central region 100 is less than 100 Shore A, specifically between 60 Shore A and 90 Shore A

[0090] The central region 100 is thus more deformable than the peripheral regions 102, 104, allowing its radial expansion towards the sheath 20 and its compression on the sheath 20.

[0091] The first peripheral front region 102 has a wedge-shaped section taken in each median axial plane passing through the axis AA. It thus has a first front lateral surface 114, perpendicular to the axis A-A', intended to extend opposite the transverse activation surface 90 and a first complementary inclined surface 116, located at the rear, applied to the first front inclined surface 106 of the central region 100.

[0092] The angle α of inclination of the first inclined surface before 106, and of the first complementary inclined surface 116 is for example between 40° and 80° with respect to the axis A-A'.

[0093] The first front lateral surface 114 is advantageously extended towards the sheath 20 by a front chamfer 114A located opposite the sheath 20.

[0094] The second peripheral region 104 has a second rear lateral surface 118, perpendicular to the axis A-A', intended to extend in relation to the transverse thrust surface 92, and a second complementary inclined surface 120, located at the front, applied against the second rear inclined surface 108 of the central region 100.

[0095] The angle β of inclination of the second rear inclined surface 108 and the second complementary inclined surface 116 with respect to the axis AA' is for example between 40° and 80°. The angle β is preferably equal to the angle α.

[0096] The second rear lateral surface 118 is advantageously extended towards the sheath 20 by a rear chamfer 118A located opposite the sheath 20.

[0097] The first front peripheral region 102 and the second rear peripheral region 104 are each formed of a material more rigid than the central region, for example a thermoplastic polymer.

[0098] For example, it is made of PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), or a fluorinated polymer, such as polytetrafluoroethylene (PTFE).

[0099] Preferably, the hardness of the material forming each peripheral region 102, 104 is greater than that of the central region 100. This hardness is for example greater than 65 shore D.

[0100] The peripheral region 102, 104 is for example made of PTFE or PEEK.

[0101] Thus, under the effect of a rearward thrust force applied to the first peripheral region 102 at the level of the first front lateral surface 114 and / or a forward thrust force applied to the second peripheral region 104 at the level of the second lateral surface 118, the first peripheral region 102 and the second peripheral region 104 are likely to move closer together to compress the central region 100 between the complementary inclined surfaces 116, 120. This causes the radial expansion of the inner tip 112 towards the sheath 20, and the application of the circumferential surface 110 to the inner face 91 of the housing 82.

[0102] The annular seal 81 thus passes from a rest configuration to a first active sealing configuration, in compression, in which it creates a seal between the sheath 20 and the front clamping flange 78 when the end piece 14 is mounted.

[0103] This seal is reinforced when the pressure increases in the annular space between the outer sheath 30 and the pressure sheath 20, tending to push the second peripheral region 104 towards the first peripheral region 102.

[0104] In a well-known way, as illustrated by the figure 3 , the rear sealing assembly 56 includes a rear crimping ring 130, a rear clamping flange 132 for the rear crimping ring 130, and a rear compression flange 134.

[0105] The rear sealing assembly 56 advantageously includes an intermediate support cannula 128 interposed between the outer sheath 30 and the armor layers 24, 25, the outer sheath 30 resting on the intermediate cannula 128.

[0106] Advantageously, in the implementation of the figure 3 , the rear sealing assembly 56 further includes an activatable external annular seal 81 disposed in an external housing 82.

[0107] The rear crimping ring 130 is interposed between a rear inclined surface 136 of the hood 51 and the outer sheath 30. It has a front bulge 137 designed to radially penetrate the outer sheath 30 by wedge effect when the rear crimping ring 130 moves on the surface 136.

[0108] The rear clamping flange 132 is fixed to the rear edge 74 of the hood 51. It pushes forward the rear crimping ring 130 to move it radially towards the axis AA' and crimp the outer sheath 30.

[0109] The outer sheath 30 rests on the intermediate cannula 128. It is axially wedged at the rear of the fixing assembly 56.

[0110] The external housing 82 of the rear sealing assembly 56 is of similar structure to the housing 82 defined for the front sealing assembly 54.

[0111] It is defined by an annular shoulder formed in the rear clamping flange 132, opposite an end region of the outer sheath 30 disposed in the end cap 14. As before, the shoulder defines a first transverse surface 90 for activation of the annular seal 81, disposed in front of the annular seal 81 and an inner circumferential face 91 extending around and opposite the sheath 30.

[0112] The housing 82 is closed at the rear by a transverse thrust surface 92 defined at the front of the rear compression flange 134. Thus, the transverse thrust surface 92 is brought close to the transverse activation surface 90 to compress the annular seal 81 as described above. The rear compression flange 134 therefore forms an additional component for activating the compression of the annular seal 81, attached to the cover 51.

[0113] The annular seal 81 of the rear sealing assembly 56 is of identical structure to the annular seal 81 of the front sealing assembly 54.

[0114] The assembly of tip 14 will now be described.

[0115] Initially, the end vault 50 is placed around the end region 27 of the pressure sheath 20, the armor layers 24, 25 having been moved radially outwards.

[0116] The crimping ring 76 is placed between the pressure sleeve 20 and the convergent surface 66 of the end arch 50.

[0117] The clamping flange 78 is then put in place to be tightened against the rear face 64 of the end arch 50. Next, the activatable annular seal 81 in its rest configuration is put in the housing 82. The housing 82 is then closed by the insertion of the spacer 79.

[0118] Then, the clamping flange 78 and the spacer 79 are clamped against the end arch 50, causing the displacement of the thrust transverse surface 92 towards the activation transverse surface 90, and the compression of the central region 100 of the activatable joint between the peripheral regions 102, 104. This causes the application and compression of the inner tip 112 against the sheath 20.

[0119] Similarly, the cannula 128 is inserted between the armor elements 24, 25 and the outer sheath 30.

[0120] The cover 51 is placed around the pipe 10 so as to form, with the end arch 50, the chamber 52. The rear crimping ring 130 is then placed between the cover 51 and the outer sheath 30. The rear clamping flange 132 is then put in place, to delimit the external housing 82, and then the annular seal 81 is inserted into the external housing 82.

[0121] Next, the compression flange 134 is mounted to the rear of the clamping flange 132. The rear clamping flange 132 is then clamped against the rear edge 74 of the hood 51. The compression flange 134 moves closer to the rear clamping flange 132, causing compression of the central region 100 of the external annular seal 81 between the first peripheral region 102 and the second peripheral region 104, and the application of the inner tip 112 against the outer sheath 30.

[0122] Advantageously, during assembly, the sealing provided by the annular seal 81 can be tested by introducing pressure through the channel 94, following an adaptation of the method described in US 6 923 477, in order to ensure that in the event of failure of the seal between the front crimping ring 76 and the pressure sleeve 20, the annular seal 81 is capable of ensuring the seal between the end arch 50 and the pressure sleeve 20.

[0123] In use, during a possible overpressure outside the flexible hose 10 relative to the inside of the flexible hose 10, even if the integrity of the crimping of the front crimping ring 76 relative to the end region 27 of the pressure sleeve 20 is lacking, the annular seal 81 maintains the seal around the pressure sleeve 20. This seal is even reinforced, since the overpressure transmitted to the annular seal 81 through the channel 94 causes additional compression of the central region 100 beyond the primary compression resulting from the mounting of the annular seal 81.

[0124] In the variant shown on the figure 4 The flexible conduit 10 further includes an intermediate sheath 150 arranged in the annular space between the pressure sheath 20 and the outer sheath 30. The nozzle further includes an intermediate cannula 152 on which the intermediate sheath 150 rests.

[0125] The intermediate cannula 152 is advantageously provided with an internal gas circulation passage.

[0126] The end cap 14 includes an intermediate sealing assembly 153 comprising a first intermediate housing flange 154, mounted on the end arch 50 at the rear face 64 and a second intermediate compression flange 156 mounted on the first intermediate flange 154. The intermediate sealing assembly 153 further includes an intermediate crimping ring 158 for the intermediate sleeve 150 and a clamping flange 159 mounted at the rear of the flanges 154, 156.

[0127] Advantageously, in the implementation of the figure 4 , the intermediate sealing assembly 153 further includes an activatable intermediate annular seal 81 disposed in an intermediate housing 82 provided between the first intermediate flange 154 and the second intermediate flange 156.

[0128] The intermediate crimping ring 158 has two opposing bulges, a front bulge 160 and a rear bulge 162, each intended to fit into the intermediate sleeve 150.

[0129] The intermediate crimping ring 158 is interposed at the front, between a rear inclined surface 164 of the intermediate crimping flange 156 and the intermediate sheath 150 and at the rear, between a front inclined surface 166 of the intermediate clamping flange 159 and the intermediate sheath 150.

[0130] This causes the front bulge 160 and the rear bulge 162 to be crimped into the intermediate sheath 150.

[0131] The intermediate housing flange 154, the intermediate crimping flange 156 and the intermediate clamping flange 159 are applied one on top of the other and are jointly fixed to the rear face 64 of the end arch 50.

[0132] The intermediate sheath 150 rests on the intermediate cannula 152.

[0133] The intermediate housing 82 of the intermediate sealing assembly 153 is of similar structure to the housing 82 defined for the front sealing assembly 54. It is located in front of the intermediate crimping ring 158.

[0134] The intermediate housing 82 is defined by an annular shoulder formed in the intermediate housing flange 154, opposite an end region of the intermediate sheath 150 disposed in the end cap 14. As before, the shoulder defines a first transverse surface 90 for activation of the annular seal 81, disposed in front of the annular seal 81 and an inner circumferential face 91 extending around and opposite the intermediate sheath 150.

[0135] The housing 82 is closed at the rear by a transverse thrust surface 92 defined at the front of the intermediate compression flange 156. Thus, the transverse thrust surface 92 is suitable for being brought close to the transverse activation surface 90 to compress the annular seal 81, as described above.

[0136] The intermediate compression flange 156 thus forms an additional part for activating the compression of the annular joint 81, attached to the end arch 50.

[0137] The annular seal 81 of the intermediate sealing assembly 153 is of identical structure to the annular seal 81 of the front sealing assembly 54. It ensures an effective seal between the intermediate sleeve 150 and the intermediate flanges 154, 156, even if the seal is not maintained by the intermediate crimping ring 158.

[0138] In a variant applicable to each of the embodiments represented on the figures 2 à 4 , the first peripheral region 102 and the second peripheral region 104 are each formed by a stiffened ring 180 embedded in the deformable material forming the central region 100. The stiffened ring 180 is for example a spring wire, a rod or a rope.

[0139] The stiffened ring 180 is for example formed of metal, a metal alloy or a material more rigid than the central region 100, for example a thermoplastic polymer, in particular of fibers.

[0140] The metal alloy is, for example, phosphor bronze. The fibers are, for example, synthetic artificial fibers made of polyester.

[0141] The more rigid material is, for example, made of PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), or a fluoropolymer, such as polytetrafluoroethylene (PTFE). The thermoplastic polymer can be reinforced with fibers such as carbon fibers.

[0142] Alternatively, the stiffened ring 180 is made of a combination of metal and thermoplastic polymer, for example arranged coaxially. In particular, the stiffened ring 180 comprises coaxial coil springs, advantageously an internal coil spring made of metal, in particular stainless steel, and an external spring made of polymer, in particular PEEK (polyetheretherketone).

[0143] Alternatively, as illustrated on the figure 6 , the stiffened ring 180 is a combination of a spring wire 180A and a rod 180B, the rod 180B being arranged inside the spring wire 180A.

[0144] In this example, the stiffened ring 180 is positioned near an inner surface of the annular joint 81 intended to apply to the sheath 20, 30, 150 on either side of the tip 112. The tip 112 is protruding at rest. It has a rounded contour.

[0145] The operation of the annular joint 81 described on the figure 6 is also similar to that described on the figure 5 .

Claims

1. An end-fitting (14) of a flexible pipe (10) for transporting a fluid, comprising: - at least one end region of a polymer sheath (20; 30; 150) of the flexible pipe (10); - end sections of armor elements (29) of the flexible pipe (10) arranged around or in the end region of the polymer sheath (20; 30; 150); - an end vault (50) defining a central bore for letting the fluid flow, extending along a central axis (A-A'); - a cover (51) defining, along with the end vault (50), a chamber (52) for receiving the end sections of armor elements (29); - an annular seal (81), arranged in contact with the polymer sheath (20; 30; 150) away from the crimping ring (76; 130; 158); the annular seal (81) including a central annular region (100) deformable radially toward the polymer sheath (20; 30; 150), characterized in that the annular seal (81) includes two stiffened annular peripheral regions (102, 104), more rigid than the central region (100), located on either side of the central region (100) along the central axis (A-A'), the peripheral annular regions (102, 104) being movable toward each other to activate the radial deformation of the central region (100) toward the polymer sheath (20; 30; 150) from a rest configuration to an active sealing configuration around the polymer sheath (20; 30; 150); the end-fitting comprising at least one sealing assembly (54; 56; 153) comprising at least one crimping ring (76; 130; 158), the crimping ring (76; 130; 158) comprising at least one bulge (84, 160, 162) radially inserted into the polymer sheath (20; 30; 150).

2. The end-fitting (14) according to claim 1, wherein at least in the active position, the central region (100) defines a radial tip (112) protruding toward the polymer sheath (20; 30; 150) beyond each peripheral annular region (102, 104).

3. The end-fitting (14) according to claim 2, wherein in the rest configuration, the central region (100) has the radial tip (112).

4. The end-fitting (14) according to one of the preceding claims, wherein the central region (100) is made of elastomer, in particular of a fluoroelastomer such as FKM, FFKM or FVMQ, or of a nitrile elastomer such as NBR or HNBR, each peripheral region (102, 104) being made of metal, or of a polymer that is more rigid than the elastomer, in particular based on PEK, PEEK, PEEKK, PEKK, PEKEKK, or containing a fluoropolymer, such as polyethylene tetrafluoride (PTFE).

5. The end-fitting (14) according to any of the preceding claims, defining a housing (82) for receiving the annular seal (81), the housing (82) being delimited by a transverse activation surface (90) of the annular seal (81), located on the end vault (50) or on a part fastened with respect to the end vault (50), the transverse activation surface (90) extending opposite the first peripheral region (102), the housing (82) being also delimited by a transverse push surface (92) of the annular seal (81), located opposite the transverse activation surface (90), on an additional compression activation part of the annular seal (81), the transverse push surface (92) extending opposite the second peripheral region (102), the transverse activation surface (90) and the transverse push surface (92) being movable relative to each other at least during the fitting of the-end-fitting (14) so as to switch the annular seal (81) from the rest configuration thereof to the active configuration thereof.

6. The end-fitting (14) according to claim 5, wherein the additional part is fastened onto the crimping ring (76; 130; 158).

7. The end-fitting (14) according to claim 5 or 6, defining a channel (94) for transmitting an external pressure to the flexible pipe (10), opening out into the housing (82) between the transverse activation surface (90) and the first peripheral region (102).

8. The end-fitting (14) according to any of the preceding claims, wherein the first peripheral region (102) and / or the second peripheral region (104) are mounted on surfaces (106, 108) of the central region (100).

9. The end-fitting (14) according to claim 8, wherein the central region (100) has a first inclined surface (106) at a non-zero angle with respect to a plane perpendicular to the central axis (A-A'), the first peripheral region (102) having a first supplementary inclined surface (116), mounted onto the first inclined surface (106), the inclination of the first inclined surface (106) being directed toward the second peripheral region (104) when moving radially towards the central axis (A-A') on the first inclined surface (106).

10. The end-fitting (14) according to claim 9, wherein the central region (100) has a second inclined surface (108) at a non-zero angle with respect to a plane perpendicular to the central axis (A-A'), the second inclined surface (108) being located opposed to the first inclined surface (106) along the central axis (A-A'), the second peripheral region (104) having a supplementary second inclined surface (120) mounted onto the second inclined surface (108), the central region (100) advantageously having a trapezoidal section.

11. The end-fitting (14) according to any of claims 1 to 7, wherein the first peripheral region (102) and the second peripheral region (104) each have a continuous or discontinuous annular member (180) embedded in the material forming the central region (100).

12. The end-fitting (14) according to any of the preceding claims, wherein the end region of the sheath (20; 30; 150) is an end region of a pressure sheath (20) of the flexible pipe (10) defining an internal passage for letting flow a fluid, an end region of an outer sheath (30) of the flexible pipe (10) defining an outer surface of the flexible pipe (10) and / or an end region of an intermediate sheath (150) located in an annular space between the pressure sheath (20) and the outer sheath (30).

13. A flexible pipe (10), comprising a central section (12) including at least one polymer sheath (20; 30; 150) and armor elements (29) arranged around or inside the polymer sheath (20; 30; 150), the flexible pipe (10) comprising at least one end-fitting (14) according to any of the preceding claims, mounted at one end of the central section (12).

14. A method of assembly of an end-fitting (14) of a flexible pipe (10), including the following steps: - providing an end region of a polymer sheath (20; 30; 150) of the flexible pipe (10) and end sections of armor elements (29) of the flexible pipe (10) arranged around or in the end region of the polymer sheath (20; 30; 150); - fitting an end vault (50) defining a central bore for the letting the fluid flow along a central axis (A-A'), and a cover (51) defining, along with the end vault (50), a chamber (52) for receiving the end sections of armor elements (29); - assembling at least one sealing assembly (54; 56; 153) comprising at least one crimping ring (76; 130; 158) comprising at least one bulge (84, 160, 162) inserted radially into the polymer sheath (20; 30; 150); - placing an annular seal (81) in contact with the polymer sheath (20; 30; 150) away from the crimping ring (76; 130; 158); characterized in that the annular seal (81) includes a central annular region (100) deformable radially toward the polymer sheath (20; 30; 150), and two stiffened annular peripheral regions (102, 104), more rigid than the central region (100), located axially on opposite sides of the central region (100), the method comprising moving the peripheral annular regions (102, 104) toward each other to activate a radial deformation of the central region (100) toward the polymer sheath (20; 30; 150) from a rest configuration to an active sealing configuration around the polymer sheath (20; 30; 150).

15. The method according to claim 14, wherein the end-fitting (14) defines a housing (82) for receiving the annular seal (81), the housing (82) being delimited by a transverse activation surface (90) of the annular seal (81), located on the end vault (50) or on a part fastened with respect to the end vault (50), the transverse activation surface (90) extending opposite the first peripheral region (102), the housing being also delimited by a transverse push surface (92) of the annular seal (81), located opposite the transverse activation surface (90), on an additional compression activation part of the annular seal (81), extending opposite the second peripheral region (104), the movement of the peripheral annular regions (102, 104) toward each other comprising the relative movement of the activation transverse surface (90) and the push transverse surface (92) relative to each other, so as to switch the annular seal (81) from the rest configuration to the active configuration thereof, the method optionally comprising the transmission of an external pressure to the flexible pipe (10) as far as a gap between the activation transverse surface (90) and the first peripheral region (102) to bring even closer the first peripheral region (102) to the second peripheral region (104).