End fitting for a flexible fluid transport pipe, provided with a plug that is at least partially permeable to gas, and associated flexible pipe

Abstract

The invention relates to an end fitting (14) comprising: - an end region of a polymer sheath (30) of a flexible pipe (10); end segments (32) of armour elements (29) disposed at least partially inside the end region of the polymer sheath (30); an end vault (50) defining a central fluid flow bore (62) extending along a central axis (A-A'); a cap (51) defining, together with the end vault (50), a chamber (52) for receiving end segments (32) of the armour elements (29); and a rear sealing assembly (56) around the polymer sheath (30). According to the invention, at least the cap (51) and / or the rear sealing assembly (56) and / or the end vault (50) define(s) at least one region for venting gas from the end fitting (14), which is impermeable to liquid water but permeable to gas.

Description

[0001] DESCRIPTION

[0002] TITLE: Flexible fluid transport hose end fitting equipped with a cap at least partially permeable to gas, and associated flexible hose

[0003] The present invention relates to a flexible fluid transport conduit fitting, comprising:

[0004] - an end region of a polymer sheath of the flexible pipe;

[0005] - end sections of flexible pipe armor elements, arranged at least partly inside the end region of the polymer sheath;

[0006] - an end arch, defining a central fluid circulation bore extending along a central axis;

[0007] - a hood defining with the end vault, a receiving chamber for the end sections of the armor elements;

[0008] - a rear sealing assembly around the polymer sheath.

[0009] The flexible pipeline is in particular a flexible pipeline of the unbonded type intended for the transport of hydrocarbons across a body of water, such as an ocean, a sea, a lake or a river.

[0010] Such flexible driving is, for example, carried out according to the API 17J, 5 normative documents e May 2024 edition and API RP 17B, 6th edition - May 2024 established by the American Petroleum Institute.

[0011] A flexible 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 adjacent layers during bending or tensioning of the pipe. In particular, an unbonded pipe is a pipe lacking bonding materials connecting the layers forming the pipe.

[0012] The flexible 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.

[0013] In a typical flexible pipe, a flexible hose consists of a polymer pressure sheath or an internal composite material structure designed to contain the fluid being transported, and an external sheath designed to protect the hose externally. In so-called "hybrid" flexible hoses, the metal casing, pressure sheath, and possibly the pressure arch of the flexible hose are replaced by an internal composite material structure, also known as a thermoplastic composite hose (TPH).

[0014] The outer protective sheath and the inner sheath define an annular space between them, which generally receives at least one layer of metallic reinforcement.

[0015] The metallic reinforcement layer includes, for example, a pressure arch formed by winding and stapling a profiled metallic wire ("interlocked") around the pressure sheath. The profile is stapled in such a way as to limit creep of the pressure sheath under the effect of internal pressure.

[0016] The metallic reinforcement layer also includes layers of tensile armor formed by sheets of metallic wires arranged around the pressure arch, in the annular space, to ensure good tensile strength.

[0017] The fluid transported by this type of pipeline is, in particular, a mixture of hydrocarbons which may contain a high content of corrosive gases, such as carbon dioxide (CO2) and / or hydrogen sulfide (H2S).

[0018] The annular space containing the pressure vault and the tensile reinforcement layers therefore receives acidic gases from the transported fluids, which diffuse through the inner liner both in the central section of the pipeline and in the end cap. The partial pressure of these acidic gases within the annular space is sometimes relatively high.

[0019] In addition, the annular space may contain water, which may originate from water contained in transported hydrocarbons that have migrated through the inner sheath into the annular space, or from the body of water in the event of a tear in the outer sheath.

[0020] Corrosive gases and water that have diffused through the central section can then migrate to the ends of the pipe in the fittings intended for connection to the bottom assembly and the surface assembly.

[0021] In the central section of the pipeline, corrosive gases are likely to diffuse through the outer sheath to escape from the pipeline.

[0022] However, corrosive gases that have diffused through the inner sheath, directly into the end piece or that have possibly risen to the pipe ends are trapped in the receiving chamber which receives the end sections of the armor elements.

[0023] Within this chamber, the steel cap of the nozzle forms a metallic barrier that is completely impermeable to the passage of gases, which is very different from the central section of the flexible hose in which the outer sheath exhibits gas permeability.

[0024] The amount of corrosive gases accumulating in the chamber, particularly carbon dioxide, can therefore be significant. This phenomenon is further exacerbated by the possible presence of an epoxy filler material in the chamber, which further reduces gas diffusion.

[0025] Furthermore, the end sections of the reinforcement elements are sometimes subjected to high levels of residual stress, resulting from the manufacturing of the flexible section and, in addition, from the fitting assembly. This assembly often involves folding the reinforcement layers to insert the arch, then unfolding them to close the cap. These stresses can be induced during the manufacturing of the flexible pipe at the factory, during factory testing, and can also be present on the pressure arch or other reinforcement layers.

[0026] In the additional presence of water, the metallic reinforcement layers located in the nozzle, in particular the end of the pressure arch and the end sections of the tensile armor layers, then undergo corrosion, in particular stress corrosion cracking (SCC).

[0027] One aim of the invention is to provide a flexible fluid transport conduit, particularly suitable for transporting fluids containing corrosive compounds, but with an improved service life, particularly at the conduit ends.

[0028] To this end, the invention relates to a flexible fluid transport conduit tip of the aforementioned type, characterized in that at least one of the hood, the rear sealing assembly and the end arch defines at least one gas evacuation region out of the tip which is impermeable to liquid water and permeable to gas.

[0029] The nozzle according to the invention may comprise one or more of the following features, taken individually or in any technically possible combination:

[0030] - at least one of the hood, rear sealing assembly and end arch defines at least one through passage opening internally into the receiving chamber and externally outside the nozzle, for the evacuation of gases, the nozzle comprising a partially permeable plug disposed in the through passage, the plug comprising a mounting body defining a central through orifice, at least one porous membrane support wedged in the mounting body and extending through the central through orifice, and at least one membrane applied to the at least one porous support extending transversely through the central through orifice, the membrane defining the gas evacuation region out of the nozzle, impermeable to liquid water, and permeable to gas;

[0031] - the cap comprises an internal porous membrane support, arranged transversely in the central through orifice and wedged in the mounting body, and an external porous membrane support, arranged parallel to the internal porous support by being arranged transversely with respect to the central through orifice and wedged in the mounting body, the membrane being interposed between the internal porous support and the external porous support;

[0032] - at least one porous support is formed of a sintered pellet or a pellet pierced with a plurality of holes;

[0033] - the cap includes a galvanic isolation ring, interposed between the porous support and the mounting body of the cap, the galvanic isolation ring being made from an electrically insulating material, in particular from a ketone polymer;

[0034] - the mounting body includes a base defining an internal central hole, and a cover, applied to the base, defining an external central hole, the internal central hole and the external central hole forming the central through orifice, the mounting body including at least one element for fixing the cover to the base;

[0035] - the base and the lid define between them an intermediate space receiving a peripheral region of the membrane, the peripheral region of the membrane being inserted between the base and the lid;

[0036] - the cap further includes at least one internal peripheral seal, disposed between the membrane and the base, around the central through orifice, and / or at least one external peripheral seal, disposed between the cover and the membrane, around the central through orifice;

[0037] - the cap further includes a perforated frame for holding the porous support arranged transversely in the central through orifice, opposite the membrane in relation to the porous support;

[0038] - the central through orifice has a concave shape, in particular a truncated cone opening towards the outside of the tip;

[0039] - the mounting body includes an external thread, at least one of the hood, of the rear sealing assembly and of the end arch including an internal thread in the through passage, the plug being screwed into the through passage;

[0040] - the membrane is formed of a polymer film, in particular of a thermoplastic polymer film, elastomer, and / or a silicone material; - it includes a radial retaining ring for the end sections of the armor elements disposed in the receiving chamber, the end arch being disposed axially on one side of the retaining ring, the gas venting region out of the nozzle being disposed axially opposite the retaining ring or on another side of the retaining ring relative to the end arch, the gas venting region out of the nozzle being disposed between the retaining ring and the rear sealing assembly;

[0041] - the rear sealing assembly includes an intermediate cannula for supporting the polymer sheath, the tip comprising at least one axial pin interposed between the intermediate cannula and the radial retaining ring opposite the gas evacuation region out of the tip to prevent the intermediate cannula and the radial retaining ring moving towards each other, the tip optionally comprising a gas collection ring disposed to rest against the retaining ring, the axial pin or pins protruding towards the intermediate cannula from the gas collection ring;

[0042] - at least one of the hood, rear sealing assembly and end arch defines a plurality of gas venting regions out of the nozzle, in particular the hood defines a plurality of gas circulation through passages opening internally into the receiving chamber, and externally outside the nozzle, each through passage being provided with a partially permeable plug disposed in the through passage, each plug comprising a mounting body defining a central through orifice, at least one porous membrane support wedged in the mounting body and extending through the central through orifice, and at least one membrane applied to the porous support extending transversely through the central through orifice, each membrane defining a gas venting region out of the nozzle impermeable to liquid water, and permeable to gas.

[0043] The invention also relates to a flexible conduit comprising a central section having at least one polymer sheath and armor elements disposed at least partly inside the polymer sheath, the flexible conduit comprising at least one end fitting as defined above, mounted at one end of the central section.

[0044] 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:

[0045] - [Fig.1] Figure 1 is a partially cutaway perspective view of a central section of a first flexible conduit according to the invention;

[0046] - [Fig.2] Figure 2 is an external perspective view of an end piece of the flexible pipe of Figure 1 according to the invention; - [Fig.3] Figure 3 is a cross-sectional view along a median axial plane of the end piece of Figure 2;

[0047] - [Fig.4] Figure 4 is a cross-sectional view along a median axial plane of a partially permeable stopper placed in a through passage made in the tip of Figure 3;

[0048] - [Fig.5] Figure 5 is a partial perspective and partial cross-sectional view of the stopper in Figure 4;

[0049] - [Fig.6] Figure 6 is a diagram illustrating the main components of the cap in Figure 4;

[0050] - [Fig.7] Figure 7 is a view analogous to figure 6 of a variant of the stopper;

[0051] - [Fig.8] Figure 8 is a view analogous to figure 4 of a variant of the stopper;

[0052] - [Fig.9] Figure 9 illustrates the assembly of the cap from figure 8 in the cap of the nozzle;

[0053] - [Fig.10] Figure 10 is a view analogous to figure 4 of a variant of a partially permeable stopper.

[0054] Throughout the following, the terms "outside" and "inside" are generally understood radially with respect to an A-A' axis of the pipe, the term "outside" being understood as relatively further radially from the A-A' axis and the term "inside" being understood as relatively closer radially to the A-A' axis of the pipe.

[0055] The terms "front" and "rear" are understood axially with respect to an axis A-A' 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.

[0056] A first flexible conduit 10 according to the invention is partially illustrated by figures 1 to 3.

[0057] The flexible conduit 10 has a central section 12 illustrated in part in Figure 1. It has, at each of the axial ends of the central section 12, an end fitting 14 (not visible in Figure 1) the relevant parts of which are shown in Figures 2 and 3.

[0058] Referring to Figure 1, the flexible pipe 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 flexible pipe 10. It opens through the fittings 14.

[0059] The flexible pipe 10 is intended to be laid across a body of water (not shown) in a fluid handling facility, particularly for hydrocarbons.

[0060] 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 4000 m.

[0061] 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.

[0062] Flexible driving 10 is preferably "unbonded" driving (designated by the English term "unbonded").

[0063] At least two adjacent layers of the flexible pipe 10 are free to move longitudinally relative to each other during bending or tensioning of the flexible pipe 10. Advantageously, all layers of the flexible pipe 10 are free to move relative to each other. Such a flexible pipe 10 is described, for example, in the normative documents published by the American Petroleum Institute (API), API 17J, 5th edition - May 2024 and API RP 17B, 6th edition - May 2024.

[0064] As illustrated by Figure 1, the flexible 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.

[0065] According to the invention, the flexible conduit 10 comprises at least a first polymer sheath advantageously constituting a pressure sheath 20.

[0066] The flexible conduit 10 further comprises layers of tensile armor 24, 25 arranged externally with respect to the pressure sheath 20.

[0067] Advantageously, and depending on the desired use, the flexible pipe 10 further comprises an internal carcass 26 arranged inside the pressure sheath 20, possibly a pressure arch 28 interposed between the pressure sheath 20 and the tensile armor layers 24, 25, possibly a collar, and an external sheath 30, intended for the protection of the flexible pipe 10.

[0068] 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, PA12 or PA-9T, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0069] 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), PPS11 (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).

[0070] The thickness of the pressure sheath 20 is, for example, between 3 mm and 20 mm.

[0071] As can be seen in Figure 3, the pressure sheath 20 has an end region 27 disposed in the nozzle 14.

[0072] 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.

[0073] 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.

[0074] 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".

[0075] 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 A-A' of the pipe, with an absolute value close to 90°, typically between 75° and 90°.

[0076] 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 pressure duct 20. The profiled wire generally has a complex geometry, such as a Z, T, U, K, X, or I shape, which allows the turns of the pressure arch 28 to be interlocked. Interlocking the turns of the pressure arch 28 allows control of the spacing between adjacent turns, in particular to prevent creep of the pressure duct 20 through the pressure arch 28 under the effect of the pressure inside the flexible pipe 10. The profiled wires are advantageously provided with openings to facilitate the passage of gases, as described in applications WO 2021 / 037902 and WO 2022 / 180100.The pressure arch 28 is wound in a short-pitch helix around the pressure sheath 20, i.e. with a helix angle around the A-A' axis of the pipe of absolute value close to 90°, typically between 75° and 90°.

[0077] Optionally, a hoop not shown in Figure 1 surrounds the pressure arch 28. The hoop is also intended to take up the radial forces related to the pressure, in addition to the pressure arch 28. The hoop is for example formed of a metal wire of substantially rectangular cross-section wound in a short-pitch helix around the pressure arch 28. The turns of the hoop are not stapled together.

[0078] 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.

[0079] In the example shown in 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.

[0080] Each layer of armor 24, 25 has longitudinal armor elements 29 wrapped at long pitch around the A-A' axis of the conduit.

[0081] By "long pitch winding", we mean that the absolute value of the helix angle is less than 60°, and is typically between 15° and 55°.

[0082] 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 15° 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 - a, with a between 15° and 55°.

[0083] The armor elements 29 are for example formed by metal wires, or by composite ribbons, in particular composite ribbons reinforced by carbon fibers.

[0084] As can be seen in Figure 3, the armor elements 29 each have an end section 32 inserted into the end piece 14. The end section 32 extends to a free end disposed in the end piece 14. It advantageously has a helical or pseudo-helical trajectory with axis A-A' in the end piece 14.

[0085] The flexible conduit 10 advantageously incorporates wear-resistant layers interposed, on the one hand, between the pressure arch 28 and the first inner reinforcement layer 24, and on the other hand, between the two reinforcement layers 24 and 25. Each wear-resistant layer is formed by helically winding a polymer strip typically between 0.5 mm and 4 mm thick. The function of each wear-resistant layer is to reduce friction between the metal wires or wear between the composite strips between which it is interposed.

[0086] 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).

[0087] 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), PPS11 (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).

[0088] The thickness of the outer sheath 30 is, for example, between 3 mm and 20 mm.

[0089] Alternatively, the flexible pipe 10 may include at least one protective sheath, for example at least two protective sheaths around the outer sheath 30. Alternatively, the flexible pipe 10 includes at least one intermediate sheath interposed between the pressure sheath 20 and the outer sheath 30 and at least one layer of thermal insulation disposed between the intermediate sheath and the outer sheath 30.

[0090] As illustrated by Figures 2 and 3, 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 outer connecting hood 51 projecting axially rearward from the end arch 50.

[0091] The hood 51 delimits, with the end vault 50, a chamber 52 for receiving the end sections 32 of the armor elements 29.

[0092] The end piece 14 further includes a front sealing assembly 54 around the pressure sheath 20, a rear sealing assembly 56 around the outer sheath 30 and an assembly 57 for retaining the end sections 32 of the armor elements 29, arranged in the chamber 52.

[0093] In this example, the tip 14 further includes a solid filler material 58, such as a thermosetting polymer resin of the epoxy or araldite type. The solid filler material 58 is arranged in the chamber 52 around the end sections 32.

[0094] In this example, the end arch 50 is intended to connect the flexible conduit 10 to another connection fitting 14 or to terminal equipment, advantageously via an end flange 60 or a fixing termination of the Grayloc® or Techlok® type.

[0095] 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 flexible conduit 10.

[0096] The hood 51 has a tubular peripheral wall 70 extending around the axis A-A'. The peripheral wall 70 has a front edge 71 fixed to the end arch 50, radially away from the armor layers 24, 25 and a rear edge 72 (visible only in figure 3) extending axially rearward beyond the end arch 50.

[0097] The hood 51 delimits at least one channel 73A for injecting fluid filling material intended to solidify and at least one channel 73B for venting air during filling, offset axially along the central axis AA' relative to the injection channel 73A.

[0098] Each channel 73A, 73B opens outside the hood 51 and internally into the chamber 52, in positions offset longitudinally along the central axis A-A'.

[0099] According to the invention, the tubular peripheral wall 70 of the hood 51 further defines at least one radial passage 74 for gas evacuation. The nozzle 14 then comprises, for each radial passage 74, a plug 75 that is partially permeable to gas and impermeable to liquids, intended to be inserted into each radial passage 74.

[0100] In the example shown in figures 2 and 3, the radial through passage 74 is connected to a test port 76 associated with the plug 75, intended to test the seals at the periphery of the plug 75, the test port 76 being fitted with a sealing plug 76A.

[0101] The radial passage 74 extends radially with respect to the axis A-A'. It connects internally the chamber 52 to the outside of the hood 51.

[0102] In the example shown in Figure 3, it includes an inner region 77A opening into chamber 52 and an outer region 77B with a transverse extent greater than the inner region 77A.

[0103] Regions 77A and 77B define a shoulder 77C for the support of the plug 75. The test port 76 opens into region 77B at the shoulder 77C. The radial through passage 74 is advantageously provided with an internal thread 78, here in its outer region 77B, to allow the plug 75 to be screwed in.

[0104] In the example shown in Figure 2, the outer cover 51 delimits a plurality of radial passages 74 distributed angularly around the axis A-A', for example between 2 and 6 radial passages. Each radial passage 74 is fitted with a partially permeable plug 75 as described below.

[0105] The chamber 52 is delimited radially outwards by the hood 51, forwards by the end arch 50, and radially inwards by the pressure duct 20 and / or the pressure arch 28.

[0106] 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.

[0107] It includes a front crimping ring (not visible), intended to engage with the pressure sheath 20, and a front flange 79 for clamping the front crimping ring.

[0108] In the example shown in Figure 3, in which the flexible pipe 10 has a pressure arch 28, the front sealing assembly 54 further includes a stop ring 80 for the pressure arch 28.

[0109] The front clamping flange 79 is screwed onto a rear face 64 of the end arch 50.

[0110] The front crimping ring is configured to be moved radially towards the A-A' axis, this relative radial displacement resulting in particular from the rearward displacement of the end arch 50 along the A-A' axis.

[0111] The front crimping ring has a front bulge designed to radially penetrate the pressure sleeve 20 by wedge effect, during the relative movement of the front crimping ring with respect to the end arch 50.

[0112] With reference to figure 3, the rear sealing assembly 56 includes a rear crimping ring 90, and a rear clamping flange 92 for the rear crimping ring 90.

[0113] The rear sealing assembly 56 advantageously includes an intermediate support cannula 94 interposed between the outer sheath 30 and the armor layers 24, 25, the outer sheath 30 resting on the intermediate cannula 94.

[0114] The rear crimping ring 90 is interposed between a rear surface of the cover 51 and the outer sheath 30. It has at least one bulge configured to radially penetrate the outer sheath 30 by wedge action when the rear crimping ring 90 is moved. The rear clamping flange 92 is fixed to the rear surface 72 of the cover 70. It pushes the rear crimping ring 90 forward to move it along the axis A-A' and crimp the outer sheath 30.

[0115] The outer sheath 30 rests on the intermediate cannula 94, the latter being axially wedged at the rear of the support assembly 57.

[0116] The intermediate retaining assembly 57 includes a retaining ring 96 for the end sections 32 of the armor elements 29 in a cylindrical configuration, and advantageously, a gas collection ring 98, offset longitudinally towards the rear relative to the retaining ring 96.

[0117] The retaining ring 96 is wedged onto the gas collection ring 98. It surrounds the armor elements 29 to keep them applied against the pressure arch 28, or when this pressure arch 28 is absent, against the pressure sheath 20.

[0118] Thus, between the rear edge 72 of the hood 70 and the retaining ring 96, the armor elements 29 are held substantially in a cylindrical envelope.

[0119] Between the retaining ring 96 and the front edge 71 of the hood 70, towards the front edge 71 of the hood 70, the armor elements 29 move away from the axis AA' before moving closer to the axis A-A' to come to rest on the end arch 50.

[0120] The gas collection ring 98 is intended to collect gases from the annular space located between the outer sheath 30 and the pressure sheath 20 over the entire central section 12. It is wedged between the retaining ring 96 and an axial stop formed for example by pins 100 projecting axially towards the rear edge 72 of the hood 70 from the gas collection ring 98.

[0121] The gas collection ring 98 is provided with a lip 102 applied against an annular shoulder 103 of the hood 70 directed radially towards the end arch 50 to achieve an annular separation between a front region 104 of the chamber 52 which contains filling material 58 and a rear region 106 of the chamber 52, devoid of filling material 58.

[0122] The gas collection ring 98 ensures both the collection and evacuation of gases to the outside of the nozzle (advantageously via a pipe 99 extending from the ring 98 through the filling material 58 to the flange 56), and the sealing of the rear region 106 when the filling material 58 is introduced in fluid form into the chamber 52.

[0123] Each radial passage 74, in particular the inner region 77A of each radial passage 74, opens internally into the rear region 106 between the front end of the cannula 94 and the gas collection ring 98. The gases from the annular space located between the outer sheath 30 and the pressure sheath 20 are therefore collected in the gas collection ring 98 and in the rear region 106 which remains clear and fluidly connected to the or each radial passage 74.

[0124] In particular, the protruding pins 100 from the gas collection ring 98 prevent forward movement of the cannula 94, allowing the gas to pass through the rear region 106 to head towards each passage through 74.

[0125] The partially permeable plug 75 inserted into the radial passage 74 will now be described in more detail, with reference to figures 4 to 6.

[0126] As can be seen in these figures, the plug 75 comprises a sealed mounting body 140, defining a central through-hole 142 extending along a plug axis B-B'. The plug axis B-B' extends radially with respect to the central axis A-A' when the plug 75 is received in the through-hole 74.

[0127] The stopper 75 further comprises, held transversely in the central orifice through 142 with respect to the stopper axis B-B', an inner porous support 144, a membrane 146 that is liquid-tight and at least partially gas-permeable, and advantageously, an outer porous support 148, the membrane 146 being sandwiched between the inner porous support 144 and the outer porous support 148.

[0128] Advantageously, the cap 75 further comprises an internal perforated frame 150, supporting the internal porous support 144 and, an external galvanic insulation ring 152, capping the external porous support 148.

[0129] The cap 75 also includes a system 154 of sealing gaskets to achieve a seal between the membrane 146 and the mounting body 140, as well as a seal between the mounting body 140 and the cap 51.

[0130] The mounting body 140 is formed from metal, for example from steel, in particular corrosion-resistant materials such as INCONEL 625, INCONEL 718, INCONEL 825, MONEL 400, or DUPLEX or SUPERDUPLEX alloys.

[0131] In the example shown in Figures 4 to 6, the mounting body 140 includes an annular base 160, and a peripheral cover 162 mounted on the annular base 160 and pinching the periphery of the membrane 146. The mounting body 140 further includes fastening members 164 holding the cover 162 in position on the base 160.

[0132] The base 160 defines an internal central hole 166 delimited at its periphery by an internal annular shoulder 168 for the support of the reinforcement 150 and / or the internal porous support 144. In this example, it defines an external peripheral shoulder 170, directed radially away from the axis of the plug B-B' for the mounting of the cover 162.

[0133] The lid 162 has an annular ring 172 defining an external central hole 174. It has an annular lip 176 at its periphery.

[0134] The cover 162 has, at the periphery of the external central hole 174, a concave surface 178, in particular frustoconical and an external shoulder 180 arranged longitudinally opposite the internal shoulder 168 of the base 160.

[0135] The outer central hole 174 extends longitudinally in continuity with the inner central hole 166 and defines, together with the inner central hole 166, the central through orifice 142.

[0136] The lip 176 is received in the external peripheral shoulder 170 to wedge the cover 162 onto the base 160.

[0137] The cover 162 further defines an external thread 177 intended to cooperate with the internal thread 78 in the radial passage 74 provided in the tubular peripheral wall 70 of the cover 51.

[0138] The fastening elements 164 are for example formed by screws which extend through the periphery of the base 160 and the lip 176 of the cover 162.

[0139] When the cover 162 is mounted on the base 160, the cover 162 and the base 160 define between them an intermediate space of annular shape 182 in which the periphery of the membrane 146 is received.

[0140] The support reinforcement 150, when present, rests on the inner shoulder 168. It defines internally through-holes with a transverse extent greater than the transverse extent of the pores of the inner porous support 144 and the outer porous support 148 or a porosity greater than that of the inner porous support 144.

[0141] The inner porous support 144 and the outer porous support 148 are each formed by a porous body such as a sintered metal body or a sintered ceramic body. The porosity of the porous body is greater than 1%, in particular greater than 5%, and is generally between 10% and 80%. The maximum transverse extent of the pores of the porous body is less than 250 mm, in particular between 10 mm and 200 mm.

[0142] The porous body is, for example, made from a metallic alloy, in particular a nickel alloy, specifically a nickel-copper alloy. This nickel-copper alloy can, for example, be made according to grade UNS N04400 (ASTM B165 or ASTM B 164).

[0143] Preferably, the porous body is made of Monel 400, which ensures high corrosion resistance and prevents the formation and development of marine life. This is particularly important for the 148 exterior porous substrate, which is in contact with seawater.

[0144] In this example, each of the inner porous support 144 and the outer porous support 148 is made in the form of a pellet.

[0145] The pellet has a thickness, taken along the B-B' axis, less than its transverse extent with respect to the B-B' axis, in particular less than five times the transverse extent along the B-B' axis. It thus has a disc shape.

[0146] The porous inner support 144 is wedged in the central inner hole 166, internally with respect to the membrane 146, advantageously with external support on the openwork reinforcement 150.

[0147] The outer porous support 148 is wedged in the outer central hole 174, externally with respect to the membrane 146 and internally with respect to the annular galvanic isolation ring 152.

[0148] The membrane 146 has a region 184 arranged transversely through the central orifice 142, between the porous supports 144, 148, and a peripheral region 186, pinched between the base 160 and the cover 162.

[0149] It generally has a thickness of less than 5 mm, in particular less than 3 mm, notably between 0.1 mm and 5 mm, taken along the B-B' axis.

[0150] It has a transverse extent, taken perpendicular to the axis B-B' greater than the transverse extent of each porous support 144, 148, between 1.1 and 2, in particular 1.5 times greater than the transverse extent of each support 144, 148.

[0151] The membrane 146 is made in particular from a liquid-tight polymer, especially impermeable to liquid water, to prevent liquid water from entering the chamber 52 through the central orifice passing through 142. Thus, the gas permeability through the membrane is less than 1 x 10 -2 (cm 3 .cm 2 / cm 3 .s.bar) and in particular between 1 x 10' 10 (cm 3 .cm / cm 2 .s.bar) and 1 x 10 -2 (cm 3 .cm 2 / cm 3 .s.bar), in particular between 1 x 10 -10 (cm 3 .cm / cm 2 .s.bar) and 1 x 10 -4 (cm 3 .cm 2 / cm 3.s.bar), following the recommendations of the aforementioned API 17J standard, at a pressure ranging from 1 bar up to 400 bars and at a temperature ranging from 3°C up to 120°C. A method for measuring permeability is described, for example, in the publication by Flaconnèche et al.: Transport Properties of Gases in Polymers: Experimental Methods, Oil & Gas Science and Technology - Revue de l'I IFP 56(3):245-259 (2001).

[0152] In contrast, membrane 146 is less partially permeable to gas, particularly to carbon dioxide and hydrogen sulfide. The membrane's permeability to carbon dioxide is greater than 2 x 10 -4 (cm 3 .cm / cm 2 .s.bar). The membrane's gas permeability is greater than 2 x 10 -4 (cm 3 .cm / cm 2 .s.bar).

[0153] The membrane 146 is advantageously made of polymer material, in particular based on a thermoplastic polymer, an elastomer, a silicone material or a mixture of these materials. The polymer is for example a polyolefin, such as polyethylene, cross-linked polyethylene (XLPE) polypropylene (PP), a polyamide, such as PA11, PA12 or PA6-12, or a fluoropolymer such as polyvinylidene fluoride (PVDF) polytetrafluoroethylene (PTFE) and / or perfluoroalkoxy (PFA) or a mixture of at least two of these polymers.

[0154] Alternatively, the polymer is a silicone polymer, such as silicone rubber, or a thermoplastic polyurethane (TPU).

[0155] Alternatively, membrane 146 is formed based on 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).

[0156] The galvanic isolation ring 152 is interposed between the outer porous support 148 and the outer shoulder 180 of the cover 162. It has a peripheral region 190 extending to the periphery of the outer porous support 148, and an annular rim 192 interposed between the cover 162 and the outer surface of the porous support 148.

[0157] The galvanic isolation ring 152, for example, is made of an electrically insulating material, advantageously exhibiting a volume electrical resistivity greater than 10 9 Q.cm, preferably greater than or equal to 10 13 Q.cm and / or a surface electrical resistivity greater than or equal to 10 13 Q as measured by Standard IEC 62631-3-1:2016.

[0158] In addition, the electrical resistance measured between the internal casing 26 of the flexible conduit 10 and the end fitting 14 including the cap 75 fitted with the galvanic isolation ring 152, is preferably greater than 1 kQ.

[0159] The insulating material is for example a polymer, in particular a ketone polymer such as polyetheretherketone (PEEK).

[0160] The sealing system 154 comprises a first outer peripheral seal 194 applied to an outer surface of the peripheral region 186 of the membrane 146 from the cover 162, and a second inner peripheral seal 196 applied to an inner surface of the peripheral region 186 of the membrane 146, from the base 160

[0161] In this example, the peripheral joints 194 and 196 are concentric and of different transverse extents. The inner peripheral joint 196 extends radially beyond the outer peripheral joint 194 with respect to the axis B-B'.

[0162] Alternatively, the peripheral joints 194, 196 are concentric but have the same transverse extent.

[0163] The sealing system 154 further includes a peripheral contact seal 198, projecting from an inner surface of the base 160 to apply to the shoulder 77C and to provide a seal between the mounting body 140 of the cap 75 and the cover 51.

[0164] Alternatively, the seal within the cap 75 is achieved without peripheral seals, for example by direct sealing between the membrane 146 and the mounting body 140 by compressing the membrane 146 and the mounting body 140.

[0165] The assembly of tip 14 will now be described.

[0166] Initially, the cannula 94 is inserted between the armor elements 24, 25 and the outer sheath 30.

[0167] The retaining assembly 57 for the end sections 32 is put in place. For this purpose, the gas collection ring 98 and then the retaining ring 96 are put in place around the end sections 32 of the armor elements 29.

[0168] The end arch 50 is placed around the end region 27 of the pressure sheath 20, the armor layers 24, 25 having been moved radially outwards and then brought back towards the rear of the end piece.

[0169] The pressure arch 28 is cut circumferentially around the region which will accommodate the crimping flange 79.

[0170] The clamping flange 79 is then placed longitudinally, then the stop ring 80 of the pressure arch 28 is brought into contact with the latter.

[0171] The crimping ring (not shown in the drawings) is placed between the pressure sleeve 20 and the end arch 50.

[0172] The end arch 50 is then put in place and then tightened against the front face of the crimping flange 79, thus creating a radial displacement towards the inside of the crimping ring, ensuring the sealing of the pressure sheath 20 in the end fitting 14. The armor layers 24, 25 are moved radially inwards into contact with the end arch 50. The cover 51 is advanced towards the end arch 50, so as to form with the end arch 50, the chamber 52.

[0173] The intermediate support cannula 94 is inserted between the outer sheath 30 and the armor layers 24, 25.

[0174] The rear crimping ring 90 is then placed between the hood 51 and the outer sheath 30. The rear clamping flange 92 is then put in place and is tightened against the rear edge 72 of the hood 51.

[0175] Next, fluid filler material 58 is introduced into chamber 52 through injection channel 73A, with degassing channel 73B open. The filler material 58 floods the end sections 32 of the armor elements 29 in the forward region 104 of chamber 52 and solidifies. The gas collection ring 98, preferably equipped with a sealing annular lip 102, prevents the passage of filler material 58 to the rear region 106.

[0176] The cap 75 is then assembled by inserting the membrane 146 on the one hand, between the lower porous support 144 and the outer porous support 148, at the level of its central region 184, and on the other hand, at the level of its peripheral region 186, between the base 160 and the cover 162. The galvanic isolation ring 152, the support frame 150, and the seals 194, 196 of the sealing system 154 are also interposed between the base 160 and the cover 162.

[0177] The assembled plug 75 is then advantageously put in place by screwing it into the radial through passage 74. The external thread 177 engages with the internal thread 78 provided in the radial through passage 74.

[0178] Alternatively, the plug 75 is pre-assembled onto the cap 51 before the fitting sequence of the nozzle 14 described above. Alternatively still, the plug 75 is fitted into the cap 51 during the fitting of the nozzle 14, but before the filling material 58 is introduced into the chamber 52.

[0179] In use, as described in Figure 6, the water present outside the hood 51 applies only to the apparent external surface of the membrane 146, without passing through the membrane 146 thanks to the impermeability to liquid provided by the membrane 146.

[0180] On the other hand, the gas collected in the annular radially outside the pressure sheath 20, in particular corrosive gases such as carbon dioxide and hydrogen sulfide, diffuse radially through the pressure sheath 20 at the rear region 106 of the receiving chamber 52 and to a lesser extent, flow radially and longitudinally until reaching the rear region 106 of the receiving chamber 52. The gases then pass through the inner region 77A of the radial passage through 74, and finally, through the membrane 146 which is partially permeable to gas, to be evacuated out of the nozzle 14.

[0181] In this way, no significant accumulation of corrosive gas, such as carbon dioxide or hydrogen sulfide, occurs in the tip 14, around the end sections 32 of the armor elements 29 and, to a lesser extent, of the pressure vault 28.

[0182] The nozzle 14 according to the invention is therefore permeable to gas in the direction from the inside of the hood 51 to the outside of the hood 51, and the hood 51 no longer constitutes an impermeable screen which promotes the accumulation of gases.

[0183] Furthermore, the presence of a plug 75 containing a membrane 146, and at least one porous support 144, 148, ensures both easy diffusion of gases through the membrane 146, and effective and robust mechanical support of the membrane 146 by means of the reinforcement 150, which prevents it from deteriorating when the differential pressure between the inside and outside of the membrane 146 is too high.

[0184] The concave, specifically frustoconical, shape of the downstream surface 178 facilitates the evacuation of gases to the outside of the nozzle 14 and prevents stagnation. If the gas were to stagnate above the outer porous support 148, then diffusion would be impaired, since such diffusion occurs from areas of high concentration to areas of low concentration.

[0185] The nozzle 14 according to the invention is simple to manufacture, and the cap 75 is easily replaceable if it is totally blocked or damaged.

[0186] In one variant, illustrated by figure 7, the stopper 75 includes a unique porous support 144 wedged through the central through orifice 142.

[0187] The membrane 146 is arranged around the porous support 144 to cover it completely, in particular in the region arranged in the central orifice passing through 142.

[0188] The operation of this stopper 75 is analogous to that described for figure 6, except that the gas evacuated from chamber 52 passes twice through membrane 146. In addition, the porous support 144 is protected from water present outside the stopper 75 by membrane 146.

[0189] Figures 8 and 9 illustrate another variant of the plug 75. Unlike the plug 75 visible in Figure 4, the plug 75 in Figure 8 is without a base 160 fixed to the cover 162. The cover 162 is without an external thread 177 and the annular lip 176 is flush with the membrane 146. The membrane 146 is thus configured to apply itself to the shoulder 77C with the interposition of at least one peripheral contact seal 196, preferably with the interposition of two concentric peripheral contact seals 196, one received in the other.

[0190] With reference to figure 9, passage 74 further defines in the wall 70 of the hood 51, internally to the shoulder 77C, an internal shoulder 77D for the support of the reinforcement 150 and / or the internal porous support 144.

[0191] The cover 162 is thus configured to fit into the outer region 77B and to be fixed to the cover 51 without rotation, for example by screwing or bolting. Once the cover 162 is fixed, the membrane 146 is then clamped in its peripheral region 186 in the annular space 182 in contact with the shoulder 77C with interposition of each seal 196. The central region 184 of the membrane 146 is also interposed between the outer porous support 148 on one side and the inner porous support 144 and possibly the reinforcement 150 resting on the inner shoulder 77D on the other side;

[0192] In another variant, at least one passage 74 equipped with a plug 75 as described above is provided in the end arch 50 and / or in the rear sealing assembly 56, for example in the rear clamping flange 92.

[0193] In one variant (not shown), the flexible pipe is a hybrid flexible pipe manufactured according to DNV-ST-F119 (Thermoplastic Composite Pipes, September 2019 edition) established by DNV (Det Norske Veritas). It advantageously comprises an inner tubular sheath made of polymer material, which advantageously acts as a pressure sheath, and a reinforcing tubular composite structure applied around and bonded to the inner sheath. Alternatively, the flexible pipe lacks an inner tubular sheath, in which case the reinforcing tubular structure is watertight.

[0194] The flexible conduit further comprises a plurality of layers of tensile armor arranged externally to the tubular reinforcement structure while not connected to the tubular reinforcement structure, and an unconnected outer sheath.

[0195] The tubular reinforcement structure comprises at least one, preferably a plurality of laminated composite reinforcement layers, and optionally, an anti-delamination layer interposed between at least two reinforcement layers.

[0196] Throughout the foregoing, a gas venting region outside the nozzle 14, impermeable to liquid water and permeable to gas, is defined by the membrane 146 carried by each plug 75 received in a through passage 74. More generally, at least one gas venting region outside the nozzle 14, impermeable to liquid water and permeable to gas, is formed directly in the wall 70 of the hood 51, in the wall of the end arch 50 and / or in at least one element of the rear sealing assembly 56, such as the clamping flange 92. For example, the wall 70 of the hood 51 is formed of a watertight and gas-porous material, for example fully sintered, and advantageously coated with a coating of a polymer similar to that of the membrane 146.

[0197] In a variant of the cap 75 of Figure 4, shown in Figure 10, the annular base 160 and the cover 162 of the cap 75 are without thread 177.

[0198] The cover 162 is thus configured to fit into the outer region 77B, for example by simple radial translation in the radial passage 74, without rotation, and to be fixed directly to the cover 51 of the end piece 14 without rotation, for example by screwing or bolting by inserting fasteners such as screws and / or bolts through the cover 162 and the outer region 77B.

[0199] In the example visible in Figure 10, the annular ring 172 includes a shoulder whose diameter considered according to the section of cut of axis A-A', taken perpendicular to the axis of plug B-B' is greater than the diameter of the base 160 taken perpendicular to the axis of plug B-B'.

[0200] Alternatively, the annular ring 172 of the cover 162 has a contour, taken in projection in a plane perpendicular to the axis of the cap B-B', which has the geometry of a quadrilateral, preferably a square, to allow the screwing or bolting, without rotation, of said cover 162 directly into the cover 51. The screwing or bolting is carried out by inserting fixing members into the corners of the cover 162.

Claims

23 DEMANDS 1. End fitting (14) of a flexible fluid conveying conduit (10) comprising: an end region of a polymer sheath (30) of the flexible conduit (10); end sections (32) of armor elements (29) of the flexible conduit (10), disposed at least partially within the end region of the polymer sheath (30); an end arch (50), defining a central bore (62) for fluid circulation extending along a central axis (A-A'); a cover (51) defining, together with the end arch (50), a receiving chamber (52) for the end sections (32) of the armor elements (29); a rear sealing assembly (56) around the polymer sheath (30); characterized in that at least one of the hood (51), rear sealing assembly (56) and end arch (50) defines at least one gas discharge region out of the nozzle (14) that is impermeable to liquid water and permeable to gas.

2. Nozzle (14) according to claim 1, wherein at least one of the cap (51), the rear sealing assembly (56), and the end arch (50) defines at least one through-passage (74) opening internally into the receiving chamber (52) and externally to the outside of the nozzle (14) for gas venting, the nozzle (14) comprising a partially permeable plug (75) disposed in the through-passage (74), the plug (75) comprising a mounting body (140) defining a central through-port (142), at least one porous membrane support (144, 148) wedged in the mounting body (140) and extending through the central through-port (142), and at least one membrane (146) applied to the at least one porous support (144, 148) extending transversely through the central through orifice (142), the membrane (146) defining the gas evacuation region out of the nozzle (14), impermeable to liquid water, and permeable to gas.

3. Tip (14) according to claim 2, wherein the cap (75) comprises an internal porous membrane support (144), disposed transversely in the central through orifice (142) and secured in the mounting body (140), and an external porous membrane support (148), disposed parallel to the internal porous support (144) by being disposed transversely with respect to the central through orifice (142) and wedged in the mounting body (140), the membrane (146) being interposed between the inner porous support (144) and the outer porous support (148).

4. Tip (14) according to any one of claims 2 or 3, in which at least one porous support (144, 148) is formed of a sintered pellet or a pellet pierced with a plurality of holes.

5. Tip (14) according to any one of claims 2 to 4, in which the cap (75) includes a galvanic isolation ring (152), interposed between the porous support (144, 148) and the mounting body (140) of the cap (75), the galvanic isolation ring (152) being made from an electrically insulating material, in particular from a ketone polymer.

6. End piece (14) according to any one of claims 2 to 5, wherein the mounting body (140) comprises a base (160) defining an internal central hole (166), and a cover (162), applied to the base (160), defining an external central hole (174), the internal central hole (166) and the external central hole (174) forming the central through orifice (142), the mounting body (140) comprising at least one fixing member (164) of the cover (162) on the base (160).

7. Tip (14) according to claim 6, in which the base (160) and the cover (162) delimit between them an intermediate space receiving a peripheral region (186) of the membrane (146), the peripheral region (186) of the membrane (146) being inserted between the base (160) and the cover (162).

8. Tip (14) according to claim 7, wherein the cap (75) further comprises at least one inner peripheral seal (196), disposed between the membrane (146) and the base (160), around the central through orifice (142), and / or at least one outer peripheral seal (194), disposed between the cover (162) and the membrane (146), around the central through orifice (142).

9. Tip (14) according to any one of claims 2 to 8, wherein the cap (75) further comprises a perforated retaining frame (150) for the porous support (144, 148) arranged transversely in the central through orifice (142), opposite the membrane (146) with respect to the porous support (144, 148).

10. Tip (14) according to any one of claims 2 to 9, wherein the central through orifice has a concave shape, in particular a frustoconical shape opening outwards from the tip (14).

11. End piece (14) according to any one of claims 2 to 10, wherein the mounting body (140) comprises an external thread (177), at least one of the hood (51), the rear sealing assembly (56) and the end arch (50) including an internal thread (78) in the through passage (74), the plug (75) being screwed into the through passage (74).

12. Tip (14) according to any one of claims 2 to 11, wherein the membrane (146) is formed of a polymer film, in particular of a thermoplastic polymer film, elastomer, and / or silicone material.

13. End piece (14) according to any one of the preceding claims, comprising a radial retaining ring (96) for the end sections (32) of the armor elements (29) disposed in the receiving chamber (52), the end arch (50) being disposed axially on one side of the retaining ring (96), the gas venting region out of the end piece (14) being disposed axially opposite the retaining ring (96) or on another side of the retaining ring (96) relative to the end arch (50), the gas venting region out of the end piece (14) being disposed between the retaining ring (96) and the rear sealing assembly (56).

14. Tip (14) according to claim 13, wherein the rear sealing assembly (56) comprises an intermediate cannula (94) for supporting the polymer sheath (30), the tip (14) comprising at least one axial pin (100) interposed between the intermediate cannula (94) and the radial retaining ring (96) opposite the gas venting region out of the tip (14) to prevent the intermediate cannula (94) and the radial retaining ring (96) from moving towards each other, the tip (14) optionally comprising a gas collection ring (98) disposed to bear against the retaining ring (96), the axial pin or pins (100) projecting towards the intermediate cannula (94) from the gas collection ring (98).

15. Tip (14) according to any one of claims 13 or 14, wherein the receiving chamber (52) defines, on the side of the retaining ring (96) facing the end arch (50), a forward region (104) of the receiving chamber (52) containing a filler material (58) for locking the end sections (32) of the armor elements (29) in position, and, on the other side of the retaining ring (96), a rear region (106) of the chamber (52) devoid of filler material (58), the gas venting region from the tip (14) being located opposite the rear region (106), the tip (14) comprising an annular sealing element (98, 102) between the forward region (104) and the rear region (106), the cap (51) optionally defining at least one material injection channel (73A) fluid filling intended to solidify and at least one air evacuation channel (73B) during filling, each channel (73A, 73B) opening into the forward region (104). 26 16. Nozzle (14) according to any one of the preceding claims, wherein at least one of the cap (51), the rear sealing assembly (56), and the end arch (50) defines a plurality of gas discharge regions from the nozzle (14), in particular wherein the cap (51) defines a plurality of gas flow passages (74) opening internally into the receiving chamber (52) and externally to the outside of the nozzle (14), each passage (74) being provided with a partially permeable plug (75) disposed within the passage (74), each plug (75) comprising a mounting body (140) defining a central through orifice (142), at least one porous membrane support (144, 148) wedged within the mounting body (140) and extending through the central through orifice (142), and at least a membrane (146) applied to the porous support (144,148) extending transversely through the central through orifice (142), each membrane (146) defining a gas evacuation region out of the nozzle (14) impermeable to liquid water, and permeable to gas.

17. Flexible conduit (10), comprising a central section (12) having at least one polymer sheath (30) and armor elements (29) disposed at least partly inside the polymer sheath (30), the flexible conduit (10) comprising at least one end fitting (14) according to any one of the preceding claims, mounted at one end of the central section (12).

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