End fitting for a flexible tube for conveying a fluid, a related flexible tube and method

Abstract

End fitting for a flexible pipe for conveying fluid, associated flexible pipe and method. The invention relates to an end fitting for a flexible pipe for conveying fluid, comprising at least one sealing assembly comprising at least one crimp ring (74) comprising at least one protrusion radially inserted into a polymeric sheath (20) of the flexible pipe; the end fitting (14) comprising an annular seal (81) arranged in contact with the polymeric sheath (20) distally from said crimp ring (76); the annular seal (81) having an annular central region (100) radially deformable towards the polymeric sheath (20), and two reinforced annular peripheral regions (102, 104) located on either side of the central region (100) along a central axis (A-A'), the annular peripheral regions (102, 104) being movable towards each other to actuate the radial deformation of the central region (100) towards the polymeric sheath (20) from a rest configuration to a working configuration sealing around the polymeric sheath (20).

Description

Technical Field

[0001] This invention relates to an end fitting for a flexible tube used for conveying fluid, comprising:

[0002] - At least one end region of the polymer sheath of the flexible tube;

[0003] - The end section of the armored element of the flexible tube is arranged around or in the end region of the polymer sheath.

[0004] - End arches define a central channel for allowing fluid flow, the central channel extending along a central axis;

[0005] - Cover, together with the end arch, defines a chamber for receiving the end section of the armored element;

[0006] - At least one sealing component, including at least one crimping ring, the crimping ring including at least one protrusion radially inserted into the polymer sheath;

[0007] - An annular seal, positioned away from the crimping ring, is arranged to contact the polymer sheath. Background Technology

[0008] This type of pipe is especially used for unbonded flexible pipes for transporting hydrocarbons through bodies of water such as oceans, lakes, or rivers.

[0009] For example, such flexible tubes are manufactured according to the American Petroleum Institute's normative documents API 17J (May 2014, fourth edition) and APIRP 17B (May 2014, fifth edition).

[0010] A tube is typically formed from a set of concentric stacked layers. A tube is considered "unbonded" as defined in this invention, provided that at least one layer is configured to move longitudinally relative to adjacent layers during tube bending. More specifically, an unbonded tube is a tube without the bonding material that connects the multiple layers forming the tube.

[0011] Pipes are typically laid across the water body between a bottom unit for collecting fluid extracted from the bottom of the water body and a floating surface unit for collecting and distributing the fluid. The surface unit can be a semi-submersible platform, an FPSO (Floating Production Storage and Offloading) unit, or other floating units.

[0012] In a known manner, a pipe includes a pressure sheath made of polymer, an intermediate sheath (if appropriate), and an outer sheath, the pressure sheath being used to contain the fluid conveyed by the pipe, and the outer sheath being used to protect the pipe from the outside.

[0013] The tube end has terminations for connecting to the bottom unit and the surface unit.

[0014] The end region of each sheath is received in the tube end fitting and is installed in a sealed manner within the end fitting.

[0015] For this purpose, one known method for making a sealing connection is to press a metal ring around the outer surface of the sheath so that the ring partially penetrates the thickness of the sheath wall.

[0016] The crimping ring is typically in the form of a hollow cone surrounding the sheath, which is arranged coaxially with the sheath. During crimping, a conical support surface machined in the end-fit body is axially pressed around the cone, which is also coaxial with the sheath and the cone to be crimped.

[0017] During this pressing process, the cone is radially compressed relative to the sheath axis, its diameter decreases, and the cone undergoes plastic deformation by partially penetrating into the sheath. The crimping operation simultaneously provides a metal / polymer seal between the cone and the sheath, and a metal / metal seal between the cone and the end-fit body.

[0018] This design can withstand very high internal pressures (over 1000 bar) over a wide temperature range (up to 130°C and above). It is particularly effective when the pressure inside the sheath is greater than the pressure outside, as the pressure difference tends to increase the sheath diameter. This results in increased contact pressure between the sheath and the crimping ring, and also increased pressure between the crimping ring and the end-fit body, thereby enhancing the assembly's seal.

[0019] In the case of a pressure jacket, the internal pressure is usually much higher than the external pressure, which enhances the seal, but the pressure gradient can sometimes be reversed, such as during decompression after production shutdown.

[0020] When the pressure gradient is reversed, the opposite effect occurs. The contact pressure between the crimp ring and the sheath decreases, reducing the seal of the component. In certain situations, this may lead to micro-leakage.

[0021] This problem is more pronounced with the outer sheath because the pressure gradient is typically persistently reversed, especially when the termination is submerged to a great depth. In this case, the hydrostatic pressure applied to the outer surface of the outer sheath is significantly higher than the pressure present in the pipe wall on the inner surface of the outer sheath.

[0022] To overcome these problems, as is known from WO2019 / 137591, a sealing ring is added between the sheath and the end fitting arch where the seal is to be achieved, in addition to the polymer crimping ring.

[0023] In some cases, annular seals may include an external radially reinforced region located radially outside the elastomeric ring.

[0024] This approach is not entirely satisfactory. In some cases, the contact pressure applied to the polymer sheath is insufficient to maintain a seal. Furthermore, the solutions proposed in the aforementioned literature are only applicable to pressure sheaths and may not be suitable for intermediate or outer sheaths that may exist within flexible tubing. Summary of the Invention

[0025] Therefore, one object of the present invention is to provide an end fitting for a flexible tube for conveying fluid, wherein the sealing between the polymer sheath and the arch of the end fitting is improved regardless of the differential pressure conditions applied to the tube and regardless of the type of sheath that seals around it in the end fitting.

[0026] Therefore, the subject of this invention is an end fitting for a flexible tube of the type described above for conveying fluid, characterized in that the annular seal includes an annular central region capable of radial deformation toward a polymer sheath, and two reinforced annular peripheral regions located on either side of the annular central region along a central axis, the two annular peripheral regions being movable toward each other to cause radial deformation of the annular central region toward the polymer sheath from a resting configuration to a working configuration that seals around the polymer sheath.

[0027] The termination according to the invention may include one or more of the following features, individually or in any combination that may be technically possible:

[0028] -At least in the working position, the annular central region defines a radial tip that protrudes toward the polymer sheath beyond each annular peripheral region;

[0029] -In the resting configuration, the annular central region has the radial tip;

[0030] - The annular central region is made of an elastomer, particularly of fluororubber such as FKM, FFKM or FVMQ, or of nitrile rubber such as NBR or HNBR. Each annular peripheral region is made of metal or of a polymer that is more rigid than the elastomer, particularly of PEK, PEEK, PEEKK, PEKK, PEKEKK, or of fluoropolymers such as polyethylene tetrafluoride (PTFE).

[0031] - The end connector defines a seat groove for receiving an annular seal, the seat groove being defined by a lateral actuating surface for actuating the annular seal, the lateral actuating surface being located on an end arch or on a component fixed to the opposite end arch, the lateral actuating surface extending towards a first annular peripheral region, the seat groove being further defined by a lateral thrust surface for pushing the annular seal, the lateral thrust surface being located opposite the lateral actuating surface on an additional component for actuating compression of the annular seal, the lateral thrust surface extending towards a second annular peripheral region, the lateral actuating surface and the lateral thrust surface being movable relative to each other at least during end connector assembly to switch the annular seal from a rest configuration to an operating configuration;

[0032] - The additional components are fixed to the crimping ring;

[0033] - The termination defines a channel for transmitting external pressure to the flexible tube, the channel opening into the seat groove between the lateral actuation surface and the first annular peripheral region;

[0034] - The first annular peripheral region and / or the second annular peripheral region are assembled on the surface of the annular central region;

[0035] - The annular central region has a first inclined surface at a non-zero angle relative to a plane perpendicular to the central axis, and the first annular peripheral region has a first complementary inclined surface directly mounted on the first inclined surface. When the first inclined surface is moved radially toward the central axis, the inclination of the first inclined surface points toward the second annular peripheral region.

[0036] - The annular central region has a second inclined surface at a non-zero angle relative to a plane perpendicular to the central axis, the second inclined surface being positioned relative to the first inclined surface along the central axis, the second annular peripheral region having a second complementary inclined surface fixed to the second inclined surface, and the annular central region advantageously having a trapezoidal cross section.

[0037] - The first and second annular peripheral regions each have continuous or discontinuous annular components embedded in the material forming the annular central region.

[0038] - The end regions of the polymer sheath are: the end regions of the pressure sheath of the flexible tube, which defines an internal channel for allowing fluid flow; the end regions of the outer sheath of the flexible tube, which defines the outer surface of the flexible tube; and / or the end regions of the intermediate sheath, which is located in an annular space between the pressure sheath and the outer sheath.

[0039] Another subject of the invention relates to a flexible tube comprising a central section including at least one polymer sheath and a plurality of armored elements arranged around or within the polymer sheath, the flexible tube including at least one termination as defined above mounted at one end of the central section.

[0040] Another subject of the present invention is a method for assembling flexible tubes, the method comprising the following steps:

[0041] - Provides an end region of the polymer sheath of the flexible tube and an end segment of the armor element of the flexible tube, the end segment being arranged around or within the end region of the polymer sheath.

[0042] - Assemble an end arch and a cover, the end arch defining a central channel for allowing fluid to flow along the central axis, and the cover, together with the end arch, defining a chamber for receiving the end section of the armored element;

[0043] - Assemble at least one sealing assembly, the sealing assembly including at least one crimping ring, the crimping ring including at least one protrusion radially inserted into the polymer sheath;

[0044] - The annular seal is positioned away from the crimping ring to contact the polymer sheath;

[0045] The annular seal is characterized by comprising an annular central region capable of radial deformation toward a polymer sheath, and two reinforced annular peripheral regions located axially on either side of the annular central region. The method comprises moving the two annular peripheral regions toward each other to cause radial deformation of the annular central region toward the polymer sheath from a resting configuration to a working configuration that seals around the polymer sheath.

[0046] The method according to the invention may include one or more of the following features, individually or in any technically possible combination:

[0047] - An end fitting defines a seat groove for receiving an annular seal, the seat groove being defined by a lateral actuating surface for actuating the annular seal, the lateral actuating surface being located on an end arch or on a component fixed to an opposite end arch, the lateral actuating surface extending toward a first annular peripheral region, the seat groove being further defined by a lateral thrust surface for pushing the annular seal, the lateral thrust surface being located opposite the lateral actuating surface on an additional component for actuating compression of the annular seal, the lateral thrust surface extending toward a second annular peripheral region, moving the two annular peripheral regions toward each other includes moving the lateral actuating surface and the lateral thrust surface relative to each other to switch the annular seal from a rest configuration to an operating configuration;

[0048] - The method involves transmitting external pressure to the flexible tube up to the gap between the transverse actuation surface and the first annular peripheral region, so that the first annular peripheral region is brought closer to the second annular peripheral region. Attached Figure Description

[0049] The invention will be better understood by reading the following description, which is given by way of example only and with reference to the accompanying drawings, in which:

[0050] -[ Figure 1 ] Figure 1 This is a partial exploded perspective view of the first flexible tube according to the present invention;

[0051] -[ Figure 2 ] Figure 2 It is along Figure 1 The cross-sectional view of the intermediate axial plane of the relevant components of the flexible tube end fitting shown shows the annular seal resting on the pressure sheath;

[0052] -[ Figure 3 ] Figure 3 It is similar to Figure 2 The view, but in the case where the annular seal rests against the outer sheath;

[0053] -[ Figure 4 ] Figure 4 It is similar to Figure 2 The view, but in the case where the annular seal rests against the intermediate sheath;

[0054] -[ Figure 5 ] Figure 5 express Figure 2-4 The operating principle of the annular seal shown;

[0055] -[ Figure 6 ] Figure 6 A variation of the annular seal that can be used in the termination according to the invention is shown. Detailed Implementation

[0056] In the following text, the terms "outer (side)" and "inner (side)" generally refer to the radial direction relative to the axis A-A' of the pipe. The term "outer (side)" indicates that it is radially farther from the axis A-A', while the term "inner (side)" indicates that it is radially closer to the axis A-A' of the pipe.

[0057] The terms "front (part, side, square)" and "rear (part, side, square)" refer to the axial direction relative to the pipe's axis A-A'. "Front (part, side, square)" means relatively farther from the middle of the pipe and closer to one end, while "rear (part, side, square)" means relatively closer to the middle of the pipe and farther from one end. The middle of the pipe is a point equidistant from both ends.

[0058] The flexible tube 10 according to the present invention is in Figures 1 to 3 The middle part is shown.

[0059] Flexible tube 10 includes Figure 1The central section 12 is shown in the middle portion. The pipe includes an end fitting 14 at each axial end of the central section 12. Figure 1 (Not visible in the middle), its related components are in Figure 2 and Figure 3 The Chinese side indicated that...

[0060] refer to Figure 1 Pipe 10 defines a central channel 16 for allowing fluid, preferably petroleum fluid, to flow. The central channel 16 extends along the central axis A-A' between the upstream and downstream ends of pipe 10. It exits through end fitting 14.

[0061] The flexible tube 10 is used to pass through a body of water (not shown) in a device for extracting fluids, particularly hydrocarbons.

[0062] The body of water is, for example, the ocean, lake, or river. The depth of the water at the location of the equipment used to extract the fluid is, for example, between 500m and 3000m.

[0063] The device for extracting fluid includes a surface unit and a bottom unit (not shown), which are typically connected to each other via a flexible tube 10.

[0064] The flexible tube 10 is preferably an "unbonded" tube.

[0065] At least two adjacent layers of the flexible tube 10 move freely longitudinally relative to each other during tube bending. Advantageously, all layers of the flexible tube move freely relative to each other. Such tubes are described, for example, in the American Petroleum Institute (API) normative documents API 17J (May 2014, fourth edition) and API RP 17B (May 2014, fifth edition).

[0066] like Figure 1 As shown, the tube 10 defines multiple concentric layers around the axis A-A', which extend continuously along the central section 12 to the end fitting 14 located at the end of the tube.

[0067] According to the invention, the tube 10 includes at least one first polymer sheath, which advantageously forms a pressure sheath 20.

[0068] The tube 10 also includes tensile armor layers 24 and 25 arranged on the outside relative to the pressure sheath 20.

[0069] Advantageously, depending on the intended use, the tube 10 further includes: an inner skeleton 26 disposed inside the pressure sheath 20; a pressure arch 28 disposed between the pressure sheath 20 (or a ring, if appropriate) and one or more tensile armor layers 24, 25; and an outer sheath 30 for protecting the tube 10.

[0070] In a known manner, the tubular sheath 20 is used to confine the conveyed fluid within the channel 16 in a sealed manner. The sheath is made of a polymeric material, such as a polyolefin like polyethylene, a polyamide like PA11 or PA12, or a fluoropolymer like polyvinylidene fluoride (PVDF).

[0071] In one variant, the tubular sheath 20 is made of high-performance polymers such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneketone), PAI (polyamideimide), PEI (polyetherimide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymer), PPA (polyphthalamide) and / or mixtures thereof, or further mixtures with PTFE (polytetrafluoroethylene) or PFPE (perfluoropolyether).

[0072] The thickness of the pressure sleeve 20 is, for example, between 5 mm and 20 mm.

[0073] like Figure 2 As can be seen, the pressure sleeve 20 has an end region 27 disposed in the termination member 14.

[0074] When the skeleton 26 is present, the skeleton 26 is formed, for example, from a spirally wound irregular metal strip. The turns of the metal strip are advantageously interlocked, thereby serving to withstand radial compressive forces.

[0075] In this example, the skeleton 26 is arranged inside the pressure sheath 20. The flexible tube 10 is referred to as a "non-smooth channel" tube due to the geometry of the skeleton 26.

[0076] In a variant (not shown), the flexible tube 10 does not have an internal skeleton 26, and is referred to by the term "smooth channel" tube.

[0077] The spiral winding of the irregular metal strip forming the skeleton 26 has a short pitch, that is, the absolute value of its helical angle around the tube axis A-A' is close to 90°, typically between 75° and 90°.

[0078] In this example, the pressure arch 28 is used to withstand radial forces associated with the pressure inside the pressure sheath 20. The pressure arch is formed, for example, by a profiled metal wire spirally wound around the sheath 20. The profiled metal wire typically has a complex geometry, particularly Z, T, U, K, X, or I shapes, used to secure the turns of the pressure arch 28 to each other. This securing of the turns of the pressure arch 28 controls the spacing between adjacent turns, in particular to prevent the pressure sheath 20 from creeping through the pressure arch 28 under the pressure inside the tube 10.

[0079] The pressure arch 28 is wound around the pressure sheath 20 in a short-pitch spiral, that is, the absolute value of the spiral angle around the tube axis A-A' is close to 90°, typically between 75° and 90°.

[0080] If appropriate, a hoop ( Figure 1 (Not shown in the image) Encircling the pressure arch 28. In addition to the pressure arch 28, hoops are also used to withstand radial forces associated with the pressure. The hoops are, for example, formed of a generally rectangular cross-section wire wound in a short-pitch helical shape around the pressure arch sheath 28. The hoop turns are not locked together.

[0081] The flexible tube 10 according to the invention includes at least one armor layer 24, 25, which is formed by spirally winding at least one elongated armor element 29.

[0082] exist Figure 1 In the example shown, the flexible tube 10 includes multiple armor layers 24, 25, particularly a first inner armor layer 24 abutting against the pressure arch 28 (or against the sheath 20 when the pressure arch 28 is not present), and a second outer armor layer 25 arranged around it by the outer sheath 30.

[0083] Each armor layer 24, 25 includes a longitudinal armor element 29, which is wound around the tube axis A-A' with a large pitch.

[0084] "Large pitch helix" refers to a helix angle with an absolute value of less than 60°, typically between 25° and 55°.

[0085] The armor elements 29 of the first layer 24 are typically wound at an opposite angle to the armor elements 29 of the second layer 25. Therefore, if the winding angle of the armor elements 29 of the first layer 24 is equal to +α (where α is between 25° and 55°), then the winding angle of the armor elements 29 of the second armor layer 25 arranged to contact the first layer 24 is, for example, -α, where α is between 25° and 55°.

[0086] Armor element 29 is formed, for example, from metal wire or composite tape, particularly composite tape reinforced with carbon fiber.

[0087] like Figure 2 As can be seen, each armored element 29 has an end section 32 inserted into the termination 14. The end section 32 extends to a free end arranged in the termination 14. It advantageously has a helical or pseudo-helical trajectory in the termination 14 with the axis A-A' as the axis.

[0088] The flexible tube 10 advantageously includes a wear-resistant layer interposed between the pressure arch 28 and the first inner armor layer 24 and between the two armor layers 24, 25.

[0089] Each wear-resistant layer is formed by spirally winding a polymer strip, typically between 2 mm and 4 mm thick. Each wear-resistant layer functions to reduce friction between metal wires or to reduce wear between composite strips with the wear-resistant layer inserted.

[0090] The outer sheath 30 is used to form a sealing barrier to prevent liquid from seeping from the outside of the flexible tube to the inside. The outer sheath is advantageously made of polymeric materials, particularly polyolefins such as polyethylene, polyamides such as PA11 or PA12, or fluoropolymers such as polyvinylidene fluoride (PVDF).

[0091] In one variant, the tubular sheath 30 is made of a high-performance polymer, such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneketone), PAI (polyamideimide), PEI (polyetherimide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymer), PPA (polyphthalamide) and / or mixtures thereof, or further mixtures with PTFE (polytetrafluoroethylene) or PFPE (perfluoropolyether).

[0092] The width of the outer sheath 30 is, for example, between 5mm and 15mm.

[0093] like Figure 2 As shown, in addition to the end region 27 of the pressure sheath 20 and the end section 32 of the armor element 29, each termination 14 also includes an end arch 50 and an outer connection cover 51 that projects axially rearward from the end arch 50. The cover 51, together with the end arch 50, defines a chamber 52 for receiving the end section 32 of the armor element 29.

[0094] Termination member 14 also includes a front sealing assembly 54 surrounding the pressure sheath 20 and a rear sealing assembly 56 surrounding the outer sheath 30 (described below). Figure 3 (Only visible in the middle).

[0095] In this example, the termination 14 also includes a solid filler material 58, such as a thermosetting polymer resin like epoxy resin or araldite. The solid filler material is disposed inside the chamber 52 around the end section 32.

[0096] In this example, the end arch 50 is used to connect the pipe 10 to another connection fitting 14 or to an end facility, advantageously via an end flange (not shown).

[0097] The end arch 50 has a central channel 62 for receiving the end region 27 of the pressure sheath 20 and allowing fluid flowing through the central channel 16 to flow out of the pipe 10.

[0098] exist Figure 2 In the example shown, the end arch 50 defines a rear surface 64 on the inside, which defines a convergent support surface 66 for the crimping ring.

[0099] The cover 51 includes a tubular peripheral wall 70 extending around axis A-A'. The peripheral wall 70 has a front edge (not visible) and a rear edge 74 fixed to the end arch 50. Figure 3 (As can be seen in the image), the front edge is radially spaced from the armor layers 24 and 25, and the rear edge 74 extends axially backward beyond the end arch 50.

[0100] The cover 51 is radially directed outward to the chamber 52.

[0101] The front sealing assembly 54 is advantageously located at the front of the end member 14, in contact with the end arch 50, and axially offset forward relative to the rear sealing assembly 56.

[0102] The front sealing assembly includes a front crimping ring 76 for engaging with the pressure sleeve 20 and a front clamping flange 78 for clamping the front crimping ring 76.

[0103] exist Figure 2 In the example shown where the pipe 10 includes a pressure arch 28, the front sealing assembly 54 also includes a stop flange 80 for stopping the pressure arch 28, and advantageously also includes a spacer 79.

[0104] According to the invention, the front sealing assembly 54 further includes an actuable annular seal 81 arranged to rest against the pressure sleeve 20, the annular seal 81 being received in an annular seat groove 82 of the end connector 14.

[0105] The front clamping flange 78 is configured to be fixed to the rear surface 64 of the end arch 50 with screws.

[0106] The front pressure ring 76 is configured to be pushed forward by the front clamping flange 78 during its mounting on the end arch 50, slide on the converging surface 66, and move forward along the axis A-A'. The front pressure ring 76 includes a front protrusion 84 configured to be radially pushed into the pressure sleeve 20 by a wedging effect during the movement of the front pressure ring 76 on the converging surface 66.

[0107] like Figure 2 and Figure 5As can be seen, the seat groove 82 is defined at the front by an annular shoulder formed in the flange 78, which faces the end region 27 of the pressure sheath 20 arranged in the end fitting. The shoulder defines a lateral actuating surface 90 for actuating the annular seal 81, and an inner circumferential surface 91, which is arranged in front of the annular seal 81 and extends around and towards the sheath 20.

[0108] The seat groove 82 is closed rearward by a lateral thrust surface 92 defined at the front of the spacer 79. Therefore, the lateral thrust surface 92 is configured close to the lateral actuation surface 90 to compress the annular seal 81. The spacer 79 here forms an additional component for actuating the compression of the annular seal 81, which is directly mounted on the end arch 50.

[0109] refer to Figure 5 The end arch 50 and the front flange 78 advantageously define at least one channel 94 for transmitting pressure from the outside of the flexible tube 10 toward the seat groove 82.

[0110] The channel 94 opens through the transverse actuation surface 90 on one hand and leads into the chamber 52 on the other. Thus, if appropriate, the external pressure applied to the chamber 52 is configured to be transmitted through the channel 94 to the intermediate space located between the transverse actuation surface 90 and the annular seal 81.

[0111] like Figure 2 and Figure 5 As shown, the actuable annular seal 81 includes: a deformable central region 100 for sealingly inserting between the sheath 20 and the inner surface 91 of the defining seat groove 82; a first reinforced front peripheral region 102 disposed on a first side of the central region 100; and a second reinforced 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 toward each other to compress the central region 100 and cause the central region 100 to expand radially toward the sheath 20.

[0112] The central region 100 is preferably formed of a deformable material such as an elastomer. The elastomer is, for example, a fluororubber, such as a fluorocarbon compound (FKM) made from vinylidene fluoride (VDF or VF2), which is selected, for example, from a copolymer of hexafluoropropylene (HFP) and VF2, tetrafluoroethylene (or "TFE"), a terpolymer of HFP and VF2, a terpolymer of TFE and perfluoromethyl vinyl ether (or "PMVE") and VF2, a terpolymer of TFE, propylene and VF2, or a pentpolymer of TFE, HFP, ethylene, PMVE and VF2.

[0113] In one variant, fluororubber is a perfluororubber (FFKM), such as TFE, PMVE, and a terpolymer of a third monomer that can be used for crosslinking. In another variant, fluororubber is a fluorosilicone rubber (FVMQ) or a propylene-tetrafluoroethylene (FEPM) copolymer.

[0114] In one variation or additionally, the central region 100 is made of nitrile rubber, more specifically, of acrylonitrile-butadiene copolymer (NBR) and / or hydrogenated acrylonitrile-butadiene copolymer (HNBR).

[0115] In this example, the central region 100 has a trapezoidal cross section that tapers from the outside to the inside between the inner surface 91 of the seat groove 82 and the pressure sleeve 20, and the cross section is cut in each intermediate axial plane passing through axis A-A'.

[0116] refer to Figure 5 The central region 100 includes a first forward inclined surface 106, a second backward inclined surface 108, and an outer peripheral surface 110 connecting the first and second inclined surfaces 106 and 108.

[0117] The central area also includes an inner tip 112 for attaching to the sheath 20.

[0118] The first inclined surface 106 tilts backward and moves from front to back. It converges toward the inner tip 112. The second inclined surface 108 tilts forward and moves from back to front. It also converges toward the tip 112.

[0119] Therefore, the width of the central region 100 measured along the axis A-A' at the inner tip 112 is smaller than the width of the central region 100 measured along the axis A-A' at the outer peripheral surface 110.

[0120] Preferably, the material forming the central region 100 has a hardness of less than 100 Shore A, particularly between 60 Shore A and 90 Shore A.

[0121] The central region 100 is therefore more deformable than the peripheral regions 102 and 104, thus allowing the central region to expand radially toward the sheath 20 and press against the sheath 20.

[0122] The first front peripheral region 102 has a wedge-shaped cross-section cut in each intermediate axial plane passing through axis A-A'. Therefore, it has a first front side surface 114 perpendicular to axis A-A' and a first complementary inclined surface 116 located at the rear, the first front side surface extending to the ground facing the lateral actuation surface 90, and the first complementary inclined surface 116 abutting against the first front inclined surface 106 of the central region 100.

[0123] The tilt angle α of the first forward tilted surface 106 and the first complementary tilted surface 116 relative to the axis A-A' is, for example, between 40° and 80°.

[0124] The first front surface 114 advantageously continues toward the sheath 20 via a front chamfer 114A located opposite the sheath 20.

[0125] The second peripheral region 104 has a second rear side surface 118 perpendicular to the axis A-A' and a second complementary inclined surface 120 located at the front. The second rear side surface 118 is designed to extend to the ground facing the lateral thrust surface 92, and the second complementary inclined surface 120 abuts against the second rear inclined surface 108 of the central region 100.

[0126] The tilt angle β of the second rearward tilted surface 108 and the second complementary tilted surface 116 relative to the axis A-A' is, for example, between 40° and 80°. Angle β is preferably equal to angle α.

[0127] The second rear surface 118 advantageously continues toward the sheath 20 via a rear chamfer 118A located opposite the sheath 20.

[0128] The first front peripheral region 102 and the second rear peripheral region 104 are each formed of a material that is harder than the central region, such as a thermoplastic polymer.

[0129] It is made, for example, from PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneketone), or from fluoropolymers such as polytetrafluoroethylene (PTFE).

[0130] Preferably, the material forming each peripheral region 102, 104 has a harder hardness than the central region 100. This hardness is, for example, greater than 65 Shore D.

[0131] The surrounding areas 102 and 104 are made of, for example, PTFE or PEEK.

[0132] Thus, under the action of the rearward thrust applied to the first peripheral region 102 at the first front surface 114 and / or the forward thrust applied to the second peripheral region 104 at the second side surface 118, the first peripheral region 102 and the second peripheral region 104 are configured to approach each other to compress the central region 100 between the complementary inclined surfaces 116, 120. This causes the inner tip 112 to expand radially toward the sheath 20, and causes the outer peripheral surface 110 to abut against the inner surface 91 of the seat groove 82.

[0133] During the assembly of the termination 14, the annular seal 81 thereby switches from a rest configuration to a first working seal configuration under compression, in which the seal forms a seal between the sleeve 20 and the front compression flange 78.

[0134] The seal is strengthened as pressure increases in the annular space between the outer sheath 30 and the pressure sheath 20, tending to push the second peripheral region 104 toward the first peripheral region 102.

[0135] In a known manner, such as Figure 3 As shown, the rear sealing assembly 56 includes a rear crimping ring 130, a rear clamping flange 132 for clamping the rear crimping ring 130, and a rear compression flange 134.

[0136] The rear sealing assembly 56 advantageously includes an intermediate support sleeve 128 inserted between the outer sheath 30 and the armor layers 24, 25, with the outer sheath 30 resting against the intermediate sleeve 128.

[0137] The advantage is that, Figure 3 In the illustrated embodiment, the rear sealing assembly 56 further includes an actuable outer annular seal 81 disposed in the outer seat groove 82.

[0138] The rear crimping ring 130 is inserted between the rear inclined surface 136 of the cover 51 and the outer sheath 30. The rear crimping ring has a front protrusion 137 configured to be radially pushed into the outer sheath 30 by a wedging effect during the movement of the rear crimping ring 130 on the surface 136.

[0139] The rear clamping flange 132 is fixed to the rear edge 74 of the cover 51. The rear clamping flange pushes the rear pressing ring 130 forward so that the ring moves radially toward the axis A-A' and presses against the outer sheath 30.

[0140] The outer sheath 30 rests against the intermediate sleeve 128. The outer sheath is axially wedged into the rear of the fixing assembly 56.

[0141] The outer seat groove 82 of the rear sealing assembly 56 has a similar structure to the seat groove 82 defined for the front sealing assembly 54.

[0142] The outer seat groove is defined by an annular shoulder formed in the rear clamping flange 132, which faces the end region of the outer sheath 30 arranged in the end connector 14. As described above, the shoulder defines a first lateral actuating surface 90 and an inner circumferential surface 91 for actuating the annular seal 81, the first lateral actuating surface being arranged in front of the annular seal 81, and the inner circumferential surface extending around and towards the sheath 30.

[0143] The seat groove 82 is closed rearward by a lateral thrust surface 92 defined at the front of the rear compression flange 134. Therefore, the lateral thrust surface 92 is configured close to the lateral actuation surface 90 to compress the annular seal 81 as described above. The rear compression flange 134 thus forms an additional component for actuating the compression of the annular seal 81, which is directly mounted on the cover 51.

[0144] The annular seal 81 of the rear sealing assembly 56 has the same structure as the annular seal 81 of the front sealing assembly 54.

[0145] The assembly of terminator 14 will now be described.

[0146] First, the end arch 50 is assembled around the end region 27 of the pressure sleeve 20, and the armor layers 24 and 25 have been moved radially outward.

[0147] The crimping ring 76 is assembled between the pressure sleeve 20 and the converging surface 66 of the end arch 50.

[0148] The clamping flange 78 is then assembled so that it is pressed against the rear surface 64 of the end arch 50. The actuating annular seal 81, in its resting configuration, is then assembled into the seat groove 82. The seat groove 82 is then closed by inserting a spacer 79.

[0149] The clamping flange 78 and spacer 79 are then pressed against the end arch 50, causing the lateral thrust surface 92 to move toward the lateral actuating surface 90 and compressing the central region 100 of the actuable seal between the peripheral regions 102 and 104. As a result, the inner tip 112 is pressed against and squeezed against the sleeve 20.

[0150] Similarly, sleeve 128 is inserted between armor elements 24, 25 and outer sheath 30.

[0151] Assemble the cover 51 around the tube 10 to form a chamber 52 together with the end arch 50. Then assemble the rear crimp ring 130 between the cover 51 and the outer sheath 30. Then assemble the rear crimp flange 132 to define the outer seat groove 82, and then insert the annular seal 81 into the outer seat groove 82.

[0152] The compression flange 134 is then assembled onto the rear of the clamping flange 132. The rear clamping flange 132 is then pressed against the rear edge 74 of the cover 51. The compression flange 134 moves closer to the rear clamping flange 132, thereby causing the central region 100 of the outer annular seal 81 to be compressed between the first peripheral region 102 and the second peripheral region 104, and causing the inner tip 112 to abut against the outer sheath 30.

[0153] Advantageously, during assembly, pressure can be introduced through channel 94 to test the sealing performance provided by the annular seal 81, according to an adaptation of the method described in US 6,923,477, to ensure that the annular seal 81 is configured to provide a seal between the end arch 50 and the pressure sleeve 20 in the event of seal failure between the front pressure ring 76 and the pressure sleeve 20.

[0154] In use, even if overpressure may exist on the outer side of the flexible tube 10 relative to the inner side, the annular seal 81 maintains a seal around the pressure sleeve 20 even if the crimp integrity of the front crimp ring 76 relative to the end region 27 of the pressure sleeve 20 fails. This seal is further enhanced because the overpressure transmitted to the annular seal 81 through the channel 94 causes additional compression on the central region 100, exceeding the main compression caused by the assembly of the annular seal 81.

[0155] exist Figure 4 In the variant shown, the flexible tube 10 further includes an intermediate sheath 150 disposed in the annular space between the pressure sheath 20 and the outer sheath 30. The termination also includes an intermediate sleeve 152 on which the intermediate sheath 150 rests.

[0156] The intermediate sleeve 152 is advantageously provided with an internal channel for gas circulation.

[0157] The end fitting 14 includes an intermediate sealing assembly 153, which includes a first intermediate receiving flange 154 mounted on the end arch 50 at the rear surface 64 and a second intermediate compression flange 156 mounted on the first intermediate flange 154. The intermediate sealing assembly 153 also includes an intermediate crimping ring 158 for crimping an intermediate sheath 150 and a clamping flange 159 mounted at the rear of the flanges 154 and 156.

[0158] The advantage is that, Figure 4 In the illustrated embodiment, the intermediate sealing assembly 153 further includes an actuable intermediate annular seal 81 disposed in an intermediate seat groove 82 formed between the first intermediate flange 154 and the second intermediate flange 156.

[0159] The intermediate crimping ring 158 includes two opposing protrusions, namely a front protrusion 160 and a rear protrusion 162, each protrusion being inserted into the intermediate sheath 150.

[0160] The intermediate crimping ring 158 is positioned at the front between the rear inclined surface 164 of the intermediate crimping flange 156 and the intermediate sleeve 150, and at the rear between the front inclined surface 166 of the intermediate clamping flange 159 and the intermediate sleeve 150.

[0161] The above causes the front protrusion 160 and the rear protrusion 162 to press into the intermediate sheath 150.

[0162] The intermediate receiving flange 154, intermediate pressing flange 156 and intermediate clamping flange 159 press against each other and are fixed together to the rear surface 64 of the end arch 50.

[0163] The intermediate sheath 150 rests on the intermediate sleeve 152.

[0164] The intermediate sealing assembly 153 has an intermediate seat groove 82 with a similar structure to the seat groove 82 defined for the front sealing assembly 54. It is located in front of the intermediate crimping ring 158.

[0165] The intermediate seat groove 82 is defined by an annular shoulder formed in the intermediate receiving flange 154, which faces the end region of the intermediate sleeve 150 arranged in the end connector 14. As described above, the shoulder defines a first lateral actuating surface 90 and an inner circumferential surface 91 for actuating the annular seal 81, the first lateral actuating surface being arranged in front of the annular seal 81, and the inner circumferential surface extending around and towards the intermediate sleeve 150.

[0166] The seat groove 82 is closed rearward by a lateral thrust surface 92 defined at the front of the intermediate compression flange 156. Thus, the lateral thrust surface 92 is configured close to the lateral actuation surface 90 to compress the annular seal 81, as described above.

[0167] The intermediate extrusion flange 156 thus forms an additional component for actuating the extrusion of the annular seal 81, which is directly mounted on the end arch 50.

[0168] The annular seal 81 of the intermediate sealing assembly 153 has the same structure as the annular seal 81 of the front sealing assembly 54. It provides an effective seal between the intermediate sleeve 150 and the intermediate flanges 154, 156, even if the seal is not maintained by the intermediate crimp ring 158.

[0169] In applicable Figures 2 to 4 In variations of the embodiments shown, the first peripheral region 102 and the second peripheral region 104 are each formed by a reinforcing ring 180 embedded in a deformable material forming the central region 100. The reinforcing ring 180 is, for example, a spring wire, a rod, or a rope.

[0170] The reinforcing ring 180 is formed, for example, of metal, metal alloy, or a material harder than the central region 100, such as thermoplastic polymer, and especially of fiber.

[0171] Metal alloys, for example, are phosphor bronze. Fibers, for example, are synthetic polyester fibers.

[0172] More rigid materials are made of PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneketone), or fluoropolymers such as polytetrafluoroethylene (PTFE). Thermoplastic polymers can be filled with fibers such as carbon fiber.

[0173] In one variation, the reinforcing ring 180 is composed of, for example, a combination of a metal and a thermoplastic polymer arranged coaxially. More specifically, the reinforcing ring 180 includes a coaxial helical spring, which advantageously has an inner helical spring made of metal, particularly stainless steel, and an outer spring made of a polymer, particularly PEEK (polyether ether ketone).

[0174] In a variant, such as Figure 6 As shown, the reinforcing ring 180 is a combination of spring wire 180A and retaining ring 180B, with retaining ring 180B arranged inside spring wire 180A.

[0175] In this example, the reinforcing ring 180 is arranged near the inner surface of the annular seal 81 for abutting against the sleeves 20, 30, and 150 on both sides of the tip 112. Here, when at rest, the tip 112 protrudes. The tip has a rounded profile.

[0176] also, Figure 6 The operation of the annular seal 81 described herein is similar to Figure 5 The operation described in the text.

Claims

1. An end fitting (14) for conveying fluid in a flexible tube (10), comprising: - At least one end region of the polymer sheath (20; 30; 150) of the flexible tube (10); - The end section of the armor element (29) of the flexible tube (10) is arranged around or in the end region of the polymer sheath (20; 30; 150); - An end arch (50) defines a central channel for allowing fluid flow, the central channel extending along a central axis (A-A'); - Cover (51), the cover together with the end arch (50) defines a chamber (52) for receiving the end section of the armored element (29); - At least one sealing assembly (54; 56; 153) includes at least one crimping ring (76; 130; 158), the crimping ring (76; 130; 158) including at least one protrusion radially inserted into the polymer sheath (20; 30; 150); - The annular seal (81), located away from the crimp ring (76; 130; 158), is arranged to contact the polymer sheath (20; 30; 150); The annular seal (81) is characterized by comprising an annular central region (100) capable of radially deforming toward the polymer sheath (20; 30; 150), and two reinforced annular peripheral regions (102, 104) located on either side of the annular central region (100) along a central axis (A-A'), the two annular peripheral regions (102, 104) being movable toward each other such that the annular central region (100) undergoes radial deformation toward the polymer sheath (20; 30; 150) from a resting configuration to a working configuration that seals around the polymer sheath (20; 30; 150).

2. The termination member (14) according to claim 1, wherein, At least in the working position, the annular central region (100) defines a radial tip (112) that protrudes beyond each annular peripheral region (102, 104) toward the polymer sheath (20; 30; 150).

3. The termination member (14) according to claim 2, wherein, In the resting configuration, the annular central region (100) has the radial tip (112).

4. The termination member (14) according to claim 1 or 2, wherein, The annular central region (100) is made of an elastomer, and each annular peripheral region (102, 104) is made of metal or a polymer that is more rigid than an elastomer.

5. The termination (14) according to claim 1 or 2, wherein the termination defines a seat groove (82) for receiving an annular seal (81), the seat groove (82) being defined by a lateral actuating surface (90) for actuating the annular seal (81), the lateral actuating surface being located on an end arch (50) or on a component fixed to the opposite end arch (50), the lateral actuating surface (90) extending towards a first annular peripheral region (102), the seat groove (82) being further defined by a lateral thrust surface (92) for pushing the annular seal (81), the lateral thrust surface being located opposite the lateral actuating surface (90) on an additional component for actuating compression of the annular seal (81), the lateral thrust surface (92) extending towards a second annular peripheral region (104), the lateral actuating surface (90) and the lateral thrust surface (92) being movable relative to each other at least during the assembly of the termination (14) to switch the annular seal (81) from a rest configuration to an operating configuration.

6. The termination member (14) according to claim 5, wherein, The additional components are attached to the crimping rings (76; 130; 158).

7. The termination member (14) according to claim 5, wherein, The termination defines a channel (94) for transmitting external pressure to the flexible tube (10), the channel opening into the seat groove (82) between the lateral actuation surface (90) and the first annular peripheral region (102).

8. The termination (14) according to claim 1 or 2, wherein, The first annular peripheral region (102) and / or the second annular peripheral region (104) are assembled on the surface (106, 108) of the annular central region (100).

9. The termination member (14) according to claim 8, wherein, The annular central region (100) has a first inclined surface (106) at a non-zero angle relative to a plane perpendicular to the central axis (A-A'), and the first annular peripheral region (102) has a first complementary inclined surface (116) assembled onto the first inclined surface (106). When the first inclined surface (106) is moved radially toward the central axis (A-A'), the inclination of the first inclined surface (106) points toward the second annular peripheral region (104).

10. The termination member (14) according to claim 9, wherein, The annular central region (100) has a second inclined surface (108) at a non-zero angle relative to a plane perpendicular to the central axis (A-A'), the second inclined surface (108) being positioned relative to the first inclined surface (106) along the central axis (A-A'), and the second annular peripheral region (104) has a second complementary inclined surface (120) fixed to the second inclined surface (108).

11. The termination (14) according to claim 10, wherein, The annular central region (100) has a trapezoidal cross section.

12. The termination (14) according to claim 1 or 2, wherein, The first annular peripheral region (102) and the second annular peripheral region (104) each have a continuous or discontinuous annular member (180) embedded in the material forming the annular central region (100).

13. The termination (14) according to claim 1 or 2, wherein, The end regions of the polymer sheaths (20; 30; 150) are: the end regions of the pressure sheath (20) of the flexible tube (10), which defines an internal channel for allowing fluid flow; the end regions of the outer sheath (30) of the flexible tube (10), which defines an outer surface of the flexible tube (10); and / or the end regions of the intermediate sheath (150), which is located in an annular space between the pressure sheath (20) and the outer sheath (30).

14. A flexible tube (10) comprising a central section (12) including at least one polymer sheath (20; 30; 150) and a plurality of armor elements (29) arranged around or within the polymer sheath, the flexible tube (10) including at least one termination (14) according to claim 1 or 2 mounted at one end of the central section (12).

15. A method for assembling an end connector (14) of a flexible tube (10), comprising the following steps: - Provides the end regions of the polymer sheath (20; 30; 150) of the flexible tube (10) and the end sections of the armor element (29) of the flexible tube (10), the end sections being arranged around or in the end regions of the polymer sheath (20; 30; 150); - Assemble an end arch (50) and a cover (51), the end arch defining a central channel for allowing fluid to flow along the central axis (A-A'), and the cover together with the end arch (50) defining a chamber (52) for receiving the end section of the armored element (29); - Assemble at least one sealing assembly (54; 56; 153), the sealing assembly including at least one crimping ring (76; 130; 158), the crimping ring including at least one protrusion radially inserted into the polymer sheath (20; 30; 150); - The annular seal (81) is arranged to contact the polymer sheath (20; 30; 150) away from the crimp rings (76; 130; 158); The annular seal (81) is characterized by comprising an annular central region (100) capable of radial deformation toward the polymer sheath (20; 30; 150) and two reinforced annular peripheral regions (102, 104) located axially on opposite sides of the annular central region (100), the method comprising moving the two annular peripheral regions (102, 104) toward each other such that the annular central region (100) undergoes radial deformation toward the polymer sheath (20; 30; 150) from a resting configuration to a working configuration that seals around the polymer sheath (20; 30; 150).

16. The method according to claim 15, wherein, The end member (14) defines a seat groove (82) for receiving an annular seal (81), the seat groove (82) being defined by a lateral actuating surface (90) for actuating the annular seal (81), the lateral actuating surface being located on an end arch (50) or on a component fixed to the opposite end arch (50), the lateral actuating surface (90) extending towards a first annular peripheral region (102), the seat groove being further defined by a lateral thrust surface (92) for pushing the annular seal (81), the lateral thrust surface being located opposite the lateral actuating surface (90) on an additional component for actuating compression of the annular seal (81), the lateral thrust surface extending towards a second annular peripheral region (104), moving the two annular peripheral regions (102, 104) toward each other includes moving the lateral actuating surface (90) and the lateral thrust surface (92) relative to each other to switch the annular seal (81) from a rest configuration to an operating configuration.

17. The method of claim 16, further comprising transmitting external pressure to the gap between the flexible tube (10) and the transverse actuation surface (90) and the first annular peripheral region (102) to bring the first annular peripheral region (102) closer to the second annular peripheral region (104).

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