Flexible pipe end fitting

Abstract

An end fitting for joining to a pipe body, a flexible pipe including such an end fitting and a pipe body, and a method of assembling a flexible pipe are disclosed. The end fitting includes a sleeve partially insertable radially inward of the polymer layer of the tube body; and a polymeric collar for receiving the polymeric layer of the tube body, the polymeric collar disposed radially outward of the sleeve and configured to be welded to the polymeric layer of the tube body. The flexible pipe includes: a pipe body including a polymer layer; and an end fitting, the end fitting comprising: a sleeve partially inserted radially inward of the polymer layer of the tube body; and a polymeric collar for receiving the polymeric layer of the tube body, the polymeric collar disposed radially outward of the sleeve and configured to be welded to the polymeric layer of the tube body.

Description

[0001] This invention relates to a flexible tube seal. In particular, but not exclusively, this invention relates to an end fitting for engagement with a tube body, a flexible tube including such an end fitting and a tube body, and a method for assembling the flexible tube.

[0002] Traditionally, flexible tubing is used to transport produced fluids such as oil and / or gas and / or water from one location to another. Flexible tubing is particularly useful for connecting subsea locations (which can be deep-sea) to sea-level locations. Tubing can typically have an inner diameter up to about 0.6 meters (e.g., diameters can range from 0.05 m to up to 0.6 m). Flexible tubing is generally formed as an assembly of a flexible tubing body and one or more end fittings. The tubing body is typically formed as a combination of layered materials that form a pressure-bearing conduit. The tubing structure allows for large flexural deformation without causing bending stresses that impair the functionality of the tubing during its lifespan. The tubing body is typically constructed as a combination of polymer layers and / or metal layers and / or composite material layers. For example, the tubing body may include polymer layers and metal layers, polymer layers and composite material layers, or polymer layers, metal layers, and composite material layers.

[0003] API Recommended Practice 17B provides guidance for the design, analysis, manufacture, testing, installation, and operation of flexible pipes and flexible pipe systems for onshore, subsea, and marine applications, while API Specification 17J, entitled "Specification for Unbonded Flexible Pipe," defines the technical requirements for safety, dimensional, and functionally interchangeable flexible pipes designed and manufactured to uniform standards and guidelines.

[0004] Unbonded flexible tubing has been used in deepwater (less than 3300 feet (1005.84 meters)) and ultra-deepwater (greater than 3300 feet) development. The demand for oil exploration at increasingly greater depths is growing, where environmental factors are becoming increasingly extreme. For example, in such deepwater and ultra-deepwater environments, seafloor temperatures increase the risk of produced fluids cooling to temperatures that could cause tubing blockage. The increased depth also increases the pressure associated with the environment in which the flexible tubing must operate. For instance, the flexible tubing may need to operate under external pressures ranging from 0.1 MPa to 30 MPa acting on it. Similarly, transporting oil, gas, or water can effectively generate high pressures acting on the flexible tubing from within, such as internal pressures from wellbore fluids ranging from 0 MPa to 140 MPa acting on it. Therefore, there is an increased demand for high-performance layers in the flexible tubing body.

[0005] Throughout this specification, reference will be made to the flexible tube. It should be understood that the flexible tube is an assembly of a tube body and one or more end fittings, the respective ends of which terminate in each of the one or more end fittings. Figure 1 An example is illustrated of how, according to one embodiment, a pipe body 100 is formed from a combination of layered materials that form a pressure-bearing conduit. Although Figure 1 Several specific layers are illustrated, but it should be understood that the tube body is broadly applicable to coaxial structures comprising two or more layers made of a variety of possible materials. For example, the tube body may be formed of polymer layers, metal layers, composite material layers, or combinations of different materials. It should also be noted that layer thicknesses are shown for illustrative purposes only. As used herein, the term "composite material" is used broadly to refer to a material formed of two or more different materials, such as a material formed of a matrix material and reinforcing fibers.

[0006] like Figure 1 As illustrated, the tube body includes an optional innermost carcass layer 101. The carcass provides an interlocking structure that can be used as the innermost layer to completely or partially prevent the inner pressure sheath 102 from collapsing due to tube decompression, external pressure, tensile armor pressure, and mechanical fracture loads. The carcass layer is typically a metal layer, for example, formed of stainless steel. The carcass layer may also be formed of composite materials, polymers, or other materials, or combinations thereof. It should be understood that certain embodiments are suitable for “smooth hole” operations (i.e., without a carcass layer) as well as such “rough hole” applications (i.e., with a carcass layer).

[0007] The internal pressure jacket 102 acts as a fluid retention layer and includes a polymer layer that ensures the integrity of the internal fluid. It should be understood that this layer itself may include multiple sublayers. It should be understood that when an optional carcass layer is used, the internal pressure jacket is generally referred to by those skilled in the art as a barrier layer. In operations without such a carcass (so-called smooth bore operation), the internal pressure jacket may be referred to as a liner.

[0008] The optional pressure armor layer 103 is a structural layer that increases the resistance of the flexible tube to internal and external pressures as well as mechanical fracture loads. This layer also structurally supports the internal pressure sheath and is typically formed by an interlocking structure of wire wound at a near 90° angle. The pressure armor layer is typically a metal layer, for example, made of carbon steel. The pressure armor layer may also be formed from composite materials, polymers, or other materials, or combinations thereof.

[0009] The flexible tube body also includes an optional first tensile armor layer 105 and an optional second tensile armor layer 106. Each tensile armor layer is used to withstand tensile loads and internal pressure. The tensile armor layer is typically formed of multiple wires (to impart layer strength), which are located above the inner layer and spirally wound along the length of the tube at an angle typically between about 10° and 55°. The tensile armor layers are typically wound in pairs in opposite directions. The tensile armor layer is typically a metal layer, for example, formed of carbon steel. The tensile armor layer may also be formed of composite materials, polymers, or other materials, or combinations thereof.

[0010] The flexible tube body shown also includes an optional strip layer 104, which helps to contain the underlying layers and, to some extent, prevents wear between adjacent layers. The strip layer may be a polymer, a composite material, or a combination of materials.

[0011] The flexible tube body typically also includes an optional insulation layer 107. The tube body includes an outer sheath 108, which includes a polymer layer for protecting the tube from seawater and other external environmental penetration, corrosion, abrasion, and mechanical damage.

[0012] Each flexible tube includes at least one portion (sometimes referred to as a section or segment of the tube body 100) and an end fitting located at at least one end of the flexible tube. The end fitting provides a mechanical means for forming a transition between the flexible tube body and the connector. For example, as... Figure 1 The different tube layers shown terminate in end fittings, allowing load transfer between the flexible tube and the connector.

[0013] End fittings for flexible pipes can be used to connect sections of the flexible pipe body together or to connect it to terminal equipment, such as rigid subsea structures or floating installations. Therefore, in other diverse applications, flexible pipes can be used to provide riser assemblies for transporting fluid from subsea flow lines to floating structures. In such riser assemblies, a first section of the flexible pipe can be connected to one or more additional sections of the flexible pipe. Each section of the flexible pipe includes at least one end fitting.

[0014] Figure 2 An example is illustrated of a riser assembly 200 suitable for conveying produced fluids such as oil and / or gas and / or water from a seabed location 201 to a floating facility. For example, in Figure 2 In the middle, seabed location 201 includes a seabed mobile pipeline. Flexible mobile pipeline 205 includes a flexible pipe wholly or partially resting on or buried beneath the seabed for static applications. Floating facilities may consist of platforms and / or buoys or, as... Figure 2The vessel 200 shown is provided. The riser assembly 200 is provided in the form of a flexible riser, i.e., a flexible tube 203 connecting the vessel to the seabed facility. The flexible tube may be located in a section of the flexible tube body with connecting end fittings. It should be understood that different types of risers exist, as are well known to those skilled in the art. The implementation can be used with any type of riser, such as a freely suspended riser (free catenary riser), a partially constrained riser (buoy, chain), a fully constrained riser, or one enclosed in a tube (I-tube or J-tube). Figure 2 It also illustrates how a portion of the flexible tube can be used as a flow line 205 or a jumper 206.

[0015] Figure 3 The diagram shows a cross-section of a known end fitting assembly 300 (such as the end fitting assembly disclosed in WO2007 / 144552 or EP1867907). The end fitting 300 includes an end fitting body 301 having an internal bore 302 extending along its length. The end fitting body is made of steel or other such rigid material. An opening region 303 is defined at a first end of the end fitting body 301, where the end of a segment of the flexible tube body 100 lies and then terminates. A connector 304 is located at the other end of the end fitting body 301. This is formed as a substantially disc-shaped flared region on the end fitting body. The connector can be directly connected to a mating connector of another end fitting body of an adjacent segment of the flexible tube body. This can be accomplished using bolts or some other form of fastening mechanism. In such a configuration, the end fittings would be located in a back-to-back configuration. Alternatively, the connector 304 can be connected to a floating or fixed structure, such as a boat, platform, or other such structure. The layers of the flexible tube body 100 are introduced into the end fitting assembly, cut to appropriate lengths, and sealed to specific portions of the end fitting. The end fitting 300 includes a sleeve 307 connected to the end fitting body 301, forming a cavity 313 between the sleeve 307 and the end fitting body 301. The end 112 of at least one of the layers of the flexible tube body 100 terminates and is secured within the cavity 313.

[0016] As is well known, there are many different problems associated with providing end fittings for the ends of flexible tube bodies. End fittings must ensure both good fastening and a good seal. The orifice of the end fitting needs to be sealed to the orifice of the flexible tube body. Specific problems arise when various specific layers of a multi-layered flexible tube body terminate. A flexible tube body can include layers with different material properties, such as a single polymer layer and / or interlocking metal layers. In the end fitting, the termination of each of these layers introduces characteristic problems. For example, a flexible tube body typically includes a fluid retention layer, which is usually formed as a polymer sheath or pressure sheath. Such a layer operates as a primary fluid retention layer. The fluid retention layer must be connected to the end fitting to ensure a complete seal to retain fluid within the orifice of the flexible tube, and parameters such as internal fluid pressure, external hydrostatic pressure, and movement from seabed motion make maintaining a seal more difficult.

[0017] The purpose of this invention is to at least partially alleviate the above-mentioned problems.

[0018] According to a first aspect of the invention, an end fitting for joining to a tube body is provided, wherein the end fitting comprises: a sleeve capable of partially inserting into a radially inner side of a polymer layer of the tube body; and a polymer collar for receiving the polymer layer of the tube body, the polymer collar being disposed radially outer side of the sleeve and configured to be welded to the polymer layer of the tube body.

[0019] Suitablely, the end fitting includes an inner collar disposed radially outside the sleeve, wherein the polymer collar is partially disposed between the sleeve and the inner collar.

[0020] Suitable, the end fitting includes a jacket disposed radially outside the sleeve, wherein the polymer collar is partially disposed between the sleeve and the jacket.

[0021] Properly, the polymer collar is sealed between the sleeve, the jacket, and the inner collar.

[0022] Suitable, the end fitting includes a first recess that can be disposed between the inner sleeve and the polymer layer of the tube body; and a first seal configured to be positioned in the first recess to prevent fluid from entering between the inner sleeve and the polymer layer of the tube body.

[0023] Appropriately, the first seal is energized during use such that the first seal is forged against the inner surface of the inner ring.

[0024] Suitablely, the end fitting includes an outer ring disposed at the end of the inner ring and capable of being disposed radially outside the polymer layer of the tube body, and suitablely, the outer ring is configured to actuate the first seal in use.

[0025] Suitable, the end fitting includes: a second recess disposed between the inner collar and the jacket; and a second seal configured to be positioned in the second recess to prevent fluid from entering between the inner collar and the jacket.

[0026] Suitable, the end fitting includes: a third recess disposed between the polymer collar and the jacket; and a third seal configured to be positioned in the third recess to prevent fluid from entering between the polymer collar and the jacket.

[0027] Appropriately, the outer surface of the polymer collar comprises polyamide.

[0028] Appropriately, the polymer collar is formed of polyamide.

[0029] According to a second aspect of the invention, a flexible tube is provided, wherein the flexible tube comprises: a tube body including a polymer layer; and an end fitting comprising: a sleeve partially inserted radially inside the polymer layer of the tube body; and a polymer collar for receiving the polymer layer of the tube body, the polymer collar being disposed radially outside the sleeve and configured to be welded to the polymer layer of the tube body.

[0030] According to a third aspect of the invention, a method for assembling a flexible tube is provided, wherein the method includes: providing a tube body comprising a polymer layer; providing a sleeve for an end fitting and partially inserting the sleeve into the radially inner side of the polymer layer of the tube body; and providing a polymer collar for receiving the polymer layer of the tube body, the polymer collar being disposed radially outer side of the sleeve, and welding the polymer collar to the polymer layer of the tube body.

[0031] Suitablely, the method includes providing an inner collar of the end fitting and disposing the inner collar radially outward of the sleeve, wherein the polymer collar is partially disposed between the sleeve and the inner collar.

[0032] Suitablely, the method includes providing a clip for the end fitting and disposing the clip radially outward from the sleeve, wherein the polymer collar is partially disposed between the sleeve and the clip.

[0033] Suitable, the method includes sealingly holding the polymer collar between the sleeve, the jacket, and the inner collar.

[0034] Certain embodiments of the present invention offer the advantage of an improved connection between the end fitting and the tube body. Some embodiments provide an arrangement in which welding the metal components of the end fitting to the polymer components of the tube body is avoided. Some embodiments offer the advantage that the metal components of the end fitting are positioned radially outside the seal between the polymer segment of the end fitting and the tube body, thus protecting the seal from failure.

[0035] The embodiments of the present invention are further described below with reference to the accompanying drawings, wherein:

[0036] Figure 1 The example tube body is shown;

[0037] Figure 2 An example of a riser assembly is shown;

[0038] Figure 3 Example end fittings are shown;

[0039] Figure 4 An end fitting for a flexible tube according to an embodiment of the present invention is illustrated;

[0040] Figure 5 Further end fittings for a flexible tube according to an embodiment of the present invention are illustrated;

[0041] Figure 6 Further end fittings for a flexible tube according to an embodiment of the present invention are illustrated;

[0042] Figure 7a A method for assembling a flexible tube according to an embodiment of the present invention is illustrated; and

[0043] Figure 7b Another method for assembling a flexible tube according to an embodiment of the present invention is illustrated.

[0044] In the accompanying drawings, similar reference numerals refer to similar parts.

[0045] Figure 4 An end fitting 400 of a flexible tube 1000 according to an embodiment of the present invention is illustrated.

[0046] The end fitting 400 includes a sleeve 402. The sleeve 402 supports the polymer layer 504 of the tube body 500 (in this case, a polymer outer sheath) and provides an outer surface for positioning a polymer collar 404 of the end fitting 400 thereon, such that the end fitting 400 can be connected to the tube body 500. The sleeve 402 is substantially tubular, such that it includes orifices adapted to allow fluid (e.g., oil or water) to flow through it. Suitably, the polymer layer 504 is the outer sheath of the tube body 500.

[0047] Sleeve 402 includes a first segment 430a and a second segment 430b. The first segment 430a and the second segment 430b are disposed adjacent to each other. The first segment 430a is disposed on a first side of the transverse axis 452, and the second segment 430b is disposed on a second side of the transverse axis 452. Sleeve 402 is integrally formed. Sleeve 402 is formed of metal. In this case, sleeve 402 is formed of stainless steel. Sleeve 402 may suitably be formed of carbon steel or alloy steel. Sleeve 402 may be formed of aluminum, titanium, or nickel alloy. Sleeve 402 may optionally be coated with a low-friction coating to facilitate radial insertion below the terminal end of the polymer layer 504 of the tube body 500.

[0048] The first segment 430a is inserted radially inside the polymer layer 504 of the tube body 500. In this way, the first segment 430a provides a transition path between the tube body 500 and the second segment 430b of the sleeve 402. The first segment 430a has a profile complementary to the inner surface of the polymer layer 504. Suitably, the inner diameter of the first segment 430a is substantially equal to the inner diameter of the polymer layer 504, and the polymer layer 504 must be stretched to receive the sleeve 402 during insertion. Optionally, the polymer layer 504 can be stretched by applying heat to the terminal end segment of the polymer layer 504. Optionally, the outer diameter of the first segment 430a is substantially equal to the inner diameter of the polymer layer 504, such that the first segment 430a and the polymer layer 504 are in contact with each other. The first segment 430a supports the inner surface of the polymer layer 504, such that the lower layer of the tube body 500 passes through the hole in the sleeve 402 and connects to other components of the end fitting 400 (not shown here for simplicity) or connects between other components of the end fitting. The first end 444 of the sleeve 402 (more specifically, the end of the first segment 430a) includes a tapered portion 454 configured to facilitate the insertion of the first segment 430a into the radially inner side of the polymer layer 504.

[0049] The second segment 430b extends away from the polymer layer 504. The inner diameter of the second segment 430b is equal to the inner diameter of the first segment 430a, such that the bore of the sleeve 402 is continuous. The second segment 430b is configured to provide support for the polymer collar 404 of the end fitting 400 and is optionally connected to the polymer collar. In this embodiment, the second segment 430b includes a flange 433 configured to restrict insertion of the sleeve 402 into the polymer layer 504, such that the sleeve 402 is partially inserted radially inward into the polymer layer 504. The outer diameter of the flange 433 is larger than the outer diameter of any other portion of the second segment 430b. In use, the flange 433 abuts the polymer collar 404 of the end fitting 400 to prevent further insertion of the sleeve 402. More specifically, in use, the flange 433 abuts the second segment 432b of the polymer collar 404. Optionally, the polymer collar 404 may be at least partially bonded to the sleeve 402. More specifically, the second segment 432b of the polymer collar 404 may be bonded to the second segment 430b of the sleeve 402.

[0050] The end fitting 400 includes a polymer collar 404. The polymer collar 404 is disposed radially outside the sleeve 402 and is connectable (e.g., welded) to the polymer layer 504 of the tube body 500, such that the end fitting 400 is connected to the tube body 500. The polymer collar 404 is configured to allow connection to additional components of the end fitting 400, such that the polymer collar 404 is securely retained within the end fitting 400.

[0051] A polymer collar 404 is disposed radially outside the second segment 430b of the sleeve 402. The polymer collar 404 has a profile complementary to the outer surface of the second segment 430b of the sleeve 402. The inner diameter of the polymer collar 404 is substantially equal to the outer diameter of the second segment 430b. The polymer collar 404 is disposed radially adjacent to the second segment 430b such that the polymer collar 404 and the second segment 430b are in contact with each other. The polymer collar 404 is formed of a polymer material. In this case, at least the outer surface of the polymer collar 404 is formed of polyamide. Suitably, the polyamide is polyamide 12. Suitably, the polyamide is polyamide 11. Optionally, the material of the polymer collar 404 is polyethylene, polypropylene, or a thermoplastic elastomer.

[0052] The polymer collar 404 includes a first segment 432a and a second segment 432b. The first segment 432a and the second segment 432b are disposed adjacent to each other. The first segment 432a is disposed on a first side of the transverse axis 456, and the second segment 432b is disposed on a second side of the transverse axis 456. The outer diameter of the second segment 432b is larger than the outer diameter of the first segment 432a. The second segment 432b is configured to allow connection to a clip 408 of the end fitting 400. The sleeve 402 is integrally constructed.

[0053] A polymer collar 404 is attached to the polymer layer 504, thereby connecting the tube body 500 and the end fitting 400 to each other. Suitablely, the polymer collar 404 is welded to the polymer layer 504. More specifically, a first segment 432a is welded to the polymer layer 504. The thickness of the first segment 432a is substantially equal to the thickness of the polymer layer 504 at its location covering the sleeve 402. Polymer welding can be used to connect the terminal end of the polymer layer 504 to the polymer collar 404 using known techniques, equipment, and suitable compatible filler materials, providing a full circumferential annular connection between the polymer layer 504 and the first segment 432a of the polymer collar 404. Suitablely, the polymer welding filler material is the same polymer as the polymer layer 504, and also the same polymer as the polymer collar 404. Suitablely, the polymers of the polymer layer 504, the welding filler material, and the polymer collar 404 are different but compatible (i.e., capable of being fused together using known welding techniques). Suitable, the polymer collar 404 may be formed of a solid polymer or of a polymer-coated metal or other rigid material.

[0054] The end fitting 400 includes an inner collar 406. The inner collar 406 is configured as part of the end fitting 400, located outside the polymer segments of the end fitting 400 and the tube body 500 (i.e., the first segment 432a of the sleeve 402 and the polymer layer 504, and the connection therebetween), thereby protecting the polymer segments of the end fitting and the tube body. The inner collar 406 is further configured to allow connection to additional components of the end fitting 400.

[0055] An inner collar 406 is partially disposed radially outside the first segment 432a of the polymer collar 404, such that the polymer collar 404 is disposed between the inner collar 406 and the sleeve 402. The inner collar 406 is further partially disposed radially outside the polymer layer 504, such that the polymer layer 504 is disposed between the inner collar 406 and the sleeve 402. The inner collar 406 is disposed adjacent to the second segment 432b of the polymer collar 404. More specifically, the second end 442 of the inner collar 406 is adjacent to the second segment 432b of the polymer collar 404.

[0056] The inner collar 406 has a profile substantially complementary to the outer surfaces of the first segment 432a and the polymer layer 504 of the polymer collar 404. The inner diameter of the inner collar 406 is substantially equal to the outer diameter of the first segment 432a and the polymer layer 504 at their position relative to the cover sleeve 402. The inner collar 406 is disposed radially adjacent to the first segment 432a and the polymer layer 504 such that the inner collar 406 contacts the first segment 432a and the polymer layer 504. The inner collar 406 is formed of metal. In this case, the inner collar 406 is formed of stainless steel. Suitablely, the inner collar 406 is made of carbon or alloy steel. Suitablely, the inner collar 406 is made of aluminum or titanium alloy. Optionally, the inner collar 406 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0057] The inner surface 458 of the inner collar 406 has a tapered segment 460. The tapered segment 460 gradually tapers from a larger diameter to a smaller diameter in a direction moving away from the first end 440 of the inner collar 406. In other words, the tapered segment 460 has a first end 462a located at the first end 440 of the inner collar 406, and a second end 462b located along the length of the inner surface 458 of the inner collar 406, and the inner diameter at the first end 462a is larger than the inner diameter at the second end 462b.

[0058] like Figure 4 As shown, the tapered segment 460 tapers non-linearly. The tapered segment 460 includes a portion oriented perpendicular to the longitudinal axis (not shown) of the end fitting 400. Suitably, the tapered segment 460 includes a sealing surface configured to engage with the opposing sealing surface of the first seal 416 (see also...). Figure 5 ).

[0059] The end fitting 400 includes a first recess 414. The first recess 414 is configured to receive a first seal 416 of the end fitting 400, and the first seal 416 is configured to prevent fluid from entering between the inner collar 406 and the polymer layer 504. The first recess 414 is disposed between the inner collar 406 and the polymer layer 504. More specifically, the first recess 414 is disposed between the tapered segment 460 and the polymer layer 504, such that the first recess 414 has at least a partially tapered profile. The first recess 414 is annular.

[0060] The end fitting 400 includes a first seal 416. The first seal 416 is configured to be actuated in use to prevent fluid ingress between the inner collar 406 and the polymer layer 504. During assembly of the end fitting 400, the first seal 416 is actuated by the outer collar 420 of the end fitting 400, as described below. This prevention of fluid ingress protects the connection between the polymer layer 504 and the polymer collar 404. The first seal 416 is disposed in a first recess 414. The first seal 416 has a profile complementary to that of the first recess 414. The first recess 414 has at least a partially tapered profile, and the first seal 416 has a complementary at least partially tapered profile. Suitably, the tapered segment of the first seal 416 includes a sealing surface configured to engage with the opposing sealing surface of the tapered segment 460 of the first recess 414 (see also...). Figure 5 ).

[0061] At least a portion of the second end 462b of the first seal 416 near the tapered segment 460 is configured to deform radially inward when the first seal 416 is pushed into the recess 414, thereby pushing it into tight engagement with the polymer layer 504.

[0062] The inner collar 406 includes an end segment 436. The end segment 436 is configured to allow connection to a clip 408 of the end fitting 400. The end segment 436 has a first end 437a located along the length of the inner surface 458 of the inner collar 406, and a second end 437b located at a second end 442 of the inner collar 406, such that the end segment 436 is adjacent to a second segment 432b of the polymer collar 404. The outer diameter of the end segment 436 may optionally be larger than any other segment of the inner collar 406.

[0063] The end fitting 400 includes an outer ring 420. The outer ring 420 is configured to activate a first seal 416 disposed in a first recess 414 to prevent fluid from entering between the inner ring 406 and the polymer layer 504, and to isolate the portion of the polymer layer 504 inside the end fitting 400 (i.e., the portion extending beyond the first seal 416) from the force or stress load present in the polymer layer 504 outside the end fitting 400 due to tension or bending of the tube body 500.

[0064] An outer ring 420 is disposed at the first end 440 of the inner ring 406 and radially outward of the polymer layer 504. The outer ring 420 has a profile complementary to the outer surface of the polymer layer 504. The inner diameter of the outer ring 420 is substantially equal to the outer diameter of the polymer layer 504. The outer ring 420 is disposed radially adjacent to the polymer layer 504 such that the outer ring 420 contacts the polymer layer 504. The outer ring 420 is formed of metal. In this case, the outer ring 420 is formed of stainless steel. Suitablely, the outer ring 420 is made of carbon or alloy steel. Suitablely, the outer ring 420 is made of aluminum or titanium alloy. Optionally, the outer ring 420 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0065] An outer ring 420 is configured to attach to an inner ring 406. In this case, multiple fasteners (e.g., bolts) are used to attach the outer ring 420 to the inner ring 406. During engagement of the outer ring 420 to the inner ring 406, the outer ring 420 moves toward the inner ring 406. The outer ring 420 then applies pressure to a first seal 416 disposed in a first recess 414, and arouses the first seal 416 to move along the first recess 414 and abut against a forked section of the inner ring 406. More specifically, the first seal 416 abuts against a tapered segment 460 forked section of the inner surface 458 of the inner ring 406.

[0066] When the first seal 416 is forged against the inner ring 406, the inner ring 406 deforms the first seal 416. This deformation presses the first seal 416 against the polymer layer 504. More specifically, the first seal 416 is pressed against the outer surface of the polymer layer 504. Pressing the first seal 416 against the polymer layer 504 in this way prevents fluid from entering between the first seal 416 and the polymer layer 504.

[0067] The end fitting 400 includes a jacket 408. The jacket 408 is configured as part of the end fitting 400, located outside the polymer segment of the end fitting 400 (i.e., the second segment 432b of the sleeve 402), and thereby protects the polymer segment. The jacket 408 is configured to connect to a polymer collar 404 and an inner collar 406, such that the polymer collar 404 is sealed between the jacket 408, the inner collar 406, and the sleeve 402. The jacket 408 is further configured to receive and enclose additional components of the flexible tube 1000.

[0068] A jacket 408 is disposed radially outside the polymer collar 404, such that the polymer collar 404 is positioned between the jacket 408 and the sleeve 402. More specifically, the jacket 408 is disposed radially outside the second segment 432b of the polymer collar 404. The jacket 408 is disposed adjacent to the inner collar 406. More specifically, the jacket 408 is disposed adjacent to the end segment 436 of the inner collar 406.

[0069] It should be understood that other configurations are conceivable, wherein the clip 408 is disposed radially outside both the polymer collar 404 and the inner collar 406, wherein each of the polymer collar 404 and the inner collar 406 has a similar outer radial diameter configured to resemble the inner diameter of the clip 408. Furthermore, it should be understood that the clip 408 may include a radially inwardly pointing flange through which the clip intersects with the end surface region of the first end 437a of the end segment 436, remote from the second end 442 of the inner collar 406. Thus, the clip 408 can at least partially enclose the end segment 436 of the inner collar 406 and can be attached to the inner collar 406 using multiple fasteners (e.g., bolts).

[0070] The jacket 408 is formed of metal. In this case, the jacket 408 is formed of stainless steel. Suitablely, the jacket 408 is made of carbon or alloy steel. Suitablely, the jacket 408 is made of aluminum or titanium alloy. Optionally, the jacket 408 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0071] The end fitting 400 includes at least one second recess 410. The second recess 410 is an annular recess configured to receive a second seal 412 of the end fitting 400, and the second seal 412 is configured to prevent fluid from entering between the jacket 408 and the inner ring 406. The second recess 410 is disposed between the jacket 408 and the inner ring 406. More specifically, the second recess 410 is disposed between an end segment 436 of the jacket 408 and the inner ring 406. The end fitting 400 includes a second seal 412 disposed in the second recess 410. Optionally, the second seal 412 has a profile complementary to the second recess 410, such that the second seal 412 substantially fills the second recess 410 and prevents fluid from entering between the jacket 408 and the inner ring 406. Optionally, the second seal 412 is an O-ring or an API 6A type gasket sealing ring or the like. Optionally, the second recess 410 includes two recesses, and the second seal 412 includes two O-rings receivable in the two recesses. Optionally, the integral second recess 410 is adapted to receive two or more O-rings in one recess, which work together to provide a seal.

[0072] The end fitting 400 includes at least one third recess 424. The third recess 424 is an annular recess configured to receive a third seal 426 of the end fitting 400, and the third seal 426 is configured to prevent fluid from entering between the jacket 408 and the polymer collar 404. The third recess 424 is disposed between the jacket 408 and the polymer collar 404. More specifically, the third recess 424 is disposed between a second segment 432b of the jacket 408 and the polymer collar 404. The end fitting 400 includes a third seal 426 disposed in the third recess 424. Optionally, the third seal 426 has a profile complementary to the third recess 424, such that the third seal 426 substantially fills the third recess 424 and prevents fluid from entering between the jacket 408 and the polymer collar 404. Optionally, the third seal 426 is an O-ring or an API 6A type gasket seal ring or the like. Optionally, the third recess 424 includes two recesses, and the third seal 426 includes two O-rings receivable in the two recesses. Optionally, the integral third recess 424 is adapted to receive two or more O-rings in one recess, which work together to provide a seal.

[0073] The end fitting 400 includes a first pressure test port 422 for testing any of the following: a first seal 416 disposed in a first recess 414, a second seal 412 disposed in a second recess 410, a connector between a polymer collar 404 and a polymer layer 504, and a third seal 426 disposed in a third recess 424. The first pressure test port 422 is disposed on an inner collar 406 and extends through the inner collar 406 to the second recess 410 and the interface between the inner collar 406 and the polymer collar 404. In use, fluid is injected through the first pressure test port 422, causing the fluid to distribute along the interfaces between the components of the end fitting 400 and toward the seal and / or connector to be tested.

[0074] The end fitting 400 includes a second pressure test port 428 for further testing of the third seal 426 disposed in the third recess 424. The second pressure test port 428 is disposed on the jacket 408 and extends through the jacket 408 to the third recess 424. In use, fluid is injected through the second pressure test port 428, causing the fluid to be distributed to the third seal 426 disposed in the third recess 424.

[0075] Figure 5 An additional end fitting 600 of the flexible tube 2000 according to an embodiment of the present invention is illustrated. As described above, similar reference numerals refer to similar components.

[0076] End fitting 600 includes sleeve 402, as relative to Figure 4 As stated above.

[0077] In this embodiment, the second segment 430b of the sleeve 402 is configured to restrict insertion of the sleeve 402 into the polymer layer 504, such that the sleeve 402 is partially inserted radially inward into the polymer layer 504. The outer diameter of the second segment 430b is larger than that of the first segment 430b of the sleeve 402. In use, the second segment 430b abuts against the end of the polymer layer 504 to prevent further insertion of the sleeve 402.

[0078] The end fitting 600 includes a polymer collar 604. The polymer collar 604 may be attached (e.g., welded) to a polymer layer 504 of the tube body 500, such that the end fitting 600 is connected to the tube body 500. The polymer collar 604 is further configured to allow connection to both a jacket 608 and an inner collar 606 of the end fitting 600.

[0079] In this embodiment, a polymer collar 604 is disposed radially outward of the polymer layer 504, such that the polymer layer 504 is partially disposed between the polymer collar 604 and the sleeve 402. The polymer collar 604 has a profile complementary to the outer surface of the polymer layer 504. The inner diameter of the polymer collar 604 is substantially equal to the outer diameter of the polymer layer 504 at its position covering the sleeve 402. The polymer collar 604 is disposed radially adjacent to the polymer layer 504, such that the polymer collar 604 can contact the polymer layer 504. The polymer collar 604 is formed of a polymer material. In this case, at least the outer surface of the polymer collar 604 is formed of polyamide. Suitably, the polyamide is polyamide 12. Suitably, the polyamide is polyamide 11. Optionally, the material of the polymer collar 604 is polyethylene, polypropylene, or a thermoplastic elastomer.

[0080] The polymer collar 604 includes an end segment 636. The end segment 636 is configured to connect to the polymer layer 504. In this embodiment, the diameter of the end segment 636 is smaller than that of any other segment along the outer surface of the polymer collar 604. The polymer collar 604 is connected to the polymer layer 504 such that the tube body 500 and the end fitting 600 are connected to each other. The polymer collar 604 is welded to the tube body 500. More specifically, the end segment 636 of the polymer collar 604 is welded to the polymer layer 504. Alternatively, the diameter of the end segment 636 may be the same as that of any other segment, but it may still be configured to be connected (e.g., welded) to the polymer layer 504.

[0081] The end fitting 600 includes an inner collar 606. The inner collar 606 is configured as part of the end fitting 600, located outside the polymer segments of the end fitting 600 and the tube body 500 (i.e., the end segment 636 of the polymer collar 604 and the polymer layer 504, and the connection therebetween), thereby protecting the polymer segments of the end fitting and the tube body. The inner collar 606 is further configured to allow connection between the polymer collar 604 and the outer collar 420 of the end fitting 600.

[0082] In this embodiment, the inner collar 606 is partially disposed radially outside the polymer collar 604. More specifically, the inner collar 606 is disposed radially outside the end segment 636 of the polymer collar 604, such that the end segment 636 is disposed between the inner collar 606 and the polymer layer 504. The inner collar 606 is further partially disposed radially outside the polymer layer 504, such that the polymer layer 504 is disposed between the inner collar 606 and the sleeve 402. The inner collar 606 is disposed adjacent to the polymer collar 604. More specifically, the inner collar 606 is disposed adjacent to the first end 643a of the polymer collar 604.

[0083] The inner collar 606 has a profile complementary to the outer surface of the end segment 636 of the polymer collar 604 and the polymer layer 504. In this embodiment, the inner diameter of the inner collar 606 is substantially equal to the outer diameter of the end segment 636 and the polymer layer 504 at the location of its covering sleeve 402. The inner collar 606 is disposed radially adjacent to the end segment 636 and the polymer layer 504 such that the inner collar 606 contacts the end segment 636 and the polymer layer 504. The inner collar 606 is formed of metal. In this case, the inner collar 606 is formed of stainless steel. Suitablely, the inner collar 606 is made of carbon or alloy steel. Suitablely, the inner collar 606 is made of aluminum or titanium alloy. Optionally, the inner collar 606 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0084] The end fitting 600 includes at least one second recess 610. The second recess 610 is an annular recess configured to receive a second seal 612 of the end fitting 600, and the second seal 612 is configured to prevent fluid from entering between the polymer collar 604 and the inner collar 606. The second recess 610 is disposed between the polymer collar 604 and the inner collar 606. The end fitting 600 includes a second seal 612 disposed in the second recess 610. Optionally, the second seal 612 has a profile complementary to that of the second recess 610, such that the second seal 612 substantially fills the second recess 610 and prevents fluid from entering between the polymer collar 604 and the inner collar 606. Optionally, the second seal 612 is an O-ring or an API 6A type gasket sealing ring or the like. Optionally, the second recess 610 includes two recesses, and the second seal 612 includes two O-rings receivable in the two recesses. Optionally, the integral second recess 610 is adapted to receive two or more O-rings in a recess, which work together to provide a seal.

[0085] The inner ring 606 has an inner surface 458 including a tapered segment 460, as relative to... Figure 4 Similarly, the end fitting 600 includes a first recess 414 and a first seal 416 disposed in the first recess 414, as described above. Figure 4 As stated above.

[0086] End fitting 600 includes an outer ring 420, as relative to Figure 4 As stated above.

[0087] The end fitting 600 includes a jacket 608. The jacket 608 is further configured to receive and enclose additional components of the flexible tube 2000.

[0088] In this embodiment, a jacket 608 is partially disposed radially outward of the sleeve 402. More specifically, the jacket 608 is disposed radially outward of the second segment 430b of the sleeve 402. The jacket 608 has a profile complementary to the outer surface of the second segment 430b. The inner diameter of the jacket 608 is substantially equal to the outer diameter of the second segment 430b. The jacket 608 is disposed radially adjacent to the second segment 430b such that the jacket 608 can contact the second segment 430b and optionally radially adjacent to the polymer layer 504. The jacket 608 may be disposed axially adjacent to the polymer collar 604. More specifically, the jacket 608 is disposed adjacent to the second end 643b of the polymer collar 604. The jacket 608 is formed of metal. In this case, the jacket 408 is formed of stainless steel. Suitablely, the jacket 608 is made of carbon or alloy steel. Suitablely, the jacket 608 is made of aluminum or titanium alloy. Optionally, the jacket 608 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0089] End fitting 600 includes a third recess 424 and a third seal 426 disposed in the third recess 424, as relative to Figure 4 As stated above.

[0090] Figure 6 Further end fittings 700 of the flexible tube 3000 according to an embodiment of the invention are illustrated. As described above, similar reference numerals refer to similar components. It will be apparent to those skilled in the art that, for simplicity, the sublayers of the tube body 500 (i.e., those radially inward sublayers of the polymer layer 504) are not shown, and therefore those layers are not shown terminated and secured in the end fittings 700 in a known manner.

[0091] The end fitting 700 includes a polymer collar 702. The polymer collar 702 is disposed radially outside the polymer layer 504 of the tube body 500 and is connectable (e.g., welded at a circumferential polymer weld 724) to the polymer layer 504, such that the end fitting 700 is connected to the tube body 500. The polymer collar 702 allows connection to the end segment 704 of the end fitting 700.

[0092] Polymer layer 504 is inserted radially inside polymer collar 702. The polymer layer 504 is inserted until the tapered portion 716 located at the first end 712 of polymer collar 702 is positioned at a desired axial position on polymer layer 504, or until the tapered initiation 506 of the first machined portion 510a of polymer layer 504 abuts the first end 712 of polymer collar 702. The tapered initiation 506 of the first machined portion 510a of polymer layer 504 is provided along the desired length of polymer layer 504. Therefore, the tapered initiation 506 provides a transition path between the first machined portion 510a of polymer layer 504, which is inserted radially inside polymer layer 702, and the second extruded portion 510b of polymer layer 504. In this embodiment, the outer diameter of the second portion 510b of polymer layer 504 is larger than the outer diameter of the first portion 510a of polymer layer 504 and the inner diameter of polymer collar 702.

[0093] The polymer collar 702 has a profile complementary to the outer surface of the first portion 510a of the polymer layer 504. The inner diameter of the polymer collar 702 is substantially equal to the outer diameter of the first portion 510a of the polymer layer 504. The polymer collar 702 is disposed radially adjacent to the first portion 510a of the polymer layer 504 such that the polymer collar 702 and the polymer layer 504 are in contact with each other. The polymer collar 702 is formed of a polymer. In this case, the polymer collar 702 is formed of polyamide. Suitably, the polyamide is polyamide 12. Suitably, the polyamide is polyamide 11. Optionally, the material of the polymer collar 702 is polyethylene, polypropylene, or a thermoplastic elastomer.

[0094] The polymer collar 702 includes an optional recess 720. The recess 720 may be configured to receive a seal (not shown) and the seal is configured to prevent fluid from entering between the polymer collar 702 and the polymer layer 504. The recess 720 is provided between the polymer collar 702 and the polymer layer 504 to receive an extension of the end segment 704.

[0095] The end fitting 700 may further include another recess 726 disposed between the end segment 704 and the polymer layer 504. The recess 726 is configured to receive a seal 728. The seal 728 has a profile complementary to the other recess 726, such that the seal 728 substantially fills the other recess 726. Fluid pressure from within the end fitting 700 cannot enter between the polymer collar 702 and the polymer layer 504, thereby preventing pressure from within the end fitting 700 from damaging the polymer weld 724.

[0096] A polymer collar 702 is attached to the polymer layer 504, thereby connecting the end fitting 700 and the tube body 500 to each other. The polymer collar 702 is welded to the polymer layer 504 at a circumferential polymer weld 724. More specifically, in this embodiment, a tapered portion 716 provided at a first end 712 of the polymer collar 702 is welded to a tapered portion 506 of the polymer layer 504 at the polymer weld 724.

[0097] The polymer collar 702 includes a receiving portion 718 for receiving a fastener (not shown) (e.g., a bolt), the fastener being configured to engage the polymer collar 702 to at least an end segment 704 of the end fitting 700. The receiving portion 718 is located radially outward of an optional recess 720. Figure 6 As shown, in this configuration, the receiving portion 718 is located at at least two points around the circumference of the polymer collar 702. Therefore, multiple fasteners can be used to engage the polymer collar 702 with the end segment 704.

[0098] The end fitting 700 includes an end segment 704. The end segment 704 is configured to maintain a connection (e.g., weld) between the polymer collar 702 and the polymer layer 504. The end segment 704 is further configured to allow connection to additional components of the flexible tube 3000.

[0099] An end segment 704 is disposed at the second end 714 of the polymer collar 702 and near the terminal end 508 of the polymer layer 504. The end segment 704 is disposed adjacent to the polymer collar 702 and the polymer layer 504. More specifically, the end segment 704 is disposed adjacent to the first portion 510a of the polymer layer 504. The end segment 704 is formed of metal. In this case, the end segment 704 is formed of stainless steel. Suitablely, the end segment 704 is made of carbon or alloy steel. Suitablely, the end segment 704 is made of aluminum or titanium alloy. Optionally, the end segment 704 may be at least partially coated with a suitable anti-corrosion coating system, such as an epoxy coating.

[0100] The end segment 704 includes a receiving portion 722 configured to receive a fastener, the fastener being configured to engage the end segment 704 and the polymer collar 702. Figure 6 As shown, in this case, the receiving portion 722 is provided at at least two points around the circumference of the end segment 704. The receiving portion 722 of the end segment 704 corresponds to the receiving portion 718 of the polymer collar 702, such that the fastener can be received by both the receiving portion 722 of the end segment 704 and the receiving portion 718 of the polymer collar 702.

[0101] Optionally, the sleeve 402 is inserted radially inward to the terminal end 508 of the polymer layer 504. More specifically, the sleeve 402 is inserted below and in contact with at least a portion of the first portion 510a, thereby supporting the polymer layer 504 when another seal 728 is forged at the outer diameter surface of the first portion 510a of the polymer layer 504 to seal against the polymer layer 504.

[0102] Figure 7a A method 800 for assembling a flexible tube 1000 according to an embodiment of the present invention is illustrated.

[0103] The method 800 of assembling the flexible tube 1000 includes step 802 of providing a tube body 500 including a polymer layer 504. Step 802 also includes providing a sleeve 402 of an end fitting 400 and partially inserting the sleeve 402 into the radially inner side of the polymer layer 504.

[0104] Method 800 further includes the step 804 of providing a polymer collar 404 for the end fitting 400. Step 804 further includes disposing the polymer collar 404 radially outward from the sleeve 402 and attaching the polymer collar 404 to the tube body 500. The polymer collar 404 is welded to the polymer layer 504 of the tube body 500.

[0105] Figure 7bAn example of a method 850 for assembling a flexible tube 1000 comprising an end fitting 400 and a tube body 500 according to an embodiment of the present invention is illustrated.

[0106] The method 850 for assembling the flexible tube 1000 includes steps 802 and 804 of the method 800 for assembling the flexible tube 1000. The method 850 also includes optional steps 808, 810, 812, 814, 816, 818, and 820.

[0107] Method 850 further includes step 806 of providing an inner collar 406 of the end fitting 400. Step 806 further includes partially disposing the inner collar 406 radially outward of the polymer collar 404 and partially disposing the inner collar 406 radially outward of the polymer layer 504.

[0108] Method 850 also includes the step 808 of providing a sleeve 408 for the end fitting 400. Method 850 also includes disposing the sleeve 408 radially outward from the polymer collar 404.

[0109] Method 850 further includes providing a first recess 414 of the end fitting 400 and disposing the first recess 414 between the inner collar 406 and the polymer layer 504 in step 810. Step 810 further includes providing a second recess 410 of the end fitting 400 and disposing the second recess 410 between the jacket 408 and the inner collar 406. Step 810 further includes providing a third recess 424 of the end fitting 400 and disposing the third recess 424 between the jacket 408 and the polymer collar 404.

[0110] Method 850 further includes the step 812 of providing a first seal 416 of the end fitting 400 and disposing the first seal 416 in a first recess 414. Step 812 further includes providing a second seal 412 of the end fitting 400 and disposing the second seal 412 in a second recess 410. Step 812 further includes providing a third seal 426 of the end fitting 400 and disposing the third seal 426 in a third recess 424, such that the polymer collar 404 is sealingly held between the jacket 408, the inner collar 406, and the sleeve 402.

[0111] Method 850 further includes the step of providing an outer ring 420 of the end fitting 400 and attaching the outer ring 420 to the end of the inner ring 406. Step 814 further includes activating the first seal 416 such that the first seal 416 is forged against the inner surface 458 of the inner ring 406.

[0112] Various modifications to the detailed arrangement described above are possible.

[0113] A sealant or adhesive may be introduced between the first segment 430a of the sleeve 402 and the polymer layer 504 of the tube body 500 to further prevent fluid from entering between the first segment 430a and the polymer layer 504.

[0114] The first segment 430a of sleeve 402 may include serrations on its outer surface, such that the first segment 430a produces an interference fit with polymer layer 504. The serrations may include a labyrinth profile to improve contact stress between components.

[0115] The polymer collar 404 may not be formed of polyamide; instead, it may be formed of any material configured to be weldable to the polymer layer 504 of the tube body 500. Furthermore, the thickness of the first segment 432a of the polymer collar 404 may not be substantially equal to the thickness of the polymer layer 504. The first segment 432a of the polymer collar 404 may have any thickness, allowing the polymer collar 404 to be weldable to the polymer layer 504.

[0116] The polymer layer 504 of the tube body 500 can be an outer sheath or an external abrasion-resistant or wear-resistant layer of the tube body 500. The polymer layer 504 can include multiple layers of tube body 500.

[0117] The tapered portion 454 of the first segment 430a of the sleeve 402 can be further configured to prevent the formation of a gap between the first segment 430a and the polymer layer 504.

[0118] The first recess 414 and / or the second recess 410 and / or the third recess 424 may not be annular. Instead, the second recess 414 and / or the second recess 410 and / or the third recess 424 may be provided at at least one point around the circumference of the end fitting 400.

[0119] The outer diameter of the end segment 436 of the inner collar 406 can be equal to the outer diameter of the other segments of the inner collar 406.

[0120] The outer diameter of the second segment 432b of the polymer collar 404 can be equal to the outer diameter of the first segment 432b of the polymer collar 404.

[0121] Instead of partially disposing the inner collar 406 on the radially outer side of the polymer collar 404, step 806 of method 850 may include disposing the inner collar 406 of the end fitting 400 at least partially below the polymer collar 404, partially disposing the inner collar 406 on the radially inner side of the polymer collar 404, and partially disposing the inner collar 406 on the radially outer side of the polymer layer 504.

[0122] The precise dimensions of the features of end fittings 400, 600, and 700 are described only as examples.

[0123] Using the above arrangement, the polymer layer of the tube body is joined (e.g., welded) to the polymer collar of the end fitting. That is, polymer-on-polymer welding can be used. This helps overcome the aforementioned difficulties in attaching the polymer layer to the metal components of the end fitting.

[0124] Using the above arrangement, fewer seals are used to connect the end fittings to the pipe body than in known arrangements. Reducing the number of seals in this way mitigates the adverse effects of polymer creep typically experienced under deep water pressure.

[0125] With the above arrangement, the inner collar and jacket of the end fitting are located radially outside both the polymer layer and the polymer collar, as well as the connection (e.g., weld) between the polymer layer and the polymer collar. Therefore, the connection between the polymer collar and the polymer layer is protected from failure, thereby providing an improved connection between the end fitting and the pipe body.

[0126] It will be apparent to those skilled in the art that the feature structures described in any of the above embodiments can be used interchangeably between different embodiments. The above embodiments are examples illustrating various feature structures of the present invention.

[0127] Throughout the detailed description and claims, the terms "comprising" and "containing," and variations thereof, mean "including but not limited to," and are not intended to (and do not) exclude other parts, additives, components, integrals, or steps. Throughout the detailed description and claims, the singular encompasses the plural unless the context requires otherwise. Specifically, where indefinite articles are used, the description should be understood to consider both the plural and the singular unless the context requires otherwise.

[0128] The features, structures, elements, properties, compounds, chemical parts, or groups described in connection with a particular aspect, embodiment, or example of the invention should be understood to be applicable to any other aspect, embodiment, or example described herein, unless incompatible therewith. All features disclosed in this specification (including any appended claims, the abstract, and the drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except that at least some of such features and / or steps are mutually exclusive combinations. The invention is not limited to the details of any of the foregoing embodiments. The invention extends to any novel feature structure or any novel combination of features disclosed in this specification (including any appended claims, the abstract, and the drawings), or to any novel step or any novel combination of steps of any method or process so disclosed.

[0129] The reader’s attention is drawn to all papers and documents filed concurrently with or prior to this specification in conjunction with this patent application that disclose a public examination of this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

1. An end fitting for joining to a pipe body, wherein, The end fitting includes: a sleeve partially inserted radially inward of the polymer layer of the pipe body; and a polymer collar for receiving the polymer layer of the pipe body, the polymer collar disposed radially outward of the sleeve and configured to be welded to the polymer layer of the pipe body.

2. The end fitting of claim 1, wherein, The end fitting includes an inner collar disposed radially outward of the sleeve, wherein the polymer collar is partially disposed between the sleeve and the inner collar.

3. The end fitting of claim 2, wherein, The end fitting includes a jacket disposed radially outward of the sleeve, wherein the polymer collar is partially disposed between the sleeve and the jacket.

4. The end fitting of claim 3, wherein, The polymer collar is sealingly retained between the sleeve, the jacket, and the inner collar.

5. The end fitting of claim 4, wherein, The end fitting includes: a first recess disposable between the inner collar and the polymer layer of the pipe body; and a first seal configured to be positioned in the first recess to prevent fluid ingress between the inner collar and the polymer layer of the pipe body.

6. The end fitting of claim 5, wherein, The first seal is, in use, energized such that a first seal is swaged against an inner surface of the inner collar.

7. The end fitting of claim 6, wherein, The end fitting includes an outer collar disposed at an end of the inner collar and disposable radially outward of the polymer layer of the pipe body, wherein the outer collar is configured to, in use, energize the first seal.

8. The end fitting of any one of claims 4-7, wherein, The end fitting includes: a second recess disposed between the inner collar and the jacket; and a second seal configured to be positioned in the second recess to prevent fluid ingress between the inner collar and the jacket.

9. The end fitting of any one of claims 4-8, wherein, The end fitting includes: a third recess disposed between the polymer collar and the jacket; and a third seal configured to be positioned in the third recess to prevent fluid ingress between the polymer collar and the jacket.

10. The end fitting according to any one of the preceding claims, wherein, An outer surface of the polymer collar comprises polyamide.

11. An end fitting according to any one of the preceding claims, wherein, The polymer collar is formed of polyamide.

12. A flexible pipe, wherein, The flexible pipe includes: a pipe body comprising a polymer layer; and an end fitting comprising: a sleeve partially inserted radially inward of the polymer layer of the pipe body; and a polymer collar for receiving the polymer layer of the pipe body, the polymer collar disposed radially outward of the sleeve and configured to be welded to the polymer layer of the pipe body.

13. A method of assembling a flexible pipe, wherein, The method includes: providing a pipe body comprising a polymer layer; providing a sleeve of an end fitting and partially inserting the sleeve radially inward of the polymer layer of the pipe body; and providing a polymer collar of the end fitting for receiving the polymer layer of the pipe body, disposing the polymer collar radially outward of the sleeve, and welding the polymer collar to the polymer layer of the pipe body.

14. The method of claim 13, wherein, The method includes providing an inner collar of the end fitting and disposing the inner collar radially outward of the sleeve, wherein the polymeric collar is partially disposed between the sleeve and the inner collar.

15. The method of claim 14, wherein, The method includes providing a clamp sleeve of the end fitting and disposing the clamp sleeve radially outward of the sleeve, wherein the polymeric collar is partially disposed between the sleeve and the clamp sleeve.

16. The method of claim 15, wherein, The method includes sealingly retaining the polymeric collar between the sleeve, the clamp sleeve, and the inner collar.

Images