Flexible pipe seal

Abstract

The present disclosure includes a seal assembly for an end fitting of a flexible pipe, an end fitting, a flexible pipe, and a method of assembling a flexible pipe. The seal assembly can be disposed between the collar of the end fitting and the polymer layer of the tube body of the flexible tube. The seal assembly includes: a deformable ring that can be disposed radially outward of the polymer layer of the tube body; and a pressure ring positionable between the deformable ring and the collar of the end fitting wherein the deformable ring has a ductility higher than the ductility of the pressure ring and lower than the ductility of the polymer layer of the tube body.

Description

[0001] This invention relates to a flexible tube seal. In particular, but not exclusively, the invention relates to a sealing assembly for an end fitting of a flexible tube, an end fitting including such a sealing assembly, a flexible tube including such an end fitting and a tube body, and a method for assembling a 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. Specifically, flexible tubing can be used to connect a seabed location (which can be deep-sea) to a sea-level location. The tubing can typically have an inner diameter up to about 0.6 meters (e.g., a diameter ranging 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 inducing bending stresses that would impair the functionality of the tubing over 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 3,300 feet (1,005.84 meters) and ultra-deepwater (greater than 3,300 feet) development. The increasing demand for oil exploration at ever-greater depths presents increasingly extreme environmental conditions. For example, in such deepwater and ultra-deepwater environments, increased ocean floor temperatures raise 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. 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. This increases the 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 shown, 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) and such “rough hole” applications (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 operations), 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 often a metal layer, for example, made of carbon steel. The pressure armor layer can 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 give the 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 layers are typically metal layers, for example, formed of carbon steel. The tensile armor layers 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 these sections 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 transporting 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 as 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 is well known to those skilled in the art. The embodiment 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 a riser enclosed in a fitting (I fitting or J fitting). 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 301. The connector 304 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 orifices of the end fittings need to seal the orifices 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 end fittings, the termination of each of these layers introduces characteristic problems. For example, a flexible tube body typically includes a fluid retention layer (called a barrier layer or liner), which is typically formed as a polymer sheath or pressure sheath. Such layers operate as the 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 orifices of the flexible tube, and parameters such as internal fluid pressure, external hydrostatic pressure, and movement from the seabed 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, a sealing assembly for an end fitting of a flexible tube is provided, wherein the sealing assembly is disposed between a collar of the end fitting and a polymer layer of a tube body of the flexible tube, the sealing assembly comprising: a deformable ring disposed radially outward of the polymer layer of the tube body; and a pressure ring disposed between the deformable ring and the collar of the end fitting, wherein the deformable ring has a higher elongation than the pressure ring and a lower elongation than the polymer layer of the tube body.

[0019] Appropriately, the pressure ring is movable between the deformable ring and the collar of the end fitting, such that the pressure ring engages the deformable ring and deforms the deformable ring.

[0020] Appropriately, the pressure ring is powered during use, causing it to be forged against the deformable ring.

[0021] Suitablely, the deformable ring includes a first surface, and the pressure ring includes a second surface, and suitablely, the first surface of the deformable ring and the second surface of the pressure ring are inclined relative to each other.

[0022] Appropriately, the second surface of the pressure ring is forged against the first surface of the deformable ring.

[0023] Appropriately, the first surface of the deformable ring is inclined at an angle of less than or equal to 45 degrees relative to the central longitudinal axis of the sealing assembly.

[0024] Deformable rings and / or pressure rings may include trapezoidal shapes.

[0025] Appropriately, the deformable ring contains brass.

[0026] Appropriately, the pressure ring contains a nickel alloy.

[0027] Appropriately, deformable rings are capable of plastic deformation.

[0028] Suitable, the sealing assembly includes a first seal disposed between the deformable ring and the pressure ring and / or a second seal disposed between the pressure ring and the collar of the end fitting.

[0029] Appropriately, the first seal and / or the second seal may include an O-ring or an elastomer ring.

[0030] Appropriately, the inner surface of the deformable ring includes serrations.

[0031] According to a second aspect of the invention, an end fitting is provided, the end fitting comprising: a sleeve capable of being inserted radially inside a polymer layer of a tube body; a collar disposed radially outside the polymer layer of the tube body, the collar including a recess adjacent to the polymer layer of the tube body in use; and a sealing assembly according to a certain aspect of the invention, the sealing assembly being configured to be located in the recess of the collar.

[0032] Appropriately, the pressure ring is movable within the recess, such that the pressure ring engages with the deformable ring and deforms the deformable ring.

[0033] Appropriately, the end fitting includes a clip disposed near the collar.

[0034] Suitablely, the recess includes a gap between the pressure ring and the jacket, and suitablely, the pressure ring is movable within the recess toward the gap.

[0035] Properly, the pressure ring is powered during use, causing it to be forged toward the gap and against the deformable ring.

[0036] Appropriately, the collar includes a pressure port configured to direct hydrostatic pressure onto the pressure collar.

[0037] According to a third aspect of the invention, a flexible tube is provided, the flexible tube comprising: a tube body including a polymer layer; and an end fitting comprising: a sleeve inserted radially inside the polymer layer of the tube body; a jacket including an outer diameter greater than the outer diameter of the sleeve; a collar disposed radially outside the polymer layer of the tube body, the collar including a recess adjacent to the polymer layer of the tube body; and a sealing assembly according to one aspect of the invention, the sealing assembly being configured to be located in the recess of the collar.

[0038] According to a fourth aspect of the invention, a method is provided, the method comprising: providing a tube body including a polymer layer; providing a sleeve for an end fitting; inserting the sleeve into the radially inner side of the polymer layer of the tube body; providing a collar for the end fitting and disposing the collar in the radially outer side of the polymer layer of the tube body, the collar including a recess adjacent to the polymer layer of the tube body; and providing a sealing assembly for the end fitting according to one aspect of the invention and positioning the sealing assembly in the recess of the collar.

[0039] Suitable, the method includes energizing the pressure ring such that the pressure ring is forged against the deformable ring, and the pressure ring engages the deformable ring and deforms the deformable ring.

[0040] Certain embodiments of the invention offer the advantage of an improved connection between the end fitting and the tube body. Certain embodiments provide an arrangement in which welding the metal components of the end fitting to the tube body is avoided. Certain embodiments provide the effect of reducing polymer creep, thereby resulting in an improved seal between the components of the end fitting, particularly under deep and ultra-deep water pressures.

[0041] The embodiments of the present invention are further described below with reference to the accompanying drawings, wherein:

[0042] Figure 1 The example tube body is shown;

[0043] Figure 2 An example of a riser assembly is shown;

[0044] Figure 3 Example end fittings are shown;

[0045] Figure 4a An example is shown of an end fitting of a flexible tube according to an embodiment of the invention during assembly;

[0046] Figure 4b Examples of partial assembly are shown. Figure 4a End fittings;

[0047] Figure 5a Examples Figure 4a Sealing components for end fittings;

[0048] Figure 5b Examples Figure 4b Sealing components for end fittings;

[0049] Figure 6 Examples of partial assembly are shown. Figure 4b End fittings;

[0050] Figure 7 An example of a fully assembled Figure 6 End fittings;

[0051] Figure 8a Examples of usage Figure 7 End fittings;

[0052] Figure 8b Examples Figure 8a Sealing components for end fittings;

[0053] Figure 9a An example is illustrated of a method for assembling a flexible tube comprising end fittings and a tube body according to an embodiment of the present invention; and

[0054] Figure 9b An alternative method for assembling a flexible tube comprising end fittings and a tube body according to an embodiment of the present invention is illustrated.

[0055] In the accompanying drawings, similar reference numerals refer to similar parts.

[0056] Figure 4a An example is shown of the end fitting 400 of the flexible tube 1000 according to an embodiment of the present invention during assembly, and Figure 4b Examples of partial assembly are shown. Figure 4a The end fitting 400 (i.e., the first collar 404a is connected to the end fitting 400).

[0057] The end fitting 400 includes a sleeve 402. The sleeve 402 is substantially tubular, such that it includes orifices suitable for allowing fluid (e.g., oil or water) to flow through it. The sleeve 402 includes a first segment 408a and a second segment 408b. The first segment 408a is disposed adjacent to the second segment 408b. The first segment 408a is disposed on a first side of the transverse axis 452, and the second segment 408b is disposed on a second side of the transverse axis 452. The sleeve 402 is integrally formed. The sleeve 402 is formed of metal. In this case, the sleeve 402 is formed of stainless steel. Optionally, the sleeve 402 may be coated with a low-friction coating system to improve the mounting of the sleeve 402 below the polymer layer 504 of the tube body 500. The polymer layer 504 may be an outer sheath of the tube body 500.

[0058] A first segment 408a is inserted radially inside the polymer layer 504 of the tube body 500. The first segment 408a has a profile complementary to the inner surface of the polymer layer 504. The outer diameter of the first segment 408a is substantially equal to the inner diameter of the polymer layer 504, such that the first segment 408a and the polymer layer 504 are in contact with each other. The first segment 408a supports the inner surface of the tube body 500, such that the tube body 500 is connected to the end fitting 400. A first end of the first segment 408a may include a tapered portion (not shown) configured to facilitate insertion of the first segment 408a radially inside the polymer layer 504. Suitably, the tapered portion of the first segment 408a of the sleeve 402 extends axially beyond the second end 442 of the first collar 404a of the end fitting 400.

[0059] Suitablely, the inner diameter of the sleeve 402 is substantially equal to the inner diameter of the polymer layer 504, such that the first segment 408a of the sleeve 402 must be pushed below the polymer layer 504, thereby locally expanding the end portions of the inner and outer diameters of the polymer layer 504, wherein the first segment 408a is inserted below. Suitablely, in this configuration, the inner diameter of the sleeve 402 is substantially equal to the lower layer of the tube body 500 inside the polymer layer 504.

[0060] The second segment 408b is not inserted radially inside the polymer layer 504. The outer diameter of the second segment 408b is larger than the outer diameter of the first segment 408a. The outer diameter of the second segment 408b is optionally equal to or greater than the outer diameter of the polymer layer 504. The inner diameter of the second segment 408b is equal to the inner diameter of the first segment 408a, such that the hole in the sleeve 402 is continuous. The end face 505 of the end portion of the polymer layer 504 abuts the second segment 408b, thereby preventing the first segment 408a from being further inserted below the polymer layer 504.

[0061] The end fitting 400 includes a jacket 448 disposed radially outside the second segment 408b of the sleeve 402 and partially disposed radially outside the polymer layer 504 of the tube body 500. Suitably, the inner diameter of the jacket 448 is equal to or greater than the outer diameter of the polymer layer 504. Suitably, the inner diameter of the jacket 448 is equal to or greater than the outer diameter of the end portion of the polymer layer 504 when the first segment 408a of the sleeve 402 is inserted below the end portion of the polymer layer 504. Suitably, the inner diameter of the jacket 448 is equal to or greater than the outer diameter of the second segment 408b of the sleeve 402. In some cases, the second segment 408b of the sleeve 402 is joined (e.g., welded) to the jacket 448. Suitably, the outer surface of the second segment 408b is connected to the inner surface of the jacket 448.

[0062] like Figure 4a As shown, the jacket 448 includes an array of first receiving portions 446a (in Figure 4a (Only one of these first receiving portions is visible), the array of first receiving portions is used to receive the array of first fasteners 456a (e.g. Figure 4b (As shown). The first fastener 456a is configured to engage the first collar 404a of the end fitting 400 to the sleeve 448 and align with a corresponding receiving portion 444 in the first collar 404a. The receiving portions 446a of the sleeve 448 and the receiving portions 444 of the first collar 404a are located at a plurality of substantially uniformly radially distributed points around the circumference of the sleeve 448 and the first collar 404a. Suitably, each first fastener 456a is configured to extend from the second end 442 of the first collar 404a, through the receiving portion 444 in the first collar 404a, and into each corresponding first receiving portion 446a in the sleeve 448, each first receiving portion 446a being configured to receive the threaded shank end of each corresponding first fastener 456a.

[0063] The jacket 448 further includes an array of second receiving portions 446b (in) Figure 4a (Only one of these second receiving portions is visible), the array of which is used to receive the array of second fasteners 456b (e.g. Figure 6 As shown, the array of second fasteners is configured to connect the second collar 404b of the end fitting 400 to the clip 448, aligned with a corresponding receiving portion in the second collar 404b. The second receiving portion 446b is located radially outward of the first receiving portion 446a. The second receiving portion 446b of the clip 448 and the receiving portion of the second collar 404b are located at a plurality of substantially uniformly radially distributed points around the circumference of the clip 448 and the second collar 404b. Suitably, each second fastener 456b is configured to extend from a second end of the second collar 404b, through the receiving portion in the second collar 404b, and into each corresponding second receiving portion 446b in the clip 448, each second receiving portion 446b being configured to receive the threaded shank end of the second fastener 456b.

[0064] The end fitting 400 includes a first collar 404a. For example... Figure 4bAs shown, when the end fitting 400 is partially assembled (i.e., the first collar 404a is connected to the end fitting 400), the first collar 404a is disposed adjacent to the jacket 448. The first collar 404a is partially disposed radially outside the polymer layer 504 of the tube body 500, and in some cases, radially outside the stepped segment 449 of the jacket 448. The stepped segment 449 may be disposed at the end of the jacket 448 adjacent to the first collar 404a. The outer diameter of the stepped segment 449 may be smaller than the rest of the jacket 448, such that the stepped segment 449 is disposed within the recess 412 of the first collar 404a. The inner diameter of the first collar 404a is substantially equal to the outer diameter of the end portion of the polymer layer 504, where the polymer layer covers the sleeve 402. When the tube body 500 is connected to the end fitting 400, the size of the inner diameter of the first collar 404a is set to be positioned above the outer surface of the tube body 500. The tube body 500 is enclosed on its outer surface by a first collar 404a and on its inner surface by a first segment 408a of a sleeve 402. The first collar 404a is formed of metal. In this case, the first collar 404a is formed of alloy steel. Optionally, a coating is applied to at least some surfaces of the first collar 404a to act as a corrosion barrier.

[0065] The first collar 404a includes a recess 412 that is partially radially adjacent to the polymer layer 504 of the tube body 500 and, in some cases, partially radially adjacent to the stepped segment 449 of the sleeve 448. The recess 412 extends from a first end 440 of the first collar 404a to a position 425 midway along the length of the first collar 404a. The recess 412 has a rectangular cross-section. The recess 412 is annular. The recess 412 is configured to receive a first sealing assembly 406a of the end fitting 400 (as will be discussed later). Figure 5a and Figure 5b (as described).

[0066] The first ring 404a optionally includes a first conduit 438a1 of a first pressure port 424a. (See also: Regarding...) Figure 4a As shown, the first conduit 438a1 optionally extends from the second end 442 of the first collar 404a, passes through the first collar 404a, and reaches the interface between the first collar 404a and the polymer layer 504, such that the first conduit 438a1 is fluidly connected to the recess 412 via the interface. The first conduit 438a1 is configured to direct hydrostatic pressure to the pressure ring 432 of the first sealing assembly 406a of the end fitting 400 (as will be discussed later). Figure 8b(As described above). In this case, the first conduit 438a1 terminates at a second position 427 midway along the length of the first collar 404a. The second position 427 is spaced apart from the recess 412 along the length of the first collar 404a. That is, the recess 412 is radially separated from each other from the extension position of the first end 440 of the first collar 404a and from the second position 427 of the second end 442 along a portion of the length of the first collar 404a. The first conduit 438a1 is provided at at least one point around the circumference of the first collar 404a.

[0067] As described above, the first collar 404a includes a receiving portion 444 for receiving a first fastener 456a, which is configured to engage the first collar 404a to the sleeve 448. The first fastener 456a reduces the annular gap 471a between the sleeve 448 and the first collar 404a and secures the first collar 404a to the sleeve 448, thereby partially assembling the end fitting 400. The first fastener 456a engages the first sealing assembly 406a (as will be discussed later). Figure 5a and Figure 5b (as described).

[0068] The end fitting 400 includes a first sealing assembly 406a. The first sealing assembly 406a is located in a recess 412 of the first collar 404a. The first sealing assembly 406a partially corresponds to the recess 412.

[0069] Figure 5a An example is shown during the assembly of the end fitting 400. Figure 4a The first sealing assembly 406a of the end fitting 400, and Figure 5b An example is illustrated when the end fitting 400 is partially assembled (i.e., the first collar 404a is connected to the end fitting 400). Figure 4b The first sealing assembly 406a of the end fitting 400.

[0070] The first sealing assembly 406a includes a deformable ring 426 and a pressure ring 432.

[0071] A deformable ring 426 is disposed radially outside the polymer layer 504 of the tube body 500. The inner diameter of the deformable ring 426 is substantially equal to the outer diameter of the polymer layer 504, such that the deformable ring 426 and the polymer layer 504 are in contact with each other. Figure 5a As shown, during the assembly of the end fitting 400, the deformable ring 426 has a first end portion disposed adjacent to the stepped segment 449 of the sleeve 448, and a second end portion disposed along the recess 412, such that an annular gap 471b exists between the deformable ring 426 and the first sleeve 404a. Figure 5bAs shown, when the end fitting 400 is partially assembled, the deformable ring 426 has a first end provided with a stepped segment 449 adjacent to the jacket 448, and a second end provided with a first collar 404a (i.e., the annular gap 471b is reduced).

[0072] The deformable ring 426 is formed of metal. In this case, the deformable ring 426 is formed of brass. The ductility of the deformable ring 426 is lower than that of the polymer layer 504.

[0073] The deformable ring 426 has a trapezoidal shape. The deformable ring 426 includes an outer surface 428. The outer surface 428 is inclined at an angle of less than or equal to 45 degrees relative to the central longitudinal axis of the first sealing assembly 406a. The outer surface 428 is inclined such that the outer diameter of the deformable ring 426 is larger at the first end of the deformable ring 426 than at the second end of the deformable ring 426.

[0074] The deformable ring 426 further includes an inner surface 430 disposed radially adjacent to the polymer layer 504. The inner surface 430 is oriented parallel to the central longitudinal axis of the first sealing assembly 406a. The inner surface 430 abuts the outer surface 428 of the deformable ring 426 through a first surface at a first end of the deformable ring 426 and a second surface at a second end of the deformable ring 426. The first and second surfaces are oriented perpendicular to the central longitudinal axis of the first sealing assembly 406a.

[0075] The first sealing assembly 406a includes a seal 418 disposed between a deformable ring 426 and a pressure ring 432. More specifically, the seal 418 is disposed between the outer surface 428 of the deformable ring 426 and the inner surface 434 of the pressure ring 432. The seal 418 is substantially disposed along the middle of the length of the outer surface 428 of the deformable ring 426. The seal 418 includes an O-ring or an elastomer ring.

[0076] A pressure ring 432 is disposed radially outside the deformable ring 426. More specifically, the pressure ring 432 is disposed between the deformable ring 426 and the first set of rings 404a. The inner diameter of the pressure ring 432 is substantially equal to the outer diameter of the deformable ring 426, such that the pressure ring 432 and the deformable ring 426 are in contact with each other. The outer diameter of the pressure ring 432 is substantially equal to the inner diameter of the first set of rings 404a, such that the pressure ring 432 and the first set of rings 404a are in contact with each other. Figure 5a and Figure 5b As shown, during the assembly of the end fitting 400 and when the end fitting 400 is partially assembled, the pressure ring 432 has a first end located along the recess 412 and a second end adjacent to the first collar 404a. The portion of the recess 412 between the first end of the pressure ring 432 and the sleeve 448 is defined as a gap 416 (as will be discussed later). Figure 8b (as described).

[0077] Pressure ring 432 is formed of metal. In this case, pressure ring 432 is formed of a nickel alloy. The deformable ring 426 has a higher ductility than pressure ring 432.

[0078] The pressure ring 432 has a trapezoidal shape. The pressure ring 432 includes an inner surface 434. The inner surface 434 is inclined at an angle less than or equal to 45 degrees relative to the central longitudinal axis of the first sealing assembly 406a. The inclination of the inner surface 434 is such that the inner diameter of the pressure ring 432 is larger at the second end of the pressure ring 432 than at the first end of the pressure ring 432. The inner surface 434 of the pressure ring 432 corresponds to the outer surface 428 of the deformable ring 426.

[0079] The pressure ring 432 further includes an outer surface 454 disposed radially adjacent to the first sleeve ring 404a. The outer surface 454 is oriented parallel to the central longitudinal axis of the first sealing assembly 406a. The outer surface 454 abuts the inner surface 434 of the pressure ring 432 through a first surface at a first end of the pressure ring 432 and a second surface at a second end of the pressure ring 432. The first and second surfaces of the pressure ring 432 are oriented perpendicular to the longitudinal axis of the first sealing assembly 406a.

[0080] The first sealing assembly 406a includes an additional seal 422 disposed between the pressure ring 432 and the first collar 404a. More specifically, the additional seal 422 is disposed between the outer surface 454 of the pressure ring 432 and the first collar 404a. The additional seal 422 is substantially disposed along the middle of the length of the outer surface 454 of the pressure ring 432. The additional seal 422 includes an O-ring or an elastomer ring.

[0081] like Figure 5a As shown, during the assembly of the end fitting 400, the first collar 404a and the clip 448 are not connected to each other, such that an annular gap 471a is provided between the first collar 404a and the clip 448. As described above, during the assembly of the end fitting 400, the second end of the deformable ring 426 is disposed along the recess 412, such that an additional annular gap 471b exists between the deformable ring 426 and the first collar 404a. The annular gap 471a between the first collar 404a and the clip 448 corresponds in width to the additional annular gap 471b between the deformable ring 426 and the first collar 404a.

[0082] like Figure 5aAs further shown, the inner surface 434 of the pressure ring 432 and the outer surface 428 of the deformable ring 426 are inclined relative to each other, such that the deformable ring 426 temporarily restricts the movement of the pressure ring 432 toward the jacket 448 along the central longitudinal axis of the first sealing assembly 406a.

[0083] To connect the first sleeve 404a to the jacket 448 and partially assemble the end fitting 400, the first sleeve 404a is moved toward the jacket 448, thereby reducing the annular gap 471a between the first sleeve 404a and the jacket 448 (and an additional annular gap 471b between the deformable ring 426 and the first sleeve 404a). As described above, the second end of the pressure ring 432 is disposed adjacent to the first sleeve 404a. Thus, moving the first sleeve 404a toward the jacket 448 powers the pressure ring 432 to move along the central longitudinal axis of the first sealing assembly 406a toward the jacket 448 and against the deformable ring 426. More specifically, the inner surface 434 of the pressure ring 432 is forged against the outer surface 428 of the deformable ring 426.

[0084] Because the deformable ring 426 has a higher ductility than the pressure ring 432, the pressure ring 432 deforms the deformable ring 426 when it is forged against the deformable ring 426. More specifically, the inner surface 434 of the pressure ring 432 deforms the outer surface 428 of the deformable ring 426. The deformation of the deformable ring 426 removes the constraint on the pressure ring 432, allowing it to move toward the jacket 448 along the central longitudinal axis of the first sealing assembly 406a. The deformation of the deformable ring 426 changes its outer diameter. For example, the outer diameter of the first end of the deformable ring 426 decreases, thereby enabling the pressure ring 432 to move toward the jacket 448. The first sealing assembly 406a is configured such that the movement of the pressure ring 432 is resisted and / or the pressure required to power the pressure ring 432 is appropriately controlled. For example, reducing the elongation ratio between the deformable ring 426 and the pressure ring 432 increases the pressure required to power the pressure ring 436 and causes the pressure ring 436 to move along the central longitudinal axis of the first sealing assembly 406a toward the jacket 448.

[0085] The pressure ring 432 is forged against the deformable ring 426, such that, in addition to deforming the deformable ring 426, it is also compressed against the polymer layer 504 of the tube body 500 and / or the stepped segment 449 of the jacket 448. As the pressure ring 432 moves toward the jacket 448, the amount of compression exerted by the deformable ring 426 on the polymer layer 504 and / or the stepped segment 449 increases. Compressing the deformable ring 426 against the polymer layer 504 and / or the stepped segment 449 in this way prevents fluid from entering between the deformable ring 426 and the polymer layer 504 and / or the stepped segment 449. In this way, fluid entry is prevented by reducing the width of the interface between the deformable ring 426 and the polymer layer 504 and / or the stepped segment 449.

[0086] The pressure ring 432 is forged against the deformable ring 426 until the first ring 404a and the jacket 448, and subsequently the deformable ring 426 and the first ring 404a, come into contact with each other. When the first ring 404a and the jacket 448, and subsequently the deformable ring 426 and the first ring 404a, are in contact with each other, the end fitting 400 is in a partially assembled configuration, such as... Figure 4b and Figure 5b As shown.

[0087] like Figure 5b As further shown, after partial assembly, the deformable ring 426 is restricted to move parallel to the central longitudinal axis of the first sealing assembly 406a. At the first end of the deformable ring 426, movement is restricted by the stepped segment 449 of the jacket 448, and at the second end of the deformable ring 426, movement is restricted by the first collar 404a. As described above, regarding Figure 5a The inner surface 434 of the pressure ring 432 and the outer surface 428 of the deformable ring 426 are inclined relative to each other, such that the deformable ring 426 temporarily restricts the movement of the pressure ring 432 along the central longitudinal axis of the first sealing assembly 406a.

[0088] Figure 6 Further examples of partial assembly are shown. Figure 4b The end fittings (i.e., the first ring 404a and the second ring 404b connected to the end fitting 400).

[0089] like Figure 6 As shown, the end fitting 400 includes a second collar 404b. The first portion of the second collar 404b is arranged in a similar manner to the first collar 404a of the end fitting 400 (as described above regarding...). Figure 4a and Figure 4bThe first collar 404a is partially disposed radially outside the polymer layer 504 of the tube body 500. A second portion of the second collar 404b is disposed radially outside the first collar 404a, such that the first collar 404a is encapsulated by the second collar 404b. The second collar 404b is integrally formed. The second collar 404b is formed of metal. In this case, the second collar 404b is formed of alloy steel.

[0090] Optionally, the coating is applied to at least some surfaces of the second ring 404b to act as a corrosion barrier.

[0091] The second collar 404b includes a recess that is radially adjacent to the polymer layer 504 of the tube body 500 and, in some cases, also radially adjacent to a stepped segment of the first collar 404a. The recess extends from a first end of the second collar 404b adjacent to the first collar 404a to a position midway along the length of the second collar 404b. The recess has a rectangular cross-section. The recess is annular. The recess is configured to receive a second sealing assembly 406b of the end fitting 400 (e.g., ...). Figure 6 (As shown). With regard to... Figure 5a and Figure 5b In a similar manner, the pressure ring of the second sealing assembly 406b is configured to abut against a corresponding deformable ring of the second sealing assembly 406b being forged, thereby preventing fluid from entering between the polymer layer 504 and the second sealing assembly 406b.

[0092] The second collar 404b includes an additional recess that is radially adjacent to the polymer layer 504 of the tube body 500 and, in some cases, also radially adjacent to a stepped segment of the third collar 404c of the end fitting 400. This additional recess extends from a second end of the second collar 404b adjacent to the third collar 404c to a position midway along the length of the second collar 404a (spaced apart from the position where the recess terminates as described above). This additional recess has a rectangular cross-section. The additional recess is annular. This additional recess is configured to receive the third sealing assembly 406c of the end fitting 400 (as per [reference to...]). Figure 7 (as described).

[0093] The second collar 404b optionally includes a second conduit 438a2 and an opening 436a of a first pressure port 424a. The second conduit 438a2 optionally extends from the opening 436a on the outer surface of the second collar 404b through the second collar 404b and reaches a first conduit 438a1 of the first collar 404a, such that the second conduit 438a2 is fluidly connected to the first conduit 438a1, and subsequently fluidly connected to a recess 412 of the first collar 404a. The second conduit 438a2 is located at at least one point around the circumference of the second collar 404b. The second conduit 438a2 is aligned with the first conduit 438a1 of the first collar 404a at the interface between the first conduit 438a1 and the second conduit 438a2. The opening 436a of the first pressure port 424a has a generally rectangular cross-section. Optionally, the opening 436a is annular. Optionally, the opening 436a is not annular and is one of a plurality of boreholes having a circular cross-section. Optionally, the opening 436a is not annular, but is one of a plurality of openings 436a milled into the second ring 404b and uniformly radially distributed, each of which has an elliptical or polygonal cross-section.

[0094] The second collar 404b optionally includes a second pressure port 424b spaced apart from the first pressure port 424a along the length of the second collar 404b. The second pressure port 424b includes a conduit 438b and an opening 436b. The conduit 438b optionally extends from the opening 436b disposed on the outer surface of the second collar 404b through the second collar 404b and reaches the interface between the second collar 404b and the polymer layer 504, such that the conduit 438b is fluidly connected via this interface to the recess and the additional recess of the second collar 404b. The conduit 438b of the second pressure port 424b is configured to direct hydrostatic pressure to the pressure rings of the second sealing assembly 406b and the third sealing assembly 406c, as will be discussed later. Figure 8b The conduit 438b is disposed at at least one point on the circumference surrounding the second collar 404b. The opening 436b of the second pressure port 424b is configured in a similar manner to the opening 436a of the first pressure port 424a.

[0095] As mentioned above, regarding Figure 4a and Figure 4bThe second collar 404b includes a receiving portion for receiving the second fastener 456b, which is configured to connect the second collar 404b to the sleeve 448. The second fastener 456b reduces the annular gap between the sleeve 448 and the second collar 404b (and between the second collar 404b and the first collar 404a), and secures the second collar 404b to the sleeve 448, such that the end fitting 400 is partially assembled (i.e., the second collar 404b is connected to the end fitting 400). The second fastener 456b further engages the second sealing assembly 406b (to correspond with the above regarding...). Figure 5a and Figure 5b (similar to the above).

[0096] The second ring 404b further includes additional receiving portions for receiving the array of third fasteners 456c1 (only one of these additional receiving portions is in...) Figure 6 (as can be seen in the middle) Figure 7 (As shown). The third fastener 456c1 is configured to connect the third collar 404c to the second collar 404b and align with a corresponding receiving portion in the third collar 404c. Further receiving portions of the second collar 404b and the third collar 404c are located at a plurality of substantially uniformly radially distributed points around the circumference of the second collar 404b and the third collar 404c. Suitably, each third fastener 456c1 is configured to extend from a second end of the third collar 404c, through a receiving portion in the third collar 404b, and into each corresponding additional receiving portion in the second collar 404b.

[0097] Figure 7 A further example of a fully assembled Figure 6 End fitting 400 (i.e., the first collar 404a, the second collar 404b and the third collar 404c connected to end fitting 400).

[0098] like Figure 7 As shown, the end fitting 400 includes a third collar 404c. The third collar 404c is arranged in a similar manner to the first collar 404a of the end fitting 400 (as described above regarding...). Figure 4a and Figure 4b The third collar 404c is disposed radially outside the polymer layer 504 of the tube body 500. The third collar 404c is formed of metal. In this case, the third collar 404c is formed of alloy steel. Optionally, a coating is applied to at least some surfaces of the third collar 404c to act as a corrosion barrier.

[0099] As mentioned above, regarding Figure 6The third collar 404c includes a receiving portion for receiving a third fastener 456c1, which is configured to connect the third collar 404c to the second collar 404c. The first fastener 456c1 secures the third collar 404c to the second collar 404b, thereby fully assembling the end fitting 400.

[0100] In some cases, the third collar 404c includes an additional receiving portion for receiving a fourth retainer 456c2, which is configured to power the pressure ring of the third sealing assembly 406c, and is disposed in an additional recess of the second collar 404b, aligned with the receiving portion of the pressure ring. The additional receiving portions of the third collar 404c and the receiving portion of the pressure ring of the third sealing assembly 404c are located at a plurality of substantially uniformly radially distributed points around the circumference of the third collar 404c and the pressure ring. Suitably, each fourth retainer 456c2 is configured to extend from a second end of the third collar 404c, through the additional receiving portion in the third collar 404c, and into each corresponding receiving portion of the pressure ring of the third sealing assembly 406c.

[0101] With regard to Figure 5a and Figure 5b In a similar manner, the pressure ring of the third sealing assembly 406c is configured to abut against a corresponding deformable ring of the third sealing assembly 406c being forged, thereby preventing fluid from entering between the polymer layer 504 and the third sealing assembly 406c.

[0102] Figure 8a Further examples of its use Figure 7 The end fitting 400, and for example, Figure 8b Examples Figure 8a The first sealing assembly 406a of the end fitting (i.e., when the end fitting 400 is in use).

[0103] In use, when the flexible tube 1000, including the end fitting 400, is deployed, the power supply to each pressure ring 432 of the corresponding sealing assemblies 406a, 406b, 406c is maintained or increased by the hydrostatic pressure acting on the pressure ring 432. The hydrostatic pressure is directed toward the pressure ring 432 via pipes 438a1, 438a2, 438b through pressure ports 424a, 424b. The amount of pressure acting on the pressure ring 432 increases with the depth to which the flexible tube 1000, including the end fitting 400, is immersed.

[0104] like Figure 8a and Figure 8bAs shown, the hydrostatic pressure acting on the pressure ring 432 moves the pressure ring 432 toward the corresponding gap 416, causing the pressure ring 432 to be forged against the corresponding deformable ring 426 and maintaining a seal between the deformable ring 426 and the polymer layer 504, thereby preventing fluid ingress. More specifically, the inner surface 434 of the pressure ring 432 is forged against the outer surface 428 of the corresponding deformable ring 426. As the hydrostatic pressure acting on the pressure ring 432 increases, the pressure ring 432 continues to be forged against the corresponding deformable ring 426, and the pressure ring 432 moves toward the gap 416 and optionally into that gap. Figure 8b As shown, the pressure ring 432 is partially disposed in the gap 416. The first seal 418 disposed between the pressure ring 432 and the deformable ring 426s and the second seal 422 disposed between the pressure ring 432 and the collars 404a, 404b, 404c further help to prevent fluid ingress.

[0105] Figure 9a An example of a method 600 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] Method 600 includes step 602 of providing a tube body 500 comprising a flexible tube 1000 including a polymer layer 504.

[0107] Method 600 further includes step 604 of providing a sleeve 402 for the end fitting 400 of the flexible tube 1000. The sleeve 402 includes a first segment 408a and a second segment 408b. The outer diameter of the second segment 408b is larger than the outer diameter of the first segment 408a.

[0108] Method 600 further includes step 606 of inserting a first segment 408a of sleeve 402 into the radially inner side of polymer layer 504 of tube body 500.

[0109] Method 600 further includes step 608 of providing a collar 404 of the end fitting 400 and disposing the collar 404 radially outside the polymer layer 504 of the tube body 500. The collar 404 includes a recess 412 adjacent to the polymer layer 504 of the tube body 500.

[0110] Method 600 further includes step 610 of providing a sealing assembly 406 and disposing the sealing assembly between a collar 404 and a polymer layer 504. The sealing assembly 406 includes a deformable ring 426 disposed radially outward of the polymer layer 504 and a pressure ring 432 disposed between the deformable ring 426 and the collar 404. The deformable ring 426 has a higher elongation than the pressure ring 432 and a lower elongation than the polymer layer 504.

[0111] Figure 9b A method 650 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.

[0112] Method 650 includes steps 602, 604, 606, 608, and 610 of method 600.

[0113] Method 650 further includes step 612 of supplying power to pressure ring 432 such that pressure ring 432 is forged against deformable ring 426, and pressure ring 432 engages deformable ring 426 and deforms deformable ring.

[0114] Various modifications to the detailed arrangement described above are possible.

[0115] The outer surface of the first segment 408a of the sleeve 402 and / or the inner surface of the polymer layer 504 of the tube body 500 may include serrations, such that the first segment 408a and the polymer layer 504 form an interference fit. The serrations may form a labyrinth profile.

[0116] The polymer layer 504 of the tube body 500 can be formed of polyethylene, polyamide or any other suitable material.

[0117] The polymer layer 504 serves as the outer sheath of the tube body 500, and the polymer layer 504 can be any layer of the tube body 500. The polymer layer 504 can include multiple layers of the tube body 500.

[0118] The tapered portion of the sleeve 402 can be configured to prevent the formation of a gap between the first segment 408a of the sleeve 402 and the polymer layer 504 of the tube body 500.

[0119] Pressure ring 432 can be corrosion resistant.

[0120] Instead of connecting the jacket 448 and the first collar 404a and / or the second collar 404b via fasteners 456a and 456b, the jacket 448 can be connected to the first collar 404a and / or the second collar 404b by any means known in the art (e.g., welding, using adhesives or mechanical connections).

[0121] Instead of a rectangular cross-section, recess 412 may include any shape suitable for receiving the respective sealing components 406a, 406b, 406c.

[0122] Instead of the recess 412 being annular, the recess 412 may not be annular (i.e., it may be located at discontinuities around the circumference of the first ring 404a and / or the second ring 404b and / or the third ring 404c).

[0123] Instead of the deformable ring 426 and the pressure ring 432 being trapezoidal in shape, the deformable ring 426 and the pressure ring 432 can include any shape, such that the pressure ring 432 can be forged against the deformable ring 426.

[0124] The deformable ring 426 can be plastically deformable or elastically deformable.

[0125] The sealing assembly 406 may not include either the first seal 418 or the second seal 422.

[0126] The first seal 418 and / or the second seal 422 may be replaced by an O-ring or an elastomer ring, and the first seal 418 and / or the second seal 422 may be a spiral washer type seal.

[0127] Replacement Figure 7 and Figure 8a The triple seal and triple collar arrangement shown can be configured similarly without requiring the third collar 404c or the third sealing assembly 406c. Figure 6 The double seal and double collar arrangement shown do not compromise performance.

[0128] The orientation of the components of sealing assemblies 406a, 406b, and 406c can be reversed, and similarly, the pipes 438a and 438b can be rewired to accommodate this change in seal orientation.

[0129] The precise dimensions of the end fitting parts have been described only as an example.

[0130] With the above arrangement, the deformable ring has a ductility value between that of the pressure ring and that of the polymer layer of the tube body. This achieves a good seal between the radially outer portion of the end fitting and the tube layers, as well as a good connection when the pressure ring and the polymer layer are joined.

[0131] With the above arrangement, the first and / or second and / or third rings of the end fitting are positioned radially outside the connection between the polymer layer and the deformable ring of the tube body. This protects the connection between the polymer layer and the deformable ring from failure, thereby providing an improved connection between the end fitting and the tube body.

[0132] With the above arrangement, the sealing assembly is placed in the recess of the polymer layer adjacent to the tube body, so that the end fitting can use hydrostatic pressure to increase the compressive force acting on the pressure ring, and then increase the compressive force acting on the deformable ring, thereby further improving the seal and preventing fluid from entering between the first and / or second and / or third rings and the polymer layer.

[0133] It will be apparent to those skilled in the art that the features described in any of the above embodiments are interchangeable between different embodiments. The above embodiments are examples illustrating various feature structures of the present invention.

[0134] 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, integers, 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.

[0135] 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, abstract, and drawings) and / or all steps of any method or process so disclosed may be combined in any combination except where 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, abstract, and drawings), or to any novel step or any novel combination of steps of any method or process so disclosed.

[0136] The reader’s attention is drawn to all papers and documents submitted concurrently with or prior to this specification in conjunction with this application that disclose public examination of this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

1. A seal assembly for an end fitting of a flexible pipe, wherein the seal assembly is positionable between a collar of the end fitting and a polymeric layer of a pipe body of the flexible pipe, the seal assembly comprising: a deformable ring positionable radially outward of the polymeric layer of the pipe body; and a pressure ring positionable between the deformable ring and the collar of the end fitting, wherein ductility of the deformable ring is higher than ductility of the pressure ring and lower than ductility of the polymeric layer of the pipe body.

2. The seal assembly of claim 1, wherein the pressure ring is movable between the deformable ring and the collar of the end fitting such that the pressure ring engages the deformable ring and deforms the deformable ring.

3. The seal assembly of claim 2, wherein the pressure ring is energised in use such that the pressure ring is swaged against the deformable ring.

4. The seal assembly of any preceding claim, wherein the deformable ring comprises a first surface and the pressure ring comprises a second surface, and wherein the first surface of the deformable ring and the second surface of the pressure ring are inclined relative to each other.

5. The seal assembly of claim 4, wherein the second surface of the pressure ring is swaged against the first surface of the deformable ring.

6. The seal assembly of claim 4 or 5, wherein the first surface of the deformable ring is inclined at an angle of less than or equal to 45 degrees relative to a central longitudinal axis of the seal assembly.

7. The seal assembly of any of claims 4 to 6, wherein the deformable ring and / or the pressure ring comprises a trapezoidal shape.

8. The seal assembly of any preceding claim, wherein the deformable ring comprises brass.

9. The seal assembly of any preceding claim, wherein the pressure ring comprises a nickel alloy.

10. The seal assembly of any preceding claim, wherein the deformable ring is plastically deformable.

11. The seal assembly of any preceding claim, wherein the seal assembly comprises: a first seal disposed between the deformable ring and the pressure ring; and / or a second seal disposed between the pressure ring and the collar of the end fitting.

12. The seal assembly of claim 11, wherein the first seal and / or the second seal comprises an O-ring or an elastomeric ring.

13. The seal assembly of any preceding claim, wherein an inner surface of the deformable ring comprises serrations.

14. An end fitting for coupling to a pipe body, wherein the end fitting comprises: a sleeve insertable radially inward of a polymeric layer of the pipe body; a collar disposed radially outward of the polymeric layer of the pipe body, the collar comprising a recess adjacent the polymeric layer of the pipe body in use; and a seal assembly according to any preceding claim. ​ ​ The sealing assembly of any one of the preceding claims, configured to be located in the recess of the collar.

15. The end fitting of claim 14, wherein the pressure ring is movable within the recess such that the pressure ring engages and deforms the deformable ring.

16. The end fitting of claim 15, wherein the end fitting comprises a jacket disposed proximate the collar.

17. The end fitting of claim 16, wherein the recess comprises a void disposed between the pressure ring and the jacket, and wherein the pressure ring is movable within the recess toward the void.

18. The end fitting of claim 17, wherein the pressure ring is energized in use such that the pressure ring is swaged toward the void and against the deformable ring.

19. The end fitting of claim 18, wherein the collar comprises a pressure port configured to direct hydrostatic pressure onto the pressure ring.

20. A flexible pipe, wherein the flexible pipe comprises: a pipe body comprising a polymer layer; and an end fitting comprising: a sleeve inserted radially inboard of the polymer layer of the pipe body; a jacket comprising an outer diameter greater than an outer diameter of the sleeve; a collar disposed radially outboard of the polymer layer of the pipe body, the collar comprising a recess adjacent the polymer layer of the pipe body; and the sealing assembly of any one of claims 1 to 13, configured to be located in the recess of the collar.

21. A method of assembling a flexible pipe, wherein the method comprises: providing a pipe body comprising a polymer layer; providing a sleeve of an end fitting; inserting the sleeve radially inboard of the polymer layer of the pipe body; providing a collar of the end fitting and disposing the collar radially outboard of the polymer layer of the pipe body, the collar comprising a recess adjacent the polymer layer of the pipe body; and providing a sealing assembly of the end fitting of any one of claims 1 to 13 and positioning the sealing assembly in the recess of the collar.

22. The method of claim 21, wherein the method comprises energizing the pressure ring such that the pressure ring is swaged against the deformable ring and the pressure ring engages and deforms the deformable ring.

23. The method of claim 22, wherein the method comprises providing a jacket of the end fitting, the jacket comprising an outer diameter greater than an outer diameter of the sleeve, and the recess comprises a void disposed between the pressure ring and the jacket, and wherein the pressure ring is movable within the recess toward the void.

24. The method of claim 23, wherein the method comprises energizing the pressure ring in use such that the pressure ring is swaged toward the void and against the deformable ring.

25. The method of claim 24, wherein the method comprises providing a pressure port of the collar configured to direct hydrostatic pressure onto the pressure ring.

26. A method of manufacturing a flexible pipe, the method comprising: providing a pipe body comprising a polymer layer; providing a sleeve of an end fitting; inserting the sleeve radially inboard of the polymer layer of the pipe body; providing a collar of the end fitting and disposing the collar radially outboard of the polymer layer of the pipe body, the collar comprising a recess adjacent the polymer layer of the pipe body; and providing a sealing assembly of the end fitting of any one of claims 1 to 13 and positioning the sealing assembly in the recess of the collar.

27. The method of claim 26, wherein the method comprises energizing the pressure ring such that the pressure ring is swaged against the deformable ring and the pressure ring engages and deforms the deformable ring.

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