A ball joint structure for a marine offloading hose

Abstract

The application discloses a spherical joint structure for ocean offloading hose, which is suitable for connecting two adjacent offloading hoses, and comprises an outer joint, an inner joint and a ring-shaped connecting piece.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering fluid transport equipment, and more particularly, it relates to a spherical joint structure for marine export hoses. Background Technology

[0002] Marine export hoses are a core component of deepwater oil and gas development systems. Their primary function is to enable flexible connections between floating production storage and offloading (FPSO), floating storage and offloading (FSO), or single-point mooring (SPM) systems and shuttle tankers, facilitating the continuous and dynamic export of crude oil, natural gas, or liquefied natural gas (LNG). As global offshore oil and gas resource development continues to advance into deep and ultra-deep water, the service environment of export hose systems exhibits significant complexity and extreme characteristics. Hoses must withstand wave-induced heave, pitch, roll, and other multi-degree-of-freedom dynamic loads, as well as the continuous impact of ocean currents, deep-sea temperature and pressure fluctuations, ship relative displacement, and long-term corrosion from highly corrosive media. This places stringent demands on the connection reliability, environmental adaptability, and service life of the entire hose system.

[0003] As the connecting hub between the export hose and the subsea pipeline, loading arm, or other transport equipment, the end joint's structural performance directly determines the flexibility, media sealing reliability, and long-term operational safety of the entire export system. Currently, the traditional flange-type or rigid joint structures widely used in the industry are gradually revealing significant technical limitations under complex ultra-deepwater conditions.

[0004] ① Insufficient angle compensation capability: Existing rigid joints typically have a small allowable deflection angle, which cannot effectively adapt to the large-angle displacement and bending deformation of hoses caused by currents and waves under extreme sea conditions.

[0005] ②Simple sealing structure: Traditional joints mostly use a single rubber sealing ring or metal end face sealing structure, which poses a risk of leakage under high pressure and dynamic working conditions.

[0006] ③ Short fatigue life: There is a significant abrupt change in stiffness at the connection between the metal joint and the non-metallic hose. Under cyclic fatigue load, stress concentration is likely to occur, which can easily lead to cracks on the surface of the metal structure.

[0007] ④ High operation and maintenance costs: Existing joint structures mostly adopt an integrated design, and vulnerable components such as seals cannot be replaced on-site in the marine environment. Once a failure occurs, the entire joint needs to be hoisted ashore for repair, with a single maintenance cost exceeding one million yuan.

[0008] To address the aforementioned technical challenges, there is an urgent need to develop a new type of export hose connector structure that features angle adaptive compensation capability, high sealing reliability, long fatigue life, and convenient underwater maintenance, in order to support the independent controllability and safe and efficient operation of ultra-deepwater oil and gas development equipment. Summary of the Invention

[0009] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention provides a spherical connector structure for marine export hoses, aiming to solve the problems of insufficient sealing reliability, limited angle compensation capability, and susceptibility to fatigue damage in traditional marine export hose connector structures under high pressure, dynamic loads, and complex marine environments. This fills a current technological gap in China regarding export hose connector structures.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: a spherical connector structure for marine export hoses, suitable for connecting two adjacent export hose segments, comprising: an outer connector, one end forming a ball-shaped socket, the other end adapted to connect to a first export hose segment, wherein a first fluid channel is formed within the outer connector; an inner connector, one end forming a ball-shaped head, the other end adapted to connect to a second export hose segment, wherein a second fluid channel is formed within the inner connector, wherein the ball-shaped head of the inner connector is embedded within the ball-shaped socket of the outer connector to form a damped ball-joint connection structure, thereby enabling the two export hose segments to communicate with each other and achieving omnidirectional angle compensation of ±15° to ±25° and a certain axial float; and an annular connector disposed on the outer periphery of the ball-shaped socket of the outer connector, forming a circumferential covering connection with the outer connector, while simultaneously providing external limiting and constraint to the ball-shaped head of the inner connector.

[0011] Preferably, multiple radial bolts are evenly distributed at 60° intervals along the circumference for radial connection of the external connector and the annular connector.

[0012] Preferably, multiple axial bolts are evenly distributed at 60° intervals along the circumference for axial connection of the external joint and the annular connector.

[0013] Preferably, the radial bolts and axial bolts are arranged alternately along the circumference of the outgoing hose, with each radial bolt at a 30° angle to the next axial bolt.

[0014] Preferably, the device also includes a front sealing ring and a rear sealing ring, which are O-rings made of nitrile rubber. The front sealing ring is disposed between the contact interface of the outer connector and the inner connector, and the rear sealing ring is disposed between the contact interface of the inner connector and the annular connector.

[0015] Preferably, both the front and rear sealing rings adopt a rectangular groove design, with a retaining ring on each side of the groove.

[0016] Preferably, an annular sealing groove is formed on the contact interface between the outer connector and the circumferential connector near the outer side of the front and rear sealing rings, and a metal ring gasket is provided in the sealing groove as a metal-to-metal seal.

[0017] Preferably, the metal ring gasket is a BX type metal ring gasket that conforms to API 6A standard and has an octagonal structure. The material is Inconel 625 or 316L stainless steel with a nickel coating, and the BX type metal ring gasket and the sealing groove form a conical-conical contact sealing pair.

[0018] Preferably, the second fluid channel inside the inner connector adopts a tapering structure that is wider on the outside and narrower on the inside.

[0019] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention uses a spherical connector as the core connection structure. Through the spherical fit, it achieves multi-degree-of-freedom angle adaptive compensation. Under dynamic working conditions such as floating marine platforms and ocean current impact, it can effectively absorb the deflection displacement at the connection of the export hose, significantly reduce the stress concentration of the hose bending, reduce fatigue damage under alternating loads, and extend the overall service life of the hose.

[0020] 2. In this invention, the radial bolts and axial bolts are arranged alternately along the circumferential direction of the outgoing hose, and the installation angle between adjacent bolts is 30°. Through this uniformly distributed fastening structure, the radial shear load and axial tensile load on the spherical joint can be balanced at the same time, avoiding connection failure caused by overload in one direction and improving the stability of the joint structure under complex loads.

[0021] 3. The O-ring used in this invention has excellent elastic deformation capability and interface adaptability, which can effectively compensate for pipeline vibration, thermal expansion and contraction caused by changes in medium temperature, and wear gaps caused by joint fretting, ensuring sealing reliability under low pressure conditions and preventing medium leakage.

[0022] 4. The BX type metal ring gasket seal used in this invention has a pressure self-reinforcing characteristic. When the medium pressure increases, the specific pressure of the sealing surface increases synchronously with the medium pressure, and the sealing performance is enhanced with the increase of pressure. It is especially suitable for harsh working conditions such as deep water high pressure and strong corrosive medium transportation.

[0023] 5. This invention forms a redundant sealing system of "main seal - auxiliary seal" through the combination sealing structure of O-ring and BX metal ring gasket: under normal working conditions, the O-ring seal performs the main sealing function, and the BX metal ring gasket provides redundancy protection as an auxiliary seal; when the main seal leaks a small amount due to accidental damage, the auxiliary seal can immediately play a sealing role to prevent the medium from leaking directly to the external environment, and significantly improve the safety of system operation.

[0024] In summary, this invention effectively solves the technical problems of insufficient sealing reliability, limited angle compensation capability, and easy fatigue damage of traditional marine export hose joints under high pressure, dynamic load, and complex marine environments by optimizing the spherical joint structure, designing a multi-directional load uniform bearing system, and using a graded redundant sealing system. It forms an export hose joint structure with multi-directional angle adaptive capability, high sealing reliability, and long service life, which can significantly improve the environmental adaptability, sealing safety, and long-term operational stability of the export hose system, and reduce the maintenance cost and leakage risk of the offshore oil and gas transportation system. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the cross-sectional structure of a ball joint for a marine export hose provided in an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of the O-ring and groove design of a ball joint for a marine export hose according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the rotation of a ball joint for a marine export hose provided in an embodiment of the present invention; The labels for the attached figures are as follows: 1-External hose; 2-External connector; 3-Internal connector; 4-Ring connector; 5-Radial bolt; 6-Axial bolt; 7-Front sealing ring; 8-Rear sealing ring; 9-Metal ring gasket; 10-Groove; 11-Retaining ring; 12-Sealing groove. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] This invention provides a spherical connector structure for marine export hoses, suitable for connecting two adjacent export hose segments. It includes: an outer connector, with one end forming a ball-shaped socket and the other end adapted to connect to a first export hose segment, and a first fluid channel formed within the outer connector; an inner connector, with one end forming a ball-shaped head and the other end adapted to connect to a second export hose segment, and a second fluid channel formed within the inner connector; the ball-shaped head of the inner connector is embedded in the ball-shaped socket of the outer connector to form a damped ball-joint connection structure, enabling the two export hose segments to communicate with each other and achieving ±15° to ±25° omnidirectional angle compensation and a certain degree of axial float; and an annular connector, disposed on the outer periphery of the ball-shaped socket of the outer connector, forming a circumferentially enveloping connection with the outer connector, while simultaneously providing external limiting and constraint to the ball-shaped head of the inner connector. This invention solves the problems of stress concentration, single-seal failure, and leakage in extreme sea conditions associated with traditional connectors, and offers advantages such as long service life, maintenance-free operation, and high safety.

[0033] The spherical connector structure for marine export hoses provided in the embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] Please see Figure 1 , Figure 2 The present invention provides a spherical connector structure for marine export hoses, suitable for connecting two adjacent export hose sections 1, comprising: The external connector 2 has a ball-shaped socket at one end and is adapted to connect to the first section of the external hose 1 at the other end. A first fluid channel is formed inside the external connector 2. The inner connector 3 has a ball head at one end and is adapted to connect to the second section of the external hose 1 at the other end. A second fluid channel is formed within the inner connector 3. The ball head of the inner connector 3 is embedded in the ball socket of the outer connector 2 to form a damped ball-joint connection structure, allowing the two sections of the external hose 1 to communicate with each other and enabling omnidirectional angle compensation of ±15° to ±25° (preferably ±20°) and a certain degree of axial float (see [reference]). Figure 3 This significantly reduces the bending moment of the export hose 1; The ring-shaped connector 4 is disposed on the outer periphery of the ball socket of the outer connector 2 and forms a circumferential covering connection with the outer connector 2, while simultaneously limiting and constraining the ball head of the inner connector 3 on the outer side.

[0035] In the above embodiments, preferably, a plurality of radial bolts 5 are evenly distributed at 60° intervals along the circumference for radial connection of the outer connector 2 and the annular connector 4. Thus, under radial load, the radial relative displacement between the outer connector 2 and the annular connector 4 is limited by the shearing action of the bolt rod and the bearing pressure of the bolt hole, and the radial load generated by the external hose 1 due to internal flow, external environment, etc. is borne, so as to avoid excessive radial pressure at the joint and failure of the joint.

[0036] In the above embodiments, preferably, multiple axial bolts 6 are evenly distributed at 60° intervals along the circumference for axial connection of the outer connector 2 and the annular connector 4. Thus, by applying preload, the bolts are mainly subjected to axial tension during the loading process, and the friction between the contact surfaces is used to resist axial separation. This bears the axial load generated by the internal flow and external environment of the external hose 1, and avoids excessive axial pressure at the joint, which could lead to joint failure.

[0037] In the above embodiments, preferably, the radial bolts 5 and axial bolts 6 are arranged alternately along the circumference of the outgoing hose 1, with each radial bolt 5 at a 30° angle to the next axial bolt 6, in order to balance the radial and axial loads of the ball joint connection structure.

[0038] In the above embodiments, preferably, please refer to Figure 1 , Figure 2 It also includes a front sealing ring 7 and a rear sealing ring 8. The front sealing ring 7 and the rear sealing ring 8 are O-rings made of nitrile rubber (NBR). The front sealing ring 7 is located between the contact interface of the outer connector 2 and the inner connector 3, and the rear sealing ring 8 is located between the contact interface of the inner connector 3 and the annular connector 4, thereby achieving sealing between the outer connector 2 and the inner connector 3 and between the inner connector 3 and the annular connector 4.

[0039] In the above embodiments, preferably, please refer to Figure 2 The front sealing ring 7 adopts a rectangular groove design. A retaining ring 11 is provided on each side of the groove 10. The retaining ring 11 is used to limit the lateral deformation of the front sealing ring 7, suppress it from being squeezed into the gap area, and prevent the front sealing ring 7 from gap biting and extrusion failure during operation. The rear sealing ring 8 is set in the same way.

[0040] In the above embodiments, preferably, please refer to Figure 1An annular sealing groove 12 is formed on the contact interface between the outer connector 2 and the circumferential connector 4 near the outer side of the front sealing ring 7 and the rear sealing ring 8. A metal ring gasket 9 is provided in the sealing groove 12 as a metal-metal seal. When the front sealing ring 7 and / or the rear sealing ring 8 fail due to aging or extreme working conditions, the metal ring gasket 9 automatically increases the sealing pressure under the action of the medium pressure to achieve secondary leakage protection.

[0041] In the above embodiments, preferably, the metal ring gasket 9 is a BX type metal ring gasket that conforms to the API 6A standard and has an octagonal structure. The material is preferably Inconel 625 or 316L stainless steel with a nickel coating. The BX type metal ring gasket and the sealing groove 12 form a conical-conical contact sealing pair, which generates a self-tightening effect under the action of medium pressure, thereby improving the sealing reliability.

[0042] In the above embodiments, preferably, the second fluid channel inside the inner connector 3 adopts a tapered structure that is wider on the outside and narrower on the inside. By achieving smooth acceleration and uniform transition of the fluid, it effectively suppresses flow separation and local eddies, reduces energy loss and erosion risk, and improves pressure distribution and structural stress state, thereby enhancing the hydraulic performance and service reliability of the spherical connector structure.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A spherical connector structure for marine export hoses, suitable for connecting two adjacent export hose sections, characterized in that, include: An external connector has a ball-and-socket portion at one end and is adapted to connect to the first section of the external delivery hose at the other end. A first fluid channel is formed inside the external connector. The inner connector has a ball head at one end and is adapted to connect to the second section of the external hose at the other end. A second fluid channel is formed inside the inner connector. The ball head of the inner connector is embedded in the ball socket of the outer connector to form a damped ball joint connection structure, so that the two sections of the external hose can be interconnected and can achieve omnidirectional angle compensation of ±15° to ±25° and a certain axial float. A ring-shaped connector is disposed on the outer periphery of the ball socket of the outer connector and forms a circumferential covering connection with the outer connector, while simultaneously limiting and constraining the ball head of the inner connector on the outer side.

2. The spherical joint structure according to claim 1, characterized in that, Multiple radial bolts are evenly distributed at 60° intervals along the circumference for radial connection of the external connector and the annular connector.

3. The spherical joint structure according to claim 2, characterized in that, Multiple axial bolts are evenly distributed at 60° intervals along the circumference for axial connection of the external joint and the annular connector.

4. The spherical joint structure according to claim 3, characterized in that, The radial bolts and axial bolts are arranged alternately along the circumference of the outgoing hose, with each radial bolt at a 30° angle to the next axial bolt.

5. The spherical joint structure according to claim 1, characterized in that, It also includes a front sealing ring and a rear sealing ring, which are O-rings made of nitrile rubber. The front sealing ring is disposed between the contact interface of the outer connector and the inner connector, and the rear sealing ring is disposed between the contact interface of the inner connector and the annular connector.

6. The spherical joint structure according to claim 5, characterized in that, Both the front and rear sealing rings adopt a rectangular groove design, and a retaining ring is provided on each side of the groove.

7. The spherical joint structure according to claim 5, characterized in that, An annular sealing groove is formed on the contact interface between the outer connector and the circumferential connector near the outer side of the front and rear sealing rings, and a metal ring gasket is provided in the sealing groove as a metal-to-metal seal.

8. The spherical joint structure according to claim 7, characterized in that, The metal ring gasket is a BX type metal ring gasket that conforms to API 6A standard and has an octagonal structure. It is made of Inconel 625 or 316L stainless steel with a nickel coating, and the BX type metal ring gasket and the sealing groove form a conical-conical contact sealing pair.

9. The spherical joint structure according to any one of claims 1 to 8, characterized in that, The second fluid channel inside the inner connector adopts a tapering structure that is wider on the outside and narrower on the inside.

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