CN207073661U - A kind of effective precompressed of ocean composite and flexible is from tight coupling - Google Patents

Abstract

The utility model discloses a pre-pressed self-tightening joint for marine composite flexible pipes, which comprises an outer ring, a wedge-shaped ring, a locking ring, an ax-shaped shaft and an internal pressure ring; A seal is arranged between the wedge-shaped ring, the front end of the outer ring is tapered, and the rear end of the outer ring is threaded with the locking ring; the locking ring is arranged between the outer ring and the ax-shaped shaft; the ax-shaped One end of the shaft is connected to the wedge-shaped ring, and the other end is connected to a flange; the internal pressure ring is arranged on the innermost layer of the joint, and the rear end of the internal pressure ring is fixedly connected to the inner wall of the ax-shaped shaft, and there is a flexible tube between the wedge-shaped ring and the wedge-shaped ring. The gap at the end is squeezed with the wedge-shaped ring to form a clamping force to limit the displacement of the pipeline; the utility model adopts a mechanical compression method, which forms and locks the pre-pressure through assembly, and can increase the compression effect of the pipeline under external load; the structural strength is high, Good performance, easy to use and operate, can be used in deep sea, high temperature, high pressure and other environments, and has extensive promotion value and practical value.

Description

A pre-pressed self-tightening joint for marine composite flexible pipe

technical field

The utility model relates to the technical field of marine composite flexible pipe joints, in particular to a novel marine fiber-reinforced composite flexible pipe joint used in high-pressure transportation of petroleum or water, which is used to strengthen the end connection of the composite flexible pipe.

Background technique

In the field of thermoplastic composite reinforced flexible pipe joints in marine engineering, for flexible reinforced composite pipes, due to the progress of its materials and the improvement of the preparation process, the use of such pipes has gradually increased in diameter and water depth, and the application conditions have become more severe and severe. Complicated, correspondingly put forward higher requirements for the design of the joint.

In the early days, the connection mechanism of small-diameter reinforced composite pipes was to heat-melt and bond the pipe and joint structure, but this method has many shortcomings in strength and sealing; most of the subsequent joint forms are mechanically compressed At present, the clamping joint is the most widely used in the shallow water field. The inner and outer joints clamp the middle pipe layer to limit its displacement to form a connection. It can be connected by various methods such as cold temperature and axial pressing. It is well applied to shallow water pipelines with small diameters, but it is not suitable for pipelines with large diameters, high pressure and high vibration conditions.

In practical applications, the joints are mainly subjected to axial tension, bending and torsion from the pipeline, as well as the external pressure of seawater and the internal pressure of the internal fluid. In addition, for mechanically compressed joints, there is also an initial assembly prestress. The problems existing in the current composite pipe joints are: 1. The problem of bearing strength: the strength of the hot-melt joint is very low, and the current mechanical compression joint is also prone to strength damage under complex load conditions; 2. The problem of sealing performance: the traditional The sealing method is single, and the sealing reliability is not high; 3. The problem of maintaining prestress: the current mechanical compression joints ensure the limit of the pipeline through prestress, but often in the actual environment, especially after fatigue deformation or creep of the structure The prestress is lost, so that the bearing capacity of the pipeline is reduced, and the sealing performance is also often reduced; 4. The problem of joint assembly and disassembly: most of the current joints are disposable joints, and often the parts cannot be replaced after the assembly is completed, and the whole piece needs to be replaced; Five. The problem of pipeline layer damage: the composite pipeline is characterized by high axial strength and small radial strength, while the traditional joint structure is prone to stress concentration problems on the pipeline layer, causing damage to the pipeline structure; six. The traditional joint is for The impact caused by temperature changes is unpredictable, and thermal stress failure is prone to occur, so the applicable temperature range is generally not large.

Utility model content

The technical problem to be solved by the utility model is to propose a pre-pressed self-tightening joint for marine composite flexible pipes in view of the defects in the prior art, such as poor bearing strength of the joint, difficulty in maintaining the prestress, inconvenient disassembly and assembly.

The utility model is realized by adopting the following technical solutions: a pre-pressed self-tightening joint for marine composite flexible pipes, including an outer ring, a wedge-shaped ring, a locking ring, an ax-shaped shaft and an internal pressure ring; the outer ring is sleeved on The outside of the wedge ring, and a seal is arranged between the outer ring and the wedge ring, the seal is a rubber seal ring or other sealing material, the front end of the outer ring is tapered, the rear end of the outer ring and the locking ring Threaded connection, the thread adopts the high-precision sealing thread form that meets international standards, otherwise, it is necessary to fill the thread with sealant or oil seal; the locking ring is set between the outer ring and the ax-shaped shaft; the ax-shaped shaft One end is in contact with the wedge-shaped ring, and the other end is connected with a flange. The flange is welded to the ax-shaped shaft and connected to the flange of the other joint through bolts, thereby laying the pipeline; the internal pressure ring is set In the innermost layer of the joint, the internal pressure ring is fixedly connected to the inner wall of the ax-shaped shaft, and there is a gap between it and the wedge ring to accommodate the end of the flexible pipe, and is squeezed with the wedge ring to form a clamping force to limit the displacement of the pipe.

Further, the outer ring is made of steel, the inner diameter of the front opening of the outer ring is larger than the outer diameter of the secondary thickening section of the flexible pipe, the inner diameter of the rear opening is slightly larger than the maximum outer diameter of the ax-shaped shaft, and the inner wall of the rear end of the outer ring is set There is an internal thread, and an arc-shaped groove is arranged on the inner wall of the front end of the outer ring, and an elastic body is arranged in the arc-shaped groove.

Further, the elastic body is made of high-strength rubber material, and its rear end includes a swelling part, and the swelling part is embedded in the arc-shaped groove to prevent slippage. After the actual assembly is completed, the elastic body will Pre-deformation, which is actually a gasket with a thicker rear end, is located between the front end of the outer ring and the outer wall of the secondary thickening section of the flexible pipe, and is squeezed to a certain amount of deformation to form a seal here, while avoiding the flexible pipe The pipe directly touches the metal structure where the outer ring is located, which acts as a buffer, and is also used to offset a certain bending stress of the pipe to achieve a transition effect.

Further, the thickness of the middle part of the internal pressure ring is greater than the thickness of both ends, the connection mode between the rear end of the internal pressure ring and the inner wall of the ax-shaped shaft is an interference connection or threaded connection, and the front end of the internal pressure ring accepts the inner wall of the flexible pipe, and the wedge-shaped Ring extrusion creates a clamping force that limits pipe displacement.

Further, the outer surface of the front end of the internal pressure ring is provided with a sandblasting layer or knurling, and the outer surface of the front end of the inner pressure ring is subjected to sandblasting or knurling treatment to increase friction with the inner wall of the flexible pipe and improve the clamping effect .

Further, the wedge-shaped ring is composed of 4-6 wedge-shaped bodies, the thickness of the rear end of the wedge-shaped bodies is greater than the thickness of the front end, and the adjacent wedge-shaped bodies closely fit to form a complete wedge-shaped ring.

Further, the rear end of the wedge ring includes a flat section, and there is a gap between the flat section and the outer ring.

Further, the inner surface of the wedge ring is provided with a friction-increasing knurled or sandblasted layer, and its outer surface is relatively smooth.

Further, the outer surface of the locking ring is provided with external threads, which match with the inner threads of the outer ring, and the inner diameter of the locking ring is slightly larger than the outer diameter of the ax-shaped shaft, so that it can be inserted.

Further, sealing grooves are provided on the outer wall of the internal pressure ring, on the outer tapered surface of the front end of the wedge ring, on the inner wall of the locking ring and on the flange, and the sealing groove is an annular groove with a trapezoidal or semicircular cross section. The groove can be used to place the O-ring. The diameter of the O-ring is greater than the maximum depth of the annular groove. When the contact surfaces are fitted together, the O-ring is squeezed and deformed to form an interference fit, which increases the sealing performance of the joint and improves the sealing performance. Effect.

Compared with the prior art, the utility model has the advantages and positive effects that:

The marine composite pipe preloaded self-tightening joint proposed in this scheme, the outer ring of the main load-bearing structure is made of high-strength stainless steel, and its structural characteristics ensure that the joint has high load-bearing performance and fatigue resistance, and can be used in deep sea. High temperature and high pressure environment; the whole joint is an integrated structure, which does not rely on bonding with the surface of the pipe, and can accommodate some relative movement between the joint structure and the composite pipe, and has a self-tightening working mechanism. Under the action of pressure, external pressure and bending moment, the internal preload can be increased, the restraining force on the pipeline can be increased, and the stability of the structure and the position of the pipeline can be ensured; its structural design solves the problem of the joint structure under load or combined load. The stress concentration phenomenon acting on the pipeline layer improves the fatigue resistance of the internal pipeline of the joint; the sealing design of the joint is effectively attached to the self-tightening mechanism of the structure, and has a double sealing structure of sealing ring sealing and surface-to-surface contact. Under the action of external load, the contact force increases to ensure the improvement of sealing performance; the internal prestress and the compression degree of the pipe can be adjusted at any time by pressing in the ax-shaped shaft and then screwing in and out of the locking ring, without affecting the pipe and internal structure The overall performance of the joint is also convenient for the loading and unloading of the joint; its structure is also reliable under temperature loads. Due to the self-tightening mechanism of the compression structure, the joint has excellent adaptability to temperature changes, and the slight deformation and relative displacement of the structure caused by heating are also small. within the acceptable range.

In specific use, in order to match the structural characteristics of the joint, the pipe is technically allowed to have a thickness change at the end, and a second thickening section can be processed on the reinforcement layer at the end of the flexible pipe pipe to increase the strength and rigidity of the pipe. The reinforcement layer can also be adjusted according to requirements. Fiber orientation is optimized to suit the structural needs of the end assembly. At the same time, the elastic body is designed in the transition area between the pipe and the joint, which can effectively reduce the problems of stress concentration and wear, thus better solving the problem of easy deformation and failure of this area when subjected to complex loads and large loads; The key central area is thickened, and at the same time, the stress of the internal pressure ring is transferred to the ax shaft area by using the characteristics of the structure, which reduces the stress intensity here, and at the same time, the aging, fatigued or corroded reinforcement ring can be replaced at any time; and the joint is installed and disassembled The process is simple and can be reused, and the components can be disassembled, cleaned, inspected and replaced at any time.

Description of drawings

Fig. 1 is the schematic diagram of joint structure described in the utility model embodiment;

Fig. 2 is the explosion schematic diagram of joint structure described in Fig. 1;

Fig. 3 is a schematic cross-sectional view of the joint described in Fig. 1;

Fig. 4 is a schematic diagram of the structure of the connection part between the joint and the flexible pipe in Fig. 3;

Fig. 5 is a schematic cross-sectional view of the flexible pipe end of the utility model embodiment;

Fig. 6 is a structural schematic diagram of a wedge-shaped ring according to an embodiment of the utility model;

Fig. 7 is a schematic diagram of the connection between the ax-shaped shaft, the inner pressure ring and the flange according to the embodiment of the present invention.

Detailed ways

In order to understand more clearly the above purpose, features and advantages of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments.

A preloaded self-tightening joint for a marine composite flexible pipe, referring to Fig. 1 and Fig. 2, includes an outer ring 2, a wedge ring 3 and an inner pressure ring 4 for clamping and limiting the displacement of a flexible pipe 1, and for generating prestress and Keep the prestressed ax-shaped shaft 5 and the locking ring 6; as shown in Figure 3, the outer ring 2 is sleeved on the outside of the wedge ring 3, and a seal 31 is arranged between the outer ring 2 and the wedge ring 3, The sealing member 31 is a rubber sealing ring or other sealing materials. The front end of the outer outer ring 2 is tapered, and the rear end of the outer outer ring is threadedly connected with the locking ring 6. The thread 61 is selected from a high-precision sealing ring that meets international standards. Thread form, otherwise, sealant or oil seal needs to be filled on the thread, and the locking ring 6 is arranged between the outer ring 2 and the ax-shaped shaft 5; contact, the other end is connected with a flange 7, and the flange 7 is welded to the ax-shaped shaft 5 with equal cross-section, and is connected to the flange of another joint through bolts, thereby laying the pipeline; the internal pressure ring 4 is arranged on In the innermost layer of the joint, the internal pressure ring 4 is fixedly connected to the inner wall of the ax-shaped shaft 5, and there is a gap between the wedge ring 3 to accommodate the end of the flexible pipe 1, and the wedge ring 3 is squeezed to form a clamping force to limit the displacement of the pipe.

In order to match the structure of the joint, with reference to Fig. 5, the outer wall of the end of the flexible pipe 1 is provided with an outer layer to form a secondary thickening section 11, and the secondary thickening section 11 of the reinforcement layer is used to strengthen the rigidity of the connection area between the joint and the flexible pipe 1, in order to To avoid the influence of concentrated stress, cut off a short length of the end of the inner lining layer of the flexible pipe at the end of the secondary thickening section 11 of the flexible pipe, refer to the position shown in 12 in Figure 5; push the wedge-shaped ring 3 along the tapered outer ring 2 The lateral movement of the inner wall and the inner pressure ring 4 produce extrusion force to compress the pipe to limit its displacement. The initial interference preload generated when the wedge ring 3 and the inner pressure ring 4 are inserted makes the rough inner surface of the wedge ring 3 fully compatible with The outer surface 11 of the secondary thickening section of the flexible pipe 1 is in contact, and the inner pressure ring 4 is fully in contact with the inner wall of the pipe. 2 The tapered inner wall moves, so that the inner wall of the wedge-shaped ring 3 is more pressed against the flexible pipe 1 to generate greater pressing force, so that the entire joint forms self-tightening.

As shown in Figures 1 and 3, the overall shape of the outer ring 2 is similar to a hemmed conical cylinder, made of steel material, and the inner diameter of the opening at the front end of the cylinder is greater than the outer diameter of the secondary thickening section 11 of the flexible pipe. The inner diameter of its rear end opening is slightly larger than the axial outer diameter of the ax-shaped shaft 5, which is convenient for installation. An internal thread is arranged on the inner wall of the rear end of the outer ring 2, as can be seen from Figures 3 and 4, its length is slightly longer than the length of the outer thread of the locking ring 6, and an arc-shaped groove 21 is also arranged on the inner wall of the front end of the outer ring 2. , used to embed the elastomer 8; the thickness of the tapered section 22 of the outer ring 2 is slightly larger than the thickness of the flat section 23, and the inner wall of the tapered section 22 is smooth, and it can be polished to reduce friction during processing, and it can also be filled with lubricant.

Wherein, the elastic body 8 is made of high-strength rubber material, and its rear end includes a swelling part, and the swelling part is embedded in an arc-shaped groove to prevent slippage. Pre-deformed, actually a gasket with a thicker rear end, located between the front end of the outer ring 2 and the outer wall of the secondary thickening section 11 of the flexible pipe 1, the initial inner diameter of the rubber elastic body 8 is smaller than the outer diameter of the secondary thickening section 11 pipe , whose thickness is greater than the difference between the diameter of the front port of the outer ring 2 and the outer diameter of the flexible pipe 1 here. During installation, the swelling part is squeezed to a certain amount of deformation to form a seal here, and at the same time prevent the flexible pipe 1 from directly touching the metal structure of the outer ring 2 here, which acts as a buffer, and the elastic body 8 at the rear end The swelling part is embedded in the arc-shaped groove to prevent slippage. After the actual assembly is completed, the elastic body is pre-deformed to a certain extent.

In this embodiment, as shown in Figure 6, the wedge-shaped ring is composed of 4-6 wedge-shaped bodies 32, preferably 4 pieces in this embodiment, the thickness of the rear end of the wedge-shaped body 32 is greater than the thickness of its front end, and the adjacent wedge-shaped The bodies 32 are closely fitted to form a complete wedge-shaped ring 3. The taper angle 33 of each wedge-shaped body 32 is slightly larger than the angle between the outer surface of the flexible pipe 1 and the inner wall of the tapered section 22 at the front end of the outer ring 2 to increase the clamping effect. In order to increase the friction with the flexible pipe 1, and its outer surface is smoothed, three sealing grooves 34 are arranged at equal intervals on the outer surface of the tapered section at the front end of the wedge ring 3, and the sealing ring is put into it during installation, and squeezed through the contact surface A complete seal is achieved. The rear end of the wedge-shaped ring 3 includes a flat portion 34 , there is a gap 35 between the flat portion 34 and the outer ring, and the end of the wedge-shaped ring 3 is kept horizontal to the front end of the ax-shaped shaft 5 .

In addition, as shown in Figure 7, the thickness of the middle part of the internal pressure ring 4 is greater than the thickness of its two ends, and there is a slight thickening between the front end and the significantly thickened section in the middle, so that when the internal pressure ring 4 is inserted into the pipeline, Can gradually produce a small interference. The middle and rear parts of the internal pressure ring 4 are closely connected with the ax-shaped shaft 5, and cold-temperature interference or threaded connection can also be used. The front end of the internal pressure ring 4 accepts the inner wall of the flexible pipe, and is squeezed with the wedge-shaped ring 3 to form a clamping force to limit the displacement of the pipe. . The thickening design in the middle effectively reduces the stress concentration and increases the structural strength of this dangerous place; In order to increase the friction between the inner wall of the flexible pipe and improve the clamping effect. Two seal grooves 34 are respectively arranged on the front end and the rear end outer wall of the inner pressure ring. Similarly, the seal groove is a trapezoidal or semicircular cross section, and an O-ring can be placed, and the diameter of the O-ring is larger than the maximum diameter of the annular groove. Depth, when the contact surface where it is located is bonded, the O-ring is squeezed and deformed to form an interference fit, which increases the sealing performance of the joint and improves the use effect.

Cooperating with the internal pressure ring 4, a recess 52 is provided on the inner wall of the front end of the ax-shaped shaft 5 to clamp the internal pressure ring 4. The front end face is consistent with the ax-shaped shaft shoulder 51, and the contact surface between the two is smooth. The outer surface of the locking ring 6 is provided with external threads, which are matched with the inner threads of the outer ring. The inner diameter of the locking ring 6 is slightly larger than that of the ax The shaft outer diameter of the type shaft 5 is so that it can be inserted, and three sealing grooves 34 are arranged on the inner wall of the locking ring 6 to increase the sealing performance.

Some descriptions of other structures in this embodiment, such as the sealing ring, in addition to being a variable-diameter ring (its thickness is greater than the height of the sealing groove, and the width is slightly smaller than the width of the sealing groove), can also inject sealing colloid; on the outer surface of the wedge ring and Lubricant is applied between the inner surfaces of the outer ring, and a thread sealant is provided at the thread connection between the outer ring and the locking ring. Among them, the flange plate and the welding structure with the ax shaft are selected according to ANSI standards. In this embodiment, all metal parts are made of high-strength steel, and the edges and corners are rounded to avoid stress concentration. The metal surface is treated with anticorrosion, and the thread is made of a material stronger than steel.

Specifically, when installing, first fix the outer ring, fix the inner pressure ring inside the ax-shaped shaft, and then push the ax-shaped shaft so that the front end is close to the wedge-shaped ring and the end of the secondary thickening section of the flexible tube, so that the outer ring, wedge-shaped ring, There is a certain initial interference between the secondary thickening section of the flexible tube and the corresponding contact surface of the inner pressure ring. Keep the position of the outer ring and the thrust of the ax-shaped shaft unchanged, and screw in the locking ring until its front end is in contact with the ax-shaped shaft. The shoulders are tightly attached, the thrust is released, and the overall interference is completed inside the entire joint; the outer wall of the inner pressure ring is provided with a sandblasting layer, and the inner wall of the wedge ring is knurled to increase friction, and the flange is welded to the ax shaft. , the ax shaft and the rear end of the wedge-shaped ring form a certain interference during installation, and the interference prestress of the internal structure can be locked through the threaded connection between the locking ring and the rear end of the outer ring to ensure the compression effect of the wedge-shaped body. It can also be changed by changing the lock The screw-in degree of the tight ring adjusts the degree to which the pipe is compressed.

When the flexible pipe moves slightly relative to the joint, the wedge ring is restricted by the inner wall of the outer ring due to the friction force, so that the compressive force is greater and the effect of self-tightening is achieved. When the long-term fatigue performance of the material changes and the compressive force of the pipe decreases , the position of the locking ring can be adjusted to make up for the loss of prestress during inspection and maintenance.

In the joint structure described in this plan, the existence of the pretightening force has three functions: 1. To ensure that the frictional force of the wedge ring and the internal pressure ring to limit the displacement of the pipeline will not be lost; 2. To ensure the interference contact between the contact surfaces of each component It will not disappear so that the seal between the flexible pipe and the joint will not fail; 3. Ensure the stability of the components under the action of the overall structure, and will not cause large or long-term vibrations due to the action of external loads.

The above is only a preferred embodiment of the utility model, and is not intended to limit the utility model in other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or remodel it into an equivalent change. The equivalent embodiments are applied to other fields, but any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present utility model still belong to the technical solution of the present utility model scope of protection.

Claims (10)

1. A preloaded self-tightening joint for marine composite flexible pipes, characterized in that it includes an outer ring, a wedge ring, a locking ring, an ax-shaped shaft and an internal pressure ring; The outer ring is set on the outside of the wedge-shaped ring, and a seal is arranged between the outer ring and the wedge-shaped ring. The front end of the outer ring is tapered, and the rear end of the outer ring is threaded with the locking ring. The locking ring It is arranged between the outer ring and the ax-shaped shaft; one end of the ax-shaped shaft is in contact with the wedge-shaped ring, and the other end is connected with a flange; The internal pressure ring is arranged on the innermost layer of the joint, and the internal pressure ring is fixedly connected to the inner wall of the ax-shaped shaft, and there is a gap between the internal pressure ring and the wedge-shaped ring to accommodate the end of the flexible pipe, and the wedge-shaped ring is squeezed to form a clamping force to limit the displacement of the pipe . 2. The joint according to claim 1, characterized in that: the outer ring is made of steel, the inner wall of the rear end of the outer ring is provided with internal threads, and the inner wall of the front end of the outer ring is also provided with an arc-shaped groove. An elastic body is arranged in the arc-shaped groove. 3. The joint according to claim 1, characterized in that: the thickness of the middle part of the internal pressure ring is greater than the thickness of its two ends, and the connection mode between the rear end of the internal pressure ring and the inner wall of the ax-shaped shaft is an interference connection or a screw connection . 4. The joint according to claim 3, characterized in that: the outer surface of the front end of the inner pressure ring is provided with a sandblasting layer. 5. The joint according to claim 1, characterized in that: the wedge-shaped ring is composed of 4-6 wedge-shaped bodies, the thickness of the rear end of the wedge-shaped bodies is greater than the thickness of the front end, and the adjacent wedge-shaped bodies are in close contact with each other. combine. 6. The joint according to claim 5, characterized in that: the rear end of the wedge-shaped ring includes a flat portion, and there is a gap between the flat portion and the outer ring. 7. The joint according to claim 6, characterized in that: the inner surface of the wedge ring is provided with knurling or sandblasting layer which increases friction. 8. The joint according to claim 2, characterized in that: the outer surface of the locking ring is provided with external threads to match the inner threads of the outer ring, and the inner diameter of the locking ring is slightly larger than the shaft outer diameter of the ax-shaped shaft . 9. The joint according to any one of claims 2, 4, 7 or 8, characterized in that: on the outer wall of the internal pressure ring, on the outer tapered surface of the front end of the wedge ring, on the inner wall of the locking ring and on the flange All are provided with sealing grooves. 10 . The joint according to claim 8 , wherein the elastic body is made of high-strength rubber material, and its rear end includes a swelling part, and the swelling part is embedded in an arc-shaped groove. 11 .