Composite material pipeline connecting method

Abstract

The invention discloses a composite material pipeline connecting method, which comprises the following steps: connecting pipelines through glue, and then gluing at the butt joint of the pipelines by adopting a first half pressing piece and a second half pressing sleeve which are matched with the butt joint of the pipelines in shape; the first half pressing piece and the second half pressing piece are connected and locked to achieve pipeline assembly type cementing with local covering or complete covering, controllable consistency of pipeline connecting quality is guaranteed, the buckling piece can improve the strength of the pipeline connecting position, the force bearing performance of the pipeline is improved, the pipeline cementing defect is overcome, fatigue and through cracks are prevented, and the service life of the pipeline is prolonged. And the water seepage risk of the marine floating type floating body is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of pipeline docking, and in particular to a composite material pipeline connection method. Background Art

[0002] At present, there are many types of composite pipes and profiles, such as carbon fiber pipes and profiles, glass fiber pipes and profiles, and basalt fiber pipes and profiles. In the process of replacing traditional metal pipes and profiles to become composite lattice structure systems, the safety and convenience of the connection method have no comparative advantages over traditional metal structure welding connections, which has always been a restrictive factor in the application of advanced composite materials to the main load-bearing structure.

[0003] In summary, the main connection methods currently used for composite pipes are: butt connection, socket-type adhesive connection, flange connection and socket-type sealing ring connection. Butt connection and socket-type adhesive connection are mostly used for fixed connection between pipes; flange connection is used for parts that are often disassembled; sealing ring connection is mostly used for connection between underground pipes, suitable for connection of large-diameter pipe bending parts and on-site repair. Sealing ring connection is divided into single O-ring connection and double O-ring connection.

[0004] These connections have a common feature: the pipe ends are coaxial. In the case of different axes, different straight or reducer or tee or cross pipe fittings are required to achieve the coaxiality of the pipe ends. The connection method is relatively mature, but the number of joints increases after adding pipe fittings, which will cause unfavorable factors such as quality reduction and cost increase; at the same time, these pipe connection methods have no requirements for connection strength, but only form internal medium transportation and do not bear the main force.

[0005] In short, there is no mature method for the case where the pipe ends are not aligned; the connection efficiency of the load-bearing structure is not guaranteed. At present, when the pipe ends are not aligned, the composite pipes are usually connected by hand paste. In the case of small batches, the plasticity and operability are strong, so it is widely used, but the quality is difficult to control and it is not suitable for mass production. Summary of the invention

[0006] The purpose of the present application is to provide a composite material pipeline connection method, to increase the load-bearing performance of the pipeline and to compensate for the defects of the pipeline bonding, to prevent fatigue and through cracks, and to reduce the risk of water seepage as an ocean floating buoy.

[0007] The embodiments of the present application can be implemented as follows:

[0008] In a first aspect, the present invention provides a composite material pipe connection method, comprising:

[0009] S1, apply structural adhesive to at least two pipes and then connect them;

[0010] S2, polish each pipe joint and apply structural adhesive;

[0011] S3, put the fastener on the joint of the pipe and squeeze out excess structural adhesive, wherein the fastener includes a first half-pressed piece and a second half-pressed piece, the shapes of the first half-pressed piece and the second half-pressed piece are both adapted to the shape of the joint of the pipe, and the two ends of the first half-pressed piece are respectively connected to the two ends of the second half-pressed piece.

[0012] In an optional implementation, before step S1, the method further includes:

[0013] S0, grind the bonding surfaces of the pipe and the fasteners.

[0014] In an optional embodiment, step S0 includes:

[0015] S01, use grinding pieces of various mesh sizes to grind the bonding surfaces of the pipe and the fasteners multiple times;

[0016] S02, remove sand and impurities on the adhesive surfaces of the pipe and the adhesive surfaces of the fasteners;

[0017] S03, check the bonding contact surface after grinding. If there are defects or uneven parts, repair or re-grind them.

[0018] In an optional implementation, step S01 includes:

[0019] S010, using a first polishing piece to preliminarily polish the adhesive joint surface of the pipe and the adhesive joint surface of the fastener;

[0020] S011, further grinding the bonding surface of the pipe and the bonding surface of the fastener using a second grinding piece;

[0021] S012, finely grinding the bonding surfaces of the pipe and the fastener using a third grinding piece;

[0022] The mesh number of the first grinding piece is smaller than that of the second grinding piece, and the mesh number of the second grinding piece is smaller than that of the third grinding piece.

[0023] In an optional embodiment, the mesh number of the first grinding piece is 60 to 200 meshes;

[0024] The mesh number of the second grinding piece is 200 to 400 meshes;

[0025] The mesh number of the third grinding piece is 400-600 meshes.

[0026] In an optional embodiment, the grinding member is sandpaper or a grinding wheel;

[0027] In step S02, cleaning is performed using a cleaning cloth or a soft brush.

[0028] In an optional embodiment, in step S1, two pipes are coaxially butt-jointed;

[0029] Step S1 includes:

[0030] S10, processing the pipe openings of the two pipes into a male cone surface and a female cone surface respectively;

[0031] S11, grind the male cone surface and the female cone surface and apply structural adhesive, and insert them into place.

[0032] In an optional embodiment, in step S1, at least two pipes are vertically butted against each other, one of which is a middle pipe;

[0033] Step S1 includes:

[0034] S10, grinding and applying structural adhesive on the pipe wall of the middle pipe and the pipe openings of other pipes;

[0035] S11, connecting the pipe openings of other pipes to the pipe wall of the middle pipe.

[0036] In an optional embodiment, all pipes are round pipes;

[0037] The pipe openings of other pipes are saddle openings.

[0038] In an optional embodiment, all pipes are square pipes;

[0039] An opening is arranged on the pipe wall of the middle pipe, and other pipes are glued together by extending the inner pipe coated with structural glue from the opening into the middle pipe.

[0040] Compared with the prior art, the beneficial effects of the embodiments of the present application include, for example:

[0041] After the pipes are connected by gluing, the first half pressing piece and the second half pressing sleeve which are matched with the shape of the pipe joint are used for gluing at the pipe joint. The first half pressing piece and the second half pressing piece are connected and locked to achieve partial or complete coverage of the pipe assembly gluing, thereby ensuring the controllable consistency of the pipe connection quality. In addition, the fasteners can improve the strength of the pipe connection, increase the bearing capacity of the pipe, and make up for the defects of the pipe gluing, prevent fatigue and through cracks, and reduce the risk of water seepage as an ocean floating body. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a flowchart of a composite material pipeline connection method according to an embodiment of the present application;

[0044] Figure 2 for Figure 1 The sub-step flow chart of step S0;

[0045] Figure 3 for Figure 2 The sub-step flow chart of step S01;

[0046] Figure 4 for Figure 1 A flowchart of sub-steps of an embodiment of step S1;

[0047] Figure 5 for Figure 1 A flowchart of sub-steps of another embodiment of step S1;

[0048] Figure 6 This is a process flow chart of coaxial docking of circular pipes in an embodiment of the present application;

[0049] Figure 7 This is a process flow chart of coaxial docking of square pipes in an embodiment of the present application;

[0050] Figure 8 This is one of the process flow charts for vertically docking circular pipes in the embodiment of the present application;

[0051] Fig. 9 This is the second process flow chart of the vertical docking of circular pipes in the embodiment of the present application;

[0052] Fig.10 This is one of the process flow charts for vertically docking square pipes in the embodiment of the present application;

[0053] Fig.11 This is the second process flow chart for vertically docking square pipes in an embodiment of the present application.

[0054] Icons: 100 - middle pipe; 110 - female cone; 120 - male cone; 130 - opening; 140 - second area; 200 - other pipes; 210 - notch; 220 - first area; 300 - fastener; 310 - first half pressed piece; 320 - second half pressed piece; 400 - inner pipe. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0057] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0058] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0059] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0060] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] At present, when the fixed connection is made and the pipe ports are not coaxial, the connection between composite pipes is usually made by hand lay-up. In the case of small batches, the plasticity and operability are strong, so it is widely used. However, the hand lay-up method has the following defects:

[0062] 1) The quality of pipe connection by hand-laying is uncontrollable and depends on the skill level of the operator.

[0063] 2) The hand lay-up method has poor consistency, and the results produced by the same operator using the same technique are completely different.

[0064] 3) The hand lay-up method requires different proportions under different temperature and humidity conditions, and its curing time is also inconsistent.

[0065] 4) The hand lay-up method takes a long time to cure and the material cannot be moved before it is completely cured, which affects the construction period.

[0066] 5) The appearance of hand-bonded connections is inconsistent, affecting the overall effect.

[0067] 6) The hand-paste method for outdoor connection has a long construction period and high site and labor costs.

[0068] In order to improve the above defects, the inventor has proposed a composite material pipe connection method after research. After the pipe is fixed by using tooling to assist positioning, it is assembled and glued with a partially or completely covered fastener 300, which can basically effectively solve the above defects. In addition, it has the advantages of low installation cost, easy defect detection, controllable quality, high safety and reliability.

[0069] Combine the following Figure 1-Figure 11 , some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0070] refer to Figure 1 The present application discloses a composite material pipeline connection method, which includes the following steps S1 to S3:

[0071] Step S1, applying structural adhesive to at least two pipes and then butting them together;

[0072] Step S2, grinding each pipe joint and applying structural adhesive;

[0073] Step S3, put the fastener 300 on the joint of the pipe and squeeze out the excess structural adhesive, wherein the fastener 300 includes a first half pressing piece 310 and a second half pressing piece 320, the shapes of the first half pressing piece 310 and the second half pressing piece 320 are both adapted to the shape of the joint of the pipe, and the two ends of the first half pressing piece 310 are respectively connected to the two ends of the second half pressing piece 320. In order to prevent falling, a rope or the like can be used to fix it for half an hour to ensure the assembly reliability of the fastener 300 on the pipe.

[0074] In this way, after the pipes are connected by gluing, the first half pressing piece 310 and the second half pressing sleeve which are adapted to the shape of the pipe joint are used to glue the pipe joint. The first half pressing piece 310 and the second half pressing piece 320 are connected and locked to achieve partial coverage or full coverage of the pipe assembly gluing, ensuring the controllable consistency of the pipe connection quality, and the fastener 300 can improve the strength of the pipe connection, increase the bearing capacity of the pipe and make up for the defects of the pipe gluing, prevent fatigue and through cracks, and reduce the risk of water seepage as an ocean floating buoy.

[0075] It should be noted that the reason why fastener 300 is used is that the performance of structural adhesive and reinforcement structure are the two most important factors in the efficiency of pipeline connection. The performance of structural adhesive is generally 10-20MPa shear strength. The molding process system of structural adhesive can be controlled by the components of structural adhesive and curing process conditions to ensure that the mechanical properties such as shear strength of structural adhesive are controllable. The connection efficiency of the connection reinforcement structure η = connection performance / raw material body performance (if the main structure of the raw material connected is two materials, take the smaller value; the main material of the connector must be greater than the main structure performance). The raw material body is the fixed performance of the material structure, so the connection efficiency is determined by the connection performance. Connection performance = lap surface connection S × shear strength τ. The shear strength is determined by the performance of the structural adhesive and the main body material. When the shear strength is fixed, the lap area and the connector are mainly regulated. The lap area is determined by the lap length. Through the pipe surface area formula S = C*L (S: area, C: circumference, L represents the lap length), it can be known that the circumference is determined by the pipeline structure. The pipeline structure and its strength performance are in an equal proportion, so only the lap length can be controlled. The shear strength τ can be obtained through testing, usually taking 10MPa (the measured value is greater than 10MPa). The tensile properties of the raw material body can also be obtained through testing, usually taking the middle value of the test sample. The connection efficiency η is generally required to be greater than 85%. Through the above relationship, the minimum value of L is obtained. Through the design and calculation of the connection reinforcement structure, a prefabricated adhesive structure reinforcement scheme is formed, including: structural adhesive scheme, structural component scheme, and prefabricated overlap three-dimensional structure.

[0076] The fastener 300 can be manufactured by vacuum introduction process, molding process, RTM process and other manufacturing methods. The assembled connecting fastener 300 can be prefabricated in the factory in advance. By controlling each link of people, machines, materials, methods and environment, the quality, dimensional stability and appearance quality of the connecting fastener 300 can be effectively controlled, thereby reducing the workload on the construction site.

[0077] For example, the principle of making the fastener 300 by vacuum infusion process is as follows: use aluminum to make the fastener 300 mold, prepare the mold, apply semi-permanent mold release agent on the mold surface, wait for a moment to start evaporation, use a second piece of lint-free cloth, gently wipe off the excess mold release agent in a circular motion. Cut the reinforcement to the appropriate size, cover all edges of the product, and lay the reinforcement into the mold. Spread the release cloth over the entire surface of the reinforcement, and then lay the guide net to ensure that the resin can freely pass from the resin guide tube into the laminate. Next, we fix the spiral tube at one end edge (that is, the end where the resin feed tube is fixed) so that the resin can be quickly and evenly distributed from one side of the mold to the other. The spiral tube must be fixed directly on the guide net to ensure that the resin can flow more easily from the spiral tube to the guide net. Next, fix the plastic nozzles at the resin feed end and the vacuum end. Stick the sealing tape to the edge of the mold, then cut a piece of vacuum film that is large enough. Starting from the corner, tear off the paper on the back of the sealing tape, press the vacuum bag film, and stick it to the exposed sealing tape. Move along the edge of the mold, tear off the paper on the back of the tape and stick it to the vacuum bag film, tearing and sticking. After sticking, connect and seal the connection port of the resin feed end and the vacuum end. Fix the resin feed tank next to the mold, connect the resin collector and the vacuum pump, and clamp the guide tube at the resin feed end. Turn on the vacuum pump to start vacuuming and perform a vacuum leak test. Then measure the resin, stir it, add it to the feed tank, and wait for half an hour to let the bubbles in the resin out. Open the pipe clamp on the guide tube at the resin feed end to allow the resin to enter the mold, and close the guide tube at the feed end when the resin enters the resin collector. Allow the resin to continue to be extracted in the vacuum tube for 10-30 seconds, then use the tube clamp to close the vacuum tube at the vacuum end and turn off the vacuum pump to wait for the product to solidify. When the product has solidified, tear off the vacuum bag, spiral tube and other auxiliary materials, then peel off the release cloth and guide net to remove the product from the mold.

[0078] During on-site construction, the dedicated two-component automatic glue mixing and coating equipment can be used to effectively control the component ratio of the structural adhesive and the thickness of the coated structural adhesive layer. The efficiency of controlling the component ratio by weighing is greatly improved compared to hand-laying. The effective control of the thickness of the adhesive layer is not limited by the proficiency of the technicians. After uniform coating, the fastener 300 is directly fastened and fixed with bolts or clamps for quick assembly.

[0079] The structural adhesive may be one or more of epoxy resin, vinyl resin, a mixture of epoxy resin and talcum powder, a mixture of vinyl ester resin and talcum powder, a mixture of epoxy resin and chopped fibers, a mixture of vinyl resin and chopped fibers, or a special structural adhesive.

[0080] In this embodiment, before step S1, the method further includes the following step S0:

[0081] Step S0, grinding the bonding surfaces of the pipe and the fastener 300.

[0082] The bonding surface is polished to remove the release agent on the surface of the pipe, profile / fastener 300 and to increase the surface activity of the material, thereby achieving high-strength bonding between the pipe, profile and connecting fastener 300.

[0083] Combination Figure 2 Specifically, the step S0 includes the following steps S01 to S03:

[0084] Step S01, using grinding pieces with different mesh sizes to grind the bonding surfaces of the pipe and the fastener 300 for multiple times.

[0085] Step S02, remove sand and impurities on the adhesive surface of the pipeline and the adhesive surface of the fastener 300 to ensure that the surface is clean. A cleaning cloth or a soft brush can be used for cleaning.

[0086] Step S03, checking the polished bonding contact surface, if there are defects or uneven parts, repair or re-polish to achieve a bonding structure surface with controllable roughness.

[0087] Combination Figure 3 In more detail, step S01 includes the following steps S010-S012:

[0088] S010, use the first grinding piece to preliminarily grind the bonding surface of the pipe and the bonding surface of the fastener 300 to remove the unevenness and protrusions on the surface. Pay attention to controlling the grinding force, keep it uniform, and avoid excessive grinding.

[0089] S011, use a second polishing piece to further polish the adhesive surface of the pipe and the adhesive surface of the fastener 300 to make the surface smoother. Also pay attention to controlling the polishing intensity and uniformity.

[0090] S012, use a third polishing piece to finely polish the adhesive joint surface of the pipe and the adhesive joint surface of the fastener 300; remove the scratches and flaws generated during the polishing process. Pay attention to the uniformity and speed of polishing to avoid excessive polishing that may cause local deformation or sand holes.

[0091] The mesh number of the first grinding piece is smaller than that of the second grinding piece, and the mesh number of the second grinding piece is smaller than that of the third grinding piece, so as to achieve the effect of three-way grinding, for example, the mesh number of the first grinding piece is 60-200 meshes; the mesh number of the second grinding piece is 200-400 meshes; the mesh number of the third grinding piece is 400-600 meshes.

[0092] The grinding piece can be sandpaper or grinding wheel.

[0093] According to the number and shape of the pipes to be connected, the corresponding structure of the fastener 300 will also change. The following examples are given: round tube fastener 300, round tube tee fastener 300 and round tube cross fastener 300, square tube fastener 300, square tube tee fastener 300 and square tube cross fastener 300, etc. Other fasteners 300 are not described in detail. Their design structure should meet six principles: simple structure, convenient transportation, easy processing, easy construction, controllable quality and beautiful appearance.

[0094] For example, in one embodiment, in combination Figure 4 , Figure 6 and Figure 7 In step S1, two pipes are coaxially butted, the pipes are round pipes or square pipes, and the corresponding first half pressing piece 310 and the second half pressing piece 320 are both arc-shaped or bent plate-shaped.

[0095] At this time, step S1 includes the following steps S10 and S11:

[0096] Step S10, the pipe openings of the two pipes are processed into a male cone surface 120 and a female cone surface 110 respectively; wherein the male cone surface 120 and the female cone surface 110 are interference fit, the male cone surface 120 can be machined, and the female cone surface 110 can be manufactured by a mold, and the cumulative deviation of the assembly is not greater than 0.2mm.

[0097] Step S11, polishing the male cone surface 120 and the female cone surface 110 and applying structural adhesive, and inserting them into place. The thickness of the structural adhesive applied is not less than 0.2 mm to ensure the quality of bonding.

[0098] In this embodiment, the area where the structural adhesive is applied for bonding of the fastener 300 is the first area 220 and the second area 140 shown in the figure.

[0099] For example, in some other embodiments, for example Figures 8 to 11 In step S1, at least two pipelines are vertically docked, one of which is the middle pipeline 100.

[0100] At this time, combined with Figure 5 , step S1 includes the following steps S10 and S11:

[0101] Step S10, grinding and applying structural adhesive on the pipe wall of the middle pipe 100 and the pipe openings of other pipes 200;

[0102] Step S11, connecting the pipe openings of other pipes 200 to the pipe wall of the middle pipe 100. The thickness of the structural adhesive applied is not less than 0.2 mm to ensure the quality of the bonding.

[0103] Specifically, for vertical pipe docking, the following situations are classified according to the shape of the pipe:

[0104] 1. Combination Figure 8 and Fig. 9 All pipes are round pipes, and the pipe openings of other pipes 200 are set as saddle openings, so that other pipes 200 can ride on the middle pipe 100 with a small gap. The area where the structural adhesive is applied for the fastener 300 to be glued is the first area 220 and the second area 140 shown in the figure.

[0105] 2. Combination Fig.10 and Fig.11 All pipes are square pipes, so an opening 130 can be provided on the pipe wall of the middle pipe 100, and other pipes 200 are extended into the middle pipe 100 from the opening 130 through an inner pipe 400 coated with structural adhesive to achieve bonding.

[0106] More specifically, for the connection of two square pipes, combined Fig.10 , you can first take a section of a small square tube (i.e., the inner tube 400) and cut it to a length equal to the side length. Open a notch 210 in the vertical pipe to be connected, and the notch 210 is connected to the pipe opening. At the same time, apply glue on both sides of the inner tube 400 and insert it into the notch 210. Then apply glue again and insert it into the opening 130 of the middle pipe 100 for gluing. The area where the structural glue is applied for the fastener 300 to be glued is the first area 220 and the second area 140 shown in the figure.

[0107] Combination Fig.11 For the connection of three square tubes, an inner tube 400 can be directly passed through the middle tube 100 and glued, and then the remaining two square tubes can be glued to the inner tube 400 located in the middle tube 100 after being glued. The area where the structural glue is applied for the fastener 300 to be glued is the first area 220 and the second area 140 shown in the figure.

[0108] It should also be noted that in step S3, the thickness of the structural adhesive can be 2 mm. This is because the pipe is made by winding technology, the outer diameter of the pipe itself has a large deviation, and the outer diameter of the pipe in the pipe connection area differs by no more than 2 mm. The combined circumference of the two fasteners 300 is made according to the minimum diameter. Therefore, the thickness of the structural adhesive here is relatively thick.

[0109] Ultrasonic nondestructive testing is used for pipes, profiles, and fasteners 300 to detect internal defects and damage by sending and receiving ultrasonic signals. The principle of ultrasonic testing is to use the characteristics of sound waves propagating in the medium to identify internal defects. It can detect defects such as corrosion and cracks in pipes, profiles, and fasteners 300, and measure parameters such as the wall thickness of pipes, profiles, and fasteners 300, and the bonding between pipe walls.

[0110] Develop a testing plan based on basic information such as the material, diameter, wall thickness, bonding length, and internal coating of the pipes, profiles, and fasteners 300. Perform equipment inspection and calibration to ensure that the ultrasonic scanner, probe, coupling agent, data acquisition and analysis software, and other equipment are in good condition and calibrated effectively. Then remove obstacles that hinder detection around the pipes, profiles, and fasteners 300, keep the operating space clean, and use cleaning tools to remove dirt, rust, grease, etc. on the surface of the pipes, profiles, and fasteners 300 to ensure good coupling between the probe and the component wall. For areas with severe corrosion or thick coatings, local grinding or sandblasting may be required to expose the substrate.

[0111] Select the probe according to the detection requirements, ensure that its frequency, angle and other parameters are adapted to the pipe material and detection depth, and evenly apply coupling agent on the contact surface between the probe and the pipe, profile, and fastener 300 to ensure effective transmission of ultrasound. Set the probe type, sound velocity, gain, threshold, gate, scanning mode and other parameters on the ultrasonic scanner.

[0112] Use standard test blocks with known thickness or defects to calibrate the system to ensure accurate instrument readings. According to the test plan, slowly move the probe along the axial or circumferential direction of the test piece to perform continuous or intermittent ultrasonic testing. Observe the scanned image, record the scan results, and determine the depth and location of the defect. Determine the defect type based on the echo characteristics and calculate the defect size, equivalent diameter and other parameters.

[0113] Compared with the existing technology, the advantages and effects produced are:

[0114] The direct fastener 300 is stronger than the common socket type. The internal contact surface is a male and female cone. The advantage of the cone surface is that the bonding effect is better when the cone surface is connected; the concentricity is better when the cone surface is connected. Applying the fastener 300 on the outside of the socket type can increase the load-bearing performance of the pipeline and make up for the bonding defects of the cone surface, prevent fatigue and through cracks, and reduce the risk of water seepage as an ocean floating body.

[0115] The 300 method of tee / cross fasteners is more convenient in engineering than the tee / cross connection method of pipe fittings. A tee pipe fitting joint requires 3 pipes and 1 tee pipe fitting to form 3 joints; a cross pipe fitting joint requires 4 pipes and 1 cross pipe fitting to form 4 joints. The 300 method of tee / cross fasteners only forms one joint, which simplifies the process.

[0116] The tee / cross fastener 300 can ensure the integrity of one of the main structural pipes or profiles with a larger diameter or size, increase the overall structural performance of the pipes and profiles, and improve the performance strength. For example, a traditional four-way pipe joint mentioned above requires four pipes and one four-way pipe joint to form four joints. The pipes are cut into four joints. The strength of the joints is generally worse than that of the pipes themselves. The performance of the four joints will drop sharply if they are concentrated.

[0117] The advantages of the assembled adhesive connection method over the traditional hand-layup connection method are that the quality is controllable (300 fasteners are prefabricated in the factory), the installation is convenient, and the appearance is neat.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composite material pipeline connection method, characterized in that: include: S1, apply structural adhesive to at least two pipes and then connect them; S2, polish each pipe joint and apply structural adhesive; S3, put the fastener on the joint of the pipe and squeeze out excess structural adhesive, wherein the fastener includes a first half-pressed piece and a second half-pressed piece, the shapes of the first half-pressed piece and the second half-pressed piece are both adapted to the shape of the joint of the pipe, and the two ends of the first half-pressed piece are respectively connected to the two ends of the second half-pressed piece.

2. The composite material pipeline connection method according to claim 1, characterized in that: Before step S1, the method further includes: S0, grind the bonding surfaces of the pipe and the fasteners.

3. The composite material pipeline connection method according to claim 2, characterized in that: Step S0 includes: S01, use grinding pieces of various mesh sizes to grind the bonding surfaces of the pipe and the fasteners multiple times; S02, remove sand and impurities on the adhesive surfaces of the pipe and the adhesive surfaces of the fasteners; S03, check the bonding contact surface after grinding. If there are defects or uneven parts, repair or re-grind them.

4. The composite material pipeline connection method according to claim 3, characterized in that: Step S01 includes: S010, using a first polishing piece to preliminarily polish the adhesive joint surface of the pipe and the adhesive joint surface of the fastener; S011, further grinding the bonding surface of the pipe and the bonding surface of the fastener using a second grinding piece; S012, finely grinding the bonding surfaces of the pipe and the fastener using a third grinding piece; The mesh number of the first grinding piece is smaller than that of the second grinding piece, and the mesh number of the second grinding piece is smaller than that of the third grinding piece.

5. The composite material pipeline connection method according to claim 4, characterized in that: The mesh number of the first grinding piece is 60 to 200 meshes; The mesh number of the second grinding piece is 200 to 400 meshes; The mesh number of the third grinding piece is 400-600 meshes.

6. The composite material pipeline connection method according to claim 3, characterized in that: The grinding piece is sandpaper or grinding wheel; In step S02, cleaning is performed using a cleaning cloth or a soft brush.

7. The composite material pipeline connection method according to claim 1, characterized in that: In step S1, two pipes are coaxially butted; Step S1 includes: S10, processing the pipe openings of the two pipes into a male cone surface and a female cone surface respectively; S11, grind the male cone surface and the female cone surface and apply structural adhesive, and insert them into place.

8. The composite material pipeline connection method according to claim 1, characterized in that: In step S1, at least two pipes are vertically connected to each other, one of which is a middle pipe; Step S1 includes: S10, grinding and applying structural adhesive on the pipe wall of the middle pipe and the pipe openings of other pipes; S11, connecting the pipe openings of other pipes to the pipe wall of the middle pipe.

9. The composite material pipeline connection method according to claim 8, characterized in that: All pipes are round pipes; The pipe openings of other pipes are saddle openings.

10. The composite material pipeline connection method according to claim 8, characterized in that: All pipes are square tubes; An opening is arranged on the pipe wall of the middle pipe, and other pipes are glued together by extending the inner pipe coated with structural glue from the opening into the middle pipe.

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