Filling and leaking stoppage structure and method for interlayer cavity of bimetal composite pipe

Abstract

The invention provides a bimetal composite pipe interlayer cavity filling and leaking stoppage structure and method, the structure comprises a clamp, the clamp is arranged on the peripheral wall of a composite pipe in a sleeving mode, a cavity exists between the clamp and the peripheral wall of the composite pipe, a grease injection hole is formed in the clamp, and the grease injection hole communicates with the cavity. The resin is injected into the cavity through the resin injection hole; the method comprises preparing a clamp; mounting a clamp; conducting drainage; fastening the clamp; injecting grease; and boosting and re-injecting grease. The method solves the problems that in the prior art, the on-site first-aid repair technology basically adopts conveying stopping and pipe replacement, the first-aid repair time is long, and the loss of production stopping, emptying and pipe replacement is large.

Description

Technical Field

[0001] The present invention relates to the technical field of oil pipelines, and more specifically to a leak plugging structure and method for filling the interlayer cavity of a bimetallic composite pipe. Background Art

[0002] Most domestic oil fields have been using a large number of bimetallic composite pipes since 2006. This pipe is composed of a seamless stainless steel liner and an outer base pipe that are strongly fitted together by a spinning composite process, providing a certain degree of protection against internal corrosion. However, due to the poor strength and corrosion resistance of the liner at the butt weld part of the bimetallic composite pipe, local corrosion perforation and leakage often occur at the circumferential weld. By leakage, it means that after a small corrosion notch appears in the liner, the conveying medium passes through the liner and contacts the base pipe, causing damage to the base pipe. In addition, due to the thin thickness and low stiffness of the liner, the liner often collapses during operation.

[0003] Due to the special structure of the bimetallic composite pipe, there are currently no special failure repair technologies, standards, and specifications for bimetallic composite pipes. The on-site repair technology is basically to stop the pipeline and replace the pipe, which takes a long time for repair and causes huge losses due to shutdown and emptying for pipe replacement. Therefore, there is an urgent need for a leak plugging technology for non-stop pressure repair. Summary of the Invention

[0004] The main purpose of the present invention is to provide a leak plugging structure and method for filling the interlayer cavity of a bimetallic composite pipe. By injecting semi-solid sealing resin into the erosion pits and collapse defects inside the leak hole, the medium is isolated from contacting the base pipe, avoiding corrosion of the base pipe, and achieving the purpose of repairing the leak defect, so as to solve the problems in the prior art.

[0005] To achieve the above purpose, according to one aspect of the present invention, a leak plugging structure for filling the interlayer cavity of a bimetallic composite pipe is provided, including: a clamp, which is sleeved on the outer peripheral wall of the composite pipe, there is a cavity between the clamp and the outer peripheral wall of the composite pipe, and a grease injection hole is opened on the clamp, and the grease injection hole is communicated with the cavity. Resin, which is injected into the cavity through the grease injection hole.

[0006] Further, the clamp includes: a first housing; a second housing, at least one of the first housing and the second housing is provided with a grease injection hole; a rotating shaft, which is arranged on the side of the first housing and the second housing, and the first housing and the second housing are rotationally connected to the rotating shaft.

[0007] Further, the clamp further includes a positioning pin, which is arranged on one side of the first housing or the second housing close to the rotating shaft, and the positioning pin pre-fixes the first housing and the second housing.

[0008] Further, the clamp further includes a flange and a connecting member, the flange is fixed on both sides of the first housing and the second housing, through holes are opened on the flange, and the connecting member passes through the through holes to connect the first housing and the second housing.

[0009] Furthermore, the interlayer cavity filling and leak plugging structure of the bimetal composite pipe further includes a connecting pipe and a valve. A drainage hole is provided on the first housing or the second housing. The connecting pipe is installed on the drainage hole, and the valve controls the opening and closing of the connecting pipe. The valve and the connecting pipe form a drainage device.

[0010] According to another aspect of the present invention, there is provided a method for filling and plugging the interlayer cavity of a bimetal composite pipe, including the interlayer cavity filling and leak plugging structure of the bimetal composite pipe, and the following steps: preparing a fixture; installing the fixture; draining; tightening the fixture; injecting grease; boosting pressure and re-injecting grease.

[0011] Furthermore, the step of preparing the fixture includes: preparing corresponding raw materials such as the fixture, grease gun, and special sealant according to the diameter of the pipeline to be plugged and the size of the puncture leak; after the pipeline leakage point is determined, start the emergency rescue plan and perform a pressure reduction operation on the leakage point.

[0012] Furthermore, the step of installing the fixture includes: after the excavation operation is completed and the leakage point is exposed, after confirming the pressure inside the pipe, hoist the fixture to the installation position to be installed, buckle the first housing and the second housing of the fixture on the defective part, and align the grease injection hole of one fixture of the first housing or the second housing directly above the leakage point, and align the center of the fixture with the leakage point position.

[0013] Furthermore, the step of tightening the fixture includes: the leak plugging personnel quickly tighten the bolts on both sides of the fixture, use a torque wrench to tighten the fastening bolts of the connecting flanges on both sides one by one. When tightening the bolts, tighten them gradually in a crosswise manner on both sides, that is, one side from left to right and the other side from right to left.

[0014] Furthermore, the step of the grease injection process includes: performing high-pressure grease injection with a grease gun, first injecting grease into the grease injection hole of the defective part, and then injecting grease into other grease injection holes in turn from near to far with the defective part as the center until the cavity inside the housing is completely filled with resin.

[0015] Furthermore, before grease injection, keep the valves of the interlayer cavity filling and leak plugging structure of the bimetal composite pipe on all drainage holes in the closed state. When injecting grease into each grease injection hole of the fixture, first fill the resin into the grease gun, connect the gun head of the grease gun to the valve; start pressurizing, when the pressure gauge shows a value, open the valve switch until the cavity is filled with the injection agent and it is difficult to press the resin into the cavity, then close the valve switch; after the grease injection is completed, after a period of curing, the resin becomes solid and seals the notch of the punctured part of the bimetal composite pipe.

[0016] Further, after the grease injection is completed, close the valve of the leak plugging structure for filling the interlayer cavity of the bimetal composite pipe and remove the drainage device of the leak plugging structure for filling the interlayer cavity of the bimetal composite pipe, and seal the drainage hole with bolts; start the pressure boosting operation, and pay attention to whether there is leakage in the fixture during the pressure boosting process. If leakage occurs, a secondary grease injection process should be adopted at the grease injection hole of the fixture at the leakage point position, and finally, when the pressure is boosted to the operating pressure, there is no leakage or seepage in the entire fixture.

[0017] Applying the technical solution of the present invention achieves the following technical effects:

[0018] A drainage type fixture is used for leak plugging and emergency repair of the bimetal composite pipe. The fixture forms a closed space with the outer wall of the base pipe, ensuring the pressure of the resin during emergency repair, enabling the resin to smoothly enter the notch part, pressing the corrosive medium into the pipeline through the notch of the lining pipe, cutting off the corrosion source, and fundamentally solving the problem of puncture leakage, and achieving the effect of permanent repair.

[0019] There is no need to empty the punctured pipeline. By virtue of the structural characteristics of the bimetal composite pipe, the pipe body defects caused by puncture leakage, and the action of the liquid pressure inside the pipeline, the purpose of leak plugging and emergency repair of the pipeline under pressure without stopping the transmission can be achieved, avoiding the economic losses caused by stopping the transmission and emptying, shortening the construction period, and improving the pipeline emergency repair efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The schematic diagrams in the specification which form a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 is an axial sectional view of the puncture leakage defect (pipe body puncture leakage) of the bimetal composite pipe provided by the present invention;

[0022] Figure 2 is an axial sectional view of the puncture leakage defect (circumferential weld puncture leakage) of the bimetal composite pipe provided by the present invention;

[0023] Figure 3 is a schematic structural diagram of the first housing provided by the present invention;

[0024] Figure 4 is a schematic structural diagram of the second housing provided by the present invention;

[0025] Figure 5 is a sectional view of the fixture grease injection process provided by the present invention;

[0026] Figure 6 is a schematic structural diagram of the fixture provided by the present invention;

[0027] Figure 7Logic block diagram of the method for plugging leaks in the interlayer cavity of the bimetallic composite pipe provided by the present invention.

[0028] Among them, the above-mentioned drawings include the following reference numerals:

[0029] 1. Base pipe; 2. Liner pipe; 3. Transport medium; 4. Leakage notch; 5. Circumferential weld; 6. Filling section; 7. Shallow groove; 8. First shell; 9. Second shell; 10. Flange; 11. Through hole; 12. Grease injection hole; 13. Drainage hole; 14. Small nut valve; 15. Fastening bolt; 16. Resin; 17. Positioning pin; 18. Rotating shaft. Detailed implementation manners

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] It should be pointed out that unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0032] In the present invention, unless otherwise stated, the orientation words such as "upper, lower, top, bottom" usually refer to the direction shown in the drawings, or refer to the vertical, perpendicular or gravitational direction of the component itself; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contour of each component itself, but the above orientation words do not limit the present invention.

[0033] The present invention provides a bimetallic composite pipe interlayer cavity filling and leak plugging structure and method. By injecting semi-solid sealing resin into the erosion pits and collapse defects inside the leakage holes, the contact between the medium and the base pipe is isolated, fundamentally avoiding the corrosion of the base pipe, so as to achieve the purpose of permanently repairing the leakage defects.

[0034] Embodiment 1

[0035] A bimetallic composite pipe interlayer cavity filling and leak plugging structure, see Figures 1 to 6 , including a fixture and resin 16. Among them, resin 16 adopts TXY-T10 non-solid expansion type resin.

[0036] When the bimetallic composite pipe leaks, a leakage notch 4 will appear. The leakage notch 4 may appear on the pipe body of the bimetallic composite pipe or on the circumferential weld 5.

[0037] The pipeline to be repaired is a 316L bimetal composite pipe, which is communicated by a base pipe 1 and a lining pipe 2. The base pipe 1 is made of L245 steel, and the lining pipe 2 is made of stainless steel. The outer diameter of the pipeline is 508 mm, and the wall thickness is 14 mm. The conveying medium 3 is crude oil, and the pressure is 10 MPa. The diameter of the notch on the outer wall of the base pipe 1 is about 3 mm.

[0038] The fixture material is 16Mn, including a first housing 8, a second housing 9, and a rotating shaft connected to the first housing 8 and the second housing 9 and arranged on the sides of the first housing 8 and the second housing 9. The first housing 8 and the second housing 9 are connected by a rotating shaft 18 on the side to form a movable part that can be buckled and opened. A positioning pin 17 is installed on the rotating shaft 18. The first housing 8 and the second housing 9 have a filling section 6 and a shallow groove 7.

[0039] The lengths of the first housing 8 and the second housing 9 are both 500 mm, and the thickness is 18 mm. The inner diameter of the filling section 6 of the first housing 8 and the second housing 9 is 479.95 mm, the depth of the shallow groove 7 is 5 mm, and the distance from the front and rear edges of the shallow groove to the end faces of the fixture is 18 mm; the width of the flange 10 is 100 mm, and a plurality of (usually 4) through holes 11 for installation are evenly distributed on the center line along the length direction of the flange 10. The diameter of the through holes 11 is 22 mm. A row of grease injection holes 12 are circumferentially distributed at the 1 / 3 and 2 / 3 positions of the axial length of the filling section of the first housing 8 and the second housing 9, and the adjacent two grease injection holes are spaced 45 degrees in arc. The grease injection hole 12 is an M20 internal thread through hole. A drainage hole 13 is opened at the center of the filling section of the second housing 9. The drainage hole 13 is a protruding section of a round pipe, with an external thread for installing drainage equipment and a sealing nut at its top and a small nut valve 14 installed. The number and thread model of the small nut valve 14 match the thread model and size of the grease injection hole 12.

[0040] During installation, first pre-fix the first housing 8 and the second housing 9 through the positioning pin 17, and then actually fix them through the through holes 11 on the flange 10. A fastening bolt 15 is provided on the flange 10, and the fastening bolt 15 can pass through the through holes 11 on the flange 10 to connect the first housing 8 and the second housing 9.

[0041] During grease injection, since a plurality of grease injection holes 12 are distributed circumferentially around the entire fixture, ensuring that the grease injection amount of each grease injection hole 12 is uniform and there is no omission. After all the plurality of grease injection holes 12 are filled with grease, the grease injection and leakage plugging of the entire fixture are completed.

[0042] The bimetal composite pipe interlayer cavity filling and leakage plugging structure provided by this example includes a fixture and resin 16. The fixture is sleeved on the outer peripheral wall of the composite pipe, there is a cavity between the fixture and the outer peripheral wall of the composite pipe, and a grease injection hole 12 is opened on the fixture. The grease injection hole 12 is communicated with the cavity. The resin 16 is injected into the cavity through the grease injection hole 12.

[0043] The clamp forms a closed space with the outer wall of the bimetallic composite pipe, ensuring the pressure of the resin 16 during emergency repair, enabling the resin 16 to smoothly enter the notch area, pressing the corrosive medium into the pipeline interior through the notch of the liner 2, cutting off the corrosion source, and fundamentally solving the problem of leakage, achieving the effect of permanent repair.

[0044] Further, the clamp includes a first housing 8, a second housing 9, and a rotating shaft 18. At least one of the first housing 8 and the second housing 9 is provided with a grease injection hole 12. The rotating shaft 18 is arranged on the side of the first housing 8 and the second housing 9, and the first housing 8 and the second housing 9 are rotatably connected to the rotating shaft 18.

[0045] By rotating the rotating shaft 18, it is convenient to open and close the clamp, thereby facilitating the placement of the clamp on the outer peripheral wall of the bimetallic composite pipe and facilitating the installation of the clamp.

[0046] Further, the clamp further includes a positioning pin 17. The positioning pin 17 is arranged on one side of the first housing 8 or the second housing 9 close to the rotating shaft 18, and the positioning pin 17 pre-fixes the first housing 8 and the second housing 9.

[0047] The positioning pin 17 pre-fixes the first housing 8 and the second housing 9, which can facilitate multiple adjustments of the clamp on the bimetallic composite pipe and facilitate subsequent drainage.

[0048] Further, the clamp further includes a flange 10 and a connecting member. The flange 10 is fixed on both sides of the first housing 8 and the second housing 9. Through holes 11 are formed on the flange 10, and the connecting member passes through the through holes 11 to connect the first housing 8 and the second housing 9.

[0049] The fastening connection of the first housing 8 and the second housing 9 through the connecting member and the flange 10 can reduce the occurrence of leakage during subsequent pressurization, and at the same time facilitate the connection of the first housing 8 and the second housing 9.

[0050] The plugging structure for filling the interlayer cavity of the bimetallic composite pipe further includes a connecting pipe and a valve. A drainage hole 13 is formed on the first housing 8 or the second housing 9. The connecting pipe is installed on the drainage hole 13, and the valve controls the opening and closing of the connecting pipe. The valve and the connecting pipe constitute a drainage device.

[0051] Wherein the valve is a small nut valve 14. The connecting pipe and the drainage hole 13 can facilitate the drainage operation, and at the same time, the setting of the valve can facilitate the operation of the drainage.

[0052] Embodiment 2

[0053] As Figure 7 shown, a method for plugging and leaking in the interlayer cavity of a bimetallic composite pipe includes the following steps:

[0054] Step 1: Prepare the fixture: Prepare corresponding split fixtures, grease guns, special sealants and other raw materials according to the diameter of the pipeline to be plugged and the size of the puncture leak. After the pipeline leakage point is determined, start the emergency repair plan, and the repair operation shall be carried out in accordance with the territorial management system. Perform a pressure reduction operation on the leakage point, and at the same time prepare the repair and emergency rescue materials.

[0055] Step 2: Install the fixture: After the excavation operation is completed and the leakage point is exposed, confirm that the internal pressure of the pipeline is between 1 and 3 MPa. Then, professional repair personnel hoist the split fixture to the installation position to be installed, buckle the first shell 8 and the second shell 9 on the defective part, and align one grease injection hole 12 of the first shell 8 directly above the leakage point position. Align the center of the fixture with the leakage point position.

[0056] Step 3: Drainage: After fixing the fixture on the pipeline through the positioning pin 17, connect the drainage pipe of the drainage device to the drainage hole 13 by thread, quickly drain the liquid and confirm the success of drainage. The drainage outlet shall be far away from the repair operation area, and arrange a special person to observe whether the drainage is normal.

[0057] Step 4: Tighten the fixture: After the drainage is successful, professional plugging personnel quickly carry out the tightening operation on the tightening bolts 15 on both sides of the fixture. Use a torque wrench to tighten the tightening bolts 15 connecting the flanges on both sides one by one. When tightening the tightening bolts, tighten them step by step in a cross manner on both sides, that is, one side from left to right and the other side from right to left. Finally, use a torque wrench to check whether the torque of each tightening bolt meets the requirements. After the tightening bolt operation is completed, check and ensure that there is no leakage at both circumferential ends of the fixture.

[0058] Step 5: Grease injection: After the inspection is completed, use a grease gun to carry out the grease injection process. There are multiple grease injection holes 12 distributed around the entire circumference of the fixture to ensure that the grease injection amount of each grease injection hole is uniform and there is no omission. After all the multiple grease injection holes are filled with grease, the grease injection and plugging of the entire fixture is completed.

[0059] During the grease injection process, a high-pressure grease gun is used for grease injection. First, grease is injected into the grease injection hole 12 at the defective part, and then, with the defective part as the center, other grease injection holes are sequentially injected from near to far until the cavity inside the shell is completely filled with the resin 16. Before grease injection, all small nut valves 14 are kept in the closed state. When injecting each grease injection hole 12, first fill the resin 16 into the grease gun, connect the gun head of the grease gun to the small nut valve 14; start pressurizing, when the pressure gauge shows a value, open the switch of the small nut valve 14 until the cavity is filled with the injection agent and it is difficult to press the resin 16 into the cavity, then close the switch of the small nut valve 14. During the grease injection process, the resin 16 enters the grease injection hole 12, gradually fills the shallow groove 7 inside the fixture, and enters the corroded or collapsed part between the base pipe and the liner pipe through the leakage notch on the wall of the base pipe. Due to the relatively large viscosity of the resin, the conveying medium infiltrating into the said part will enter the pipeline interior under the pressure of the resin through the leakage holes of the liner pipe, or be drained to the outside of the pipeline through the drainage hole 13; when the corrosion medium completely enters the pipeline interior, the resin 16 at the notch will, under the action of tension and the pressure of the conveying medium inside the pipeline, completely fill the notch of the liner pipe and block at the notch. Finally, under the action of pressure, the resin completely fills the space between the leakage notch of the liner pipe and the wall of the base pipe. After the grease injection is completed, after a period of curing, the resin becomes solid, sealing the notch of the leaking part of the bimetal composite pipe and achieving the purpose of permanent leak stoppage.

[0060] Step 6, pressure boosting and re-grease injection: After the grease injection is completed, close the small nut valve 14 and remove the drainage device, and seal the drainage hole 13 with bolts. Start the pressure boosting operation, and pay attention to whether there is leakage in the fixture during the pressure boosting process. If leakage occurs, a secondary grease injection process should be adopted for the grease injection hole 12 at the leakage point position to finally ensure that there is no leakage and seepage in the whole fixture when the pressure is boosted to the operating pressure.

[0061] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0062] Using a drainage-type fixture to repair the leak of a bimetal composite pipe, the fixture forms a closed space with the outer wall of the base pipe, ensuring the pressure of the resin during the repair, enabling the resin to smoothly enter the notch part, pressing the corrosion medium into the pipeline interior through the notch of the liner pipe, cutting off the corrosion source, and fundamentally solving the leakage problem, and achieving the effect of permanent repair.

[0063] There is no need to empty the leaking pipeline. By virtue of the structural characteristics of the bimetal composite pipe, the pipe body defects caused by leakage, and the action of the liquid pressure inside the pipeline, the purpose of pipeline repair with pressure and without stopping the transportation can be achieved, avoiding the economic losses caused by stopping transportation and emptying, shortening the construction period, and improving the pipeline repair efficiency.

[0064] Obviously, the embodiments described above are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0065] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0066] It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein.

[0067] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leak plugging structure for filling the interlayer cavity of a bimetallic composite pipe, characterized in that Comprising: A clamp, which is sleeved on the outer peripheral wall of the composite pipe. There is a cavity between the clamp and the outer peripheral wall of the composite pipe. A grease injection hole (12) is opened on the clamp, and the grease injection hole (12) communicates with the cavity; Resin (16), which is injected into the cavity through the grease injection hole (12).

2. The leak plugging structure for filling the interlayer cavity of the bimetallic composite pipe according to claim 1, characterized in that, The clamp includes: A first housing (8); A second housing (9), at least one of the first housing (8) and the second housing (9) is provided with a grease injection hole (12); A rotating shaft (18), which is arranged on the side of the first housing (8) and the second housing (9), and the first housing (8) and the second housing (9) are rotatably connected to the rotating shaft (18).

3. The leak plugging structure for filling the interlayer cavity of the bimetallic composite pipe according to claim 2, characterized in that, The clamp further includes a positioning pin (17), which is arranged on one side of the first housing (8) or the second housing (9) close to the rotating shaft (18), and the positioning pin (17) pre-fixes the first housing (8) and the second housing (9).

4. The leak plugging structure for filling the interlayer cavity of the bimetallic composite pipe according to claim 2, wherein, The clamp further includes a flange (10) and a connecting member. The flange (10) is fixed on both sides of the first housing (8) and the second housing (9). A through hole (11) is opened on the flange (10), and the connecting member passes through the through hole (11) to connect the first housing (8) and the second housing (9).

5. The leak plugging structure for filling the interlayer cavity of the bimetallic composite pipe according to claim 2, wherein The double-metal composite pipe interlayer cavity filling and leak plugging structure further includes a connecting pipe and a valve. A drainage hole (13) is opened on the first housing (8) or the second housing (9). The connecting pipe is installed on the drainage hole (13), and the valve controls the on-off of the connecting pipe. The valve and the connecting pipe constitute a drainage device.

6. A method for plugging leakage by filling the interlayer cavity of a bimetallic composite pipe, characterized in that, The double-metal composite pipe interlayer cavity filling and leak plugging structure according to any one of claims 1-5 applies the double-metal composite pipe interlayer cavity filling and leak plugging method, and the double-metal composite pipe interlayer cavity filling and leak plugging method includes the following steps: Prepare the clamp; Install the clamp; Drainage; Clamp fastening; Grease injection; Pressure boosting and re-grease injection.

7. The method for plugging leakage in the interlayer cavity of the bimetallic composite pipe according to claim 6, characterized in that, The step of preparing the clamp includes: preparing raw materials such as the corresponding clamp, grease gun, and special sealant according to the diameter of the pipeline to be leak plugged and the size of the puncture leak; after the pipeline leakage point is determined, start the emergency rescue plan and perform a pressure reduction operation on the leakage point.

8. The method for plugging and leak stopping of the interlayer cavity filling of the bimetallic composite pipe according to claim 6, characterized in that, The step of installing the clamp includes: after the excavation operation is completed and the leakage point is exposed, after confirming the internal pressure of the pipe, hoist the clamp to the installation position to be installed, buckle the first housing (8) and the second housing (9) of the clamp on the defective part, and align one of the grease injection holes (12) of the clamp of the first housing (8) or the second housing (9) directly above the leakage point, and align the center of the clamp with the leakage point position.

9. The method for plugging leakage in the interlayer cavity of the bimetallic composite pipe according to claim 6, characterized in that, The step of clamp fastening includes: the leak plugging personnel quickly tighten the bolts on both sides of the clamp, use a torque wrench to tighten the fastening bolts (15) of the connecting flanges (10) on both sides one by one. When tightening the bolts, tighten them step by step in a crosswise manner on both sides, that is, one side from left to right and one side from right to left.

10. The method for plugging and leaking stoppage of the interlayer cavity of the bimetallic composite pipe according to claim 6, characterized in that, The steps of the grease injection process include: performing high-pressure grease injection with a grease gun. First, inject grease into the grease injection hole (12) at the defective part, and then successively inject grease into other grease injection holes (12) from near to far with the defective part as the center until the cavity in the shell is completely filled with resin (16).

11. The method for plugging and leak stoppage of the interlayer cavity of the bimetallic composite pipe according to claim 10, characterized in that, Before grease injection, keep the valves of the leak stoppage structure for filling the interlayer cavity of the bimetal composite pipe on all drainage holes (13) in the closed state. When injecting grease into the grease injection hole (12) of each fixture, first fill the resin (16) into the grease gun, and connect the gun head of the grease gun to the valve. Start pressurizing. When a value is displayed on the pressure gauge, open the valve switch until the cavity is filled with the injection agent and it is difficult to press the resin (16) into the cavity, then close the valve switch. After the grease injection is completed, after a period of curing, the resin (16) becomes solid and seals the notch of the punctured part of the bimetal composite pipe.

12. The method for plugging and leaking prevention of the interlayer cavity filling of the bimetallic composite pipe according to claim 6, characterized in that, After the grease injection is completed, close the valves of the leak stoppage structure for filling the interlayer cavity of the bimetal composite pipe and remove the drainage device of the leak stoppage structure for filling the interlayer cavity of the bimetal composite pipe, and seal the drainage holes (13) with bolts. Start the pressure boosting operation. During the pressure boosting process, pay attention to whether there is leakage in the fixture. If leakage occurs, a secondary grease injection process should be adopted for the grease injection hole (12) of the fixture at the leakage point position, so that finally there is no leakage or seepage in the entire fixture when the pressure is boosted to the operating pressure.

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