A device and method for the anticorrosive treatment of the walls of oil pipes

Abstract

The application belongs to the technical field of petroleum pipeline processing equipment, and discloses a pipe wall corrosion prevention treatment device and method for a petroleum pipeline. The device comprises a polishing head, a driving rod and a circumferential driving unit. The output end of the circumferential driving unit is fixedly connected with one end of the driving rod. The central axis of the polishing head is parallel to the central axis of the driving rod. The polishing head rotates around the central axis of the driving rod, so that a polishing part for intermittent polishing of the pipeline is formed on the outer circumference of the polishing head. The polishing head only polishes the pipe wall intermittently through the polishing part when rotating, so that a cleaning gap is formed. The corrosion prevention treatment method comprises the following steps: forming a cladding layer by circular surfacing of corrosion-resistant material on both ends of the pipeline; after pretreatment, coating a corrosion prevention coating on the non-surfacing area of the pipeline; after shielding protection of the coating, processing a butt joint groove; using argon arc welding of corrosion-resistant material to perform backing welding, and using a material matched with the base body to perform cover welding; after welding, completing penetration detection and performance inspection. The application can form a multilayer composite corrosion prevention structure, and improve the corrosion resistance of the petroleum pipeline.

Description

Technical Field

[0001] This solution belongs to the technical field of oil pipeline processing equipment, specifically involving a device and method for anti-corrosion treatment of oil pipeline walls. Background Technology

[0002] Oil pipelines are essential infrastructure for oil and gas extraction and long-distance transportation, operating for extended periods in highly corrosive environments containing chloride ions, hydrogen sulfide, carbon dioxide, and acidic or alkaline media. Currently, the industry commonly employs anti-corrosion coatings for the pipe body, applying epoxy, phenolic, or heavy-duty anti-corrosion coatings to the main body of the pipeline to achieve protection.

[0003] Pipe wall surface pretreatment is the first step in the anti-corrosion coating protection of oil pipelines. Impurities such as scale, rust, burrs, and oil on the pipe surface can form a barrier layer between the coating and the metal substrate, reducing coating adhesion and mechanical bonding, and easily leading to coating detachment and failure during subsequent processing and service. To ensure a strong bond between the coating and the substrate and stable anti-corrosion performance, standardized pretreatment such as rust removal, impurity removal, and anchor pattern forming is required before coating protection. These pretreatment steps are typically achieved through pipe wall grinding, usually using specialized grinding equipment such as mechanical grinding or sandblasting in industrial production.

[0004] An existing pipe inner wall grinding device with publication number CN121199791A adopts a structure in which the base, guide rod, and grinding rod are coaxial. The grinding head is directly fixed to the end of the grinding rod, and the inner wall of the pipe is ground by the axial feed of the grinding rod. It can be adapted to different pipe diameters. However, since the grinding head and the drive output end are completely coaxial, the grinding head needs to maintain continuous contact with the pipe wall during operation. An existing environmentally friendly ductile iron pipe inner wall grinding device with publication number CN104985495A, although connecting the motor and grinding head through a universal joint and an intermediate drive shaft, and improving the grinding uniformity with a pipe rotation device, still has the grinding head coaxial with the drive shaft, and the grinding head is always in contact with the pipe wall during the grinding process.

[0005] Both types of devices require the grinding head and the output end of the drive unit to be coaxial, and the grinding head to maintain continuous contact with the pipe wall throughout the grinding process. However, metal shavings are inevitably generated during grinding. These shavings can get stuck between the grinding head and the pipe wall, causing secondary scratches and accelerating the wear of the grinding head. Therefore, it is generally necessary to clean the shavings in real time during the grinding process. Currently, high-pressure gas purging or negative pressure dust collection is commonly used in industrial production to handle shavings. However, due to the continuous contact between the grinding head and the pipe wall, the contact surface between the grinding head and the pipe wall forms a closed compression zone, and the shavings are repeatedly crushed within the contact area and cannot be discharged naturally. At the same time, the dust collection or purging device can only be placed in front of (behind) the grinding head and cannot directly act on the real-time location where the shavings are generated, making it difficult for conventional purging to remove the shavings at the grinding location in real time. Summary of the Invention

[0006] This invention provides a device and method for anti-corrosion treatment of oil pipeline walls, in order to solve the problem of real-time cleaning of grinding debris during pipeline grinding.

[0007] The first aspect of the present invention provides a pipe wall anti-corrosion treatment device for oil pipelines, including a grinding device and a cleaning device arranged in cooperation. The cleaning device is used to blow clean the grinding area of ​​the pipeline. The grinding device includes a grinding head, a drive rod and a circumferential drive unit. The output end of the circumferential drive unit is fixedly connected to one end of the drive rod and is used to drive the drive rod to rotate circumferentially around its own axis. The free end of the drive rod is used to connect to the grinding head. The central axis of the grinding head is parallel to the central axis of the drive rod. The grinding head rotates around the central axis of the drive rod, so that a grinding part for intermittently grinding the pipeline is formed on the outer circumference of the grinding head.

[0008] The principle and effect of this solution are as follows: Because the central axis of the grinding head is parallel to the central axis of the drive rod, and they are spatially offset, the grinding head makes an eccentric circular motion around the central axis of the drive rod. This allows the grinding head to intermittently grind the pipe wall only through its circumferential grinding section during rotation. During grinding, the grinding section rotates and contacts the pipe wall to complete the grinding operation. When it rotates to the side away from the pipe wall, it disengages, forming a cleaning gap (i.e., the gap between the grinding head and the pipe wall). This allows the cleaning device to easily blow away the just-grinded pipe wall surface (i.e., the cleaning gap), without requiring airflow to pass through the contact area between the grinding head and the pipe wall. This allows for the real-time removal of metal debris generated during grinding. Compared to existing grinding heads that are in continuous contact with the pipe wall throughout the entire process, this solution utilizes eccentric intermittent grinding, avoiding obstruction of the cleaning airflow by the grinding head, thus preventing secondary scratches on the pipe wall caused by debris and accelerated wear of the grinding head.

[0009] Furthermore, the grinding device also includes a rotary clamping assembly for clamping and driving the pipe to rotate circumferentially. The rotary clamping assembly includes a frame, a drive roller, and a clamping roller. The drive roller is rotatably mounted on the frame. The number of drive rollers includes at least two. Each drive roller is parallel to each other and spaced apart. At least one drive roller is connected to a circumferential drive source for driving its rotation. The clamping roller is mounted on the frame and is spaced apart from the drive roller to form a receiving space for clamping the pipe.

[0010] The principle and effect of this solution are as follows: the drive roller and the clamping roller cooperate to form a pipe clamping and accommodating space. The friction between the drive roller and the outer wall of the pipe is used to drive the drive roller to rotate by the circumferential drive source, thereby driving the pipe to rotate around its own axis. During grinding, it is best to control the rotation direction of the pipe to be opposite to the rotation direction of the grinding head, so as to grind the entire circumference (one circle) of the pipe. After grinding one circle, the pipe or grinding head is moved axially to grind the remaining section of the pipe.

[0011] Furthermore, the grinding device also includes a feed assembly for driving the grinding head to move axially along the drive rod. The feed assembly includes a bracket and a support plate. The support plate is slidably disposed along the length direction of the bracket. The circumferential drive unit is fixedly disposed on the support plate. The support plate is provided with a feed drive source for driving the support plate to slide.

[0012] The principle and effect of this solution are as follows: the circumferential drive unit is mounted on the support plate as a whole. The feed drive source drives the support plate to drive the circumferential drive unit, drive rod and grinding head to feed synchronously along the axis of the drive rod. In coordination with the reverse rotation of the pipe, continuous grinding operation of the entire length and circumference of the pipe can be realized.

[0013] Optionally, the free end of the drive rod is eccentrically fixedly connected to the grinding head.

[0014] The principle and effect of this solution are as follows: by setting the drive rod and the grinding head eccentrically, the rotation axis of the grinding head and the rotation axis of the drive rod form a radial eccentricity. When the circumferential drive unit drives the drive rod to rotate around its own axis, the grinding head as a whole makes synchronous eccentric circular motion with the drive rod. Only a section of the outer circumference will periodically contact the pipe wall during the rotation. This section is the grinding part, thus naturally forming an intermittent working cycle of contact grinding and separation gap.

[0015] Preferably, a drive gear is coaxially fixedly connected to the free end of the drive rod, the drive gear meshes with a driven gear, and the driven gear is eccentrically fixedly connected to the grinding head; a support member is coaxially rotatably connected to the driven gear, and the support member is fixedly connected to the circumferential drive unit.

[0016] The principle and effect of this solution are as follows: the drive rod drives the active gear to rotate, and the active gear meshes with the driven gear to rotate. Due to the eccentric setting of the driven gear and the grinding head, the rotation axis of the grinding head and the rotation axis of the driven gear form a radial eccentricity. When the drive rod rotates around its own axis, the entire grinding head makes synchronous eccentric circular motion with the driven gear, so that the grinding head forms a periodic intermittent contact grinding part while rotating with the driven gear.

[0017] Furthermore, the support includes a connecting rod and a sleeve. One end of the connecting rod is fixedly connected to the sleeve, and the other end is rotatably connected to the driven gear on the same axis. One end of the sleeve is fixedly connected to the circumferential drive unit. The sleeve and the drive rod are coaxially arranged, and the drive rod passes through the cavity of the sleeve.

[0018] The principle and effect of this solution is that the driven gear is supported by the above structure, so that the driven gear meshes and rotates with the driving gear.

[0019] Furthermore, both the driving gear and the driven gear are elliptical gears, and the grinding part is configured to cooperate with the short shaft of the driven gear.

[0020] The principle and effect of this solution are as follows: (1) In the pipeline grinding operation, in order to improve the grinding efficiency and facilitate grinding around the pipeline, it is necessary to continuously drive the pipeline to rotate circumferentially in the opposite direction to the grinding head. However, the intermittent grinding head used in this application only contacts the pipe wall on a section of the circumference. Theoretically, when the grinding head finishes grinding a section and rotates to the next grinding position, the reverse rotation of the pipeline will cause the original adjacent un-grinded area to move circumferentially, thus forming an uncovered gap at the junction of the next grinding. Although the grinding head speed is much higher than the pipeline speed under normal grinding conditions, the gap can be naturally overlapped and covered, and the above situation can be ignored. However, in the initial stage of pipe grinding, hard impurities such as hard oxide scale and protruding burrs often adhere to the pipe wall surface. Most importantly, because the grinding head in this application uses intermittent contact grinding, if the grinding head rotates too fast during the initial grinding, the grinding section will intermittently contact the protruding hard impurities. This high-frequency, intermittent impact of the grinding section against these hard protrusions will directly transmit the resulting impact vibrations to the external rotating clamping assembly, causing slight slippage between the drive roller, clamping roller, and the outer wall of the pipe. This leads to periodic fluctuations in clamping force, resulting in unstable circumferential rotation speed of the pipe and uneven grinding. However, simply reducing the pipe rotation speed is not advisable, as this would also reduce the relative cutting speed between the two components. Therefore, at least during the initial grinding stage, the grinding head rotation speed must be controlled at a low level to reduce the impact frequency, extend the contact time between the grinding section and the hard impurities, and output a larger torque, thereby ensuring stable cutting rather than impacting the hard impurities. However, after the overall rotation speed of the grinding head is reduced, the circumferential positional offset caused by the reverse rotation of the pipeline will be amplified, the time for the grinding head to complete one grinding cycle will be longer, the angle through which the pipeline rotates during this time period will be larger, and an un-grinded gap will be formed at the junction of two grinding operations, resulting in incomplete coverage of the single circumferential grinding. (2) In this application, the grinding head has a grinding stage and a non-grinding stage. During the grinding stage, the grinding part of the grinding head needs to be rotated to a faster speed when it contacts the pipe wall, so as to facilitate grinding and reduce vibration, etc. During the non-grinding stage, the idle stroke time of the grinding head needs to be shortened so that the speed when the grinding part rotates to a speed away from the grinding area is faster, thereby offsetting the circumferential positional offset caused by the reverse rotation of the pipeline, and thus avoiding the un-covered gap at the junction of two grinding operations during low-speed grinding. (3) In this application, although the rotational speed of the circumferential drive unit can be controlled by servo / frequency conversion, thereby controlling the rotational speed of the drive rod, and thus controlling the grinding part to slow down and increase torque during the grinding stage and speed up during the idle stroke stage, frequent speed and torque switching will inevitably lead to severe motor heating, and speed regulation also has a response delay, making instantaneous switching impossible. Therefore, this solution sets both the driving gear and the driven gear as elliptical gears, and sets the short shaft of the grinding part and the driven gear to be matched (i.e., the grinding part is closer to the short shaft of the driven gear on the circumference), utilizing the inherent variable angular velocity transmission characteristics of a pair of elliptical gears meshing to achieve low speed during the grinding stage and high speed during the idle stroke in the non-grinding stage.Specifically, when the drive rod drives the active gear to rotate at a constant speed, when the grinding part rotates with the driven gear to the grinding stage where it contacts the pipe wall, the long axis of the driven gear is exactly facing the meshing point, naturally outputting the lowest angular velocity. At this time, the speed of the grinding part is relatively slow, which prolongs the contact time between the grinding part and the hard impurities, thereby reducing the impact vibration frequency. When the grinding part leaves the pipe wall and enters the non-grinding stage, the remaining area of ​​the grinding head in this stage will not contact the protruding hard impurities due to the gap between it and the pipe wall. Moreover, the driven gear switches to the highest angular velocity condition with the short axis facing the meshing point, quickly rotating through the idle stroke area, thereby compensating for and offsetting the circumferential position offset caused by the reverse rotation of the pipe, and eliminating the uncovered gap at the junction of the two grinding operations. (4) Through the above settings, this scheme adopts a pure mechanical speed change method, without any electronic speed control. The active gear always maintains uniform rotation and constant torque, avoiding the heating and response delay problems caused by frequent acceleration and deceleration of the motor. The structure is simple and reliable.

[0021] Furthermore, the grinding head has a cooling chamber, and an air inlet is provided at one end of the grinding head facing away from the drive rod, the air inlet being connected to the cooling chamber; the cleaning device includes a cleaning pipe, one end of which is rotatably connected to the air inlet, and the inner cavity of the cleaning pipe is connected to the air inlet, the other end of which is used to connect to an air supply unit, the air supply unit being used to provide a cold air source for the cleaning pipe; the side wall of the grinding head has a plurality of spray holes along its own circumference, the spray holes being connected to the cooling chamber.

[0022] The principle and effect of this solution are as follows: The high temperatures generated during the grinding process can cause the abrasive grains on the grinding head surface to overheat and soften, shortening the grinding head's lifespan. Therefore, this solution addresses this by creating a cooling chamber inside the grinding head, allowing cool air to enter and cool the head. More importantly, the airflow can ultimately be ejected outwards through nozzles on the outer periphery of the grinding head, effectively cleaning the grinding surface of the tube wall and removing metal debris generated during grinding.

[0023] Furthermore, several of the spray holes are located circumferentially away from the grinding part of the grinding head; the cleaning pipe is equipped with a solenoid valve in series, which is used to open the cleaning pipe when the grinding part rotates to a grinding position away from the pipe.

[0024] The principle and effect of this solution are as follows: by setting all the nozzles in a position away from the grinding part around the grinding head, the solenoid valve controls the air supply pipe to disconnect when the grinding head is grinding; the solenoid valve only opens the air supply pipe when the nozzles rotate with the grinding head to face the surface of the pipe wall that has just been ground. At this time, there is a gap between the grinding head and the pipe wall, so that the cold airflow blows through the grinding area, avoiding the problem of ineffective blowing during the grinding stage.

[0025] A second aspect of the present invention provides a method for corrosion protection of the pipe wall of an oil pipeline, comprising the application of the corrosion protection device for oil pipelines as described above, and including the following steps: Step S10: Cut the pipe blank and inspect the defects of the base material, and remove rust from the areas to be welded at both ends of the pipe; Step S20: Using corrosion-resistant welding materials that match the pipe substrate, perform circular overlay welding on the inner wall, outer wall, or both inner and outer walls of the pipe ends, and allow it to cool naturally to room temperature after the overlay welding is completed. Step S30: The pipe wall anti-corrosion treatment device for oil pipelines is used to continuously grind the entire pipe wall. During the grinding process, the pipe and the grinding head are controlled to rotate in opposite directions, and the cleaning device blows away the debris. Step S40: Apply an anti-corrosion coating to the non-welded areas of the pipeline; Step S50: After masking and protecting the coated area, V-shaped butt weld bevels are machined at both ends of the pipe, and finally the burrs and oxide scale on the bevel surface are ground off. Step S60: Connect the two pipe sections and correct their coaxiality. First, use a corrosion-resistant material that matches the weld overlay for argon arc welding as the root pass, and then use a material that matches the substrate for the cover pass. The coating is protected against heat throughout the welding process, and a penetration test is performed after welding. Step S70: Test the coating adhesion, weld quality, sealing performance and dimensions of the finished product. Once all indicators are qualified, mark and put it into the warehouse. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the grinding device (assembly pipe) in Example 1; Figure 2 This is a schematic diagram of the overall structure of the grinding device (without the pipes) in Example 1; Figure 3 This is a schematic diagram of the overall structure of the feed component and drive component in Embodiment 1; Figure 4 This is a schematic diagram of the overall structure of the rotating clamping assembly in Embodiment 1.

[0027] Figure 5 This is a schematic diagram of the overall structure of the drive rod, grinding head, and cleaning device in Embodiment 1; Figure 6 This is a schematic diagram of the drive rod, grinding head, and cleaning device in Embodiment 1; Figure 7 This is a schematic diagram of the working state of the grinding head in Example 1; Figure 8 This is a schematic diagram of the working state of the nozzle in Example 1; Figure 9 This is a partial structural diagram of the grinding device (without the pipes) in Example 2; Figure 10 This is a schematic diagram of the drive rod and grinding head in Example 2; Figure 11 This is a schematic diagram of the working state of the grinding head in Example 2; Figure 12 This is a schematic diagram of the working state of the nozzle in Example 3; Figure 13 This is a schematic diagram of the composite anti-corrosion pipeline structure in Example 4.

[0028] The reference numerals in the accompanying drawings include: Grinding device 1; Grinding head 11, grinding part 111, cooling chamber 112, spray hole 113, base part 114; Drive lever 12; Circumferential drive unit 13, circumferential drive motor 131; Rotary clamping assembly 14, frame 141, drive roller 142, clamping roller 143, rotary drive motor 144, sprocket 145, cylinder 146; Feed assembly 15, bracket 151, bearing plate 152, slide rail 153, rack 154, feed drive motor 155, auxiliary roller 156; Drive gear 16; Driven gear 17, short shaft 171; Connecting rod 18, sleeve 19; Cleaning device 2, cleaning pipe 21, solenoid valve 22, sealing ball 23, spring 24; Pipeline 3. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] Example 1: The following is in conjunction with the appendix Figure 1-12 This invention describes in detail a pipe wall anti-corrosion treatment device for oil pipelines according to an embodiment of the present invention, which is used to realize the grinding operation of the entire circumference and length of the pipeline 3, and is mainly adapted to the pretreatment grinding requirements of oil pipelines.

[0033] Please see Figure 1 and Figure 2 , Figure 1 and Figure 2 This is a schematic diagram of the overall structure of the grinding device. The device as a whole includes a grinding device 1 and a cleaning device 2 that are arranged in a mutually cooperating manner. The cleaning device 2 is used to blow clean the grinding area of ​​the pipe 3 and remove the metal debris generated during grinding. The grinding device 1 mainly consists of a grinding head 11, a drive assembly, a rotary clamping assembly 14, and a feed assembly 15; wherein, the drive assembly is used to drive the eccentric circumferential rotation of the grinding head 11, the rotary clamping assembly 14 is used to clamp and drive the pipe 3 to rotate around its own axis, and the feed assembly 15 is used to drive the grinding head 11 to move along the axial direction of the pipe 3.

[0034] Please see Figure 3 , Figure 3 This is a schematic diagram of the overall structure of the feed assembly 15 and the drive assembly. The feed assembly 15 includes a bracket 151 and a support plate 152. A slide rail 153 is fixedly arranged parallel to the top surface of the bracket 151 along its length. A slider (not shown) is fixedly connected to the bottom surface of the support plate 152. The slider and the slide rail 153 form a sliding pair, allowing the support plate 152 to slide along the length of the bracket 151.

[0035] Please see Figure 3The support plate 152 is equipped with a feed drive source for driving its sliding. Specifically, a rack 154 is fixedly installed on the support 151 along its length, and the length of the rack 154 is the same as that of the slide rail 153. A feed drive motor 155 is installed on the top surface of the support plate 152. A three-phase asynchronous motor with a planetary reducer can be used. The output shaft of the feed drive motor 155 passes vertically downward through the surface of the support plate 152, and a gear is fixedly connected to the output shaft on the same axis. The gear meshes with the rack 154 for transmission. It should be noted that the lengths of the support 151, rack 154, and slide rail 153 need to be determined according to the processing requirements. They should be longer than the maximum length of the pipe 3 to be ground, so as to drive the grinding head 11 to cover the entire length of the pipe 3 to be ground.

[0036] Please see Figure 3 The drive assembly is mounted on the top surface of the support plate 152 and includes a drive rod 12 and a circumferential drive unit 13. The support plate 152 is provided with a mounting seat for mounting the drive rod 12. The drive rod 12 is rotatably mounted in the mounting seat. A pair of auxiliary rollers 156 for clamping the outer wall of the drive rod 12 are fixedly provided at the right end of the bracket 151 to limit the movement path of the drive rod 12 and avoid radial deflection deformation. The output end of the circumferential drive unit 13 is fixedly connected to one end of the drive rod 12, and is used to drive the drive rod 12 to rotate circumferentially around its own axis. The circumferential drive unit 13 specifically includes a circumferential drive motor 131 and a pulley group (not shown). The circumferential drive motor 131 is fixedly mounted on the support plate 152, and one of the pulleys is coaxially fixedly connected to the output shaft of the circumferential drive motor 131. The other pulley is coaxially fixedly connected to one end of the drive rod 12. The two pulleys are connected by belt drive, thereby driving the drive rod 12 to rotate around its own axis. The free end of the drive rod 12 extends to the right and is fixedly connected to the grinding head 11, thereby driving the rotation of the grinding head 11.

[0037] Please see Figure 4 , Figure 4 This is a schematic diagram of the overall structure of the rotary clamping assembly. The rotary clamping assembly 14 is located on the right side of the feed assembly 15, and includes a frame 141, drive rollers 142, and clamping rollers 143. The height of the frame 141 should be equal to the center height of the drive rod 12 of the feed assembly 15. Two sets of drive rollers 142 are provided, and the two sets of drive rollers 142 are spaced apart in a direction perpendicular to the axis of the drive rollers 142. Each set has two drive rollers 142 that are radially concentrically spaced. The roller surface of the drive rollers 142 is provided with a rubber coating layer to provide sufficient friction to drive the pipe 3 to rotate, and is rotatably mounted on the upper part of the frame 141.

[0038] Please see Figure 4At least one of the drive rollers 142 has its roller shaft connected to a circumferential drive source. In this embodiment, the circumferential drive source includes a rotary drive motor 144 and four sprockets 145. The rotary drive motor 144 is fixedly mounted on the lower part of the frame 141. The output shaft of the rotary drive motor 144 is coaxially fixedly connected to one of the sprockets 145. One of the drive rollers 142 of the two sets of drive rollers 142 has a sprocket 145 coaxially fixedly connected to its roller shaft. The last sprocket 145 is a tension sprocket, fixedly mounted on the frame 141, located between the output shaft of the rotary drive motor 144 and the roller shaft of the drive roller 142, and can slide in the vertical direction to adjust the tension of the chain on the sprocket 145. A chain is wound around the four sprockets 145, and the synchronous rotation of the two sets of drive rollers 142 in the same direction is achieved through the transmission of the chain.

[0039] Please see Figure 4 In this embodiment, three clamping rollers 143 are provided and spaced apart along the axial direction of the drive roller 142. They are mounted on the frame 141 via a support platform, located above the drive roller 142, and the clamping rollers 143 and drive roller 142 are spaced apart and opposite to each other, forming a space for clamping the pipe 3. A cylinder 146 is fixedly mounted on the support platform. The piston rod of the cylinder 146 passes vertically downward through the support platform and is fixedly connected to the roller frame of the clamping roller 143. It is used to drive the clamping roller 143 to move towards the drive roller 142 and adjust the height of the clamping roller 143 to accommodate oil pipes 3 of different diameters. During operation, the cylinder 146 pushes the clamping roller 143 downward, clamping the pipe 3 between the drive roller 142 and the clamping roller 143. The friction between the drive roller 142 and the outer wall of the pipe 3 causes the pipe 3 to rotate around its own axis, and the rotation direction of the pipe 3 is controlled to be opposite to the rotation direction of the grinding head 11. The relative cutting line speeds of the two are superimposed, improving the grinding effect.

[0040] Please see Figure 5 and Figure 6 , Figure 5 and Figure 6 This diagram mainly shows the structure of the drive rod 12, the grinding head 11, and the cleaning device 2. In this embodiment, the free end of the drive rod 12 is directly and eccentrically fixedly connected to the grinding head 11, thereby allowing the rotation axis of the drive rod 12 to be ( Figure 6 In section A), the rotation axis of the drive assembly output is defined. Specifically, an eccentric mounting hole can be formed on the end face of the grinding head 11, and the free end of the drive rod 12 can be interference-fitted into the eccentric mounting hole, thereby adjusting the rotation axis of the grinding head 11. Figure 6B) is parallel to the rotation axis of the drive rod 12 and forms a fixed radial eccentricity e. When the circumferential drive unit 13 drives the drive rod 12 to rotate, the grinding head 11 moves synchronously and eccentrically in a circular motion with the drive rod 12. Only a section of the outer circumferential surface will periodically contact the pipe wall of the pipe 3 during the rotation. This section is the grinding part 111, thus naturally forming an intermittent working cycle of contact grinding and separation gap.

[0041] Please see Figure 7 , Figure 7 This is a schematic diagram of the working state of the grinding head 11. When the grinding part 111 rotates to the side facing the pipe wall, it contacts and completes the grinding operation (e.g., Figure 7 (As shown in the right-hand diagram); when rotated to the side away from the pipe wall, the grinding head 11 separates from the pipe wall, forming a 2-3cm cleaning gap (as shown in the diagram on the right-hand side). Figure 7 As shown in the left side of the middle figure), the blowing airflow output by the cleaning device 2 can directly act on the surface of the pipe wall that has just been polished, without having to pass through the contact area between the polishing head 11 and the pipe wall. It can completely blow away the metal debris generated during polishing from the polishing surface in real time, thereby avoiding the problem of the debris being repeatedly crushed due to continuous contact of the polishing head 11.

[0042] Please see Figure 6 The grinding head 11 consists of two parts: a replaceable, wear-resistant grinding part 111 and a long-term usable base part 114. The grinding part 111 is made of tungsten carbide abrasive grains, but can also be replaced with ceramic abrasive grains depending on the grinding conditions. It is fixed in the corresponding mounting groove of the base with screws. After wear, it only needs to be disassembled and replaced individually, without the need to scrap the entire grinding head 11. The base part 114 corresponds to the non-grinding area and can be reused for a long time.

[0043] Please see Figure 5 and Figure 6The grinding head 11 has a cooling chamber 112 inside, which is cylindrical along the axial direction of the grinding head 11. An air inlet (not shown) is located at the end of the grinding head 11 facing away from the drive rod 12, and this air inlet communicates with the cooling chamber 112. Spray holes 113 are provided on the outer periphery of the base portion 114 of the grinding head 11, penetrating the base portion 114 and communicating with the cooling chamber 112. There are multiple spray holes 113, all evenly spaced along their circumference. These spray holes 113 are located circumferentially away from the grinding portion 111 of the grinding head 11, i.e., facing away from the grinding portion 111. The cleaning device 2 includes a cleaning pipe 21 and a solenoid valve 22. One end of the cleaning pipe 21 is rotatably connected to the air inlet, and the inner cavity of the cleaning pipe 21 is connected to the air inlet. The solenoid valve 22 is connected in series on the cleaning pipe 21. The other end of the cleaning pipe 21 is used to connect to the air supply unit, which is used to provide a cold air source for the cleaning pipe 21. The air supply unit can be an air compressor in conjunction with a refrigeration dryer (not shown), which can output dry low-temperature compressed air.

[0044] Please see Figure 8 , Figure 8 This is a schematic diagram of the working state of the nozzle 113. High-pressure cold air flows through the cleaning pipe 21, solenoid valve 22, and air inlet into the cooling chamber 112. Heat is dissipated from the grinding head 11 via convection heat exchange, cooling the grinding head 11. The cooled airflow is then ejected outwards through the nozzle 113, simultaneously purging the grinding surface of the pipe wall under high pressure while completing the cooling process. Regarding the on / off state of the solenoid valve 22, it should control the cleaning pipe 21 to disconnect when the grinding head 11 is grinding, and open the cleaning pipe 21 when the grinding head 11 is not grinding. This ensures that the nozzle 113 only opens the cleaning pipe 21 when it rotates with the grinding head 11 to face the just-grinded pipe wall surface. At this time, a gap exists between the grinding head 11 and the pipe wall, facilitating the cold airflow to purge the grinding area and avoiding ineffective purging during the grinding stage.

[0045] It should be noted that, in actual operation, in order to facilitate the overall transfer of the grinding debris inside pipe 3 to the outside of pipe 3, an axial flow fan needs to be installed on one side of pipe 3, and the air outlet of the fan should face the inner or outer wall of pipe 3, so that it is arranged in the same direction as the feed direction of grinding head 11, so that the blown debris can be discharged from the other end of pipe 3, avoiding the accumulation of debris inside pipe 3.

[0046] Please see Figure 6It should be noted that although the cleaning pipe 21 and the air inlet of the grinding head 11 are rotatably connected, the grinding head 11 needs to rotate eccentrically. To avoid problems such as the grinding head 11 causing the cleaning pipe 21 to become entangled or break, the air inlet and the drive rod 12 need to be coaxially aligned, thus preventing the cleaning pipe 21 and the drive rod 12 from rotating eccentrically. Secondly, to ensure a sealed rotatable connection between the cleaning pipe 21 and the air inlet, a rotary joint (not shown) can be provided at the connection between the cleaning pipe 21 and the air inlet. Specifically, the fixed end of the rotary joint is fixedly connected to one end of the cleaning pipe 21, and the rotating end of the rotary joint is rotatably connected to the air inlet, with the inner cavity of the rotary joint communicating with both the air inlet and the cleaning pipe 21. Thirdly, since the two ends of the grinding head 11 need to be connected to the drive rod 12 and the cleaning pipe 21 respectively, and the pipe 3 shown in this embodiment needs to have its inner wall ground, this is necessary. Therefore, before polishing, the polishing head 11 needs to be moved to the right side of the pipe 3, and then the cleaning pipe 21 is connected to the air inlet. During polishing, the feed proceeds from the right side of the pipe 3 to the left, thus polishing the inner wall of the pipe 3. Finally, since the cleaning pipe 21 needs to move with the polishing head 11, the cleaning pipe 21 needs to be set as a flexible cleaning pipe 21, and it is best to set a coiling machine on the radial side of the pipe 3, so that the cleaning pipe 21 is wound and placed on the coiling machine's plate, preventing the cleaning pipe 21 from loosening and facilitating the release of the cleaning pipe 21.

[0047] Example 2: The difference between this embodiment and Embodiment 1 is that the drive rod 12 and the grinding head 11 are connected by a gear transmission mechanism.

[0048] Please see Figure 9 and Figure 10 Specifically, the free end of the drive rod 12 is coaxially and fixedly connected to a drive gear 16 via a flat key. The drive gear 16 meshes with a driven gear 17. Both the drive gear 16 and the driven gear 17 are identical elliptical gears with a major-to-minor axis ratio of 1.2 to 1.5:1. The center distance between the two gears is equal to the length of the major axis of the elliptical gear. One end face of the driven gear 17 is eccentrically and fixedly connected to the grinding head 11, and the axis of rotation of the driven gear 17 (… Figure 10 (A) and the central axis of the grinding head 11 ( Figure 10 In section B), the settings are staggered.

[0049] Please see Figure 10To support the driven gear 17 and enable it to mesh and rotate with the driving gear 16, the driven gear 17 is coaxially connected to a support member, which is fixedly connected to the circumferential drive unit 13. In one embodiment, the support includes a connecting rod 18 and a sleeve 19. One end of the driven gear 17 is rotatably connected to the connecting rod 18 via a bearing. The connecting rod 18 has an "L"-shaped structure. The free end of the connecting rod 18 is fixedly connected to the outer wall of the sleeve 19. The sleeve 19 is open at both ends and hollow inside. One end of the sleeve 19 extends to be fixedly connected to the circumferential drive unit 13, which can be the housing of the circumferential drive unit 13 or other fixed components. The sleeve 19 does not rotate with the circumferential drive unit 13. The sleeve 19 is coaxially arranged with the drive rod 12, and the drive rod 12 passes through the cavity of the sleeve 19. The connecting rod 18 and the sleeve 19 provide support for the driven gear 17, so that the center position of the driven gear 17 remains fixed and can only rotate around its own axis, and will not revolve with the driving gear 16. The grinding part 111 is configured to mate with the short shaft 171 of the driven gear 17, meaning the grinding part 111 is positioned as close as possible to the short shaft 171 of the driven gear 17 on its circumference. In other embodiments, the support member may consist only of a connecting rod 18, one end of which is rotatably connected to the rotation center of one end of the driven gear via a bearing, and the other end of which extends to be fixedly connected to the circumferential drive unit 13. This connection may be to a bearing housing of the circumferential drive unit 13, or any component that can be fixed relative to the drive rod 12 and provide rotational support for the driven gear 17.

[0050] Please see Figure 10 and Figure 11 , Figure 11 This is a schematic diagram of the working state of the grinding head 11. By utilizing the inherent variable angular velocity transmission characteristics of a pair of meshing elliptical gears, this embodiment can automatically achieve variable speed rotation with low speed and high torque during the grinding stage and high speed and idle stroke during the non-grinding stage in a purely mechanical manner. The drive rod 12 drives the drive gear 16 to rotate at a constant speed. When the grinding part 111 rotates with the driven gear 17 to the grinding stage where it contacts the tube wall, the long axis of the driven gear 17 is exactly aligned with the meshing point (e.g., ...). Figure 11 As shown in the right-hand diagram), at this time, the driven gear 17 outputs the lowest angular velocity, and the speed of the grinding part 111 is relatively slow, which prolongs the contact time between the grinding part 111 and the hard impurities and reduces the impact vibration frequency. When the grinding part 111 detaches from the tube wall and enters the non-grinding stage, the remaining area of ​​the grinding head 11 in this stage will not contact the protruding hard impurities due to the gap between it and the tube wall, and the driven gear 17 switches to the highest angular velocity condition with the short shaft 171 facing the meshing point (e.g., Figure 11 (As shown in the left side of the middle figure), quickly rotate through the empty travel area to compensate for and offset the circumferential positional offset caused by the reverse rotation of pipe 3, and eliminate the uncovered gap at the joint of the two grinding processes.

[0051] Example 3: Based on Example 2, this embodiment omits the solenoid valve 22 and uses a mechanical valve structure to control the opening and closing of the nozzle 113.

[0052] Please see Figure 12 , Figure 12 This is a schematic diagram of the working state of the nozzle 113. In this embodiment, the nozzle 113 is configured as a nozzle with a tapered flared structure, that is, a nozzle 113 with a small air inlet and a large air outlet. A sealing ball 23 is provided inside the nozzle 113. The diameter of the sealing ball 23 is larger than the diameter of the air inlet of the nozzle 113 and smaller than the diameter of the air outlet of the nozzle 113, so that the sealing ball 23 can move freely within the flared section of the nozzle 113 but cannot be removed from the air inlet. A spring 24 is connected to the side of the sealing ball 23 facing the cooling chamber 112. The other end of the spring 24 is fixedly connected to the inner wall of the cooling chamber 112, which is used to pull the sealing ball 23 to seal the nozzle 113 when the grinding head 11 rotates at a low speed.

[0053] Please see Figure 12 The working process of this embodiment is coordinated with the variable angular velocity transmission characteristics of the elliptical gear. When the grinding part 111 rotates with the driven gear 17 to the grinding stage where it contacts the wall of the pipe 3, the driven gear 17 is in a low-speed condition with its long axis facing the meshing point (e.g., Figure 12 (As shown in the right side of the figure), the rotational speed of the grinding head 11 is lower than the rated average speed. At this time, the centrifugal force on the sealing ball 23 is less than the sum of the preload tension of the spring 24 and the thrust exerted by the high-pressure airflow in the cooling chamber 112 on the end face of the sealing ball 23. The sealing ball 23 remains in a compressed state, the nozzle 113 is in a closed state, and the cooling airflow only cools the grinding head 11. When the grinding section 111 detaches from the pipe wall and enters the non-grinding stage, the driven gear 17 switches to a high-speed condition with the short shaft facing the meshing point (e.g., Figure 12 As shown in the left side of the middle figure, the instantaneous rotation speed of the grinding head 11 is higher than the rated average rotation speed. At this time, the centrifugal force on the sealing ball 23 increases and exceeds the sum of the pre-tension of the spring 24 and the airflow thrust. The sealing ball 23 moves towards the air outlet of the nozzle 113, the nozzle 113 opens, and the high-pressure cold air in the cooling chamber 112 is sprayed out through the nozzle 113, which acts on the surface of the pipe wall that has just been ground, blowing away the metal debris completely. When the grinding head 11 rotates to the grinding stage again, the rotation speed decreases, the centrifugal force decreases, the spring 24 pulls the sealing ball 23 to reset, and the nozzle 113 closes automatically, completing one working cycle.

[0054] It should be noted that, in order to ensure that the timing of the opening and closing of the sealing ball 23 matches the grinding cycle, those skilled in the art can adaptively select the elastic coefficient of the spring 24 according to the rotation speed of the grinding head 11, so that the sealing ball 23 and the spring 24 can be closed during the grinding stage and opened during the non-grinding stage according to the change in the magnitude of the centrifugal force.

[0055] Example 4: Next, refer to the appendix. Figure 1 , Figure 2 , Figure 9 and Figure 13 (Schematic diagram of finished pipeline structure) This invention describes a method for anti-corrosion treatment of oil pipeline walls, based on an embodiment of the present invention. Using the anti-corrosion treatment device for oil pipeline walls described in Embodiment 1 or Embodiment 2 above, a composite anti-corrosion pipeline structure comprising a substrate, a 316L stainless steel cladding layer, an anti-corrosion coating, a stainless steel weld layer, and a carbon steel weld layer is finally obtained. The specific steps include: Step S10: Cut pipe blanks of the correct dimensions, leaving a 10-15mm allowance for subsequent machining of the end face; use ultrasonic flaw detection and visual inspection to check for defects such as cracks, sand holes, deformation, uneven wall thickness, rust perforation, etc. in the base material, and directly remove unqualified products; perform basic rust removal treatment on the 70-80mm area to be welded at both ends of pipe 3, and use this device to perform light grinding to remove surface rust and expose the metallic luster; Step S20: Using 316L stainless steel special welding material that matches the carbon steel base, perform continuous circular overlay welding on the inner wall, outer wall or inner and outer walls of both ends of the pipe 3. The overlay welding length at a single end is 70~80mm, and the overlay layer thickness is 1.3~1.7mm, forming a uniform 316L stainless steel cladding layer; after the overlay welding is completed, allow it to cool naturally to room temperature. Step S30: The inner wall, outer wall or inner and outer walls of the pipeline 3 are continuously ground using the above-mentioned anti-corrosion treatment device for oil pipelines. During the grinding process, the rotation direction of the pipeline 3 is controlled to be opposite to the rotation direction of the grinding head 11. The cleaning device 2 blows away the metal debris generated by the grinding and removes the oxide scale, rust, burrs and weld beads and oxide layer on the surface of the substrate and the 316L stainless steel cladding layer. Step S40: Apply an epoxy-based heavy-duty anti-corrosion coating to the inner and outer walls of the non-welded area of ​​pipe 3 using a high-pressure airless coating equipment. Control the overlap length between the coating and the 316L stainless steel cladding layer to be 8~12mm to form a smooth overlap interface. Control the dry film thickness of the coating within ±10% of the design value. Inspect each section to ensure there are no defects such as missed coating, sagging, peeling, or pinholes. Allow the coating to air dry naturally at room temperature for 72 hours or cure at a constant temperature of 60℃ for 24 hours according to the coating technical specifications. Step S50: First, use high-temperature resistant soft rubber protective plugs and protective sleeves to shield and protect all coated areas of pipe 3; then, process standard V-shaped butt welding bevels at both ends of pipe 3, controlling the bevel angle on one side to be 27.5~32.5°, the blunt edge height to be 0.5~1.0mm, and the root gap to be 1.0~2.0mm; after the bevel processing is completed, use 320-grit fine sandpaper to manually grind away burrs, oxide scale, and oil stains on the bevel surface; Step S60: Connect the two processed pipe sections 3 together, and use a coaxiality calibrator to correct the coaxiality, controlling the misalignment to ≤0.5mm; first, use 316L stainless steel welding wire that matches the 316L stainless steel cladding layer to perform argon arc welding for the root pass, with a root pass thickness of 1.3~1.7mm, welding only on the 316L stainless steel cladding layer area at both ends to form a continuous stainless steel weld layer; then, use carbon steel welding wire that matches the carbon steel base to perform cover welding, so that the weld is connected with the base material and the stainless steel root pass to form a carbon steel weld layer; throughout the welding process, use heat-insulating asbestos cloth to insulate and protect the coated area, and allow it to cool naturally to room temperature after welding, clean and grind the weld excess to 0.5~1mm, and perform penetrant testing, requiring it to reach Level I qualification, with no cracks, pores, or slag inclusions; Step S70: Conduct comprehensive performance testing on the completed composite anti-corrosion pipeline, including: coating adhesion test (using the pull-out method, adhesion ≥ 5MPa required), 316L stainless steel cladding layer penetration test, weld quality test, pipeline sealing performance test (water pressure test pressure is 1.5 times the design pressure, pressure held for 30 minutes without leakage), dimensional inspection, and coating integrity test; after all test indicators pass, the pipeline is labeled with specifications, material, batch, and anti-corrosion grade, classified and stored, and finally produced as shown in the attached figure. Figure 13 The diagram shows a five-layer composite anti-corrosion pipe structure comprising a base, a 316L stainless steel cladding layer, an anti-corrosion coating, a stainless steel weld layer, and a carbon steel weld layer.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pipe wall anti-corrosion treatment device for oil pipelines, characterized in that: The device includes a polishing device (1) and a cleaning device (2) that are configured to work together. The cleaning device (2) is used to blow clean the polished part of the pipe (3). The polishing device (1) includes a polishing head (11), a drive rod (12) and a circumferential drive unit (13). The output end of the circumferential drive unit (13) is fixedly connected to one end of the drive rod (12) and is used to drive the drive rod (12) to rotate circumferentially around its own axis. The free end of the drive rod (12) is used to connect with the polishing head (11). The central axis of the polishing head (11) is parallel to the central axis of the drive rod (12). The polishing head (11) rotates around the central axis of the drive rod (12) so that a polishing part (111) for intermittently polishing the pipe (3) is formed on the outer circumference of the polishing head (11).

2. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 1, characterized in that: The grinding device (1) further includes a rotary clamping assembly (14) for clamping and driving the pipe (3) to rotate circumferentially. The rotary clamping assembly (14) includes a frame (141), a drive roller (142) and a clamping roller (143). The drive roller (142) is rotatably mounted on the frame (141). The number of drive rollers (142) includes at least two. Each drive roller (142) is parallel to each other and spaced apart. At least one of the drive rollers (142) is connected to a circumferential drive source for driving its rotation. The clamping roller (143) is mounted on the frame (141) and is spaced apart from the drive roller (142) to form a receiving space for clamping the pipe (3).

3. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 2, characterized in that: The grinding device (1) further includes a feed assembly (15) for driving the grinding head (11) to move axially along the drive rod (12). The feed assembly (15) includes a bracket (151) and a support plate (152). The support plate (152) can be slidably arranged along the length direction of the bracket (151). The circumferential drive unit (13) is fixedly arranged on the support plate (152). The support plate (152) is provided with a feed drive source for driving the support plate (152) to slide.

4. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 1, characterized in that: The free end of the drive rod (12) is eccentrically fixedly connected to the grinding head (11).

5. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 1, characterized in that: The free end of the drive rod (12) is coaxially fixedly connected to a drive gear (16), the drive gear (16) is meshed with a driven gear (17), the driven gear (17) is eccentrically fixedly connected to the grinding head (11); the driven gear (17) is coaxially rotatably connected to a support member, the support member is fixedly connected to the circumferential drive unit (13).

6. The pipe wall corrosion protection device for oil pipelines according to claim 5, characterized in that: The support includes a connecting rod (18) and a sleeve (19). One end of the connecting rod (18) is fixedly connected to the sleeve (19), and the other end is rotatably connected to the driven gear (17) on the same axis. One end of the sleeve (19) is fixedly connected to the circumferential drive unit (13). The sleeve (19) is coaxially arranged with the drive rod (12), and the drive rod (12) passes through the cavity of the sleeve (19).

7. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 5, characterized in that: Both the driving gear (16) and the driven gear (17) are elliptical gears, and the grinding part (111) is configured to cooperate with the short shaft (171) of the driven gear (17).

8. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 1, characterized in that: The grinding head (11) has a cooling chamber (112), and an air inlet is provided at one end of the grinding head (11) facing away from the drive rod (12). The air inlet is connected to the cooling chamber (112). The cleaning device (2) includes a cleaning pipe (21). One end of the cleaning pipe (21) is rotatably connected to the air inlet, and the inner cavity of the cleaning pipe (21) is connected to the air inlet. The other end of the cleaning pipe (21) is used to connect to an air supply unit, which is used to provide a cold air source for the cleaning pipe (21). The side wall of the grinding head (11) is provided with several spray holes (113) along its own circumference. The spray holes (113) are connected to the cooling chamber (112).

9. The pipe wall anti-corrosion treatment device for oil pipelines according to claim 8, characterized in that: Several of the spray holes (113) are located circumferentially away from the grinding part (111) of the grinding head (11); the cleaning pipe (21) is connected in series with a solenoid valve (22), which is used to open the cleaning pipe (21) when the grinding part (111) rotates to the grinding position away from the pipe (3).

10. A method for corrosion protection of oil pipeline walls, comprising applying the corrosion protection device for oil pipeline walls as described in any one of claims 1-9, characterized in that, Includes the following steps: Step S10: Cut the pipe blank and inspect the defects of the base material, and remove rust from the areas to be welded at both ends of the pipe (3); Step S20: Use corrosion-resistant welding material that matches the base of pipe (3) to perform circular overlay welding on the inner wall, outer wall or inner and outer walls at both ends of pipe (3), and allow it to cool naturally to room temperature after the overlay welding is completed; Step S30: The pipe wall anti-corrosion treatment device for oil pipelines is used to continuously grind the entire pipe wall of the pipeline (3). During the grinding process, the pipeline and the grinding head are controlled to rotate in opposite directions, and the cleaning device blows away the debris. Step S40: Apply an anti-corrosion coating to the non-welded areas of the pipe (3); Step S50: After masking and protecting the coated area, V-shaped butt weld bevels are processed at both ends of the pipe (3), and finally the burrs and oxide scale on the bevel surface are removed by grinding. Step S60: Connect the two pipe sections (3) and correct their coaxiality. First, use a corrosion-resistant material that matches the weld overlay for argon arc welding as the root pass, and then use a material that matches the substrate for the cover pass. Heat insulation protection is applied to the coating throughout the welding process, and penetration testing is performed after welding. Step S70: Test the coating adhesion, weld quality, sealing performance and dimensions of the finished product. Once all indicators are qualified, mark and put it into the warehouse.

Images