Repair device and method for repairing defects of sealing surface of valve on line

Abstract

The invention provides a repairing device and method for repairing defects of a sealing surface of a valve online. The repairing device and method are suitable for online repairing of the valve in a nuclear power high-level radioactive environment. The online valve is disassembled until a valve seat sealing surface with defects can be exposed; defects on the valve seat sealing surface are ground and removed through a grinding assembly of the valve seat sealing surface repairing device, repair welding is conducted on the grinding position through a welding assembly so as to fill grinding cracks, and the surface of a welding seam protrudes out of the portion, in the non-grinding area, of the valve seat sealing surface; the surface of the welding seam protruding out of the sealing face of the valve seat is polished to be flush with the sealing face of the valve seat through the polishing assembly; and finally, the valve disassembling part is reassembled on the valve seat, so that the whole valve or the valve seat does not need to be replaced. The repairing device can be remotely operated, so that operators can be far away from a radiation area, the industrial safety risk is effectively reduced, and the exposure dose of the operators in a radiation field is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of valve repair devices, and more specifically, it relates to a repair device and method for online repair of defects in valve sealing surfaces. Background Technology

[0002] During the use of high-level radioactive valves in nuclear power plants, the valve base sealing surface operates under harsh conditions such as high temperature, high pressure, and strong radiation for extended periods. Simultaneously, it is subjected to the combined effects of media corrosion, erosion, and material fatigue, making it prone to defects such as cracks, spalling, or localized damage after long-term service. This damage not only reduces the valve's sealing reliability but may also further lead to media leakage, posing a potential threat to the safe and stable operation of the nuclear power plant.

[0003] Currently, the conventional approach to dealing with this type of sealing surface damage is to replace the entire valve or valve seat component. This method is not only expensive in terms of materials and complex in terms of disassembly and assembly, but it is also often accompanied by long downtime and high on-site construction intensity, resulting in low maintenance efficiency and poor economic performance. Summary of the Invention

[0004] This application aims to provide an online repair device and method for repairing defects on the valve sealing surface, in order to solve the technical problems of high maintenance cost and low maintenance efficiency of high-voltage valves in the prior art.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: A valve sealing surface repair device is provided, comprising: An adapter is installed on the valve seat to be repaired. The adapter has a mating hole that corresponds to the mounting hole on the valve seat to be repaired. A drive slide, the fixed end of which is connected to the adapter; A grinding assembly is installed at the movable end of the drive slide, and the drive slide is used to drive the grinding assembly to move in order to grind the working position. Alternatively, a welding assembly may be mounted on the movable end of the drive slide, the drive slide being used to drive the welding assembly to move in order to perform fusion welding at the working position.

[0006] As a further improvement to the above technical solution: Optionally, the polishing component includes: The mounting base is installed on the movable end of the drive slide. A grinding head extension is mounted on the mounting base, and the first end of the grinding head extension can extend to the target working length. A grinding head is installed at the first end of the grinding head extension, which is used to drive the grinding head to extend into the target working position. A grinding head drive component is installed at the second end of the grinding head extension and is connected to the grinding head drive to drive the grinding head to work.

[0007] Optionally, the mounting base includes a clamping seat with a mounting hole, the clamping seat including clamping flaps arranged circumferentially around the mounting hole and fasteners for tightening or loosening each of the clamping flaps; The grinding head extension is inserted into the mounting hole. When the fastener is used to tighten each of the clamping segments, the grinding head extension is clamped on the clamping seat. When the fastener is loosened, the grinding head extension can move in the mounting hole along the axial direction of the mounting hole.

[0008] Optionally, a limiting protrusion is provided on one of the clamping base and the grinding head extension, and a limiting groove is provided on the other of the clamping base and the grinding head extension, wherein the extending direction of the limiting groove is parallel to the axial direction of the mounting hole. When the grinding head extension is inserted into the mounting hole, the limiting protrusion extends into the limiting groove to restrict the grinding head extension from moving along the axial direction in the mounting hole.

[0009] Optionally, the mounting base includes: A mounting base plate is installed on the movable end of the drive slide. A slide block is slidably connected to the mounting base plate, and the grinding head extension is mounted on the slide block; A slide block limiting member is mounted on the mounting base plate; the slide block can move closer to or further away from the slide block limiting member, and the slide block limiting member is used to push the slide block to move along the feed direction; A sliding buffer component, one end of which is connected to the slide block limiting component, and the other end of which is connected to the slide block; A limit sensor is used to detect the distance between the slide block and the slide block limiting member. When the distance between the slide block and the slide block limiting member is less than a threshold, the limit sensor is triggered to stop the slide block from moving along the feed direction.

[0010] Optionally, the mounting base further includes an angle adjusting seat for adjusting the axial angle of the grinding head extension, the angle adjusting seat comprising a fixed seat and a swing seat. The fixed seat is mounted on the slide, the swing seat is rotatably connected to the fixed seat, and the relative angle between the swing seat and the fixed seat can be fixed. The grinding head extension is mounted on the swing seat.

[0011] Optionally, the welding assembly includes a welding torch holder, a welding torch, and a wire feeding assembly. The welding torch holder is mounted on the movable end of the drive slide, and both the welding torch and the wire feeding assembly are mounted on the welding torch holder. The wire feeding assembly is used to feed welding wire to the welding position.

[0012] This application also provides a method for repairing defects on the valve sealing surface online, including the following steps: Disassemble the online valve to expose the defective valve seat sealing surface; The defects on the valve seat sealing surface are removed by the grinding component of the valve sealing surface repair device described above. Then, the welding component of the valve sealing surface repair device described above welds the ground area to fill the grinding marks and make the weld surface protrude from the valve seat sealing surface of the unground area. The weld surface protruding from the valve seat sealing surface is then ground by the grinding component until it is flush with the valve seat sealing surface. Reassemble the disassembled valve components onto the valve seat.

[0013] As a further improvement to the above technical solution: Optionally, the grinding assembly is installed on the disassembled valve seat, and the grinding head of the grinding assembly extends into the valve seat sealing surface through the valve cavity channel on the valve seat. After the defects on the valve seat sealing surface are ground away, the grinding assembly is replaced with a welding assembly, and the welding gun of the welding assembly extends into the valve seat sealing surface through the valve cavity channel on the valve seat, and the welding assembly repairs the grinding area by welding.

[0014] Optionally, before welding, the welding assembly heats the grinding mark to a preheating temperature; after welding, the weld continues to be heated while gradually reducing the temperature of the weld. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A three-dimensional structural diagram of the first working mode of the valve sealing surface repair device provided in this application; Figure 2 A first perspective structural schematic diagram of the polishing component provided in this application; Figure 3 A second perspective structural diagram of the polishing component provided in this application; Figure 4 A three-dimensional structural diagram of the second working mode of the valve sealing surface repair device provided in this application.

[0017] The following are the labeling elements in the figure: 1. Adapter; 2. Drive slide; 3. Grinding assembly; 31. Mounting base; 311. Clamping seat; 3111. Fastener; 3112. Limiting protrusion; 312. Mounting base plate; 313. Slide; 314. Slide limiting component; 315. Limit sensor; 316. Angle adjustment seat; 3161. Fixed seat; 3162. Swing seat; 32. Grinding head extension; 321. Limiting groove; 33. Grinding head; 34. Grinding head drive component; 4. Welding assembly; 5. Valve seat. Detailed Implementation

[0018] 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.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] 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 connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of the present invention.

[0024] In the following description, suffixes such as "circuit," "component," "assembly," or "unit" are used only for the purpose of illustrative purposes and do not have any specific meaning in themselves. Therefore, they can be used interchangeably.

[0025] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0026] like Figure 1 and Figure 4 As shown, this application provides a valve sealing surface repair device, including an adapter 1, a drive slide 2, and a grinding assembly 3 or a welding assembly 4 installed on the movable end of the drive slide 2.

[0027] Adapter 1 is installed on the valve seat 5 to be repaired. Adapter 1 has multiple mating holes, the positions and number of which correspond to the inherent mounting holes on the valve seat flange of a specific valve model. To accommodate the grinding requirements of valve seat sealing surfaces of different types and specifications of valves, a valve seat adapter plate with a corresponding mating hole layout can be provided according to the specific model of the valve to be ground. During installation, adapter 1 is reliably fixed to the flange using fasteners through the existing threaded holes on the valve seat flange. Adapter 1 serves as a standardized mechanical interface between the grinding device and different valves. By replacing the pre-made adapter 1 for different valve models, this grinding device can be quickly adapted to various valve specifications, significantly improving the equipment's versatility and the efficiency of field applications.

[0028] The drive slide 2 provides the driving capability for the grinding assembly 3 and welding assembly 4 to move and position in space, and can specifically adopt an existing three-axis drive slide structure. This three-axis drive slide includes a transverse adjustment electric slide, a vertical adjustment electric slide, and a longitudinal adjustment electric slide. The transverse adjustment electric slide enables remote electric fine-tuning of the position of the grinding head 33, thereby assisting in precise positioning. The vertical adjustment electric slide is mounted on the transverse adjustment electric slide via a slide adapter plate and is used for remote electric fine-tuning of the height position of the grinding head 33. The longitudinal adjustment electric slide is fixed to the vertical adjustment electric slide via another slide adapter plate, and its function is to adjust the distance from the grinding head 33 to the surface to be ground, and to achieve automatic feed control of the grinding amount during the grinding process. The grinding assembly 3 and welding assembly 4 as a whole can be securely mounted to the end of the longitudinal adjustment electric slide using a quick-locking wrench. Through the coordinated movement of the three electric slides in the horizontal, vertical and longitudinal directions, the grinding component 3 and the welding component 4 can be precisely controlled in three-dimensional coordinates, ensuring that they can accurately reach and be positioned in the working area, thereby effectively guaranteeing the accessibility and accuracy of the processing.

[0029] Furthermore, a manually adjustable slide can be integrated into the three-axis drive slide. Specifically, a transverse electric slide is fixedly mounted on the manually adjustable slide with screws. Before precise positioning, a large-scale coarse adjustment can be performed using the manually adjustable slide to quickly move the grinding component 3 or welding component 4 to the vicinity of the target working area, followed by locking the manually adjustable slide in place. Then, a fine-tuning adjustment is performed using the three-axis drive system consisting of transverse, vertical, and longitudinal electric slides, ultimately achieving precise positioning and fit. This dual adjustment method, combining coarse and fine adjustments, ensures both positioning efficiency and final positioning accuracy, effectively improving the adaptability and ease of operation of the entire grinding device.

[0030] The grinding component 3 can extend into the valve seat to grind the defects on the sealing surface; the welding component 4 is used to melt and fill the ground depression with solder, so that the depression is filled.

[0031] like Figure 2 and Figure 3As shown in a specific embodiment of this application, the grinding assembly 3 mainly includes a mounting base 31, a grinding head extension 32, a grinding head 33, and a grinding head drive 34. The mounting base 31 can be reliably assembled with an external feeding device. Through the precision motion control system of the drive slide 2, the entire grinding assembly 3 is driven to perform position adjustments in multiple directions within three-dimensional space, ensuring that the grinding head 33 can be accurately positioned to the processing area of ​​the valve sealing surface. The grinding head extension 32 is mounted on the mounting base 31, and its first end can extend axially to a preset target working length to adapt to different depth processing scenarios and narrow space operation requirements. Its maximum extension should be able to cover the repair range of internal defects in the valve base. The grinding head 33 is mounted on the first end of the grinding head extension 32 and enters or exits the target working position as the grinding head extension 32 moves, realizing the grinding processing of the confined surface of the valve sealing surface and other internal surfaces. The grinding head drive 34 is located at the second end of the grinding head extension 32 and is drivenly connected to the grinding head 33 to provide the power required for cutting or grinding to the grinding head 33.

[0032] like Figure 2 and Figure 3 As shown in a specific embodiment of this application, the mounting base 31 includes a clamping seat 311, which has a mounting hole for the grinding head extension 32 to pass through. The clamping seat 311 facilitates the quick assembly, disassembly, and position adjustment of the grinding head extension 32. The clamping seat 311 includes multiple clamping segments arranged circumferentially along the mounting hole, and fasteners 3111 for controlling the opening and closing state of each clamping segment. When a fastening force is applied to each clamping segment by the fasteners 3111, the clamping segments move closer together and clamp the grinding head extension 32 into the mounting hole, thereby ensuring a stable connection between the grinding head extension 32 and the mounting base 31, preventing relative displacement during operation, and ensuring the accuracy and reliability of the grinding action. When it is necessary to adjust the position of the grinding head extension 32, the clamping segments can be loosened by adjusting the fasteners 3111. At this time, the grinding head extension 32 can move freely in the axial direction of the mounting hole, thereby achieving flexible adjustment of the axial position to meet the requirements of different target working positions.

[0033] like Figure 2 and Figure 3As shown, in one specific embodiment of this application, a guide and limiting structure is provided between the clamping base 311 and the grinding head extension 32. Specifically, a limiting protrusion 3112 is provided on one of the clamping base 311 and the grinding head extension 32, and a limiting groove 321 is formed on the other. The extending direction of the limiting groove 321 is configured to be parallel to the axial direction of the mounting hole. When the grinding head extension 32 is inserted into the mounting hole of the clamping base 311, the limiting protrusion 3112 extends into and engages with the limiting groove 321 accordingly. Through the engagement of the protrusion and the groove, the movement trajectory of the grinding head extension 32 within the mounting hole is effectively constrained to linear movement only along the axial direction of the mounting hole, while also reliably preventing the grinding head extension 32 from rotating circumferentially around its own axis. While allowing the axial position adjustment of the grinding head extension 32 to adapt to different working depths, it ensures the stability of its circumferential orientation, thereby ensuring that the grinding head 33 installed at the end of the grinding head extension 32 has a definite posture and direction during operation, which is conducive to improving grinding accuracy and operational controllability.

[0034] In one specific embodiment of this application, the grinding assembly 3 further includes a transmission component, specifically a flexible shaft. This transmission component employs a flexible shaft structure. One end of the flexible shaft is connected to the drive output end of the grinding head drive 34, and the other end is connected to the drive input end of the grinding head 33. Through the flexible transmission characteristics of the flexible shaft, the rotational power generated by the grinding head drive 34 can be effectively transmitted to the grinding head 33, thereby driving the grinding head 33 to perform rotary grinding operations. This transmission method can flexibly adapt to different spatial layout requirements, achieving both coaxial transmission between the grinding head drive 34 and the grinding head 33, and reliable power transmission even when their axes are at a certain angle, effectively overcoming the limitations imposed by the limited internal space of the valve on equipment arrangement.

[0035] In one specific embodiment of this application, the grinding head extension 32 is specifically a hollow tube with a through-cavity inside. The aforementioned transmission component, i.e., the flexible shaft, is housed and arranged inside the cavity of the hollow tube. Through this transmission component that penetrates the cavity, the grinding head 33 and the grinding head drive component 34 are effectively connected, thus forming a complete power transmission chain. The grinding head drive component 34 can specifically be a hoisting grinder, while the grinding head 33 can specifically be a right-angle grinding head. This configuration allows the hoisting grinder, which serves as the power source, to be located at a remote position, and its output power is transmitted to the right-angle grinding head at the front end through the transmission component located in the cavity of the grinding head extension 32, driving it to perform grinding operations. This design, which separates the drive component from the execution component and connects them through the transmission component, can significantly reduce the structural size of the right-angle grinding head portion that is directly involved in the grinding operation at the end of the grinding head extension 32, making it more compact. This allows it to better adapt to and penetrate working conditions with extremely limited operating space, such as valve sealing surfaces, effectively meeting the needs of grinding processing in confined spaces.

[0036] In one specific embodiment of this application, the output end of the right-angle grinding head can be equipped with two different types of grinding heads, namely a ball grinding head and a surface grinding wheel, according to different grinding process requirements. When it is necessary to remove the original defects on the valve sealing surface, the ball grinding head can be installed on the right-angle grinding head, and its spherical shape can be used to facilitate targeted grinding of local defects such as cracks. After the defective area is repaired by welding, the surface grinding wheel needs to be installed on the right-angle grinding head to grind the protrusions generated by the welding to make it flat with the surrounding original sealing surface. In order to accurately control the grinding depth and ensure flatness during the grinding process, a hard limiting device can also be used. The hard limiting device has a slot structure that can be locked onto the right-angle grinding head and reliably fixed to the right-angle grinding head by three set screws. When installing the hard limiting device, its end face position needs to be adjusted so that it is coplanar with the end face of the installed surface grinding wheel. During the grinding operation, the end face of the hard limiter will contact and slide with the original sealing surface to be ground as a reference plane, thereby limiting the feed depth of the surface grinding wheel and ensuring that the weld repair area is ground to be flush with the original sealing surface, effectively guaranteeing the overall flatness after repair.

[0037] like Figure 2 and Figure 3As shown, in a specific embodiment of this application, the mounting base 31 further includes a mounting base 312, a slide 313, and a slide limiting member 314. The mounting base 312 is used to achieve a fixed connection with an external feed device, serving as the mounting base for the entire grinding assembly 3 on the external feed device. The slide 313 is slidably connected to the mounting base 312, and the grinding head extension 32 is fixedly mounted on the slide 313. The slide limiting member 314 is disposed on the mounting base 312, and its position can be adjusted as needed. When the slide limiting member 314 is set in a certain position, the slide 313 can move closer to or further away from the slide limiting member 314, and the slide limiting member 314 can apply a pushing force to the slide 313, thereby pushing the slide 313 to move along a predetermined feed direction. The movement of the slide 313 drives the grinding head extension 32 mounted thereon and the grinding head 33 located at the end of the grinding head extension 32 to move synchronously along the feed direction, thereby achieving precise control of the feed amount of the grinding head 33.

[0038] The mounting base 31 further integrates a limit sensor 315 and a sliding buffer to improve the accuracy and smoothness of feed control. One end of the sliding buffer is connected to the slide limiter 314, and the other end is connected to the slide 313. This buffer provides a cushioning effect during the movement of the slide 313, reducing the impact that may occur when the slide 313 contacts the slide limiter 314, ensuring smooth movement. The limit sensor 315 is configured to detect the relative distance between the slide 313 and the slide limiter 314 in real time. When the distance decreases to a preset threshold, the limit sensor 315 is triggered and generates a signal. This signal can be used to control the drive source to stop working or trigger the braking mechanism, thereby causing the slide 313 to stop moving immediately in the feed direction, effectively preventing the slide 313 from excessively advancing and colliding, and achieving precise end-point limit protection for the feed stroke.

[0039] like Figure 2 and Figure 3As shown in a specific embodiment of this application, the mounting base 31 further includes an angle adjustment seat 316, which is used to precisely adjust the angle of the axis of the grinding head extension 32 relative to the vertical direction. The angle adjustment seat 316 includes a fixed seat 3161 and a swing seat 3162, wherein the fixed seat 3161 is fixedly mounted on the slide 313, and the swing seat 3162 is rotatably connected to the fixed seat 3161 via a rotating shaft, so that the swing seat 3162 can swing relative to the fixed seat 3161 within a certain angle range. To achieve reliable fixation of the angle after swinging and facilitate precise fine-tuning, a worm gear mechanism is provided between the fixed seat 3161 and the swing seat 3162. By operating the worm, the worm gear can be driven to rotate the swing seat 3162 at a certain angle, and self-locking fixation can be achieved at any desired angle. The grinding head extension 32 is finally mounted on the swing seat 3162, so that its axial direction can be adjusted together with the swing seat 3162. To facilitate observation and precise setting of angle values, a pointer is provided on the fixed base 3161, and an angle scale is provided on the swing base 3162. The pointer and the scale work together to intuitively read the real-time angle of the current grinding head extension 32.

[0040] like Figure 2 and Figure 3 As shown in a specific embodiment of this application, to further enhance the adaptability and ease of installation, an adapter is provided between the swing seat 3162 and the grinding head extension 32. This adapter has a C-shaped structure; one end is fixedly connected to the swing seat 3162 by screws, and the other end is detachably connected to the clamping seat 311 via a fastening handle. The grinding head extension 32 is mounted on the clamping seat 311 as described above. This C-shaped adapter provides a stable and quick-release connection between the swing seat 3162 and the clamping seat 311, allowing the grinding head extension 32 and its clamping seat 311 to function as a single module, easily installed or removed from the angle adjustment seat 316, facilitating maintenance or replacement of grinding head extensions 32 of different specifications.

[0041] like Figure 4As shown, in one specific embodiment of this application, the welding assembly 4 includes a welding torch holder, a welding torch, and a wire feeding assembly. When the grinding assembly 3 is replaced with the welding assembly 4, the clamping base 311 is removed from the adapter by rotating the fastening handle, and the welding torch holder is installed instead. The welding torch holder is fixedly installed on the movable end of the drive slide 2 and can move and be positioned with the movement of the drive slide 2. The welding torch and the wire feeding assembly are both integrated and installed on the welding torch holder. The wire feeding assembly is used to continuously and stably feed the welding wire to the welding position during the welding process, while the welding torch is used to perform the welding operation. By driving the welding torch holder and the welding torch and wire feeding assembly on it to move in coordination by the drive slide 2, the repair welding operation can be automated or semi-automated, which is beneficial to improving the accuracy and efficiency of the repair operation.

[0042] This application also provides a method for online repair of valve sealing surface defects. The method first involves partially disassembling the online valve to be repaired until the defective valve seat sealing surface is fully exposed. Then, an adapter 1 and a drive slide 2 are installed on the valve seat. Next, using the grinding assembly 3 of the valve sealing surface repair device described in the previous embodiment, and controlled by the drive slide 2, the grinding head 33 of the grinding assembly 3 is driven to extend through the valve cavity channel on the valve seat to the valve seat sealing surface, grinding away the defective area on the valve seat sealing surface.

[0043] After grinding is completed, the grinding assembly 3 is removed from the drive slide 2 and replaced with the welding assembly 4 in the aforementioned embodiment. The welding torch of the welding assembly 4 extends into the valve seat sealing surface through the valve cavity channel on the valve seat, and the welding assembly 4 performs repair welding at the ground area. The welding assembly 4 performs repair welding in the ground area to fill the grinding marks and make the weld surface slightly higher than the original valve seat sealing surface of the unground area.

[0044] Next, welding assembly 4 was replaced again, and grinding assembly 3 was reinstalled. Grinding assembly 3 was used to grind the weld surface protruding from the valve seat sealing surface until it was flush with the surrounding sealing surface. Finally, a blue oil test was performed on the repaired sealing surface to verify its sealing performance. After the test was passed, the previously disassembled parts of the valve were reinstalled into the valve seat, and the overall performance of the valve was tested. Once it was confirmed to be qualified, the normal operation of the nuclear power system could be restored.

[0045] This repair method eliminates the need to replace the entire valve or valve seat, thus saving direct costs associated with spare parts procurement. Secondly, it significantly reduces project time by avoiding complex procedures such as cutting pipes or valve seats and assembling and welding new components. Thirdly, high-precision grinding control enables accurate grinding of weld allowances, greatly reducing the workload of subsequent grinding of the valve seat sealing surface and further saving project time. Most importantly, the drive slide 2 supports remote operation, allowing operators to stay away from radioactive areas. This not only effectively reduces industrial safety risks but also significantly reduces the radiation dose received by personnel in the radiation field.

[0046] In one specific embodiment of this application, the welding assembly 4 requires appropriate heat treatment control before and after the repair welding operation. Specifically, before performing the repair welding operation, the grinding marks on the valve seat sealing surface are preheated to the required preheating temperature of approximately 250°C-350°C. This preheating helps reduce thermal stress during subsequent welding and prevents cracking of the hard alloy layer. After the repair welding operation is completed, heating is not stopped immediately, but heat is continued to be applied to the weld area for post-heating, with the temperature range controlled between 250°C and 400°C and the holding time not less than 3 hours. Subsequently, it is gradually cooled to room temperature. This gradual cooling post-heating process effectively promotes the homogenization of the weld metal structure, further releases and reduces residual welding stress, thereby significantly improving the material properties and structural integrity of the repaired area and ensuring that the repaired valve sealing surface has a long-term reliable sealing capability.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A valve sealing surface repair device, characterized in that, include: The adapter (1) is installed on the valve seat to be repaired. The adapter (1) has a mating hole that corresponds to the mounting hole on the valve seat to be repaired. The drive slide (2) has its fixed end connected to the adapter (1). A grinding assembly (3) is installed on the movable end of the drive slide (2). The drive slide (2) is used to drive the grinding assembly (3) to move so as to grind the working position. Alternatively, a welding assembly (4) may be installed at the movable end of the drive slide (2), the drive slide (2) being used to drive the welding assembly (4) to move in order to perform fusion welding on the working position.

2. The valve sealing surface repair device as described in claim 1, characterized in that, The polishing component (3) includes: Mounting base (31) is mounted on the movable end of the drive slide (2); A grinding head extension (32) is mounted on the mounting base (31), and the first end of the grinding head extension (32) can extend to the target working length; A grinding head (33) is installed at the first end of the grinding head extension (32), and the grinding head extension (32) is used to drive the grinding head (33) to extend into the target working position; A grinding head drive (34) is installed at the second end of the grinding head extension (32) and is driven to connect with the grinding head (33) to drive the grinding head (33) to work.

3. The valve sealing surface repair device as described in claim 2, characterized in that, The mounting base (31) includes a clamping seat (311) having a mounting hole, the clamping seat (311) including clamping segments arranged circumferentially around the mounting hole and fasteners (3111) for tightening or loosening each of the clamping segments. The grinding head extension (32) is inserted into the mounting hole. When the fastener (3111) is used to fasten each of the clamping segments, the grinding head extension (32) is clamped on the clamping seat (311). When the fastener (3111) loosens each of the clamping segments, the grinding head extension (32) can move in the mounting hole along the axial direction of the mounting hole.

4. The valve sealing surface repair device as described in claim 3, characterized in that, A limiting protrusion (3112) is provided on one of the clamping base (311) and the grinding head extension (32), and a limiting groove (321) is provided on the other of the clamping base (311) and the grinding head extension (32). The extending direction of the limiting groove (321) is parallel to the axial direction of the mounting hole. When the grinding head extension (32) is inserted into the mounting hole, the limiting protrusion (3112) extends into the limiting groove (321) to restrict the grinding head extension (32) from moving along the axial direction in the mounting hole.

5. The valve sealing surface repair device according to any one of claims 1 to 4, characterized in that, The mounting base (31) includes: Mounting base plate (312) is mounted on the movable end of the drive slide (2); A slide (313) is slidably connected to the mounting base (312), and the grinding head extension (32) is mounted on the slide (313); A slide block limiting member (314) is mounted on the mounting base plate (312); the slide block (313) can move closer to or further away from the slide block limiting member (314), and the slide block limiting member (314) is used to push the slide block (313) to move along the feed direction; The sliding buffer is connected at one end to the slide seat limiting member (314) and at the other end to the slide seat (313). The limit sensor (315) is used to detect the distance between the slide (313) and the slide limit member (314). When the distance between the slide (313) and the slide limit member (314) is less than a threshold, the limit sensor (315) is triggered to stop the slide (313) from moving along the feed direction.

6. The valve sealing surface repair device as described in claim 5, characterized in that, The mounting base (31) also includes an angle adjustment seat (316) for adjusting the axial angle of the grinding head extension (32), the angle adjustment seat (316) including a fixed seat (3161) and a swing seat (3162). The fixed seat (3161) is mounted on the slide (313), the swing seat (3162) is rotatably connected to the fixed seat (3161), and the relative angle between the swing seat (3162) and the fixed seat (3161) can be fixed. The grinding head extension (32) is mounted on the swing seat (3162).

7. The valve sealing surface repair device as described in claim 1, characterized in that, The welding assembly (4) includes a welding torch holder, a welding torch, and a wire feeding assembly. The welding torch holder is installed on the movable end of the drive slide (2). The welding torch and the wire feeding assembly are both installed on the welding torch holder. The wire feeding assembly is used to feed welding wire to the welding position.

8. A method for repairing defects on the valve sealing surface online, characterized in that, Includes the following steps: Disassemble the online valve to expose the defective valve seat sealing surface; The defects on the valve seat sealing surface are removed by the grinding component (3) of the valve sealing surface repair device as described in any one of claims 1 to 7, and then the welding component (4) of the valve sealing surface repair device as described in claim 1 or 7 is used to weld at the grinding point to fill the grinding marks and make the weld surface protrude from the valve seat sealing surface of the ungrinded area; the weld surface protruding from the valve seat sealing surface is ground again by the grinding component (3) until it is flush with the valve seat sealing surface. Reassemble the disassembled valve components onto the valve seat.

9. The method for repairing defects on the valve sealing surface online as described in claim 8, characterized in that, The grinding assembly (3) is installed on the disassembled valve seat. The grinding head (33) of the grinding assembly (3) extends into the valve seat sealing surface through the valve cavity channel on the valve seat. After the defects on the valve seat sealing surface are ground off, the grinding assembly (3) is replaced by the welding assembly (4). The welding gun of the welding assembly (4) extends into the valve seat sealing surface through the valve cavity channel on the valve seat, and the welding assembly (4) repairs the welding at the grinding point.

10. The method for repairing defects on the valve sealing surface online as described in claim 9, characterized in that, Before welding, the welding assembly (4) heats the grinding marks to a preheating temperature; after welding, it continues to heat the weld and gradually reduces the temperature of the weld.

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