A valve face repair method and apparatus

Abstract

The application relates to the technical field of valve repairing, in particular to a valve sealing surface repairing method and device, which comprises the following steps: turning the surface of a valve core and a valve seat; detecting whether the valve core and the valve seat are damaged by using PT nondestructive testing, and if the valve core and the valve seat are damaged, the damaged parts are continuously turned; performing surfacing treatment on the turned parts; detecting whether the surfacing parts are damaged; turning the surfacing parts; adopting Stellite alloy as cladding material to perform laser cladding; after the laser cladding, detecting whether the valve core and the valve seat have pores, sand eyes, cracks and uncombined areas by using PT nondestructive testing; finely grinding the surface of the valve core and the valve seat; and grinding the sealing surface by using a grinding device. After the valve core and the valve seat are repaired, the valve core and the valve seat have good wear resistance, heat resistance and corrosion resistance, the strength of the combined surface is high, and the service life is long.

Description

Technical Field

[0001] This invention relates to the field of valve repair technology, and in particular to a method and apparatus for repairing valve sealing surfaces. Background Technology

[0002] In heat energy transmission systems, heat energy is mainly transmitted and controlled through pipelines and valves. However, during operation, especially under the high pressure of the system pipelines, valves are tightened to the maximum to ensure that no parts of the valve leak. In addition, the huge pressure of the system itself causes high sealing force between valve parts. Over a long period of time, this increases the force required to open and close the valve, making it more difficult to open and close.

[0003] When minor damage to the valve core and seat is found during valve maintenance, in order to reduce maintenance costs and improve economic efficiency, the valve is usually repaired. The valve core and seat are ground, exposed to light, and re-threaded to meet the usage requirements.

[0004] During valve maintenance in power plants, to improve energy efficiency, large defects on the valve seat mating surface are typically addressed. However, after repeated grinding, the hard alloy mating surface is significantly reduced, decreasing the hardness of the valve mating surface and drastically shortening its service life. This prevents effective system-level control during equipment startup, hindering the maximization of efficiency. Ultimately, this leads to maintenance failure and valve scrapping.

[0005] Furthermore, the smoothness of the mating surfaces of valve cores is usually achieved using a milling machine, while valve seats cannot generally be milled and must be manually ground. During manual grinding, the immaturity of the technology and the unevenness of the force result in uneven valve seats, which seriously affects the performance of the valve and poses certain safety hazards to the equipment system.

[0006] Therefore, a method and apparatus for repairing valve sealing surfaces are proposed. Summary of the Invention

[0007] In view of the problems existing in the above or prior art, the present invention is proposed.

[0008] Therefore, the purpose of this invention is to provide a method and apparatus for repairing valve sealing surfaces.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a valve sealing surface repair method, comprising: turning the surfaces of the valve core and valve seat; using PT non-destructive testing to detect whether the valve core and valve seat are damaged; if damage exists, continuing to turn off the damaged parts; performing weld overlay treatment on the turned parts; detecting whether the weld overlay parts are damaged; turning the weld overlay parts; using Stellite alloy as the cladding material for laser cladding; after laser cladding, using PT non-destructive testing to detect whether the valve core and valve seat have pores, pinholes, cracks, and unbonded areas; fine grinding the surfaces of the valve core and valve seat; and grinding the sealing surface using a grinding device.

[0010] In a preferred embodiment of the valve sealing surface repair method of the present invention, the material used for welding is Stellite6 alloy.

[0011] As a preferred embodiment of the valve sealing surface repair method of the present invention, the thickness of the valve core and valve seat sealing surfaces after repair is increased by 2mm compared with that before repair.

[0012] The beneficial effects of the valve sealing surface repair method of the present invention are as follows: the valve core and valve seat of the present invention have good wear resistance, heat resistance and corrosion resistance after repair, the joint surface has high strength and long service life.

[0013] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a grinding device, comprising: a support mechanism including a mounting base and a connecting rod disposed on the mounting base; an expansion mechanism including a housing and limiting plates disposed at both ends of the housing, a push rod slidably disposed on the limiting plates, and a connecting rod rotatably disposed on the push rod, one end of the connecting rod being rotatably connected to a connecting seat, and a mounting plate disposed on the push rod; a first locking mechanism including a support ring rotatably disposed on the housing and a snap-fit ​​frame slidably disposed within the support ring, and a return spring disposed on the snap-fit ​​frame; one end of the connecting seat and one end of the connecting rod being fixedly connected, and the mounting plate being used to mount a grinding block; the connecting rod having a smooth surface, a locking groove, a fitting surface within the locking groove, and an inclined surface on the locking groove.

[0014] In a preferred embodiment of the grinding device of the present invention, the snap-fit ​​frame includes a connecting frame slidably disposed within the support ring, and an arc-shaped plate disposed on the connecting frame. The arc-shaped plate has a snap-fit ​​plate. The device also includes a guide rod disposed on the connecting frame, and a return spring sleeved on the outer wall of the guide rod. A counterweight sleeve is provided on the outer wall of the guide rod. In another preferred embodiment of the grinding device of the present invention, a buffer mechanism is further included. The buffer mechanism includes an upper support plate and a support spring disposed on the upper support plate. One end of the support spring has a lower support plate. The lower support plate and the support ring are rotatably connected. A sliding cavity is provided within the mounting base, and a sliding block is provided at one end of the connecting rod. The sliding block is slidably disposed within the sliding cavity.

[0015] As a preferred embodiment of the grinding device of the present invention, it further includes a second locking mechanism, which has the same structure as the first locking mechanism; the second locking mechanism is rotatably connected to the mounting base.

[0016] As a preferred embodiment of the grinding device of the present invention, it further includes: an adjustment mechanism, the adjustment mechanism including a sliding sleeve slidably disposed on the outer wall of the mounting base, and a vertical groove and an annular groove disposed on the inner wall of the sliding sleeve, and a push spring disposed at the end of the sliding sleeve; a positioning block is provided on the outer wall of the mounting base; a snap-fit ​​block is provided on the outer wall of the support ring; the first locking mechanism and the second locking mechanism are arranged vertically.

[0017] In a preferred embodiment of the grinding device of the present invention, it further includes an adjusting screw, which is threaded through the limiting plate and the connecting seat.

[0018] In a preferred embodiment of the grinding device of the present invention, the limiting plate is provided with a limiting groove, the end of the push rod is provided with an upper slider, and the end of the push rod is provided with a lower slider.

[0019] The beneficial effects of the grinding device of the present invention are as follows: by adjusting the position of the mounting plate, the grinding diameter can be changed, so that the device can grind both the door core sealing surface and the door seat sealing surface. Moreover, the grinding is circumferential, which improves the grinding efficiency and flatness, thereby improving the quality of the door core and door seat after grinding. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the grinding device.

[0022] Figure 2 This is a schematic diagram of the internal structure of the sliding sleeve of the grinding device.

[0023] Figure 3 This is a schematic cross-sectional view of the grinding device.

[0024] Figure 4 This is a schematic diagram of the first locking mechanism and the second locking mechanism of the grinding device.

[0025] Figure 5 This is a schematic diagram of the internal structure of the first and second locking mechanisms of the grinding device.

[0026] Figure 6 This is a schematic diagram of the clamping frame of the grinding device.

[0027] In the diagram: 100, Support mechanism; 101, Mounting seat; 101a, Sliding cavity; 101b, Positioning block; 102, Connecting rod; 102a, Sliding block; 102b, Smooth surface; 102c, Locking groove; 102c-1, Fitting surface; 102c-2, Inclined surface; 200, Expansion mechanism; 201, Housing; 202, Limiting plate; 202a, Limiting groove; 203, Push rod; 203a, Upper slider; 203b, Lower slider; 204, Connecting rod; 205, Connecting seat; 206, Mounting plate; 300, ... A locking mechanism; 301, support ring; 302, snap-fit ​​frame; 302a, connecting frame; 302b, arc plate; 302c, snap-fit ​​plate; 302d, guide rod; 302e, counterweight sleeve; 303, return spring; 304, snap-fit ​​block; 400, buffer mechanism; 401, upper support plate; 402, support spring; 403, lower support plate; 500, second locking mechanism; 600, adjusting mechanism; 601, sliding sleeve; 602, vertical groove; 603, annular groove; 604, push spring; 700, adjusting screw. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0031] Example 1 is the first embodiment of the present invention. This embodiment provides a method for repairing valve sealing surfaces, including turning the surfaces of the valve core and valve seat; in this embodiment, the worn and damaged parts of the valve core and valve seat surfaces are turned.

[0032] The door core and door seat are inspected for damage using PT non-destructive testing. If damage is found, the damaged parts are machined off. In this embodiment, by performing multiple inspections and machining, damage inside the door core and door seat is avoided, which can extend the service life of the repaired door core and door seat.

[0033] The machined parts are then welded together.

[0034] Check for damage to the weld overlay area; in this embodiment, if damage is detected, the damaged area needs to be machined and the weld overlay re-performed.

[0035] The weld overlay area is machined; in this embodiment, the weld overlay area is basically machined to make its dimensions and specifications meet the requirements.

[0036] Stellite alloy is used as the cladding material for laser cladding. In this embodiment, Stellite alloy has excellent wear resistance and toughness, and can be used as the working layer to improve service life.

[0037] After laser cladding, PT non-destructive testing is used to check whether there are air holes, pinholes, cracks, and unbonded areas on the door core and door seat. In this embodiment, if air holes, pinholes, cracks, and unbonded areas are detected, cladding needs to be repeated to ensure quality.

[0038] The surfaces of the door core and door seat are finely ground; this reduces wear during use and improves the fit between the door core and door seat.

[0039] The sealing surface is ground using a grinding device. In this embodiment, the sealing performance is improved by further grinding the sealing surface.

[0040] Specifically, the material used for welding is Stellite6 alloy. In this embodiment, the chemical composition of Stellite6 alloy is similar to that of Stellite alloy, which can improve the bonding effect of welding and cladding, and maintain good corrosion resistance, heat resistance and wear resistance.

[0041] Furthermore, the thickness of the sealing surface of the repaired door core and door seat is increased by 2mm compared with that before the repair. In this embodiment, increasing the thickness of the sealing surface of the repaired door core and door seat can improve the buffering effect of the instantaneous surge of steam and improve the sealing performance, making it convenient for reuse and easy to repair again after being blown away.

[0042] For surfacing, manual tungsten inert gas (TIG) welding is used. Suitable welding wires include ERCoCr-A. For cobalt-based alloy welding electrodes, DC reverse polarity is used, while DC positive polarity is used for TIG welding. To prevent cracking, preheating is necessary before surfacing, and slow cooling is required after welding or stress relief treatment. Cobalt-based alloy surfacing is generally put into operation in the welded state. For large-area surfacing, stress relief treatment should be performed, or a post-heat treatment at the same temperature as preheating (approximately 350–450℃) should be used.

[0043] Example 2, refer to Figures 1-6 This is the second embodiment of the present invention. Unlike the previous embodiment, this embodiment provides a grinding device for grinding the sealing surfaces of door cores and door seats. It includes a support mechanism 100, which includes a mounting base 101 and a connecting rod 102 disposed on the mounting base 101. In this embodiment, the mounting base 101 is used to mount the grinding device, and the device can be mounted on the drive shaft of a rotatable device through the mounting base 101.

[0044] The expansion mechanism 200 includes a housing 201 and limiting plates 202 disposed at both ends of the housing 201. A push rod 203 is slidably disposed on the limiting plate 202. The mechanism also includes a connecting rod 204 rotatably disposed on the push rod 203. One end of the connecting rod 204 is rotatably connected to a connecting seat 205. A mounting plate 206 is disposed on the push rod 203. In this embodiment, four push rods 203 are provided and are distributed in an equally spaced circular pattern on the limiting plate 202. Each push rod 203 is provided with two parallel connecting rods 204. After the push rod 203 and the connecting seat 205 are connected by the parallel connecting rods 204, the push rod 203 will generate parallel expansion or contraction movements when the connecting seat 205 moves.

[0045] The first locking mechanism 300 includes a support ring 301 rotatably mounted on the housing 201, and a snap-fit ​​frame 302 slidably mounted within the support ring 301. It also includes a return spring 303 mounted on the snap-fit ​​frame 302. In this embodiment, two symmetrically arranged snap-fit ​​frames 302 are slidably mounted within each support ring 301. The return spring 303 allows the two snap-fit ​​frames 302 to have a tendency to move away from each other.

[0046] One end of the connecting seat 205 is fixedly connected to one end of the connecting rod 102, and the mounting plate 206 is used to install the grinding block. In this embodiment, by controlling the positional relationship between the connecting seat 205 and the limiting plate 202, the push rod 203 can be expanded or contracted, which in turn allows the mounting plate 206 to expand or contract. After the grinding block is installed on the mounting plate 206, the sealing surfaces of the door core and door seat are ground by the grinding block. Since the door core and door seat are matched with each other, but the diameter of the parts to be ground on their sealing end faces is different, the grinding radius needs to be changed during use. Furthermore, since the parts to be ground on the door core and door seat are located in grooves or protrude from the grinding end face, conventional grinding methods cannot be used. The movement path of the grinding block is circular. By changing the diameter of the circle, it can be applied to the grinding of the sealing surfaces of the door core and door seat.

[0047] The connecting rod 102 has a smooth surface 102b and a locking groove 102c. The locking groove 102c has a mating surface 102c-1 and a slope 102c-2. In this embodiment, the smooth surface 102b and the mating surface 102c-1 are perpendicular to each other, and the width of the smooth surface 102b is the same as the width of the mating surface 102c-1. The slope 102c-2 facilitates the snapping between the snapping frame 302 and the locking groove 102c.

[0048] Specifically, the snap-fit ​​frame 302 includes a connecting frame 302a slidably disposed within the support ring 301, and an arc-shaped plate 302b disposed on the connecting frame 302a. The arc-shaped plate 302b is provided with a snap-fit ​​plate 302c. It also includes a guide rod 302d disposed on the connecting frame 302a, and a return spring 303 is sleeved on the outer wall of the guide rod 302d. In this embodiment, two arc-shaped plates 302b are connected to the connecting frame 302a. The two arc-shaped plates 302b are connected together to the snap-fit ​​plate 302c. The snap-fit ​​plate 302c is used to snap into the locking groove 102c. The return spring 303 can push the guide rod 302d so that the snap-fit ​​plate 302c is snapped into the locking groove 102c.

[0049] Preferably, the outer wall of the guide rod 302d is provided with a counterweight sleeve 302e. In this embodiment, the counterweight sleeve 302e enables the grinding device to engage the locking plate 302c and the locking groove 102c more tightly through centrifugal force when rotating at high speed.

[0050] Furthermore, the limiting plate 202 is provided with a limiting groove 202a, the end of the push rod 203 is provided with an upper slider 203a, and the end of the push rod 203 is provided with a lower slider 203b. In this embodiment, the upper slider 203a is slidably connected to the upper limiting groove 202a, and the lower slider 203b is slidably connected to the lower limiting groove 202a, which can improve the stability of the push rod 203. The mounting plate 206 is connected to the push rod 203 through the lower slider 203b.

[0051] The rest of the structure is the same as in Example 1.

[0052] In use, adjust the position of the mounting plate 206 according to the grinding diameter, rotate the support ring 301, and the snap-fit ​​plate 302c will slide due to the contact surface 102c-1 when rotating, so that the return spring 303 is compressed until the connecting rod 102 rotates 90 degrees, and the snap-fit ​​plate 302c is attached to the smooth surface 102b. Under the elastic force of the return spring 303, the snap-fit ​​plate 302c will remain attached to the smooth surface 102b. At this time, the housing 201 can be pushed, so that the connecting seat 205 moves relative to the limiting plate 202, thereby controlling the push rod 203 to expand or contract, changing the grinding diameter. The setting of the arc plate 302b can facilitate the sliding of the snap-fit ​​frame 302 without contacting the connecting rod 102 when the snap-fit ​​plate 302c is attached to the smooth surface 102b.

[0053] After adjusting the grinding diameter, rotate the support ring 301 to make the snap plate 302c fit against the mating surface 102c-1. At this time, the snap plate 302c is locked in the locking groove 102c, and the housing 201 will not be able to move relative to the connecting rod 102. Therefore, the grinding diameter is constant. When the grinding device is performing high-speed rotation grinding, the first locking mechanism 300 can be kept rotating together by the elastic force of the return spring 303 during the initial rotation. The centrifugal force generated by the rotation will make the snap plate 302c fit more tightly against the mating surface 102c-1 to ensure that the first locking mechanism 300 will not lose its limit on the expansion mechanism 200 due to relative rotation between it and the connecting rod 102.

[0054] In summary, by adjusting the position of the mounting plate 206, the grinding diameter can be changed, allowing the device to grind both the door core sealing surface and the door seat sealing surface. Furthermore, the grinding is performed in a circular motion, which improves grinding efficiency and flatness, thereby enhancing the quality of the door core and door seat after grinding.

[0055] Example 3, referring to Figures 1-6This is the third embodiment of the present invention. Unlike the previous embodiment, it also includes a buffer mechanism 400. The buffer mechanism 400 includes an upper support plate 401 and a support spring 402 disposed on the upper support plate 401. One end of the support spring 402 is provided with a lower support plate 403. In this embodiment, the lower support plate 403 and the support ring 301 are rotatably connected, which facilitates the operator to rotate the first locking mechanism 300.

[0056] Specifically, the mounting base 101 is provided with a sliding cavity 101a, and one end of the connecting rod 102 is provided with a sliding block 102a. The sliding block 102a is slidably disposed in the sliding cavity 101a. In this embodiment, by setting the buffer mechanism 400, the grinding block can have a certain buffering capacity during grinding, and the applied pressure is more balanced, which can further improve the grinding effect.

[0057] Specifically, it also includes a second locking mechanism 500, which has the same structure as the first locking mechanism 300. In this embodiment, the second locking mechanism 500 is rotatably connected to the mounting base 101. By rotating the second locking mechanism 500, the sliding block 102a can be in a slidable state or in a non-slidable state.

[0058] In use, the locking mechanism 300 and the connecting rod 102 can be released, allowing the housing 201 to move. Therefore, under the elastic force of the support spring 402, the housing 201 will move away from the mounting base 101, causing the grinding blocks to move closer together. When the second locking mechanism 500 and the connecting rod 102 are locked, the sliding block 102a cannot slide. When the device rotates for grinding, it can expand or contract the grinding blocks according to the pressure applied to the grinding object, performing variable diameter grinding and changing the grinding area according to the pressure change.

[0059] Furthermore, it also includes an adjustment mechanism 600, which includes a sliding sleeve 601 slidably disposed on the outer wall of the mounting base 101, and a vertical groove 602 and an annular groove 603 disposed on the inner wall of the sliding sleeve 601, and a push spring 604 disposed at the end of the sliding sleeve 601; a positioning block 101b is provided on the outer wall of the mounting base 101; a snap-fit ​​block 304 is provided on the outer wall of the support ring 301; in this embodiment, both the positioning block 101b and the snap-fit ​​block 304 slide within the vertical groove 602, and the positioning block 101b can slide into the vertical groove 602.

[0060] Preferably, the first locking mechanism 300 and the second locking mechanism 500 are arranged vertically.

[0061] During use, the elastic force of the push spring 604 allows the sliding sleeve 601 to have a downward movement tendency. Therefore, the annular groove 603 can maintain a misaligned state with the positioning block 101b. During grinding, the vertical groove 602 connects with both the positioning block 101b and the snap-fit ​​block 304, which can prevent the rotation of the first locking mechanism 300 and the second locking mechanism 500, thus improving stability. When it is necessary to rotate the first locking mechanism 300 and the second locking mechanism 500, the sliding sleeve 601 can be pushed up to align the annular groove 603 with the positioning block 101b. At this time, the sliding sleeve 601 can rotate, and when the sliding sleeve 601 rotates, it will drive the first locking mechanism 300 and the second locking mechanism 500 to rotate together.

[0062] Since the first locking mechanism 300 and the second locking mechanism 500 are arranged vertically, during use, they will be engaged with the connecting rod 102 only through the first locking mechanism 300 or the second locking mechanism 500. When the first locking mechanism 300 is not engaged, variable diameter grinding can be performed. When the second locking mechanism 500 is not engaged, the diameter of the grinding block will not change, and the elastic force of the supporting spring 402 in both states can make the grinding block apply balanced pressure.

[0063] Preferably, it also includes an adjusting screw 700, which is threaded through the limiting plate 202 and the connecting seat 205. In this embodiment, the minimum shrinkage diameter of the grinding block can be controlled by adjusting the depth of the threaded connection of the adjusting screw 700.

[0064] The rest of the structure is the same as in Example 2.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A grinding apparatus for grinding the valve core and valve seat sealing surfaces, characterized in that: include, The support mechanism (100) includes a mounting base (101) and a connecting rod (102) disposed on the mounting base (101). An expansion mechanism (200) includes a housing (201) and limiting plates (202) at both ends of the housing (201). A push rod (203) is slidably provided on the limiting plate (202). The mechanism also includes a connecting rod (204) rotatably provided on the push rod (203). One end of the connecting rod (204) is rotatably connected to a connecting seat (205). A mounting plate (206) is provided on the push rod (203). The first locking mechanism (300) includes a support ring (301) rotatably disposed on the housing (201), and a snap-fit ​​frame (302) slidably disposed within the support ring (301), and also includes a return spring (303) disposed on the snap-fit ​​frame (302). One end of the connecting seat (205) is fixedly connected to one end of the connecting rod (102), and the mounting plate (206) is used to mount the grinding block; The connecting rod (102) is provided with a smooth surface (102b), the connecting rod (102) is provided with a locking groove (102c), the locking groove (102c) is provided with a fitting surface (102c-1), and the locking groove (102c) is provided with an inclined surface (102c-2). The snap-fit ​​frame (302) includes a connecting frame (302a) slidably disposed within the support ring (301), and an arc-shaped plate (302b) disposed on the connecting frame (302a). The arc-shaped plate (302b) is provided with a snap-fit ​​plate (302c). It also includes a guide rod (302d) disposed on the connecting frame (302a). The return spring (303) is sleeved on the outer wall of the guide rod (302d). The outer wall of the guide rod (302d) is provided with a counterweight sleeve (302e); The snap-fit ​​plate (302c) is used to snap into the locking slot (102c); It also includes an adjusting screw (700), which is threaded through the limiting plate (202) and the connecting seat (205); Adjust the position of the mounting plate (206) according to the grinding diameter, rotate the support ring (301), and the snap plate (302c) will slide when it is rotated due to the contact surface (102c-1), so that the return spring (303) is compressed until the connecting rod (102) rotates ninety degrees, and the snap plate (302c) is attached to the smooth surface (102b). Under the elastic force of the return spring (303), the snap plate (302c) will remain attached to the smooth surface (102b). At this time, the housing (201) can be pushed, so that the connecting seat (205) moves relative to the limiting plate (202), thereby controlling the push rod (203) to expand or contract and change the grinding diameter. After adjusting the grinding diameter, rotate the support ring (301) so that the snap plate (302c) fits onto the mating surface (102c-1). At this time, the snap plate (302c) is locked in the locking groove (102c), and the housing (201) will not be able to move relative to the connecting rod (102), and the grinding diameter is in a constant state.

2. The grinding apparatus as described in claim 1, characterized in that: It also includes a buffer mechanism (400), which includes an upper support plate (401) and a support spring (402) disposed on the upper support plate (401), and a lower support plate (403) is provided at one end of the support spring (402). The lower support plate (403) and the support ring (301) are rotatably connected; The mounting base (101) is provided with a sliding cavity (101a), and one end of the connecting rod (102) is provided with a sliding block (102a), which is slidably disposed in the sliding cavity (101a).

3. The grinding apparatus as described in claim 2, characterized in that: It also includes a second locking mechanism (500), which has the same structure as the first locking mechanism (300); The second locking mechanism (500) and the mounting base (101) are rotatably connected.

4. The grinding apparatus as described in claim 3, characterized in that: It also includes an adjustment mechanism (600), which includes a sliding sleeve (601) slidably disposed on the outer wall of the mounting base (101), and a vertical groove (602) and an annular groove (603) disposed on the inner wall of the sliding sleeve (601), and also includes a push spring (604) disposed at the end of the sliding sleeve (601). The mounting base (101) has a positioning block (101b) on its outer wall; The outer wall of the support ring (301) is provided with a snap-fit ​​block (304); The first locking mechanism (300) and the second locking mechanism (500) are arranged vertically.

5. The grinding apparatus according to any one of claims 1 to 4, characterized in that: The limiting plate (202) is provided with a limiting groove (202a), the end of the push rod (203) is provided with an upper slider (203a), and the end of the push rod (203) is provided with a lower slider (203b).

6. A method for repairing valve sealing surfaces, characterized in that: include, The surfaces of the door core and door seat are machined; Use PT non-destructive testing to check whether there is any damage to the door core and door seat. If damage is found, continue to machine away the damaged parts. The machined parts are then welded together. Inspect the weld overlay area for damage; The weld overlay area is machined. Stellite alloy was used as the cladding material for laser cladding. After laser cladding, PT non-destructive testing is used to check whether the door core and door seat have air holes, sand holes, cracks and unbonded areas; The surfaces of the door core and door seat are finely ground; The sealing surface is ground using the grinding apparatus described in any one of claims 1 to 5.

7. The valve sealing surface repair method as described in claim 6, characterized in that: The material used for welding is Stellite 6 alloy.

8. The valve sealing surface repair method as described in claim 7, characterized in that: The thickness of the door core and door seat sealing surface increased by 2mm after the repair.

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