Safety valve grinding apparatus and grinding method

Abstract

The embodiment of the present disclosure provides a safety valve grinding device and a grinding method, the safety valve comprises a valve seat and a valve core matched with each other, the valve seat comprises a first valve seat and a second valve seat arranged in the first valve seat in an extendable manner, the device comprises a guide sleeve, a support sleeve, a fastener and a grinding plate; the support sleeve is arranged on the grinding plate, the guide sleeve is sleeved in the support sleeve, the first end of the first valve seat is fixed to the first end of the guide sleeve, the second end of the first valve seat penetrates through the support sleeve and is in contact with the grinding plate; the fastener is inserted into the second end of the guide sleeve and is in abutment with the second valve seat, so that the extension amount of the second valve seat is adjusted, and the sealing surface of the first valve seat is flush with the sealing surface of the second valve seat; the grinding plate is used for synchronous grinding of the sealing surface of the valve seat when the guide sleeve rotates. The device solves the problem that the first valve seat and the second valve seat cannot be effectively fixed during grinding, and can achieve good grinding effect, high grinding stability and high grinding efficiency.

Description

TECHNICAL FIELD

[0001] The embodiment of the present disclosure belongs to the technical field of safety valve grinding tools, and particularly relates to a safety valve grinding device and a grinding method. BACKGROUND

[0002] The helium medium safety valve of the high-temperature gas cooled reactor is installed in a loop pressure relief system, which undertakes the protection function of the loop pressure boundary equipment. The helium safety valve is an important key equipment of the loop pressure relief system and performs the pressure relief function. The helium medium safety valve is an important pressure-bearing boundary equipment of the reactor loop, and the inner seal and outer seal requirements are very strict. The inner leakage and outer leakage of the safety valve will cause the leakage of the loop radioactive medium.

[0003] In order to ensure the sealing performance index of the safety valve, the loop pressure relief system helium safety valve uses a pilot safety valve with more reliable sealing performance. Compared with the spring safety valve, the pilot safety valve has higher sealing reliability, but its structure is complex, the number of sealing pairs is large, and the workload of maintenance and repair is large.

[0004] The helium medium safety valve adopts the pilot safety valve. The pilot valve part of the pilot safety valve is designed as a double-valve seat structure, and its flow channel and structure are called an upper three-way structure, as shown in Figure 1 The upper three-way structure includes a sleeve-shaped first valve seat 210 and a needle-shaped second valve seat 220. The valve core 230 is also divided into a valve core inner ring and a valve core outer ring. The valve core inner ring cooperates with the needle-shaped second valve seat 220, and the valve core outer ring cooperates with the sleeve-shaped first valve seat 210. The needle-shaped second valve seat 220 is configured with a metal bellows structure and can freely stretch and contract to realize adhesion and separation with the valve core.

[0005] The structure size of the upper three-way component is small. The diameter of the valve core 230 is only 9.5 mm, the diameter of the second valve seat 220 ring cooperating with it is only 6 mm, and the effective grinding amount of the sealing surface is only 0.5 mm. The sealing requirement of the upper three-way component is high. During the overhaul of the unit, the upper three-way component needs to be ground for repair to ensure the effective sealing of the upper three-way part. The second valve seat 220 in the upper three-way is an irregular structure and needs to be effectively fixed. The first valve seat 210 and the second valve seat 220 of the upper three-way need to be ground synchronously. The valve seat of the upper three-way is a slender structure, and direct manual grinding will cause the parts to fall during the grinding process, thereby affecting the grinding efficiency.

[0006] The effective grinding allowance of the safety valve is limited, and a special grinding process method needs to be configured. Through the effective grinding process method and the acceptance evaluation method, the number of rework is controlled.

[0007] In the prior art, the grinding of the safety valve mainly has the following problems:

[0008] 1) the parts cannot be effectively fixed during grinding, and the stability of grinding is poor;

[0009] 2) the grinding operation requires a higher skill level of the operator;

[0010] 3) the grinding process and the evaluation method of the grinding quality;

[0011] 4) the effective grinding amount is small, and the control of the grinding repair times is strict.

[0012] In view of the above problems, it is necessary to provide a safety valve grinding device and a grinding method which are reasonable in design and effective in solving the above problems. SUMMARY

[0013] The embodiments of the present disclosure aim to at least solve one of the technical problems existing in the prior art, and provide a safety valve grinding device and a grinding method.

[0014] An aspect of the embodiments of the present disclosure provides a safety valve grinding device, the safety valve comprising a valve seat and a valve core cooperating with each other, the valve seat comprising a first valve seat and a second valve seat telescopically arranged in the first valve seat, the grinding device comprising a guide sleeve, a support sleeve, a fastener and a grinding plate;

[0015] The support sleeve is arranged in the grinding plate, and the guide sleeve is sleeved in the support sleeve, wherein the first end of the first valve seat is fixed to the first end of the guide sleeve, and the second end of the first valve seat passes through the support sleeve and contacts the grinding plate;

[0016] The fastener is inserted into the second end of the guide sleeve and abuts against the second valve seat to adjust the telescopic amount of the second valve seat, so that the sealing surface of the first valve seat is flush with the sealing surface of the second valve seat;

[0017] The grinding plate is used to synchronously grind the sealing surface of the first valve seat and the sealing surface of the second valve seat when the guide sleeve is rotated.

[0018] Optionally, a locking member is further included, which is sleeved on the outside of the fastener and arranged on the top wall of the second end of the guide sleeve to lock the fastener.

[0019] Optionally, the outside wall of the fastener is provided with external threads, the inside wall of the second end of the guide sleeve is provided with internal threads matched with the external threads, and the fastener is screwed into the second end of the guide sleeve.

[0020] Optionally, the first end of the guide sleeve is provided with a first stepped structure, and the first end of the first valve seat is clamped on the first stepped structure.

[0021] Optionally, the inner side wall of the support sleeve is sequentially provided with a second stepped structure and a third stepped structure from one end towards the grinding plate to an end away from the grinding plate.

[0022] The second stepped structure is clamped with the second end of the first valve seat, and the third stepped structure is clamped with the first end of the guide sleeve.

[0023] Optionally, the support sleeve is provided with a plurality of exhaust holes at one end towards the grinding plate.

[0024] Another aspect of the embodiments of the present disclosure provides a safety valve grinding method, which adopts the safety valve grinding device described above for grinding, and the method comprises:

[0025] The first valve seat and the second valve seat are fixed by the grinding device, and the sealing surface of the first valve seat and the sealing surface of the second valve seat are adjusted to be flush;

[0026] The sealing surface of the first valve seat and the sealing surface of the second valve seat are pre-inspected;

[0027] If the grinding condition is met, the sealing surface of the first valve seat and the sealing surface of the second valve seat are sequentially subjected to rough grinding, fine grinding, fine grinding and polishing by rotating the guide sleeve, and the surface roughness and surface gloss of the sealing surface are judged after each grinding.

[0028] Optionally, the pre-inspection of the sealing surface of the first valve seat and the sealing surface of the second valve seat comprises:

[0029] The appearance condition of the sealing surface of the first valve seat and the sealing surface of the second valve seat is observed under a high-power microscope, and the distribution of defects of the sealing surface is checked; wherein,

[0030] If the defect depth of the sealing surface is > 0.2mm, it is judged that the grinding condition is not met;

[0031] If the defect depth of the sealing surface is ≤ 0.2mm, it is judged that the grinding condition is met.

[0032] Optionally, the rotating of the guide sleeve for the sealing surface of the first valve seat and the sealing surface of the second valve seat sequentially performs rough grinding, fine grinding, fine grinding and polishing, and the surface roughness and surface gloss of the sealing surface are judged after each grinding, comprising:

[0033] The sandpaper with a particle size range of 25μ-35μ is fixed on the grinding plate, the guide sleeve is rotated in the same direction and a pressure of 15N-20N is applied to the second valve seat, and the sealing surface is rough ground;

[0034] After 10 to 20 rounds of grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the micro scratches and pits of the sealing surface are eliminated, the sealing surface is gray-black, and the surface gloss is uniform, then stop rough grinding;

[0035] After rough grinding, fix the sandpaper with a particle size range of 15μ to 20μ on the grinding plate, rotate the guide sleeve in the same direction and apply a pressure of 10N to 15N to the second valve seat, and fine grind the sealing surface;

[0036] After 30 to 40 rounds of grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the micro scratches generated by grinding are evenly distributed and have consistent depth, the sealing surface is basically bright, the surface gloss is basically uniform, and there is no local darkening phenomenon, then stop fine grinding.

[0037] Optionally, the rotating the guide sleeve sequentially rough grinds, fine grinds, fine grinds, and polishes the sealing surface of the first valve seat and the sealing surface of the second valve seat, and judges the surface roughness and surface gloss of the sealing surface after each grinding, and further comprises:

[0038] After fine grinding, fix the sandpaper with a particle size range of 8μ to 10μ on the grinding plate, rotate the guide sleeve without applying additional pressure, and fine grind the sealing surface in the same direction;

[0039] The grinding speed is 50 to 100 revolutions per minute. After 2 to 3 minutes of rotation grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the sealing surface has no obvious grinding lines, the sealing surface is bright, and the surface gloss is completely uniform, then stop fine grinding;

[0040] After fine grinding, fix the sandpaper with a particle size range of 1μ to 5μ on the grinding plate, rotate the guide sleeve without applying additional pressure, and fine grind the sealing surface in the same direction;

[0041] The grinding speed is 100 to 150 revolutions per minute. After 5 to 6 minutes of rotation grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the sealing surface has no grinding marks and is bright, the surface gloss is consistent, then the grinding of the sealing surface is completed.

[0042] The safety valve grinding device and the grinding method of the embodiment of the present disclosure, the device fixes the first valve seat through the guide sleeve, adjusts the sealing surface of the first valve seat and the sealing surface of the second valve seat to be flush through the fastener, fixes the second valve seat, and realizes the synchronous grinding of the sealing surface of the first valve seat and the sealing surface of the second valve seat through rotating the guide sleeve. The grinding device can well match the components of the safety valve to be ground, has small size and flexible and convenient operation. The grinding device solves the problem that the first valve seat and the second valve seat cannot be effectively fixed during grinding, can achieve good grinding effect, and has high grinding stability and high grinding efficiency. The grinding method provides a judgment method for grinding quality, can effectively control the number of grinding repair, and increases the service life of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a schematic diagram of the assembly structure of the safety valve seat and the valve core in the prior art;

[0044] Figure 2 It is a structural schematic diagram of a safety valve grinding device in an embodiment of the present disclosure;

[0045] Figure 3 It is an exploded view of a safety valve grinding device in another embodiment of the present disclosure;

[0046] Figure 4 It is an assembly schematic diagram of the guide sleeve and the valve seat in another embodiment of the present disclosure;

[0047] Figure 5 It is a structural schematic diagram of the support sleeve and the exhaust hole in another embodiment of the present disclosure;

[0048] Figure 6 It is a structural schematic diagram of the second step structure and the third step structure in the support sleeve in another embodiment of the present disclosure;

[0049] Figure 7 It is a structural schematic diagram of the support sleeve in another embodiment of the present disclosure;

[0050] Figure 8 It is a flow schematic diagram of a safety valve grinding method in another embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] In order for those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are described in further detail below in combination with the drawings and specific embodiments.

[0052] An aspect of the embodiment of the present disclosure provides a safety valve grinding device 100 for grinding a safety valve, as shown in Figure 1As shown, the safety valve includes a valve seat and a valve core 230 matched with each other, and the valve seat includes a first valve seat 210 and a second valve seat 220 arranged in the first valve seat 210 in a telescopic manner.

[0053] Specifically, in the embodiment, as shown in the drawings, Figure 1 As shown, the safety valve is a helium medium safety valve applied to a high-temperature gas cooled reactor, and the helium medium safety valve adopts a pilot safety valve, and a pilot valve part of the pilot safety valve is designed as a double-valve-seat structure, and an upper three-way valve seat of the pilot valve is divided into a sleeve-shaped first valve seat 210 and a needle-shaped second valve seat 220, and is in contact with a butterfly-shaped valve core 230 to realize sealing. The matching mode of the first valve seat 210, the second valve seat 220 and the butterfly-shaped valve core 230 is as shown in the drawings, Figure 1 from top to bottom, the needle-shaped second valve seat 220, the sleeve-shaped first valve seat 210, the butterfly-shaped valve core 230 and a valve core support ring 240, and the needle-shaped second valve seat 220 is arranged in the sleeve-shaped first valve seat 210 in a telescopic manner, so that the sleeve-shaped first valve seat 210 can serve as a guide and support for the needle-shaped second valve seat 220.

[0054] During normal operation of the safety valve, the needle-shaped second valve seat 220 and the butterfly-shaped valve core 230 are in contact with each other, and the two are plane sealing structures, when the safety valve is tripped, the needle-shaped second valve seat 220 and the butterfly-shaped valve core 230 are separated, and the butterfly-shaped valve core 230 is in contact with the sleeve-shaped first valve seat 210, and the two are plane sealing structures.

[0055] The needle-shaped second valve seat 220 is designed as a bellows structure, and an external force is needed to make the valve core extend outward. The plane sealing structure is very difficult to seal helium, and the flatness and surface roughness of the valve seat and the valve core need to be ensured to realize effective sealing of the helium medium. The structure size of the needle-shaped second valve seat 220 is small, and considering the sealing principle of the pilot safety valve, the needle-shaped second valve seat 220 and the sleeve-shaped first valve seat 210 must be ground synchronously, and the needle-shaped second valve seat 220 and the sleeve-shaped first valve seat 210 need to be fixed. In view of this, as shown in the drawings, Figure 2 the present embodiment provides a safety valve grinding device 100, which comprises a guide sleeve 110, a support sleeve 120, a fastener 130 and a grinding plate 140.

[0056] The support sleeve 120 is arranged on the grinding plate 140, the guide sleeve 110 is arranged in the support sleeve 120, and the support sleeve 120 supports and guides the guide sleeve 110. The first end of the first valve seat 210 is fixed to the first end of the guide sleeve 110, and the second end of the first valve seat 210 penetrates through the support sleeve 120 and is in contact with the grinding plate 140.

[0057] The fastener 130 is inserted into the second end of the guide sleeve 110 and abuts against the second valve seat 220 to adjust the expansion and contraction of the second valve seat 220 so that the sealing surface of the first valve seat 210 is flush with the sealing surface of the second valve seat 220 .

[0058] Specifically, in this embodiment, the second valve seat 220 is a bellows-type structure. When no external force is applied, the bellows is in a contracted state. The second valve seat 220 is telescopically positioned above the first valve seat 210. A certain load must be applied to the top of the second valve seat 220 to cause it to extend. Once the external force is removed, the second valve seat automatically rebounds. The fastener 130 abuts the second valve seat 220, applying pressure to the second valve seat 220. Under this pressure, the second valve seat 220 extends toward one side of the grinding plate 140, aligning the sealing surface of the first valve seat 210 with the sealing surface of the second valve seat 220.

[0059] The grinding plate 140 is used to synchronously grind the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 when the guide sleeve 110 is rotated.

[0060] like Figure 2 and Figure 3 As shown, the assembly process of the safety valve grinding device is as follows: Insert the needle-shaped second valve seat 220 into the sleeve-shaped first valve seat 210. Sleeve the sleeve-shaped first valve seat 210 within the guide sleeve 110. Insert the fastener 130 into the guide sleeve 110, with the bottom of the fastener 130 contacting the top of the second valve seat 220. Apply pressure to the top of the second valve seat 220 through the fastener 130, causing the second valve seat 220 to extend toward the grinding plate 140. Adjust the relative positions of the first valve seat 210 and the second valve seat 220 using the fastener 130 so that the sealing surface of the first valve seat 210 is flush with the sealing surface of the second valve seat 220. Place the guide sleeve 110 and the valve seat assembly as a whole within the support sleeve 120. Place the support sleeve 120 on the grinding plate 140, grasp the outer edge of the fastener 130 by hand, use the support sleeve 120 as a guide, rotate the guide sleeve 110 as a whole, and grind the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 synchronously.

[0061] The safety valve grinding device of the disclosed embodiment fixes the first valve seat by means of a provided guide sleeve, adjusts the sealing surface of the first valve seat to be flush with the sealing surface of the second valve seat by means of fasteners, and fixes the second valve seat, and realizes synchronous grinding of the sealing surface of the first valve seat and the sealing surface of the second valve seat by rotating the guide sleeve. The grinding device can be well matched with the components of the safety valve to be ground, has a small outer size, and is flexible and convenient to operate. The grinding device solves the problem that the first valve seat and the second valve seat cannot be effectively fixed during grinding, and can achieve a better grinding effect, high grinding stability and high grinding efficiency.

[0062] As shown in Figure 2 and Figure 3 The grinding device 100 further comprises a locking member 150, which is sleeved on the outer side of the fastener 130 and arranged on the top wall of the second end of the guide sleeve 110 to lock the fastener 130 and fix the relative position between the fastener 130 and the guide sleeve 110.

[0063] Specifically, the fastener 130 is inserted into the guide sleeve 110, the locking member 150 is sleeved on the outer side of the fastener 130, and after the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 are adjusted to be flush by the fastener 130, the position of the locking member 150 is adjusted to lock the fastener 130 and fix the relative position between the fastener 130 and the guide sleeve 110.

[0064] As shown in Figure 2 and Figure 3 In this embodiment, the fastener 130 is a bolt, that is, the outer side wall of the fastener 130 is provided with external threads 131, and the inner side wall of the second end of the guide sleeve 110 is provided with internal threads (not shown in the figure) matched with the external threads 131, and the fastener 130 is screwed to the second end of the guide sleeve 110.

[0065] Specifically, the fastener 130 is screwed to the guide sleeve 110, the corrugated tube structure of the second valve seat 220 is stretched by rotating the fastener 130, and the corrugated tube is elongated under stress. When the corrugated tube of the second valve seat 220 is elongated to a certain length, the sealing surfaces of the first valve seat 210 and the second valve seat 220 are in a flush state, and the grinding can be carried out.

[0066] In order to reduce the difference between the relative positions of the first valve seat 210 and the second valve seat 220 as much as possible, in order to achieve accurate adjustment, the internal threads of the second end of the guide sleeve 110 and the external threads 131 of the fastener 130 are all fine threads, which can increase the adjustment accuracy.

[0067] Correspondingly, in this embodiment, the locking member 150 is a locking nut, which is screwed on the outer side of the bolt to lock the bolt.

[0068] It should be noted that, as shown in Figure 3 The tightening and loosening of the fastener 130 is manually operated, a hob pattern is processed on the top of the fastener 130 to increase the friction of the hand, and a locking nut is arranged on the external threads 131 of the fastener 130. After the position of the fastener 130 is determined, the fastener 130 is locked by the locking nut to prevent the position of the fastener 130 from changing during the grinding process. The locking nut can be locked by a special wrench 250.

[0069] As shown in Figure 4As shown, the first end of the guide sleeve 110 is provided with a first stepped structure 111, and the first end of the first valve seat 210 is clamped on the first stepped structure 111. In this way, the guide sleeve 110 can guide and support the first valve seat 210. Specifically, as shown in Figure 4 As shown, in this embodiment, the first end of the guide sleeve 110 is provided with an inner recess, and the first end of the first valve seat 210 can be directly fixed in the inner recess.

[0070] As shown in Figure 6 and Figure 7 As shown, the inner side wall of the support sleeve 120 is sequentially provided with a second stepped structure 121 and a third stepped structure 122 from the end facing the grinding plate 140 to the end away from the grinding plate 140. The second stepped structure 121 clamps the second end of the first valve seat 210, and the third stepped structure 122 clamps the first end of the guide sleeve 110, thereby fixing the second end of the first valve seat 210 and the first end of the guide sleeve 110. That is, the shape of the inner side wall of the support sleeve 120 matches the shape of the second end of the first valve seat 210 and the shape of the first end of the guide sleeve 110, and the support sleeve 120 supports and guides the guide sleeve 110 and the first valve seat 210.

[0071] As shown in Figure 3 and Figure 5 As shown, the end of the support sleeve 120 facing the grinding plate 140 is provided with a plurality of exhaust holes 123. The number of exhaust holes 123 is not specifically limited in this embodiment, and the plurality of exhaust holes 123 can be equally spaced or unequally spaced, which can be selected according to actual needs. The shape of the exhaust hole 123 is also not specifically limited in this embodiment and can be selected according to actual needs.

[0072] During the grinding operation, the support sleeve 120 is placed above the grinding plate 140. Because the gap between the outer side wall of the guide sleeve 110 and the inner side wall of the support sleeve 120 is very small, when the guide sleeve 110 is placed in the support sleeve 120, air cannot be normally discharged because of the air inside the guide sleeve 110 and the support sleeve 120. Therefore, the exhaust hole 123 is provided at the bottom of the support sleeve 120, which facilitates the installation of the guide sleeve 110 and can discharge the compressed air inside.

[0073] As shown in Figure 8 The embodiment of the present disclosure provides a safety valve grinding method S100, which is ground by using the safety valve grinding device 100 described above. The specific structure of the safety valve grinding device 100 has been described in detail above, and will not be described again here.

[0074] The safety valve grinding method S100 specifically includes:

[0075] S110, fixing the first valve seat and the second valve seat by the grinding device, and adjusting the sealing surface of the first valve seat and the sealing surface of the second valve seat to be flush.

[0076] Specifically, as shown in Figure 2 and Figure 3 the first end of the first valve seat 210 is fixed to the first end of the guide sleeve 110, and the second end of the first valve seat 210 is in contact with the grinding plate 140 through the support sleeve 120. The fastener 130 is inserted into the second end of the guide sleeve 110 and abuts against the second valve seat 220 to adjust the amount of expansion of the second valve seat 220, so that the sealing surface of the first valve seat 210 is flush with the sealing surface of the second valve seat 220.

[0077] S120, pre-checking the sealing surface of the first valve seat and the sealing surface of the second valve seat.

[0078] Specifically, first, the appearance condition of the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 is observed under a high-power microscope, and the distribution of defects of the sealing surface is checked, such as scratch, pit and pockmark defects of the sealing surface.

[0079] Then, the grinding condition of the sealing surface is preliminarily judged. If the defect depth of the sealing surface is >0.2mm, it is judged that the grinding condition is not met. That is, it has no value for grinding repair and needs to be replaced as a whole. If the defect depth of the sealing surface is ≤0.2mm, it is judged that the grinding condition is met and grinding can be performed.

[0080] S130, if the grinding condition is met, rotating the guide sleeve to sequentially perform coarse grinding, fine grinding, fine grinding and polishing on the sealing surface of the first valve seat and the sealing surface of the second valve seat, and judging the surface roughness and surface gloss of the sealing surface after each grinding.

[0081] Specifically, rotating the guide sleeve 110 to sequentially perform coarse grinding, fine grinding, fine grinding and polishing on the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 as follows:

[0082] First, fix the sandpaper with a particle size range of 25μ-35μ on the grinding plate 140, rotate the guide sleeve 110 in the same direction and apply a pressure of 15N-20N to the second valve seat 220 to perform coarse grinding on the sealing surface.

[0083] Every 10-20 rounds of grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the tiny scratches and pits on the sealing surface have been eliminated, the sealing surface is gray-black and the surface gloss is uniform, then stop coarse grinding.

[0084] In this embodiment, the specific process of coarse grinding is as follows:

[0085] In the grinding plate 140, the sandpaper with the granularity of 30μ is pasted, and the air bubbles in the bottom of the sandpaper should be completely removed. The guide sleeve 110 is rotated and the guide sleeve 110 is given the pressure of about 15N by the fastener 130, and the grinding is carried out along the same direction.

[0086] During the grinding, one hand holds the support sleeve 120 and the other hand rotates the guide sleeve 110, and the force should be evenly exerted. After every 10 to 20 circles of grinding, the grinding should be stopped, the grinding debris above the sealing surface is cleaned, and the appearance of the sealing surface is checked. The check should be carried out by the naked eye first to check whether there are defects visible to the naked eye. After the naked eye check, the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 are placed under the high-power microscope for checking. The appearance of the entire sealing surface is checked, and the overall surface roughness of the sealing surface is focused on. If the overall surface roughness of the sealing surface is consistent, the next process can be entered. If it is not consistent, the grinding is continued until it is consistent.

[0087] After a period of rough grinding, the valve seat sealing surface should be placed under the high-power microscope for observation. After checking, if the defects such as micro scratches and pits have been eliminated, and the external gloss of the valve seat sealing surface is consistent, and the sealing surface is gray-black, the rough grinding process can be stopped.

[0088] Secondly, after the rough grinding is completed, the sandpaper with the granularity range of 15μ-20μ is fixed on the grinding plate 140, the guide sleeve 110 is rotated along the same direction and the pressure of 10N-15N is applied to the guide sleeve 110, and the fine grinding of the sealing surface is carried out.

[0089] After every 30 to 40 circles of grinding, the grinding is stopped, and the surface roughness and surface gloss of the sealing surface are judged. If the micro lines generated by the grinding are evenly distributed and the depth is consistent, the sealing surface is basically bright, and the surface gloss is basically consistent, and there is no local darkening phenomenon, the fine grinding is stopped.

[0090] In this embodiment, the specific process of fine grinding is as follows:

[0091] The fine grinding should use the sand paper with the granularity of 15μ, and the grinding plate 140 should be cleaned before the new sand paper is replaced, the guide sleeve 110 is rotated and the second valve seat 220 is pressed with the force of about 10N, the grinding is carried out in the same direction, one hand holds the supporting sleeve 120 and the other hand rotates the guide sleeve 110, the force should be evenly exerted during the grinding, the grinding should be stopped after 30-40 rounds, the grinding debris above the sealing surface is cleaned, the appearance of the sealing surface is checked, the sealing surface of the first valve seat 210 and the sealing surface of the second valve seat 220 are placed under the high-power microscope for checking, the appearance of the whole sealing surface is checked, the surface roughness of the whole sealing surface should be consistent under the microscope, the micro lines of the grinding are uniformly distributed, the depth of the lines should be consistent, and then the next process can be entered, if not, the grinding is continuously carried out until the consistency is achieved.

[0092] After the fine grinding for a period of time, the sealing surface of the valve seat is placed under the high-power microscope for observation, and the sealing surface of the valve seat is comprehensively checked, the sealing surface is basically bright, the surface gloss is basically consistent, there is no local darkening phenomenon, the micro lines generated by the grinding are uniformly distributed and the depth is consistent, and then the fine grinding process can be stopped.

[0093] Secondly, after the fine grinding is completed, the sand paper with the granularity range of 8μ-10μ is fixed on the grinding plate 140, the guide sleeve 110 is rotated, and the fine grinding is carried out on the sealing surface in the same direction without additional pressing force.

[0094] The grinding rotation speed is 50-100 rounds per minute, the grinding is stopped after 2-3 minutes, the surface roughness and the surface gloss of the sealing surface are judged, if the sealing surface has no obvious grinding lines and the sealing surface is bright and the surface gloss is completely consistent, the fine grinding is stopped.

[0095] In the embodiment, the specific process of the fine grinding is as follows:

[0096] The fine grinding should use the sand paper with the granularity of 9μ, and the grinding plate 140 should be cleaned before the new sand paper is replaced, the guide sleeve 110 is rotated without additional pressing force, the fine grinding is carried out in the same direction, one hand holds the supporting sleeve 120 and the other hand rotates the guide sleeve 110, only the circumferential force is exerted during the grinding, the rotation speed can be appropriately increased and controlled at about 80 rounds per minute, the grinding is stopped after 2-3 minutes, the grinding debris above the sealing surface is cleaned, the appearance of the sealing surface is checked, the sealing surface of the valve seat is placed under the high-power microscope for checking, the appearance of the whole sealing surface is checked, the surface roughness of the whole sealing surface should be consistent under the microscope, there is no obvious grinding line, the surface gloss is consistent, and then the next process can be entered, if not, the grinding is continuously carried out until the consistency is achieved.

[0097] After the fine grinding for a period of time, the sealing surface of the valve seat should be placed under a high-power microscope for observation, and a comprehensive inspection of the sealing surface should be performed. If the sealing surface is bright and the surface gloss is completely consistent without obvious grinding lines, the fine grinding process can be stopped.

[0098] Finally, after the fine grinding is completed, the sandpaper with a particle size range of 1-5μ is fixed on the grinding plate 140, the guide sleeve 110 is rotated, and the sealing surface is ground and polished in the same direction without applying additional pressing force.

[0099] The grinding speed is 100-150rpm, and after 5-6 minutes of rotation grinding, the grinding of the sealing surface should be stopped, and the surface roughness and surface gloss of the sealing surface should be evaluated. If the sealing surface roughness is consistent, there are no grinding marks, the sealing surface is bright as a whole, and the surface gloss is consistent, the grinding of the sealing surface is completed.

[0100] In this embodiment, the specific process of grinding and polishing is as follows:

[0101] During polishing, sandpaper with a particle size of 5μ should be used, and the grinding plate 140 should be cleaned before replacing the new sandpaper. The guide sleeve 110 is rotated without applying additional pressing force, and the grinding is performed in the same direction. During grinding, one hand holds the support sleeve 120 and the other hand rotates the guide sleeve 110. Only the circumferential force is applied during grinding, and the rotation speed can be appropriately increased to about 100rpm. After 5-6 minutes of rotation, the grinding should be stopped, the grinding debris above the sealing surface should be cleaned, and the appearance of the sealing surface should be inspected. The sealing surface of the valve seat should be placed under a high-power microscope for inspection, and the appearance of the entire sealing surface should be inspected. Under the microscope, the surface roughness of the entire sealing surface should be consistent, the surface gloss should be consistent, the appearance of the sealing surface should be bright as a whole, and there should be no grinding marks. Then the grinding of the sealing surface is completed.

[0102] In this embodiment, the safety valve grinding device is used to grind the valve seat of the safety valve, providing a grinding process method for the upper three-way valve seat and a method for evaluating the grinding quality, which can effectively control the number of grinding repairs and increase the service life of the equipment.

[0103] It should be noted that the valve core of the upper three-way valve is small in size and has no clamping position, and manual grinding is used to perform the grinding repair process method of the valve core, which is as follows:

[0104] 1) Pre-grinding inspection

[0105] Step 1: Observe the appearance of the valve core sealing surface under a high-power microscope, and check the distribution of defects such as scratches, pits, and pockmarks on the valve core sealing surface.

[0106] Step 2: Preliminary evaluation of the grinding process, when the defect depth above the valve core is >0.2mm, it is not worth repairing by grinding, and the whole needs to be replaced. When the defect is ≤0.2mm, it can be repaired by grinding.

[0107] 2) Grinding process

[0108] Step 1: Rough grinding, paste the sandpaper with a particle size of 30μ on the grinding plate, when pasting the sandpaper, the bubbles at the bottom of the sandpaper should be completely removed. Press the top of the valve core with the index finger, and give the ground part about 20N pressure, shake the finger, and the valve core follows the finger movement. The trajectory of the movement can take the "8" character or envelope line, and the force should be uniform during grinding. Every 10 to 20 circles of grinding, the grinding should be stopped, the grinding debris above the sealing surface should be cleaned, and the appearance of the sealing surface should be checked. The check should be done first by naked eye to check if there are visible defects, and then the valve core should be placed under a high-power microscope for inspection. The entire appearance of the sealing surface should be checked, focusing on the overall surface roughness of the sealing surface. If the overall surface roughness of the sealing surface is consistent, it can proceed to the next process. If it is not consistent, continue to grind until it is consistent.

[0109] Step 2: After a period of grinding according to the operation method of step 1, the sealing surface of the valve core should be placed under a high-power microscope for observation. After inspection, if the defects such as micro scratches and pits have been eliminated, and the external gloss of the sealing surface of the valve core is consistent, the sealing surface is gray-black, then the rough grinding process can be stopped.

[0110] Step 3: Fine grinding, when fine grinding, sandpaper with a particle size of 15μ should be used, and the grinding plate should be cleaned before replacing the new sandpaper. Rotate the valve core and give it about 15N pressure, shake the finger, and the valve core follows the finger movement. The trajectory of the movement can take the "8" character or envelope line, and the force should be uniform during grinding. Every 30 to 40 circles of grinding, the grinding should be stopped, the grinding debris above the sealing surface should be cleaned, and the appearance of the sealing surface should be checked. The ground part should be placed under a high-power microscope for inspection. The entire appearance of the sealing surface should be checked, and under the microscope, the overall surface roughness of the sealing surface should be consistent, the distribution of the micro lines produced by grinding should be uniform, and the depth of the lines should be uniform and consistent. If it is not consistent, continue to grind until it is consistent.

[0111] Step 4: After a period of grinding according to the operation method of step 3, the sealing surface of the valve core should be placed under a high-power microscope for observation. The sealing surface of the valve core should be checked comprehensively. The sealing surface is basically bright, the surface gloss is basically consistent, there is no local darkening phenomenon, the distribution of the micro lines produced by grinding is uniform, and the depth is consistent. Then the fine grinding process can be stopped.

[0112] Step 5: Use sandpaper with a grit size of 9μ for fine grinding. Clean the grinding plate before replacing the new sandpaper. Turn the valve core and apply a pressure of about 5N to the valve core. Shake your finger and the valve core will follow the movement of your finger. The trajectory of the movement can be in the shape of an "8" or an envelope. Apply force evenly during grinding and increase the rotation speed appropriately. The speed should be controlled at around 60 rpm. After 2 to 3 minutes of rotation, stop grinding, clean the grinding debris above the sealing surface, check the appearance of the sealing surface, place the grinding piece under a high-power microscope for inspection, and check the appearance of the entire sealing surface. Observe under the microscope that the surface roughness of the entire sealing surface should be consistent, without obvious grinding lines, and the surface gloss should be consistent before proceeding to the next process. If not, continue grinding until it is consistent.

[0113] Step 6: After grinding for a period of time according to the operating method in step 5, the valve core sealing surface should be placed under a high-power microscope for observation and a comprehensive inspection of the valve core sealing surface. If the sealing surface is bright, the surface gloss is completely consistent, and there are no obvious grinding lines, the fine grinding process can be stopped.

[0114] Step 7: Use sandpaper with a grit size of 5μ for polishing. Clean the grinding plate before replacing the sandpaper. Rotate the valve core and apply a pressure of about 5N to the valve core. Shake your finger and the valve core will follow the movement of your finger. The trajectory of the movement can be an "8" figure or an envelope. Apply force evenly during grinding and increase the speed appropriately. The speed should be controlled at around 100 rpm. After 5 to 6 minutes of rotation, stop grinding and clean the grinding debris above the sealing surface. Check the appearance of the sealing surface. Place the valve core under a high-power microscope for inspection. Check the appearance of the entire sealing surface. Under the microscope, the surface roughness and gloss of the entire sealing surface should be consistent. The sealing surface should be shiny and free of processing marks.

[0115] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the embodiments of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the embodiments of the present disclosure.

Claims

1. A safety valve grinding apparatus, said safety valve comprising a valve seat and a valve core cooperating with each other, said valve seat comprising a first valve seat and a second valve seat arranged in a telescopic manner within said first valve seat, characterized in that, The grinding device comprises a guide sleeve, a support sleeve, a fastener and a grinding plate; The support sleeve is arranged on the grinding plate, and the guide sleeve is sleeved in the support sleeve, wherein the first end of the first valve seat is fixed to the first end of the guide sleeve, and the second end of the first valve seat is in contact with the grinding plate through the support sleeve; The fastener is inserted into the second end of the guide sleeve and abuts against the second valve seat to adjust the extension amount of the second valve seat, so that the sealing surface of the first valve seat is flush with the sealing surface of the second valve seat; The grinding plate is used to synchronously grind the sealing surface of the first valve seat and the sealing surface of the second valve seat when the guide sleeve is rotated; Further comprising a locking member, which is sleeved on the outside of the fastener and arranged on the top wall of the second end of the guide sleeve to lock the fastener, the outside wall of the fastener is provided with external threads, the inside wall of the second end of the guide sleeve is provided with internal threads matched with the external threads, and the fastener is screwed into the second end of the guide sleeve.

2. The polishing apparatus according to claim 1, wherein The first end of the guide sleeve is provided with a first step structure, and the first end of the first valve seat is clamped on the first step structure.

3. The grinding device according to claim 1 or 2, characterized in that The inside wall of the support sleeve is sequentially provided with a second step structure and a third step structure from one end facing the grinding plate to one end away from the grinding plate; The second end of the first valve seat is clamped on the second step structure, and the first end of the guide sleeve is clamped on the third step structure.

4. The polishing apparatus according to claim 1 or 2, wherein The one end of the support sleeve facing the grinding plate is provided with a plurality of exhaust holes.

5. A method of grinding a safety valve, characterized by, The safety valve grinding device of any one of claims 1 to 4 is used for grinding, and the method comprises: The first valve seat and the second valve seat are fixed by the grinding device, and the sealing surface of the first valve seat is adjusted to be flush with the sealing surface of the second valve seat; The sealing surface of the first valve seat and the sealing surface of the second valve seat are pre-inspected; If the grinding condition is met, the sealing surface of the first valve seat and the sealing surface of the second valve seat are sequentially subjected to rough grinding, fine grinding, fine grinding and polishing by rotating the guide sleeve, and the surface roughness and surface gloss of the sealing surface are evaluated after each grinding.

6. The polishing method according to claim 5, wherein The pre-inspection of the sealing surface of the first valve seat and the sealing surface of the second valve seat comprises: The appearance of the sealing surface of the first valve seat and the sealing surface of the second valve seat is observed under a high-power microscope, and the distribution of defects of the sealing surface is inspected; wherein, If the defect depth of the sealing surface is >0.2mm, it is judged that the grinding condition is not met; If the defect depth of the sealing surface is ≤0.2mm, it is judged that the grinding condition is met.

7. The polishing method according to claim 5, wherein The rotating of the guide sleeve to sequentially perform rough grinding, fine grinding, fine grinding and polishing on the sealing surface of the first valve seat and the sealing surface of the second valve seat, and the evaluation of the surface roughness and surface gloss of the sealing surface after each grinding, comprises: The sandpaper with a particle size range of 25μ~35μ is fixed on the grinding plate, the guide sleeve is rotated in the same direction, and a pressure of 15N~20N is applied to the second valve seat to perform rough grinding on the sealing surface; After 10 to 20 rounds of grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the micro scratches and pits of the sealing surface are eliminated, the sealing surface is gray-black, and the surface gloss is uniform, then stop rough grinding; After rough grinding, fix the sandpaper with a particle size range of 15μ~20μ on the grinding plate, rotate the guide sleeve in the same direction and apply a pressure of 10N~15N to the second valve seat, and fine grind the sealing surface; After 30 to 40 rounds of grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the micro scratches produced by grinding are evenly distributed and have consistent depth, the sealing surface is basically bright, the surface gloss is basically uniform, and there is no local darkening phenomenon, then stop fine grinding.

8. The polishing method according to claim 7, wherein The rotating guide sleeve sequentially rough grinds, fine grinds, fine grinds, and polishes the sealing surface of the first valve seat and the sealing surface of the second valve seat, and judges the surface roughness and surface gloss of the sealing surface after each grinding. It also includes: After fine grinding, fix the sandpaper with a particle size range of 8μ~10μ on the grinding plate, rotate the guide sleeve without applying additional pressure, and fine grind the sealing surface in the same direction; The grinding speed is 50 to 100 revolutions per minute. After 2 to 3 minutes of rotation grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the sealing surface has no obvious grinding lines, the sealing surface is bright, and the surface gloss is completely uniform, then stop fine grinding; After fine grinding, fix the sandpaper with a particle size range of 1μ~5μ on the grinding plate, rotate the guide sleeve without applying additional pressure, and polish the sealing surface in the same direction; The grinding speed is 100 to 150 revolutions per minute. After 5 to 6 minutes of rotation grinding, stop grinding and judge the surface roughness and surface gloss of the sealing surface. If the sealing surface roughness is consistent, there is no grinding trace, the sealing surface is bright overall, and the surface gloss is consistent, then the grinding of the sealing surface is completed.

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