A ball valve flushing method

Abstract

The present invention belongs to the field of hydraulic valves, and specifically relates to a flushing method for a ball valve. The ball valve comprises a main valve body, a side valve body, a ball, a valve stem, and a drive device. The main valve body is provided with a spring chamber and a valve chamber, respectively. The main valve body is also provided with a first flushing pipe and a second flushing pipe, respectively communicating with the spring chamber and the valve chamber. Flushing oil at a first pressure is controlled to flow into the first flushing pipe to flush the spring chamber, and flushing oil at a second pressure is controlled to flow into the second flushing pipe to flush the valve chamber. This flushing method can clean and maintain the valve cavity during valve operation, ensuring stable and reliable valve operation.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic valves, and in particular relates to a flushing method for a ball valve. Background Art

[0002] When residual oil enters the valve cavity and spring chamber during valve conveying, it is prone to coking in related areas. The spring cavity is most susceptible to coking in the gap between the valve seat and the spring chamber, as well as in the spring chamber itself. Coking in the valve cavity also occurs on the spherical surface and the inner wall of the valve body. Valve coking can increase valve operating torque or even cause valve failure, necessitating downtime for maintenance, significantly impacting pipeline transportation. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a flushing method for a ball valve, which can clean and maintain the valve cavity during the operation of the valve, so that the valve can be used stably and reliably.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A flushing method for a ball valve, the ball valve comprising a main valve body, a side valve body, a ball, a valve stem, and a drive device; one end of the valve stem is drivingly connected to the ball, and the other end is connected to the drive device; a controller controls the drive device to operate to open the valve; the drive device is further provided with a detection device for detecting the valve operating torque, and the detection device is electrically connected to the controller;

[0006] A spring cavity and a valve cavity are respectively provided in the main valve body, the right side of the main valve body is connected to the side valve body, the ball is arranged in the valve cavity between the main valve body and the side valve body, and the main valve body is further provided with a first flushing pipe and a second flushing pipe which are respectively connected to the spring cavity and the valve cavity;

[0007] The flushing method comprises the following steps:

[0008] Step S1: The controller determines whether the valve operation time reaches the maintenance period. When the operation time reaches the maintenance period, the controller starts the valve flushing maintenance and controls the driving device to operate so that the ball rotates a predetermined angle and then returns to the initial position.

[0009] Step S2: During the valve flushing maintenance, the detection device detects the torque during the valve rotation process in real time and transmits the detected torque data to the controller;

[0010] Step S3: The controller determines whether the received torque is greater than or equal to a predetermined threshold value. If it is greater than or equal to the predetermined threshold value, it controls the flow of flushing oil of a first pressure into the first flushing pipe to flush the spring chamber, and controls the flow of flushing oil of a second pressure into the second flushing pipe to flush the valve chamber.

[0011] Preferably, after step S3, the method further includes the following steps:

[0012] Step S4: After the predetermined flushing time, the flushing oil is stopped from being supplied to the first flushing pipe and the second flushing pipe, and the driving device is controlled again to rotate the ball by a predetermined angle and then return to the initial position;

[0013] Step S5: The controller determines whether the torque received at this time is greater than a predetermined threshold. If it is greater than or equal to the predetermined threshold, steps S3 to S4 are repeated until the torque is less than the predetermined threshold.

[0014] Preferably, the step S1 further comprises: the controller continuously controls the driving device to move N times, that is, the driving device controls the sphere to rotate a predetermined angle and then return to the initial position N times; wherein N≥2.

[0015] Preferably, step S3 also includes: the controller determines whether the N torques received are all greater than or equal to a predetermined threshold value; if the N torques are all greater than or equal to the predetermined threshold value, the controller controls the introduction of flushing oil into the first flushing pipe and the second flushing pipe; otherwise, the flushing oil is not introduced into the first flushing pipe and the second flushing pipe until the valve enters the next maintenance cycle.

[0016] Preferably, the predetermined angle is smaller than the angle required for the valve to rotate when closed.

[0017] Preferably, the first pressure is lower than the second pressure.

[0018] Preferably, the step S4 further includes: the controller continuously controlling the driving device to act N times again; wherein N≥2.

[0019] Preferably, step S5 further includes: the controller determines whether the N received torques are all greater than or equal to a predetermined threshold; if the N received torques are all greater than or equal to the predetermined threshold, steps S3 to S4 are repeated until the torques are all less than the predetermined threshold.

[0020] Preferably, a first channel and a second channel are respectively provided on the main valve body, and a third channel and a fluid channel are respectively provided on the sphere; one end of the first channel is connected to the first flushing pipe, and the other end is communicated with the spring chamber; one end of the second channel is connected to the second flushing pipe, and the other end is communicated with the valve chamber; one end of the third channel is communicated with the valve chamber, and the other end is communicated with the fluid channel.

[0021] Preferably, an upstream valve seat assembly is provided between the ball and the main valve body, one end of the upstream valve seat assembly is provided in the spring cavity on the main valve body, and the other end is in sealing contact with the ball;

[0022] The upstream valve seat assembly includes an upstream valve seat and a flushing ring arranged on the outer peripheral surface of the upstream valve seat; wherein, the upstream valve seat has a first mounting section, the first mounting section is inserted into the medium channel of the main valve body, and has a gap a between it and the main valve body; the flushing ring is mounted on the outer peripheral surface of the first mounting section, one end of the flushing ring is provided with a mounting positioning portion, the mounting positioning portion cooperates with the first mounting section, and the other end is arranged in a mounting groove provided on the main valve body, and has a gap a between it and the outer peripheral surface of the first mounting section; the flushing ring is provided with a plurality of guide holes connected to the gap a;

[0023] In the axial direction, the flushing ring is closer to the upstream of the valve relative to the first channel, and the guide hole includes: ① a first guide surface close to the first channel and having an acute angle θ with the axis of the flushing ring; ② a second guide surface connected to the first guide surface; ③ a third guide surface away from the first channel and perpendicular to the axis of the flushing ring, thereby making the guide hole a hole shape with a larger top and a smaller bottom.

[0024] Compared with the prior art, the ball valve flushing method provided by the present invention has the following beneficial technical effects:

[0025] During valve flushing maintenance, this invention introduces flushing oil into both the first and second flushing pipes to flush the ball valve's spring and valve cavities. This protects the valve and spring cavities by utilizing the pressure differential between the flushing oil and the medium, preventing the medium (residual oil) from entering. Furthermore, the flushing oil softens and dissolves coke deposits in the valve and spring cavities, discharging them through a pre-defined path. This ensures stable and reliable valve operation.

[0026] 2. The flushing method of the present invention can be cleaned online during valve operation without shutting down the valve. When the valve needs maintenance, flushing oil is simply pumped into the valve cavity and spring cavity for flushing and maintenance, improving production continuity and reducing downtime losses.

[0027] 3. The present invention positions the flushing ring closer to the upstream side of the valve relative to the first channel and configures the guide hole to be larger at the top and smaller at the bottom. This hole shape accelerates the flow of flushing oil into gap a through the flushing hole, achieving more effective flushing of gap a and preventing coking in gap a. This arrangement also reduces the need for excessive flushing oil pressure P1 entering the spring chamber to meet flushing requirements, which reduces energy consumption. However, excessive flushing oil pressure P1 increases the sealing preload of the upstream valve seat, making it difficult for the ball to rotate. This arrangement ensures flushing efficiency even at low pressure P1, preventing interference with ball rotation. Furthermore, due to the smaller bottom opening area, residual oil is less likely to enter the spring chamber through gap a.

[0028] 4. The present invention arranges the first guide surface so that its distal end connects with the arcuate second guide surface, effectively directing the flushing oil within the spring cavity to gap a and enhancing the flushing effect within gap a. The third guide surface is flush with the side of the spring cavity, preventing the mounting groove from obstructing the flushing oil and ensuring effective flushing of gap a. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a top view of the metal-sealed ball valve;

[0030] Figure 2 for Figure 1 A partial enlarged schematic diagram of point A in the middle;

[0031] Figure 3 It is a structural diagram of the metal sealing ball valve in the closed state;

[0032] Figure 4 This is the main view of the metal-sealed ball valve;

[0033] Figure 5 Schematic diagram of the structure of the valve seat;

[0034] Figure 6 It is a structural diagram of the flushing ring;

[0035] Figure 7 for Figure 6 Partial cross-sectional view of the middle flushing ring.

[0036] The meanings of the symbols in the figure are as follows:

[0037] 1. Upstream valve seat assembly; 2. Main valve body; 3. Side valve body; 4. Ball; 5. First flushing pipe; 6. Second flushing pipe; 7. Downstream valve seat assembly; 8. Valve stem; 9. Drive unit; 11. Upstream valve seat; 12. Flushing ring; 13. Disc spring; 14. Packing ring; 15. Sealing packing;

[0038] 111. First installation section; 112. Second installation section; 113. Third installation section; 114. Fourth installation section; 115. Metal sealing portion;

[0039] 121. Guide hole; 122. First guide surface; 123. Second guide surface; 124. Third guide surface; 125. Mounting positioning portion;

[0040] 21. Spring chamber; 22. Valve chamber; 23. First channel; 24. Second channel; 25. Mounting groove; 26. Side of spring chamber;

[0041] 41. Third channel; 42. Fluid channel; 71. Downstream valve seat; 72. Valve seat pressure ring. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0043] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0044] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0047] See attached Figure 1 -Attached Figure 7As shown in the figure, the present invention discloses a metal-sealed ball valve with a flushing device. The ball valve includes a main valve body 2, a side valve body 3, a ball 4, a valve stem 8, and a drive device 9. A spring chamber 21 and a valve chamber 22 are defined within the main valve body 2. The right side of the main valve body 2 is connected to the side valve body 3. The ball 4 is disposed in the valve chamber 22 between the main valve body 2 and the side valve body 3. One end of the valve stem 8 is in driving connection with the ball 4, and the other end is connected to the drive device 9. A controller (not shown) controls the operation of the drive device 9 to open the valve. The drive device 9 is also equipped with a detection device for detecting the valve operating torque, which is electrically connected to the controller.

[0048] An upstream valve seat assembly 1 is disposed between the ball 4 and the main valve body 2, and a downstream valve seat assembly 7 is disposed between the ball 4 and the side valve body 3. One end of the upstream valve seat assembly 1 is disposed in the spring cavity 21 on the main valve body 2, and the other end is in sealing contact with the ball 4. One end of the downstream valve seat assembly 7 is connected to the side valve body 3, and the other end is in sealing contact with the ball 4.

[0049] Among them, a first channel 23 and a second channel 24 are respectively opened on the main valve body 2, and a third channel 41 and a fluid channel 42 are respectively opened on the ball 4; one end of the first channel 23 is connected to the first flushing pipe 5, and the other end is connected to the spring chamber 21; one end of the second channel 24 is connected to the second flushing pipe 6, and the other end is connected to the valve chamber 22; one end of the third channel 41 can be connected to the valve chamber 22, and the other end is connected to the fluid channel 42.

[0050] Preferably, the upstream valve seat assembly 1 includes an upstream valve seat 11 and a flushing ring 12, a disc spring 13, a packing pressure ring 14 and a sealing packing 15 arranged in sequence on the outer peripheral surface of the upstream valve seat 11; the upstream valve seat 11 includes a first mounting section 111, a second mounting section 112, a third mounting section 113 and a fourth mounting section 114 arranged in sequence; the first mounting section 111 is inserted into the medium channel of the main valve body 2, and has a gap a between it and the main valve body 2, a flushing ring 12 is installed on the outer peripheral surface of the first mounting section 111, and one end of the flushing ring 12 is provided with a mounting positioning portion 125, which cooperates with the first mounting section 111, and the other end is provided in the mounting groove 25 opened on the main valve body 2, and is engaged with the first mounting section 111. There is a gap a between the outer circumferential surfaces of the first mounting section 111, and a plurality of guide holes 121 connected to the gap a are opened on the flushing ring 12; a disc spring 13 is installed on the outer circumferential surface of the second mounting section 112, and an L-shaped packing pressure ring 14 and a sealing packing 15 are respectively installed on the outer circumferential surface of the third mounting section 113, one end of the sealing packing 15 abuts against the fourth mounting section 114, and the other end abuts against the packing pressure ring 14, the disc spring 13 is located between the flushing ring 12 and the packing pressure ring 14, and its two ends abut against the flushing ring 12 and the packing pressure ring 14 respectively; the fourth mounting section 114 is located in the spring cavity 21, and has a gap b between it and the spring cavity 21, and one end thereof is provided with a metal sealing part 115 that is in sealing contact with the ball 4.

[0051] In the present invention, the installation positioning portion 125 of the flushing ring 12 cooperates with the upstream valve seat 11 for positioning, so that the radial gap a of the upstream valve seat 11 is always a concentric ring, so that the flushing oil is flushed evenly along the circumference of the gap a.

[0052] Preferably, the downstream valve seat assembly 7 includes a downstream valve seat 71 and a valve seat pressure ring 72 . A groove is provided on the side valve body 3 . The valve seat pressure ring 72 is connected to the side valve body 3 to press and fix the downstream valve seat 71 into the groove.

[0053] With respect to the metal-sealed ball valve provided above, the present invention provides a flushing method to achieve online cleaning during valve operation. The method comprises the following steps:

[0054] Step S1: The controller determines whether the valve working time reaches the maintenance cycle. When the working time reaches the maintenance cycle, the valve flushing maintenance is started, and the driving device 9 is controlled to operate so that the ball 4 rotates a predetermined angle and then returns to the initial position.

[0055] Preferably, the predetermined angle is smaller than the angle required to rotate when the valve is closed, and can be set according to actual needs.

[0056] Step S2: During the valve flushing maintenance, the detection device detects the torque during the valve rotation process in real time and transmits the detected torque data to the controller.

[0057] Step S3: The controller determines whether the received torque is greater than or equal to a predetermined threshold. If so, the controller controls the flow of flushing oil at a first pressure into the first flushing pipe 5 to flush the spring chamber 21, and controls the flow of flushing oil at a second pressure into the second flushing pipe 6 to flush the valve chamber 22. Preferably, the first pressure is lower than the second pressure.

[0058] Step S4: After the predetermined flushing time, the flushing oil is stopped from being introduced into the first flushing pipe 5 and the second flushing pipe 6, and the driving device 9 is controlled to operate again, so that the ball 4 rotates a predetermined angle and then returns to the initial position.

[0059] Step S5: The controller determines whether the torque received at this time is greater than a predetermined threshold. If it is greater than or equal to the predetermined threshold, steps S3 to S4 are repeated until the torque is less than the predetermined threshold.

[0060] Preferably, step S1 further comprises: the controller continuously controls the driving device 9 to move N times, that is, the driving device 9 controls the sphere 4 to rotate a predetermined angle and then return to the initial position N times; wherein N≥2.

[0061] Preferably, step S3 also includes: the controller determines whether the N torques received are all greater than or equal to a predetermined threshold value; if the N torques are all greater than or equal to the predetermined threshold value, the controller controls the introduction of flushing oil into the first flushing pipe 5 and the second flushing pipe 6; otherwise, flushing oil is not introduced into the first flushing pipe 5 and the second flushing pipe 6 until the valve enters the next maintenance cycle.

[0062] Preferably, step S4 further includes: the controller continuously controls the driving device 9 to move N times again, that is, the number of times the driving device 9 controls the sphere 4 to rotate a predetermined angle and then return to the initial position is N; wherein N≥2.

[0063] Preferably, step S5 further includes: the controller determines whether the N received torques are all greater than or equal to a predetermined threshold; if the N received torques are all greater than or equal to the predetermined threshold, steps S3 to S4 are repeated until the torques are all less than the predetermined threshold.

[0064] When flushing spring cavity 21, flushing oil enters spring cavity 21 through first flushing conduit 5, first passage 23, and then flows into the conduit through guide hole 121 in flushing ring 12 from gap a. During use, the flushing oil pressure P1 is set to be greater than the medium pressure P2. The pressure differential between the flushing oil and the medium protects spring cavity 21, preventing residual oil from entering spring cavity 21 and gap a.

[0065] During flushing of the valve cavity 22, both the high- and low-pressure side valve seats remain sealed. When the valve is fully open, flushing oil enters the valve cavity 22 from the second flushing pipe 6 via the second channel 24, filling the valve cavity 22 before being discharged into the pipeline via the third channel 41 and fluid channel 42. During use, the flushing oil pressure P3 is set to be greater than the medium pressure P2. The pressure differential between the flushing oil and the medium protects the valve cavity 22, preventing the medium from "backflowing" into the valve cavity 22 through the third channel 41. When the valve is fully closed, the flushing principle is similar to that of the fully open valve and will not be further elaborated here.

[0066] During the process of conveying residual oil in the valve, when the residual oil enters the valve cavity and the spring cavity, it is easy to coke on the relevant parts. The parts of the spring cavity that are easy to coke include gap a, gap b, and the spring cavity body, and the parts of the valve cavity that are easy to coke include the spherical surface, the inner wall of the valve body, etc. Coking will cause the valve to increase in actuation torque or even fail to actuate. Therefore, the present invention uses flushing oil to clean the valve cavity so that the valve can be used stably and reliably. Specifically, during the valve flushing and maintenance process, the present invention introduces flushing oil into the first flushing pipe and the second flushing pipe respectively to flush the spring cavity and valve cavity of the ball valve. On the one hand, the pressure difference between the flushing oil and the medium is used to protect the valve cavity and the spring cavity to prevent the medium (residual oil) from entering the valve cavity and the spring cavity; on the other hand, the flushing oil is used to soften and dissolve the coked materials in the valve cavity and the spring cavity, and is discharged through the set path, so that the valve can be used stably and reliably.

[0067] The flushing method provided by the present invention allows for online cleaning during valve operation without downtime. When the valve requires maintenance, flushing oil is simply pumped into the valve cavity and spring cavity for flushing and maintenance, thereby improving production continuity and reducing downtime losses.

[0068] In some preferred embodiments, in the axial direction, the flushing ring 12 is closer to the upstream of the valve relative to the first channel 23, and the flushing ring 12 is evenly provided with a plurality of guide holes 121 along the circumferential direction. The guide holes 121 include: (1) a first guide surface 122 close to the first channel 23 and having an acute angle θ with the axis of the flushing ring 12; (2) a second guide surface 123 connected to the first guide surface 122; (3) a third guide surface 124 away from the first channel 23 and perpendicular to the axis of the flushing ring 12, thereby making the guide holes 121 have a hole shape with a larger top and a smaller bottom (as shown in the attached figure). Figure 5 -Attached Figure 6 Preferably, the second guide surface 123 is an arc-shaped guide surface facing the gap a, and the third guide surface 124 is flush with the spring cavity side surface 26.

[0069] In the above embodiment, the flushing ring is positioned closer to the upstream side of the valve relative to the first channel, and the guide hole is configured as a larger-at-top, smaller-at-bottom hole. This hole shape accelerates the flow rate of flushing oil entering gap a through the flushing hole, achieving more effective flushing of gap a and preventing coking in gap a. This arrangement also reduces the need for excessively high flushing oil pressure P1 entering the spring chamber to meet flushing requirements. This reduces energy consumption. However, excessive flushing oil pressure P1 increases the sealing preload of the upstream valve seat, making it difficult for the ball to rotate. This arrangement ensures flushing efficiency even at low pressure P1, preventing interference with ball rotation. Furthermore, due to the smaller bottom opening area, residual oil is less likely to enter the spring chamber through gap a.

[0070] Furthermore, the first guide surface is configured so that its distal end connects to the curved second guide surface, which better directs the flushing oil within the spring cavity to gap a, enhancing the flushing effect within gap a. The third guide surface is flush with the side of the spring cavity, preventing the mounting groove from obstructing the flushing oil and ensuring a flushing effect within gap a.

[0071] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A ball valve flushing method, characterized in that: The ball valve includes a main valve body, a side valve body, a ball, a valve stem, and a drive device; one end of the valve stem is transmission-connected to the ball, and the other end is connected to the drive device. A controller controls the drive device to operate to open the valve. The drive device is also provided with a detection device for detecting the valve operating torque, and the detection device is electrically connected to the controller. A spring cavity and a valve cavity are respectively provided in the main valve body, the right side of the main valve body is connected to the side valve body, the ball is arranged in the valve cavity between the main valve body and the side valve body, and the main valve body is further provided with a first flushing pipe and a second flushing pipe which are respectively connected to the spring cavity and the valve cavity; The flushing method comprises the following steps: Step S1: The controller determines whether the valve operation time reaches the maintenance period. When the operation time reaches the maintenance period, the controller starts the valve flushing maintenance and controls the driving device to operate so that the ball rotates a predetermined angle and then returns to the initial position. Step S2: During the valve flushing maintenance, the detection device detects the torque during the valve rotation process in real time and transmits the detected torque data to the controller; Step S3: The controller determines whether the received torque is greater than or equal to a predetermined threshold value. If it is greater than or equal to the predetermined threshold value, it controls the flow of flushing oil of a first pressure into the first flushing pipe to flush the spring chamber, and controls the flow of flushing oil of a second pressure into the second flushing pipe to flush the valve chamber.

2. The flushing method according to claim 1, wherein After step S3, the following steps are also included: Step S4: After the predetermined flushing time, the flushing oil is stopped from being supplied to the first flushing pipe and the second flushing pipe, and the driving device is controlled again to rotate the ball by a predetermined angle and then return to the initial position; Step S5: The controller determines whether the torque received at this time is greater than a predetermined threshold. If it is greater than or equal to the predetermined threshold, steps S3 to S4 are repeated until the torque is less than the predetermined threshold.

3. The flushing method according to claim 2, wherein: The step S1 further includes: the controller continuously controls the driving device to move N times, that is, the driving device controls the sphere to rotate a predetermined angle and then return to the initial position for N times; wherein N≥2.

4. The flushing method according to claim 3, wherein: The step S3 also includes: the controller determines whether the N torques received are all greater than or equal to a predetermined threshold value; if the N torques are all greater than or equal to the predetermined threshold value, the controller controls the introduction of flushing oil into the first flushing pipe and the second flushing pipe; otherwise, the flushing oil is not introduced into the first flushing pipe and the second flushing pipe until the valve enters the next maintenance cycle.

5. The flushing method according to claim 4, wherein: The predetermined angle is smaller than the angle required for the valve to rotate when closing.

6. The flushing method according to claim 5, wherein: The first pressure is lower than the second pressure.

7. The flushing method according to claim 6, wherein: The step S4 further includes: the controller continuously controlling the driving device to act N times again; wherein N≥2.

8. The flushing method according to claim 7, wherein: The step S5 further includes: the controller determines whether the N received torques are all greater than or equal to a predetermined threshold; if the N received torques are all greater than or equal to the predetermined threshold, the steps S3 to S4 are repeated until the torques are all less than the predetermined threshold.

9. The flushing method according to claim 8, wherein: A first channel and a second channel are respectively provided on the main valve body, and a third channel and a fluid channel are respectively provided on the sphere; one end of the first channel is connected to the first flushing pipe, and the other end is communicated with the spring chamber; one end of the second channel is connected to the second flushing pipe, and the other end is communicated with the valve chamber; one end of the third channel is communicated with the valve chamber, and the other end is communicated with the fluid channel.

10. The flushing method according to claim 9, wherein: An upstream valve seat assembly is provided between the ball and the main valve body, one end of the upstream valve seat assembly is provided in the spring cavity on the main valve body, and the other end is in sealing contact with the ball; The upstream valve seat assembly includes an upstream valve seat and a flushing ring arranged on the outer peripheral surface of the upstream valve seat; wherein, the upstream valve seat has a first mounting section, the first mounting section is inserted into the medium channel of the main valve body, and has a gap a between it and the main valve body; the flushing ring is mounted on the outer peripheral surface of the first mounting section, one end of the flushing ring is provided with a mounting positioning portion, the mounting positioning portion cooperates with the first mounting section, and the other end is arranged in a mounting groove provided on the main valve body, and has a gap a between it and the outer peripheral surface of the first mounting section; the flushing ring is provided with a plurality of guide holes connected to the gap a; In the axial direction, the flushing ring is closer to the upstream of the valve relative to the first channel, and the guide hole includes: ① a first guide surface close to the first channel and having an acute angle θ with the axis of the flushing ring; ② a second guide surface connected to the first guide surface; ③ a third guide surface away from the first channel and perpendicular to the axis of the flushing ring, thereby making the guide hole a hole shape with a larger top and a smaller bottom.

Images