Oil pressure driven automatic valve detection method

Abstract

The invention belongs to the technical field of valve detection, and particularly relates to an oil pressure driven automatic valve detection method, which comprises the following steps of S10, mounting a blind plate, connecting the blind plate with a second interface, and communicating the blind plate with an air pump through an air inlet pipe; s20, the oil cylinder is pressurized through a pressurizer, the pressure reaches the working pressure value, the hydraulic rod abuts against the valve plate from the first connector, and the third connector is closed by the valve plate; s30, compressed air is added into the valve chamber from the air inlet pipe until the set working pressure is reached, and the pressure is kept for 30 minutes; s40, during the pressure maintaining period, soapy water is used for checking the sealing face of the valve cover and the valve seat, and the sealing face is qualified if no bubble is generated; and S50, the valve is slowly opened for pressure relief, the blind plate and the pressurizer are dismantled, and inspection is completed. According to the valve pressure resistance detection method, the quality of the valve is ensured, and the maintenance cost and time are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of valve detection, and in particular relates to a method for detecting an automatic valve driven by oil pressure. Background Art

[0002] Valves are common components in chemical production. In order to ensure the integrity of valves installed on process equipment, tightness tests must be performed before installation. Manually switched valves and pneumatically switched valves are easy to test on valve-specific pressure testing machines, but hydraulically driven valves are difficult to test. Since hydraulically driven valves are not commonly used in our company, it is not economical to build an oil station. If they are installed on process equipment without offline testing, there will be certain hidden dangers of valve internal leakage.

[0003] At present, there is a valve air tightness detection device with the existing announcement number CN115824530A, which includes a workbench, a support plate is symmetrically arranged in the middle position of the upper surface of the workbench, the support plate is used to support and place the valve, a threaded sealing detection mechanism is arranged on the upper surface of the workbench, the threaded sealing detection mechanism is used to perform sealing detection on the valve with internal threads, and a valve twisting mechanism is arranged above one side of the workbench; through the rotation of the double-rotation screw rod, the rotating threaded sealing head will be driven to be threadedly connected to the threaded valve ports at both ends of the valve body, thereby realizing threaded sealing connection of the valve ports at both ends of the internal threaded valve, and at the same time, the internal threaded valve can be fixed to the support plate, thereby not only preventing the internal threaded valve from leaking due to poor sealing during air tightness detection, but also preventing the valve from moving due to the push of high-pressure gas filled into the valve.

[0004] But there is also a problem: this method requires complex equipment, high cost, and is not conducive to on-site testing. Summary of the invention

[0005] The present invention provides a method for detecting an automatic valve driven by hydraulic pressure, comprising the following steps:

[0006] Step S10: installing a blind plate, connecting the blind plate to the second interface, and connecting the blind plate and the air pump through an air inlet pipe;

[0007] Step S20: using a pressurizer to pressurize the oil cylinder until the pressure reaches the working pressure value, so that the hydraulic rod presses against the valve plate from the first interface, so that the valve plate closes the third interface;

[0008] Step S30: Add compressed air from the air inlet pipe to the valve chamber to a set working pressure, and maintain the pressure for 30 minutes;

[0009] Step S40: During the pressure maintenance period, the sealing surface between the valve cover and the valve seat is checked with soapy water. If no bubbles are generated, it is qualified;

[0010] Step S50: Slowly open the valve to release the pressure, remove the blind plate and the pressurizer, and the inspection is completed.

[0011] The beneficial effects of this solution are: 1. This valve pressure resistance testing method ensures the quality of the valve and saves maintenance costs and time. 2. The use of this valve pressure resistance testing method reduces the labor intensity of inspection and maintenance personnel and reduces the company's material loss.

[0012] Furthermore, the pressure in step S30 reaches 1.1 times the valve design pressure, ensuring that the valve can still operate safely when the normal working pressure exceeds the pressure. This pressure is the best test pressure and can well detect whether the valve is qualified.

[0013] Furthermore, the pressurizer is a manual pressurizer, which can be applied to various occasions and is not limited by the venue.

[0014] Furthermore, in step S20, after the hydraulic rod abuts against the valve plate from the first interface, a seal is installed at the first interface. The seal can ensure the sealing of the first interface and prevent excessive gas from flowing out of the first interface, resulting in poor pressure maintenance effect.

[0015] Further, in step S30, when the valve chamber reaches the set working pressure, the pressure-maintaining mechanism keeps the pressure stable. The pressure-maintaining mechanism includes a blocking block, a spring, a reflux pipe and a sliding block, the blind plate is provided with an inner groove, the inner groove is connected to the air inlet pipe, the blocking block is slidably and sealedly connected to the inner groove, the blocking block is matched with the air inlet pipe, one end of the spring is fixedly connected to the blocking block, and the other end is fixedly connected to the sliding block, the sliding block is matched with the inner groove, one end of the reflux pipe is connected to the inner groove, and the other end is connected to the air pump, and the reflux pipe is matched with the blocking block.

[0016] When the intake pipe is ventilated, as the air pressure in the valve body increases, the blocking block will also move into the inner groove under pressure, which compresses the spring. When the set pressure is reached, the blocking block retreats to the set position, just connecting the return pipe with the intake pipe, so that the intake pipe and the return pipe form a loop to maintain pressure.

[0017] Further, it also includes step S25: when the operator ventilates the intake pipe, the self-locking mechanism will automatically lock the blind plate. The sliding block is connected to the inner groove in a sliding and sealing manner, and the sliding block is an inverted T-shaped, the self-locking mechanism includes a cylinder body, a piston, a guide tube, a piston rod, a T-block, an insertion block and a locking rod, the blind plate is provided with a connecting hole, the connecting hole is connected to the inner groove, the connecting hole is matched with the flange hole of the second interface, the cylinder body is fixedly connected to the blind plate, the piston is connected to the cylinder body in a sliding and sealing manner, one end of the piston rod is fixedly connected to the piston, and the other end is fixedly connected to the T-block through the connecting hole, the T-block is matched with the sliding block, the T-block is located in the inner groove, and the T-block is fixedly connected to the insertion block, the insertion block is matched with the flange hole, and the insertion block is provided with an insertion cavity, one end of the guide tube is connected to the cylinder body, and the other end is connected to the insertion cavity, the locking rod is connected to the insertion cavity in a sliding and sealing manner, and the locking rod is matched with the flange hole.

[0018] When the intake pipe is ventilated, the air pressure will push the pressure-maintaining mechanism to move together, the sliding block will contact the T-block, and the T-block will move up at the same time. The upward movement of the T-block will cause the piston rod to move up, and the upward movement of the piston rod will cause the piston to move up. The upward movement of the piston will cause the gas in the cylinder to enter the insertion cavity through the guide tube, causing the locking rod to extend, and the length is greater than the diameter of the flange hole. At the same time, the rise of the T-block will drive the insertion block to rise, so that the locking rod is against the flange hole, forming a self-locking. This solution eliminates the traditional bolt connection, because bolt connection is very troublesome and increases the labor of the staff, while this mechanism only needs to align the insertion block with the flange hole and put it on.

[0019] Furthermore, in step S50, when the pressure in the valve chamber is relieved to atmospheric pressure, the blind plate is automatically opened by the self-locking mechanism. When the pressure in the valve chamber is relieved to atmospheric pressure, the piston rod and the T-block will move downward due to gravity, so that the pressure-maintaining mechanism returns to its original position, and the T-block also returns to its original position. As the piston moves downward, the gas in the insertion cavity enters the cylinder body, and the locking rod retracts into the insertion cavity, automatically opening the self-locking, and the operator can easily remove the blind plate.

[0020] This mechanism eliminates the traditional bolt connection, because the bolt will be under pressure due to the principle of air pressure, which can easily damage the thread, making it difficult to remove the bolt and troublesome to disassemble. This mechanism automatically retracts the locking rod and automatically opens when the atmospheric pressure is restored in the valve body, simplifying the steps and improving efficiency.

[0021] Furthermore, the method further includes step S05: the operator cleans and inspects each interface surface of the valve as required.

[0022] Furthermore, the blocking block is a blocking block with a slope, and the slope is located in the intake pipe when the intake pipe is not ventilated. When the intake pipe is inlet, the gas will hit the slope, which causes the blocking block to be subjected to a force in the direction of the inner groove, so that the blocking block can enter the inner groove faster.

[0023] Furthermore, two of the pressure-maintaining mechanisms and the self-locking mechanisms are provided, and are symmetrically arranged on both sides of the air intake pipe with the air intake pipe as the center.

[0024] Furthermore, a reset member is provided in the cylinder body, and the reset member is a reset spring, one end of which is fixedly connected to the cylinder body, and the other end is fixedly connected to the piston. The reset spring can quickly return the piston to its original position when the valve body returns to atmospheric pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a structural diagram of an embodiment 1 of a method for detecting an automatic valve driven by oil pressure.

[0026] Figure 2 is a cross-sectional view of Example 1 of a hydraulically driven automatic valve detection method,

[0027] Figure 3 is a state diagram of a hydraulically driven automatic valve detection method without air intake in Example 2,

[0028] Figure 4 FIG. 2 is a pressure holding state diagram of Example 2 of an oil pressure driven automatic valve detection method.

[0029] Figure 5 This is an enlarged view A of the embodiment 2 of a method for detecting an automatic valve driven by oil pressure without air intake,

[0030] Figure 6 This is an enlarged view B of the pressure maintenance of Example 2 of an oil pressure-driven automatic valve detection method.

[0031] The figure marks in the specification include: 1. manual pressurizer; 2. first pressure gauge; 3. blind plate; 4. intake pipe; 5. valve; 6. second pressure gauge; 7. oil cylinder; 8. pressure relief port; 9. valve body; 10. second interface; 11. connecting hole; 12. flange hole; 13. third interface; 14. valve plate; 15. hydraulic rod; 16. return pipe; 17. blocking block; 18. inner groove; 19. sliding block; 20. spring; 21. piston rod; 22. cylinder body; 23. conducting pipe; 24. T-block; 25. insertion block; 26. insertion cavity; 27. locking rod; 28. limit block. DETAILED DESCRIPTION

[0032] Embodiment 1:

[0033] As attached Figure 1 , Figure 2 As shown:

[0034] The present invention provides a method for detecting an automatic valve driven by hydraulic pressure, comprising the following steps:

[0035] Step S05: The operator needs to clean the first interface, the second interface 10, the third interface 13 and the surface of the valve plate 14 of the valve 5 to ensure that there is no oil stain, rust or foreign matter. Use an endoscope to check the inner wall of each interface to confirm that there is no damage.

[0036] Step S10: Connect the blind plate 3 to the second interface 10 of the valve body 9 through the flange hole 12, and ensure that the blind plate 3 is aligned with the flange hole 12 (12).

[0037] The blind plate 3 is connected to the air pump through the air inlet pipe 4. The air inlet pipe 4 is made of a pressure-resistant rubber hose, and the rated pressure must be ≥1.5 times the design pressure of the valve 5.

[0038] Check the sealing performance between the blind plate 3 and the second interface 10, and use an O-ring (made of fluororubber) to ensure airtightness.

[0039] Step S20: the manual pressurizer 1 is connected to the oil cylinder 7 through an oil pipe, and ISO VG46 hydraulic oil is injected into the oil cylinder 7.

[0040] Operate the manual pressurizer 1 to slowly increase the pressure to the designed working pressure of the valve 5 (such as 10 MPa), and monitor the pressure value through the first pressure gauge 2.

[0041] The hydraulic rod 15 is driven by oil pressure, extends from the first interface and abuts against the valve plate 14, forcing the third interface 13 to be closed. After the hydraulic rod 15 is fully extended, a prefabricated polytetrafluoroethylene seal (thickness 3mm) is immediately installed at the first interface to prevent gas leakage during subsequent pressurization.

[0042] Step S30: Start the air pump and inject compressed air into the valve chamber through the air inlet pipe 4. The pressure rises to 1.1 times (such as 11 MPa) of the design pressure of the valve 5, and is monitored in real time by the second pressure gauge 6.

[0043] Step S40: During the pressure maintenance period, apply soapy water (concentration 5%) evenly on the sealing surface of the valve cover and the valve seat. If no bubbles are generated within 30 minutes (visual inspection or camera-assisted monitoring), the seal is considered qualified; if there are continuous bubbles, mark the leakage position and terminate the test.

[0044] Step S50: Slowly open the pressure relief port 8 to release the pressure in the valve chamber to atmospheric pressure at a rate of ≤0.5MPa / min. Remove the blind plate 3. Remove the manual pressurizer 1 and the oil pipe, clean up the site and record the test data.

[0045] As attached Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown:

[0046] Embodiment 2:

[0047] Add self-locking mechanism and pressure-maintaining mechanism, and the rest are the same.

[0048] This solution provides self-locking mechanism and pressure-maintaining mechanism:

[0049] The pressure maintaining mechanism includes a blocking block 17, a spring 20, a reflux pipe 16 and a sliding block 19. The blind plate 3 is provided with an inner groove 18, which is communicated with the intake pipe 4. The blocking block 17 is slidingly and sealingly connected to the inner groove 18. When there is no ventilation, the blocking block 17 is located at the slope in the intake pipe 4. One end of the spring 20 is fixedly connected to the blocking block 17, and the other end is fixedly connected to the sliding block 19. One end of the reflux pipe 16 is communicated with the inner groove 18, and the other end is connected to the air pump. When there is no air intake, the reflux pipe 16 is located on the right side of the blocking block 17.

[0050] The sliding block 19 is slidably sealed and connected to the inner groove 18, and the sliding block 19 is inverted T-shaped. The blocking block 17 is a blocking block 17 with a slope, and the slope is located in the intake pipe 4 when the intake pipe 4 is not ventilated. When the intake pipe 4 is inlet, the gas will hit the slope, which causes the blocking block 17 to be subjected to a force in the direction of the inner groove 18, so that the blocking block 17 can enter the inner groove 18 faster.

[0051] The self-locking mechanism includes a cylinder body 22, a piston, a guide tube 23, a piston rod 21, a T-block 24, an insertion block 25 and a locking rod 27. A connecting hole 11 is provided on the blind plate 3, and the connecting hole 11 is connected to the inner groove 18. The connecting hole 11 is consistent in size with the flange hole 12 of the second interface 10 and has a corresponding position.

[0052] The cylinder body 22 is fixedly connected to the blind plate 3, the piston is slidably sealed to the cylinder body 22, one end of the piston rod 21 is fixedly connected to the piston, and the other end passes through the connecting hole 11 and is fixedly connected to the T-block 24, the T-block 24 is located in the inner groove 18, and the T-block 24 is fixedly connected to the insertion block 25, the insertion block 25 can be inserted into the flange hole 12, and the insertion block 25 is provided with an insertion cavity 26, and the insertion cavity 26 is also provided with a limit block 28, and the limit block 28 can ensure that the locking rod 27 will not be separated from the insertion cavity 26. One end of the guide tube 23 is connected to the cylinder body 22, and the other end is connected to the insertion cavity 26, the locking rod 27 is slidably sealed to the insertion cavity 26, and the locking rod 27 will prevent the insertion block 25 from passing through the flange hole 12 when it is extended.

[0053] A return member is also provided in the cylinder body 22, and the return member is a return spring, one end of which is fixedly connected to the cylinder body 22, and the other end is fixedly connected to the piston. The return spring can quickly return the piston to its original position when the valve body returns to atmospheric pressure.

[0054] There are two pressure-maintaining mechanisms and two self-locking mechanisms, which are symmetrically arranged on both sides of the air intake pipe 4 with the air intake pipe 4 as the center.

[0055] The present invention provides a method for detecting an automatic valve driven by hydraulic pressure, comprising the following steps:

[0056] Step S05: The operator needs to clean the first interface, the second interface 10, the third interface 13 and the surface of the valve plate 14 of the valve 5 to ensure that there is no oil stain, rust or foreign matter. Use an endoscope to check the inner wall of each interface to confirm that there is no damage.

[0057] Step S10: Connect the blind plate 3 to the second interface 10 of the valve body 9 through the flange hole 12, and ensure that the blind plate 3 is aligned with the flange hole 12 (12).

[0058] The blind plate 3 is connected to the air pump through the air inlet pipe 4. The air inlet pipe 4 is made of a pressure-resistant rubber hose, and the rated pressure must be ≥1.5 times the design pressure of the valve 5.

[0059] Check the sealing performance between the blind plate 3 and the second interface 10, and use an O-ring (made of fluororubber) to ensure airtightness.

[0060] Step S20: the manual pressurizer 1 is connected to the oil cylinder 7 through an oil pipe, and ISO VG46 hydraulic oil is injected into the oil cylinder 7.

[0061] Operate the manual pressurizer 1 to slowly increase the pressure to the designed working pressure of the valve 5 (such as 10 MPa), and monitor the pressure value through the first pressure gauge 2.

[0062] The hydraulic rod 15 is driven by oil pressure, extends from the first interface and abuts against the valve plate 14, forcing the third interface 13 to be closed. After the hydraulic rod 15 is fully extended, a prefabricated polytetrafluoroethylene seal (thickness 3mm) is immediately installed at the first interface to prevent gas leakage during subsequent pressurization.

[0063] Step S25: Start the air pump. When the air inlet pipe 4 is ventilated, the air pressure pushes the blocking block 17 and the sliding block 19 to move toward the inner groove 18. The inverted T-shaped slope of the sliding block 19 just contacts the T-block 24. When the blocking block 17 enters the inner groove 18, the T-block 24 rises to the set height. The upward movement of the T-block 24 will cause the piston rod 21 to move upward. The upward movement of the piston rod 21 will cause the piston to move upward. The upward movement of the piston will cause the gas in the cylinder body 22 to enter the insertion cavity 26 through the guide tube 23, so that the locking rod 27 extends out, and the length is greater than the diameter of the flange hole 12. At the same time, the rise of the T-block 24 will drive the insertion block 25 to rise, so that the locking rod 27 is against the flange hole 12, so that the locking rod 27 cannot pass through the flange hole 12, thereby ensuring the stability of the blind plate 3 under high pressure.

[0064] Step S30: Compressed air is injected into the valve chamber through the air inlet pipe 4, and the pressure rises to 1.1 times (such as 11 MPa) of the design pressure of the valve 5, and is monitored in real time by the second pressure gauge 6.

[0065] When the pressure reaches the set value, the blocking block 17 slides along the inner groove 18 under the action of air pressure, and then compresses the spring 20 until the return pipe 16 is connected with the intake pipe 4 to form a loop, automatically maintaining the pressure stable (error ± 0.2MPa). The pressure holding time is strictly controlled at 30 minutes.

[0066] Step S40: During the pressure maintenance period, apply soapy water (concentration 5%) evenly on the sealing surface of the valve cover and the valve seat. If no bubbles are generated within 30 minutes (visual inspection or camera-assisted monitoring), the seal is considered qualified; if there are continuous bubbles, mark the leakage position and terminate the test.

[0067] Step S50: Slowly open the pressure relief port 8 to release the pressure in the valve chamber to atmospheric pressure at a rate of ≤0.5 MPa / min.

[0068] The piston rod 21 and the T-block 24 will move downward due to gravity, so that the pressure-maintaining mechanism returns to its original position, and the T-block 24 also returns to its original position. As the piston moves downward, the gas in the insertion chamber 26 enters the cylinder body 22, and the locking rod 27 retracts into the insertion chamber 26, automatically opening the self-locking, and the operator can easily remove the blind plate 3. Remove the manual pressurizer 1 and the oil pipe, clean up the site and record the test data.

[0069] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for detecting an automatic valve driven by hydraulic pressure, characterized in that: The following steps are involved: Step S10: installing the blind plate (3), connecting the blind plate (3) to the second interface (10), and connecting the blind plate (3) and the air pump via the air inlet pipe (4); Step S20: using a pressure booster to apply pressure to the oil cylinder (7) until the pressure reaches the working pressure value, so that the hydraulic rod (15) presses against the valve plate (14) from the first interface, so that the valve plate (14) closes the third interface (13); Step S30: Add compressed air from the air inlet pipe (4) to the valve chamber to a set working pressure, and maintain the pressure for 30 minutes; Step S40: During the pressure maintenance period, the sealing surface between the valve cover and the valve seat is checked with soapy water. If no bubbles are generated, it is qualified; Step S50: Slowly open the valve (5) to release the pressure, remove the blind plate (3) and the pressurizer, and the inspection is completed.

2. A method for detecting an oil pressure driven automatic valve according to claim 1, characterized in that: The pressure in step S30 reaches 1.1 times the design pressure of the valve (5).

3. The method for detecting an oil pressure driven automatic valve according to claim 1, characterized in that: The pressurizer is a manual pressurizer (1).

4. The method for detecting an oil pressure driven automatic valve according to claim 1, characterized in that: In the step S20, the hydraulic rod (15) is pressed against the valve plate (14) from the first interface and then a sealing member is installed at the first interface.

5. The method for detecting an oil pressure driven automatic valve according to claim 1, characterized in that: In step S30, when the valve chamber reaches the set working pressure, the pressure maintaining mechanism will keep the pressure stable.

6. A method for detecting an oil pressure driven automatic valve according to claim 5, characterized in that: The method further comprises step S25: when the operator ventilates the air inlet pipe (4), the self-locking mechanism causes the blind plate (3) to be automatically locked.

7. A method for detecting an oil pressure driven automatic valve according to claim 6, characterized in that: In the step S50, when the pressure in the valve chamber is released to atmospheric pressure, the blind plate (3) is automatically opened by the self-locking mechanism.

8. The method for detecting an oil pressure driven automatic valve according to claim 1, characterized in that: The method further comprises step S05: the operator cleans and inspects each interface surface of the valve (5) as required.

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