Gasket sealing performance testing device and testing method thereof

Abstract

The invention provides a gasket sealing performance testing device and a testing method thereof, and solves the problems that an existing sealing gasket leakage testing device is complex in structure and difficult to quickly and accurately test the high-pressure sealing performance of an annular sealing gasket. According to the technical scheme, a lower pressing block arranged at the telescopic end of a hydraulic oil cylinder of a press workbench and a bearing disc clamp a sealing gasket to form a hollow cavity in the middle of the sealing gasket, and a communicating hole in the bottom of the bearing disc is connected with a standard volume gas tank and high-pressure gas pressurizing equipment through a main testing pipeline of a testing pipeline via a low-pressure pipeline and a high-pressure pipeline respectively. According to the testing method, the leaked gas amount and the gas leakage rate are calculated according to a measured value of the pressure sensor and the volume and pressure change relation of the Boyle law. Therefore, the device is simple in structure, convenient and rapid to test, outstanding in gasket sealing leakage test capability, capable of meeting corresponding test requirements, convenient for temperature environment adjustment and capable of improving the accuracy of test results.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing test, in particular to a gasket sealing test device and a test method thereof, which are suitable for testing annular sealing gaskets of equipment in cutting-edge fields such as oil production, navigation, and aerospace. Background Art

[0002] At present, gaskets for equipment in frontier fields such as oil production, navigation, and aerospace are key components affecting connection sealing performance. A sealing gasket is a sealing spare part used in facilities with fluids such as machinery, equipment, and pipelines, and is a material that seals between the inside and outside, usually in a circular ring shape. It can be divided into metal sealing gaskets and non-metal sealing gaskets according to the material. The sealing of fluids is achieved through the close contact between the equipment contact surface and the gasket. Relying on the elastic-plastic deformation of the gasket to prevent or reduce leakage. The rapid development of modern industry has imposed increasingly strict requirements on gasket sealing. Strict quantitative control of the pressure rate is an important condition to ensure the safe operation of modern systems and equipment. Although there have been many gasket sealing performance tests at home and abroad, there is still no perfect gasket pressure rate test method. The existing gasket sealing performance test devices have low measurement accuracy for the pressure in the leak detection cavity and are prone to large test errors caused by poor leak detection and loose cavity sealing. Especially when testing the gasket sealing performance, due to problems such as unstable accuracy of gasket pre-pressure setting, unbalanced guarantee of gasket ambient temperature, and difficulty in measuring gasket leakage, it is very difficult to achieve gasket sealing measurement. The existing gasket sealing test device uses a press workbench with a hydraulic cylinder set through a bracket. A lower flange and an upper flange are set on the press workbench. A flexible gasket specimen is set in the annular sealing cavity formed between the inner side wall of the lower flange ring and the outer side wall of the upper flange. A gland is set at the upper end of the annular cavity. Pressure sealing is formed by applying pressure to the upper flange through the hydraulic cylinder. The annular cavity is connected to a high-pressure gas pipeline to test the sealing performance and leakage of the gasket specimen. Its disadvantages are: the test device has a complex structure and cannot conveniently, quickly, and accurately test the gas leakage of the gasket under the set high pressure and high temperature conditions. The patent document with the publication number CN117470444A discloses a sealing gasket sealing performance test device, which uses a gasket specimen placed in a C-shaped structure on a fixed seat, and the telescopic end of the hydraulic cylinder of the press workbench applies pressure to the gasket specimen. By performing ultrasonic detection, it is found that the gasket specimen will have different degrees of deformation and failure under hot pressing conditions, such as ablation, deformation, cracks, etc. Its disadvantages are: the test device has a complex structure and cannot accurately test the gas leakage of the gasket under the set high pressure and high temperature conditions. The patent document with the publication number CN118408689A discloses a sealing gasket leakage rate test method, which uses an upper pressing plate and a lower pressing plate to form a sealing cavity, and a detection component composed of a high-pressure side pipeline, a switch valve, a balance chamber differential pressure sensor, etc. Its disadvantages are: the connection structure of the detection component is complex, the volume test of the sealing cavity and the measurement pipeline is inaccurate, the operation process is cumbersome, and it is difficult to quickly and accurately measure the pressure result. Summary of the Invention

[0003] The purpose of the present invention is to provide a gasket sealing test device and a test method thereof, which solves the problem that the existing sealing gasket leakage test device has a complex structure and is difficult to quickly and accurately test the high-pressure sealing performance of the annular sealing gasket. The structure is simple and the annular sealing gasket can be tested conveniently and accurately.

[0004] The technical solution adopted by the present invention is: the gasket sealing test device comprises: a press workbench on which a hydraulic cylinder is arranged through a support frame, a support tray is arranged in the middle of the press workbench, and a lower pressure block arranged at the telescopic end of the hydraulic cylinder of the press workbench corresponds to the upper opening of the support tray. The technical key points are: the lower pressure block and the support tray form a hollow cavity in the middle of the sealing gasket by clamping the sealing gasket, a connecting hole connected to an external test pipeline is arranged at the bottom of the support tray, the rear end of the main test pipeline of the test pipeline is connected to the connecting hole, the external inlet of the main test pipeline is respectively connected to a low-pressure pipeline provided with a low-pressure stop valve and a high-pressure pipeline provided with a high-pressure stop valve, the front end of the low-pressure pipeline is connected to a standard volume gas tank, the pipeline between the standard volume gas tank and the low-pressure stop valve is provided with a first pressure sensor, the front end of the high-pressure pipeline is connected to a high-pressure gas pressurizing device, a second pressure sensor is arranged between the high-pressure stop valve and the inlet of the main test pipeline, and the outer wall of the support tray is provided with a heating tile and a thermometer.

[0005] The testing method of the gasket sealing testing device includes the following testing steps: S1. Place the sealing gasket specimen to be tested in the tray of the press workbench, control the hydraulic cylinder to press down, so that the lower pressing block presses the sealing gasket specimen, simulating the actual pressing state environment of the sealing gasket specimen; S2. Take a standard volume gas tank, measure the volume of the gas tank to be V1, and the pressure inside the gas tank to be P1. Connect the standard volume gas tank to the low-pressure pipeline, open the low-pressure stop valve, and measure the value P2 after the pressure is reduced. At this time, the volume of the gas tank V1 and the volume of the test pipeline V 管 The hollow volume V of the sealing gasket specimen 腔 The total volume of the gas V2 = V1 + V 管 +V 腔 ; S3. According to Boyle's law formula: V=k / P, V is the volume of the gas, P is the pressure, k is a constant, then we get the formula: V1P1=V2P2; According to the measured V1, P1, P2 values, Calculation: V2 = V1P1 / P2 value; Calculation: V 管 +V 腔 =V2 - value of V1; S4, turning on the heating tile of the tray to heat up the temperature to the test set temperature; S5. Open the high-pressure stop valve, and apply the test high pressure to the pipeline to P3 through the high-pressure gas pressure equipment. After the pressure stabilizes, close the high-pressure stop valve pipeline, wait for the test time T, and measure the pipeline pressure P4 after leakage; S6. Calculate the gas leakage of the sealing gasket specimen after the test time T, that is, the leakage gas volume V 泄 According to Boyle's law, we get P3 (V 管 +V 腔 ) = P4 (V 管 +V 腔 +V 泄 ),calculate: V 泄 = (P3 (V 管 +V 腔 )-P4V 管 -P4V 腔 ) / P 4， The amount of leaked gas is obtained after calculation; S7. Calculate the gas leakage rate of the sealing gasket specimen: V 泄 / The value of T; S8. Raise the hydraulic cylinder to release the pressure, take out the sealing gasket test piece, clean up the site, and the test is completed.

[0006] The advantages and positive effects of the present invention are as follows: since the gasket sealing test device of the present invention adopts the lower pressing block and the support tray clamp arranged at the telescopic end of the hydraulic cylinder of the press workbench to hold the sealing gasket to form a hollow cavity in the middle of the sealing gasket, and a connecting hole connected to the external test pipeline is arranged at the bottom of the support tray, a closed sealing test space can be formed; the rear end of the main test pipeline is connected to the connecting hole, and the external inlet of the main test pipeline is respectively connected to a low-pressure pipeline with a low-pressure stop valve and a high-pressure pipeline with a high-pressure stop valve, the front end of the low-pressure pipeline is connected to a standard volume gas tank, and the pipeline between the standard volume gas tank and the low-pressure stop valve is provided with a first pressure sensor, The low-pressure stop valve is used to control the formation of a test space for the low-pressure pipeline, and the pressure change in the standard volume tank cavity can be used to assist in measuring the leakage. A high-pressure gas pressure device is connected to the front end of the high-pressure pipeline, and a second pressure sensor is set between the high-pressure stop valve and the main test pipeline inlet, which can easily form a test space for the low-pressure pipeline by controlling the high-pressure stop valve switch. The outer wall of the tray is provided with a heating tile and a thermometer, which is convenient for adjusting to the set high-temperature test environment, providing a relatively balanced gasket test temperature environment, and the test device is in a stable temperature environment. The standard volume cavity is converted through pressure leakage volume, and the leakage is accurately and complexly calculated. The structure is simple and the test environment is formed quickly and conveniently. The testing method of the present invention utilizes a standard volume gas tank and a high-pressure gas pressure device that can form a closed sealing test space, switches the pressure of the pipeline through the connection of the test pipeline, and cleverly utilizes Boyle's law to convert pressure into a volume change to obtain a volume and pressure formula, so as to facilitate and accurately calculate the amount of gas leakage and the leakage rate of the sealing gasket specimen. Therefore, it has a simple structure, is convenient and quick to test, has an outstanding gasket sealing leakage test capability, meets the corresponding test requirements, is convenient for temperature environment adjustment, and improves the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention is further described below in conjunction with the accompanying drawings.

[0008] Figure 1 is a schematic structural diagram of an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a sealing gasket specimen according to an embodiment of the present invention.

[0009] Explanation of the serial numbers in the figure: 1 press workbench, 2 bearing tray, 3 sealing gasket, 4 lower pressure block, 5 support frame, 6 hydraulic cylinder, 7 hollow cavity, 8 thermometer, 9 connecting hole, 10 heating tile, 11 main test pipeline, 12 standard volume gas tank, 13 low-pressure pipeline, 14 first pressure sensor, 15 low-pressure stop valve, 16 high-pressure pipeline, 17 second pressure sensor, 18 high-pressure stop valve, 19 high-pressure gas pressurizing equipment. DETAILED DESCRIPTION

[0010] according to Figure 1and Figure 2 The specific structure of the present invention is described in detail, and the implementation example Figure 1 and Figure 2 As shown, a gasket sealing test device comprises: a press workbench 1, which can adopt a commercially available servo press workbench, which is provided with a hydraulic cylinder 6 through a support frame 5, a supporting tray 2 for placing a sealing gasket 3 test piece is provided in the middle of the press workbench 1, and a lower pressing block 4 is provided at the telescopic end of the hydraulic cylinder of the press workbench to correspond to the upper opening of the supporting tray 2. The tray is a circular tray with side walls. The lower pressing block 4 and the tray 2 form a hollow cavity 7 in the middle of the sealing gasket by clamping the sealing gasket 3. The bottom of the tray is provided with a connecting hole 9 connected to the external test pipeline. The rear end of the main test pipeline 11 of the test pipeline is connected to the connecting hole 9. The external entrance of the main test pipeline 11 is respectively connected to the low-pressure pipeline 13 and the high-pressure pipeline 16. The low-pressure pipeline 13 and the high-pressure pipeline 16 are respectively provided with a low-pressure stop valve 15 and a high-pressure stop valve 18. The front end of the low-pressure pipeline is connected to a standard volume gas tank 12. The pipeline between the standard volume gas tank and the low-pressure stop valve 15 is provided with a first pressure sensor 14. The standard volume gas tank is a tank body with a closed space volume cavity of a specified and uniform capacity. The front end of the high-pressure pipeline 16 is connected to a high-pressure gas pressure device 19 for providing high-pressure gas. A second pressure sensor 17 is provided between the high-pressure stop valve 18 and the entrance of the main test pipeline 11. The outer wall of the tray 2 is provided with a heating tile 10 for heating the tray, and a temperature sensor 8 for measuring the temperature of the tray. The test device can be used to test the sealing effect of graphite gaskets of different specifications.

[0011] The testing method of the gasket sealing testing device includes the following testing steps: S1. Prepare a sealing gasket 3 specimen and a gasket sealing test device, place the sealing gasket specimen to be tested in the support tray 2 of the press workbench, control the hydraulic cylinder 6 to press down, so that the lower pressing block tightly presses the sealing gasket specimen, simulating the actual pressing state environment of the sealing gasket specimen; S2, take the standard volume gas tank 12, measure the volume of the gas tank to be V1, the volume of the standard volume gas tank is the calibrated volume value of the gas tank, the pressure in the gas tank is P1, connect the standard volume gas tank to the low-pressure pipeline 13; open the low-pressure stop valve 15, the gas in the standard volume gas tank enters the test pipeline and enters the hollow cavity of the sealing gasket, and the value P2 after the pressure reduction is measured by the first pressure sensor 14. At this time, the volume of the standard volume gas tank V1 and the volume of the test pipeline V 管 The hollow volume V of the sealing gasket specimen 腔 The total volume of the gas V2 = V1 + V 管 +V 腔 ; S3. According to Boyle's law (also known as Mariotte's Law): Under constant temperature and constant quantity, the volume of an ideal gas is inversely proportional to the pressure of the gas. It was proposed by British chemist Boyle in 1662 based on experimental results and is called Boyle's law. Boyle's law formula: V=k / P, V is the volume of the gas, P is the pressure, k is a constant. If the temperature is the same, the relationship between the gas in the two states A and B can be expressed as: P A V A =P B V B Then we get the formula: V1P1=V2P2; According to the measured V1, P1, P2 values, Calculation: V2 = V1P1 / P2 value; Calculation: V 管 +V 腔 =V2 - value of V1; S4, then turn on the heating tile 10 of the tray to heat up and make the temperature reach the test set temperature, such as the test high temperature to 600 degrees Celsius; S5. Open the high-pressure stop valve 18 and apply a test high pressure to the pipeline through the high-pressure gas pressure device 19. The high-pressure gas enters the test pipeline and the hollow cavity of the sealing gasket, and the high-pressure gas pressure reaches P 3， The test high pressure can be set according to the test needs, and the P3 value is measured by the second pressure sensor 17. After the pressure stabilizes, the high pressure stop valve pipeline is closed, and the test time T is waited. Then, the pipeline pressure P4 value after the leakage is measured by the second pressure sensor; S6. Calculate the gas leakage of the sealing gasket specimen after the test time T, that is, the leakage gas volume V 泄 According to Boyle's law, we get P3 (V 管 +V 腔 ) = P4 (V 管 +V 腔 +V 泄 ),calculate: V 泄 = (P3 (V 管 +V 腔 )-P4V 管 -P4V 腔 ) / P 4， The amount of leaked gas is obtained after calculation; S7. Calculate the gas leakage rate of the sealing gasket specimen: V 泄 / The value of T; S8. Raise the hydraulic cylinder to release the pressure, take out the sealing gasket test piece, clean up the site, and the test is completed.

[0012] The test method of the present invention utilizes the formation of a closed sealing test space, switches the pressure of the pipeline through the standard volume gas tank and the high-pressure gas pressure device connected by the test pipeline, and cleverly utilizes Boyle's law to convert the pressure into the volume change to obtain the volume and pressure formula, so as to conveniently and accurately calculate the gas leakage amount and leakage rate of the sealing gasket test piece, and can utilize PLC and computer storage and operation calculation formulas and methods, obtain the detection values ​​of the first pressure sensor and the second pressure sensor through automatic detection, and automatically obtain the gas leakage amount and gas leakage rate. Therefore, it has a simple structure, is convenient and quick to test, has outstanding gasket sealing leakage test capabilities, meets the corresponding test requirements, is convenient for temperature environment adjustment, and improves the accuracy of the test results.

[0013] In summary, the purpose of the present invention is achieved.

Claims

1. A gasket sealing test device, comprising: A press workbench of a hydraulic oil cylinder is arranged through a supporting frame, a supporting tray is arranged in the middle of the press workbench, and a lower pressing block arranged at the telescopic end of the hydraulic oil cylinder of the press workbench corresponds to the upper opening of the supporting tray, wherein the lower pressing block and the supporting tray form a hollow cavity in the middle of the sealing gasket by clamping the sealing gasket, a connecting hole connected to an external test pipeline is arranged at the bottom of the supporting tray, the rear end of the main test pipeline of the test pipeline is connected to the connecting hole, the external inlet of the main test pipeline is respectively connected to a low-pressure pipeline provided with a low-pressure shut-off valve and a high-pressure pipeline provided with a high-pressure shut-off valve, a standard volume gas tank is connected to the front end of the low-pressure pipeline, a first pressure sensor is arranged on the pipeline between the standard volume gas tank and the low-pressure shut-off valve, a high-pressure gas pressurizing device is connected to the front end of the high-pressure pipeline, a second pressure sensor is arranged between the high-pressure shut-off valve and the inlet of the main test pipeline, and a heating tile and a thermometer are arranged on the outer wall of the supporting tray.

2. The testing method of the gasket sealing testing device according to claim 1, comprising the following testing steps: S1. Place the sealing gasket specimen to be tested in the tray of the press workbench, control the hydraulic cylinder to press down, so that the lower pressing block presses the sealing gasket specimen, simulating the actual pressing state environment of the sealing gasket specimen; S2. Take a standard volume gas tank, measure the volume of the gas tank to be V1, and the pressure inside the gas tank to be P1. Connect the standard volume gas tank to the low-pressure pipeline, open the low-pressure stop valve, and measure the value P2 after the pressure is reduced. At this time, the volume of the gas tank V1 and the volume of the test pipeline V 管 The hollow volume V of the sealing gasket specimen 腔 The total volume of the gas V2 = V1 + V 管 +V 腔 ; S3. According to Boyle's law formula: V=k / P, V is the volume of the gas, P is the pressure, k is a constant, then we get the formula: V1P1=V2P2; According to the measured V1, P1, P2 values, Calculation: V2 = V1P1 / P2 value; Calculation: V 管 +V 腔 =V2 - value of V1; S4, turning on the heating tile of the tray to heat up the temperature to the test set temperature; S5. Open the high-pressure stop valve, and apply the test high pressure to the pipeline to P3 through the high-pressure gas pressure equipment. After the pressure stabilizes, close the high-pressure stop valve pipeline, wait for the test time T, and measure the pipeline pressure P4 after leakage; S6. Calculate the gas leakage of the sealing gasket specimen after the test time T, that is, the leakage gas volume V 泄 According to Boyle's law, we get P3 (V 管 +V 腔 ) = P4 (V 管 +V 腔 +V 泄 ),calculate: V 泄 = (P3 (V 管 +V 腔 )-P4V 管 -P4V 腔 ) / P 4， The amount of leaked gas is obtained after calculation; S7. Calculate the gas leakage rate of the sealing gasket specimen: V 泄 / T value; S8. Raise the hydraulic cylinder to release the pressure, take out the sealing gasket test piece, clean up the site, and the test is completed.

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