An apparatus for testing the relationship between the specific pressure of a sealing ring and the leakage rate of a vacuum valve channel

Abstract

This invention belongs to the field of sealing ring performance testing technology, and particularly relates to a device for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel. It includes a universal testing machine, an upper mold, a lower mold, and a testing component. The lower mold is fixed on the fixed platform of the universal testing machine and has a cavity. The top of the lower mold is used to fix the sealing gasket to be tested, and the center of the sealing gasket is connected to the air inlet of the cavity. The upper mold is connected to the moving crossbeam of the universal testing machine and moves it towards the lower mold until the upper mold and the sealing gasket together seal the air inlet of the cavity. The testing component is used to evacuate the cavity and detect the amount of helium gas entering the cavity from outside the sealing gasket, obtaining the leakage rate Q of the sealing gasket. The specific pressure is calculated by combining the force and deformation data and curve (x-F) of the universal testing machine and the cross-section of the sealing gasket.

Description

Technical Field

[0001] This invention belongs to the field of sealing ring performance testing technology, and particularly relates to a device for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel. Background Technology

[0002] In vacuum valve design, controlling the sealing pressure is crucial. Excessive pressure accelerates valve wear and reduces its lifespan, while insufficient pressure compromises sealing performance. Currently, the nuclear fuel industry primarily relies on specialized laboratory gasket performance testing devices for testing the leakage rate of vacuum valve channels. These devices consist of a gasket loading system, a media supply system, and a leak detection system. This equipment requires multiple sensors for pressure and load measurements, and the sheer number of sensors, along with external pressure and gas sources and containers, makes it complex and difficult to operate. The device uses nitrogen, which makes it difficult to accurately identify minute leaks in the vacuum system. It also fails to consider the impact of mold roughness on the leakage rate, relying on calculations for each test, resulting in significant errors. Furthermore, the device cannot directly obtain the leakage rate; it requires conversion using the gas state equation. However, the sealing pressure data used in these calculations is largely empirical, lacking reliable experimental support, making it difficult to select appropriate gaskets with the required leakage rate based on engineering needs. Therefore, a solution is urgently needed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device for testing the relationship between the specific pressure and leakage rate of the sealing ring in a vacuum valve channel. The device is easy to operate, provides reliable results, and can accurately and intuitively measure the correspondence between the specific pressure and leakage rate, thereby guiding the efficient design and selection of sealing gaskets. To achieve the aforementioned objective, the technical solution of the present invention is as follows: a device for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel. The system includes a universal testing machine, an upper mold, a lower mold, and a testing component. The lower mold is fixed on the fixed platform of the universal testing machine and has a cavity. The top of the lower mold is used to fix the sealing gasket to be tested, and the center of the sealing gasket is connected to the air inlet of the cavity. The upper mold is connected to the moving crossbeam of the universal testing machine and moves towards the lower mold until the upper mold and the sealing gasket to be tested make contact and jointly seal the air inlet of the cavity. The testing component is used to evacuate the cavity and detect the amount of helium gas entering the cavity from outside the sealing gasket to obtain the leakage rate Q of the sealing gasket. Combined with the force and deformation data and curve (xF) recorded by the universal testing machine and the cross-section of the sealing gasket to be tested, the strain q when the sealing gasket to be tested achieves the sealing effect is calculated, which is the specific pressure of the sealing gasket to be tested.

[0004] Preferably, the system further includes a first fixing frame and a second fixing frame; the detection assembly includes a dial indicator, a helium mass spectrometer leak detector, and a helium gun; one end of the first fixing frame is fixed to the top surface of the upper mold, and the other end is connected to the dial indicator; one end of the second fixing frame is fixed to the lower mold, and the other end of the second fixing frame is provided with a vertical column; the rebound pin of the dial indicator passes through the through hole on the first fixing frame and, after contacting and pressing with the top end of the vertical column, can extend and retract in the vertical direction, and the extension and retraction stroke of the rebound pin is the same as the deformation of the sealing gasket under test after being pressed by the upper mold; the helium mass spectrometer leak detector is connected to the outlet of the cavity for evacuating the cavity, and the helium mass spectrometer leak detector is electrically connected to a universal testing machine; the helium gun is used to spray helium gas at the inlet of the sealed cavity.

[0005] Preferably, the sealing gasket to be tested includes an O-ring with a circular cross-section and a flat washer with a rectangular cross-section; the bottom end of the upper mold and the top end of the lower mold are both set as horizontal planes; the bottom end of the upper mold is provided with two annular protrusions of different diameters, and the two annular protrusions have the same center and are vertically opposite to the air inlet of the cavity; the top end of the lower mold is provided with a first groove and a second groove, and the first groove and the second groove respectively form a tenon-groove fit with the two annular protrusions of different diameters on the upper mold; the O-ring and the flat washer are placed in the first groove and / or the second groove.

[0006] Preferably, it also includes a cylindrical cap; the sealing gasket to be tested includes an L-shaped ring; the top of the lower mold is set as a boss, and the center of the boss is provided with an arc-shaped groove, which communicates with the air inlet of the cavity; the L-shaped ring is fitted onto the outer edge of the top of the boss; the top of the cylindrical cap is provided with a through hole, and the inner wall is provided with an internal thread, which forms a threaded connection with the external thread on the outer wall of the top of the boss, and the cylindrical cap is pressed on the L-shaped ring; the bottom of the upper mold is set as a hemispherical shape, and the bottom surface of the upper mold hemispherical shape forms a tenon groove with the arc-shaped groove, and forms a compression with the top of the L-shaped ring.

[0007] Preferably, the sealing gasket to be tested includes an L-shaped ring; it also includes an annular cap and a fixing bolt; the top of the lower mold has a flat surface and is provided with an annular pressure cap groove and an annular mounting groove for placing the L-shaped ring, and the center of the top of the lower mold has an arc-shaped groove that communicates with the air inlet of the cavity; the annular pressure cap groove and the annular cap form a tenon joint, and the annular mounting groove has a bolt hole; the fixing bolt passes through the through hole on the annular cap and presses the annular cap onto the L-shaped ring; the bottom of the upper mold is set as a hemispherical shape, and the bottom surface of the upper mold hemispherical shape forms a tenon joint with the arc-shaped groove, and forms a compression with the top of the L-shaped ring.

[0008] Preferably, it also includes a pin, an upper connecting post, a lower connecting post, and a fastening nut; the upper connecting post is vertically connected to the top of the upper mold, the lower connecting post is vertically connected to the bottom of the lower mold, and both the upper and lower connecting posts are provided with pin holes. The upper connecting column is inserted into the moving crossbeam of the universal testing machine. The pin is inserted through the hole on the moving crossbeam and then engages with the pin hole of the upper connecting column. The fastening nut is fitted onto the upper connecting column and forms a threaded connection with the upper connecting column. The lower connecting column is inserted into the fixed platform of the universal testing machine. The pin is inserted through the hole on the fixed platform and then engages with the pin hole of the lower connecting column. The fastening nut is fitted onto the lower connecting column and forms a threaded connection with it.

[0009] Preferably, it also includes a connecting pipe; one end of the connecting pipe is connected to the air outlet of the cavity, and the other end is connected to a helium mass spectrometer leak detector.

[0010] The beneficial effects of this invention are reflected in: (1) The device provided by the present invention compresses the sealing gasket using a universal testing machine. The universal testing machine has a high-precision sensor that can measure the force on the sealing gasket in real time. A dial indicator and a micrometer are fixed on the mold. The micrometer accurately measures the minute deformation of the sealing gasket and feeds it back to the universal testing machine in real time, thereby controlling the compression amount of the sealing gasket in a closed loop. By compressing the sealing gasket with the universal testing machine, the sealing gasket and the mold form a sealed cavity. After evacuation, the leakage rate of the sealing gasket is directly detected by a helium mass spectrometer leak detector. The sealing force and compression amount are obtained through the universal testing machine to obtain the accurate sealing specific pressure of the corresponding material and to obtain the correspondence between the sealing specific pressure and the leakage rate.

[0011] (2) The device provided by the present invention has simple mold processing and manufacturing, compact sealing cavity structure, short test time, and can quickly obtain results; a single mold can be adapted to sealing gaskets of various sizes (inner diameter, width, thickness), shapes (flat gaskets, O-rings and other shapes) and materials (rubber, polymer, metal), making it more versatile; and molds with different rough surfaces can be selected for testing according to actual working conditions, making the test results more accurate.

[0012] (3) The helium molecules used in the device provided by the present invention are small in size and can easily penetrate tiny gaps and leaks. The detection sensitivity is high. The helium mass spectrometer leak detector is connected to the sealing cavity, which can quickly and accurately detect the leakage rate of the sealing gasket, thus improving the detection efficiency. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the upper and lower molds in Embodiment 1 of the present invention.

[0014] Figure 2This is a top view of the mold structure in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the upper and lower molds in Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the upper and lower molds in Embodiment 3 of the present invention.

[0015] Figure labels and descriptions: a1. Fixed platform; a2. Moving crossbeam; b. Helium gun; c1. O-ring; c2. Flat washer; c3. L-ring; 11. Upper connecting column; 111. Pin hole; 12. Upper mold; 13. Fastening nut; 14. First fixing frame; 2. Lower mold; 21. First groove; 22. Second fixing frame; 23. Vertical column; 24. Second groove; 25. Cavity; 26. Connecting pipe; 27. Lower connecting column; 28. Bolt hole; 291. Annular mounting groove; 6. Dial gauge; 41. Cylindrical cover; 411. Annular cover; 412. Fixing bolt; 30. Helium mass spectrometer leak detector. Detailed Implementation

[0016] The technical solutions of 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 a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1-4 As shown, this invention provides an apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel. Since the sealing gaskets to be tested have various structures, different embodiments of the testing fixture are designed for sealing gaskets with different structures.

[0018] Example 1 like Figure 1-2 As shown: It includes a universal testing machine, an upper mold 12, a lower mold 2, a pin, an upper connecting post 11, a lower connecting post 27, a fastening nut 13, and a testing assembly.

[0019] The upper connecting column 11 is vertically connected to the top of the upper mold 12, and the lower connecting column 27 is vertically connected to the bottom of the lower mold 2. Both the upper connecting column 11 and the lower connecting column 27 are provided with pin holes 111.

[0020] The upper connecting column 11 is inserted into the moving crossbeam a1 of the universal testing machine. The pin is inserted through the hole on the moving crossbeam a1 and then into the pin hole 111 of the upper connecting column 11. The fastening nut 13 is fitted on the upper connecting column 11 and forms a threaded connection with the upper connecting column 11. By adjusting the position of the fastening nut 13 on the upper connecting column 11, the stability of the connection between the upper connecting column 11 and the moving crossbeam a1 of the universal testing machine can be adjusted.

[0021] The lower connecting post 27 is inserted into the fixed platform a2 of the universal testing machine. The pin passes through the hole on the fixed platform a2 and engages with the pin hole 111 of the lower connecting post 27. The fastening nut 13 is fitted onto the lower connecting post 27 and forms a threaded connection with it. By adjusting the position of the fastening nut 13 on the lower connecting post 27, the stability of the connection between the lower connecting post 27 and the fixed platform a2 of the universal testing machine can be adjusted.

[0022] A cavity 25 is provided in the lower mold 2. The top of the lower mold 2 is used to fix the sealing gasket to be tested, and the center of the sealing gasket to be tested is connected to the air inlet of the cavity 25. The upper mold 12 is connected to the moving crossbeam a1 of the universal testing machine and drives the upper mold 12 to move towards the lower mold 2 until the upper mold 12 and the sealing gasket to be tested form a contact connection and jointly seal the air inlet of the cavity 25.

[0023] It also includes a first fixing frame 14 and a second fixing frame 22; the detection components include a dial indicator 6, a helium mass spectrometer leak detector 30, and a helium gun b; one end of the first fixing frame 14 is fixed to the top surface of the upper mold 12, and the other end is connected to the dial indicator 6; one end of the second fixing frame 22 is fixed to the lower mold 2, and the other end of the second fixing frame 22 is provided with a vertical column 23; the rebound needle 61 of the dial indicator 6 passes through the through hole on the first fixing frame 14, and after contacting and pressing with the top end of the vertical column 23, it can extend and retract in the vertical direction, and the extension and retraction stroke of the rebound needle 61 is the same as the deformation of the sealing gasket under test after being pressed by the upper mold 12; It also includes a connecting pipe 26; one end of the connecting pipe 26 is connected to the outlet of the cavity 25, and the other end is connected to the helium mass spectrometer leak detector 30. The helium gun b is used to spray helium gas at the inlet of the sealed cavity 25.

[0024] After the air inlet of cavity 25 is sealed, the helium mass spectrometer leak detector 30 begins to evacuate cavity 25 and detects the amount of helium gas entering cavity 25 from outside the gasket under test, thus obtaining the leakage rate Q of the gasket under test. Combined with the force and deformation data and curve (xF) recorded by the universal testing machine and the cross-section of the gasket under test, the strain q when the gasket under test achieves the sealing effect is calculated, which is the specific pressure of the gasket under test.

[0025] Specific pressure = sealing force / sealing cross-sectional area. At this time, the leakage rate and specific pressure of the gasket to be tested can be obtained directly, and the corresponding relationship can be obtained.

[0026] When the gaskets to be tested are an O-ring c1 with a circular cross-section and a flat washer c2 with a rectangular cross-section, the bottom end of the upper mold 12 and the top end of the lower mold 2 are both set as horizontal surfaces. The bottom end of the upper mold 12 is provided with two annular protrusions 21 of different diameters, and the centers of the two annular protrusions 21 are the same and are vertically opposite to the air inlet of the cavity 25. The top end of the lower mold 2 is provided with a first groove 21 and a second groove 24, and the first groove 21 and the second groove 211 respectively form a tenon-groove fit with the two annular protrusions 21 of different diameters on the upper mold 12. The O-ring c1 and the flat washer c2 are placed in the first groove 21 and / or the second groove 24. This arrangement can accommodate sealing tests of gaskets of various sizes.

[0027] Therefore, when it is necessary to test the specific pressure of O-ring c1 or flat washer c2, place O-ring c1 or flat washer c2 in the first groove 21 and / or the second groove 24, reset the force value recorded by the universal testing machine to zero, and then manually adjust the moving beam a1 to move the upper mold 12 downward until the annular convex ring 21 enters the first groove 21 or the second groove 24 and slightly adheres to O-ring c1 or flat washer c2; at this time, the force value of the universal testing machine shows slight fluctuations. Then start the helium mass spectrometer leak detector 30 to evacuate the cavity 25, and continuously fine-tune the moving beam a1. Press the O-ring c1 or flat washer c2 downwards until a vacuum of 4-6 Pa stabilizes. Stop pressing and observe the deformation data of the O-ring c1 or flat washer c2 output by dial gauge 6. The operator uses a helium gas bag and helium gun b to fill the cavity 25 with helium gas. After 5 minutes, wait for the helium mass spectrometer leak detector 30 reading to stabilize, record the leakage rate Q, and obtain the force-deformation data and curve (xF) recorded by the universal testing machine. Calculate the strain q required to achieve a seal using the cross-section of the O-ring c1 or flat washer c2; this is the specific pressure of the O-ring c1 or flat washer c2. Depending on the repeatability of the test data, the test should be repeated three times, and the results recorded.

[0028] Example 2 like Figure 3 As shown, when the cross-section of the sealing gasket to be tested is a stepped L-shaped ring c3; based on implementation 1, an upper mold 12 and a lower mold 2 with another structure are provided, and a cylindrical cover 41 is also included.

[0029] The top of the lower mold 2 is set as a boss, and the center of the boss is provided with an arc-shaped groove, which is connected to the air inlet of the cavity 25; the L-shaped ring c3 is fitted on the outer edge of the top of the boss; the top of the cylindrical cover 41 is provided with a through hole, and the inner wall is provided with an internal thread, which is connected to the external thread on the outer wall of the top of the boss, and the cylindrical cover 41 is pressed on the L-shaped ring c3; the bottom of the upper mold 12 is set as a hemispherical shape, and the bottom surface of the hemispherical shape of the upper mold 12 forms a tenon groove with the arc-shaped groove, and forms a compression with the top of the L-shaped ring c3.

[0030] The subsequent operation process is the same as in Example 1.

[0031] Example 3 like Figure 4 As shown, when the cross-section of the sealing gasket to be tested is a stepped L-shaped ring c3; based on embodiment 1, an upper mold 12 and a lower mold 2 with another structure are provided, which also include an annular cover 411 and a fixing bolt 412. The top of the lower mold 2 is provided with a flat surface, and is provided with an annular pressure groove and an annular mounting groove 291 for placing the L-shaped ring c3. The center of the top of the lower mold 2 is provided with an arc-shaped groove, which is connected to the air inlet of the cavity 25. The annular pressure groove and the annular cover 411 form a tenon joint, and the annular mounting groove 291 is provided with a bolt hole 28. After the fixing bolt 412 passes through the through hole on the annular cover 411, it can press the annular cover 411 onto the L-shaped ring c3. The bottom of the upper mold 12 is set as a hemispherical shape, and the bottom surface of the hemispherical shape of the upper mold 12 forms a tenon joint with the arc-shaped groove, and can form a compression with the top of the L-shaped ring c3.

[0032] The subsequent operation process is the same as in Example 1.

[0033] As shown in Examples 2 and 3, the lower mold 2 and the upper mold 12 can also be used for non-planar sealing tests, such as spherical seals and conical seals. Here, only the spherical seal test will be used for explanation. For non-planar sealing tests, the contact surface between the upper mold 12 and the sealing gasket to be tested is made with different shapes.

[0034] In all the above embodiments, the lower mold 2 and the upper mold 12 must be used as a set. The lower mold 2 has a hole drilled in the center to serve as a gas channel and is welded to the side quick-release connector or air nozzle to form a sealed cavity, which is the cavity 25.

[0035] A set of molds consisting of lower mold 2 and upper mold 12 uses the same processing and manufacturing process, and their sealing grooves have the same roughness. The test can be carried out according to the actual working conditions of the actual sealing gasket, and multiple sets of molds with different roughnesses can be processed to make the test results more reliable.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An apparatus for testing the relationship between the specific pressure of a seal ring and the leak rate of a vacuum valve channel, characterized in that The test assembly includes a universal testing machine, an upper mold (12), a lower mold (2), and a testing component. The lower mold (2) is fixed on the fixed platform (a2) of the universal testing machine, and a cavity (25) is provided in the lower mold (2). The top of the lower mold (2) is used to fix the gasket to be tested, and the center of the gasket to be tested is connected to the air inlet of the cavity (25). The upper mold (12) is connected to the moving crossbeam (a1) of the universal testing machine and drives the upper mold (12) to move towards the lower mold (2) until the upper mold (12) and the gasket to be tested form a contact connection and jointly seal the air inlet of the cavity (25). The testing component is used to evacuate the cavity (25) and detect the amount of helium gas outside the gasket to be tested entering the cavity (25), obtain the leakage rate of the gasket to be tested, and calculate the specific pressure of the gasket to be tested by combining the force and deformation data and curves recorded by the universal testing machine and the cross section of the gasket to be tested.

2. A device for testing the relationship between the specific pressure of a sealing ring and the leakage rate of a vacuum valve channel according to claim 1, characterized in that It also includes a first fixing frame (14) and a second fixing frame (22); the detection assembly includes a dial indicator (6), a helium mass spectrometer leak detector (30), and a helium gun (b); one end of the first fixing frame (14) is fixed to the top surface of the upper mold (12), and the other end is connected to the dial indicator (6); one end of the second fixing frame (22) is fixed to the lower mold (2), and the other end of the second fixing frame (22) is provided with a vertical column (23); the spring pin (61) of the dial indicator (6) passes through the first fixing frame (14). The through hole on the frame (14) and after contacting and pressing the top of the vertical column (23), it can extend and retract in the vertical direction, and the extension and retraction stroke of the rebound pin (61) is the same as the deformation of the sealing gasket under test after being squeezed by the upper mold (12); the helium mass spectrometer leak detector (30) is connected to the outlet of the cavity (25) and is used to evacuate the cavity (25), and the helium mass spectrometer leak detector (30) is electrically connected to the universal testing machine; the helium gun (b) is used to spray helium at the inlet of the sealed cavity (25).

3. The apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel according to claim 2, characterized in that, The sealing gasket to be tested includes an O-ring (c1) with a circular cross-section and a flat washer (c2) with a rectangular cross-section; the bottom end of the upper mold (12) and the top end of the lower mold (2) are both set as horizontal planes; the bottom end of the upper mold (12) is provided with two annular protrusions (21) of different diameters, and the two annular protrusions (21) have the same center and are vertically opposite to the air inlet of the cavity (25); the top end of the lower mold (2) is provided with a first groove (21) and a second groove (24), and the first groove (21) and the second groove (211) respectively form a tenon-groove fit with the two annular protrusions (21) of different diameters on the upper mold (12); the O-ring (c1) and the flat washer (c2) are placed in the first groove (21) and / or the second groove (24).

4. The apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel according to claim 2, characterized in that, It also includes a cylindrical cover (41); the sealing gasket to be tested includes an L-shaped ring (c3) with a cross section; the top of the lower mold (2) is set as a boss, and the center of the boss is provided with an arc-shaped groove, which is connected to the air inlet of the cavity (25); the L-shaped ring (c3) is fitted on the outer edge of the top of the boss; the top of the cylindrical cover (41) is provided with a through hole, and the inner wall is provided with an internal thread, which is connected to the external thread on the outer wall of the top of the boss, and the cylindrical cover (41) is pressed on the L-shaped ring (c3); the bottom of the upper mold (12) is set as a hemispherical shape, and the bottom surface of the hemispherical shape of the upper mold (12) and the arc-shaped groove form a tenon groove fit, and form a compression with the top of the L-shaped ring (c3).

5. The apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel according to claim 2, characterized in that, The sealing gasket to be tested includes an L-shaped ring (c3) with an L-shaped cross section; it also includes an annular cover (411) and a fixing bolt (412); the top of the lower mold (2) is provided with a flat surface, and is provided with an annular pressure cap groove and an annular mounting groove (291) for placing the L-shaped ring (c3) in an interconnected manner; and the center of the top of the lower mold (2) is provided with an arc-shaped groove, which is connected to the air inlet of the cavity (25); the annular pressure cap groove and the annular cover (411) form a tenon groove fit, and the annular mounting groove (291) is provided with a bolt hole (28); the fixing bolt (412) passes through the through hole on the annular cover (411) and presses the annular cover (411) onto the L-shaped ring (c3); the bottom of the upper mold (12) is set as a hemispherical shape, and the bottom surface of the hemispherical shape of the upper mold (12) forms a tenon groove fit with the arc-shaped groove, and forms a compression with the top of the L-shaped ring (c3).

6. The apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel according to claim 2, characterized in that, It also includes a pin, an upper connecting post (11), a lower connecting post (27), and a fastening nut (13); the upper connecting post (11) is vertically connected to the top of the upper mold (12), the lower connecting post (27) is vertically connected to the bottom of the lower mold (2), and both the upper connecting post (11) and the lower connecting post (27) are provided with pin holes (111). The upper connecting column (11) is inserted into the moving crossbeam (a1) of the universal testing machine. The pin is inserted through the hole on the moving crossbeam (a1) and then engages with the pin hole (111) of the upper connecting column (11). The fastening nut (13) is fitted on the upper connecting column (11) and forms a threaded connection with the upper connecting column (11). The lower connecting post (27) is inserted into the fixed platform (a2) of the universal testing machine. The pin is inserted through the hole on the fixed platform (a2) and then forms an insertion fit with the pin hole (111) of the lower connecting post (27). The fastening nut (13) is fitted on the lower connecting post (27) and forms a threaded connection with the lower connecting post (27).

7. The apparatus for testing the relationship between the specific pressure and leakage rate of a sealing ring in a vacuum valve channel according to claim 2, characterized in that, It also includes a connecting pipe (26); one end of the connecting pipe (26) is connected to the outlet of the cavity (25), and the other end is connected to the helium mass spectrometer leak detector (30).

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