High-temperature and high-pressure visual elemental sulfur reaction device and elemental sulfur analysis method

Abstract

The invention discloses a high-temperature and high-pressure visual elemental sulfur reaction device and an elemental sulfur analysis method. The reaction device comprises a reaction kettle mechanism, a heating mechanism, a pressure control mechanism and a visual monitoring mechanism; the analysis method comprises the following steps: (1) transferring a sample under simulated temperature and pressure conditions; (2) checking the gas tightness of the natural gas elemental sulfur equipment; (3) measuring elemental sulfur and the like. The device can be used for elemental sulfur reaction under high-temperature and high-pressure conditions, meanwhile, the visual window can observe the whole reaction evolution process in real time and online through a high-definition camera monitoring system, videos are recorded, and a playback viewing function is achieved; the problem of detecting the content of natural gas dissolved elemental sulfur in oil and gas reservoir fluid is solved.

Description

Technical Field

[0001] The invention belongs to the field of chemical reaction analysis methods, and specifically relates to a high-temperature and high-pressure visualized elemental sulfur reaction device and an elemental sulfur analysis method. Background Art

[0002] In chemical experiments and petroleum exploration, development and production, reaction processes under high temperature and high pressure conditions are of special significance. In particular, the reaction of elemental sulfur under high temperature and high pressure conditions plays an important role in understanding the chemical properties of sulfur and developing new chemical processes. However, existing high temperature and high pressure reaction devices usually do not have online visualization functions, and the details of the reaction process cannot be intuitively observed. Therefore, the development of a high temperature and high pressure visualized elemental sulfur reaction device has important practical value. Summary of the invention

[0003] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a high-temperature and high-pressure visualized elemental sulfur reaction device and an elemental sulfur analysis method.

[0004] The present invention is achieved through the following technical solutions:

[0005] A high-temperature and high-pressure visualized elemental sulfur reaction device, comprising a reactor mechanism, a heating mechanism, a pressure control mechanism and a visualized monitoring mechanism; the reactor mechanism comprises a reactor body, a reactor body cover, a glass cup arranged inside the reactor body and a storage rack arranged inside the reactor body; the glass cup is placed on the storage rack; observation windows are symmetrically arranged on the reactor body, and sapphire glass is arranged in the observation window; the sapphire glass on one side is fixed to the reactor body through a flange, and the sapphire glass on the other side is fixed to the reactor body through a light source flange; an inlet, a temperature detection port and an outlet are formed on the reactor body cover A temperature sensor is arranged at the temperature detection port; the reactor body and the reactor head are fixed by a clamp ring; the heating mechanism comprises a heating element and a constant temperature sleeve which are sequentially sleeved on the outside of the reactor body from the inside to the outside; the pressure control mechanism comprises an inlet needle stop valve arranged at the inlet of the reactor head, an outlet needle stop valve arranged at the outlet of the reactor head and a pressure sensor arranged inside the reactor body; the visual monitoring mechanism comprises a high-definition camera arranged outside the observation window on one side and a flexible light source arranged outside the observation window on the other side, and the flexible light source is arranged between the sapphire glass and the light source flange.

[0006] In the above technical solution, the reactor body consists of an upper cylindrical reactor body and a lower rectangular reactor body, an observation window is arranged on the short side of the rectangular reactor body, the observation window is communicated with the inner cavity of the reactor body, and an emptying port is arranged at the bottom of the reactor body.

[0007] In the above technical solution, the sapphire glass on one side is fixed to the reactor body through a flange, and the sapphire glass on the other side is fixed to the reactor body through a light source flange.

[0008] In the above technical solution, the storage rack includes a disc-shaped chassis and a vertical rod vertically connected to the chassis. A limiting groove is arranged in the middle of the chassis, and the glass is placed in the limiting groove.

[0009] In the above technical solution, the clamping ring is composed of two semicircular clamping half rings, and the inner walls of the clamping half rings form an annular groove.

[0010] In the above technical solution, the top outer wall of the reactor body forms a lower convex ring, and the bottom surface of the lower convex ring is a conical surface; the bottom outer wall of the reactor head forms an upper convex ring, and the top surface of the upper convex ring is a conical surface. The bottom surface of the lower convex ring and the top surface of the upper convex ring have the same taper; the upper convex ring and the lower convex ring are embedded in the annular groove of the clamping half ring.

[0011] In the above technical solution, a seal is provided between the reactor body and the reactor head.

[0012] In the above technical solution, a concave groove is arranged inside the light source flange, the LED lamp beads of the flexible light source are placed in the concave groove, and the light source wires of the flexible light source extend out of the light source flange.

[0013] A high temperature and high pressure visual elemental sulfur analysis method, comprising the following steps:

[0014] (I) Transferring the sample into the PVT analysis kettle and elemental sulfur equipment under simulated temperature and pressure conditions;

[0015] (II) Inspection of gas tightness of natural gas elemental sulfur equipment;

[0016] (III) Elemental sulfur measurement.

[0017] The beneficial effects of the present invention are:

[0018] The present invention provides a high-temperature and high-pressure visualized elemental sulfur reaction device and an elemental sulfur analysis method, which can be used for elemental sulfur reactions carried out under high-temperature and high-pressure conditions. At the same time, the visualization window can observe the entire reaction evolution process online in real time through a high-definition video monitoring system, and record the video with a playback function; it solves the problem of detecting the dissolved elemental sulfur content of natural gas in oil and gas reservoir fluids. The present invention forms a visualized detection and evaluation technology suitable for trace sulfur content in natural gas, which is a method that can be easily implemented in elemental sulfur detection at present. It not only visualizes the elemental sulfur experimental process, deepens the understanding of the elemental sulfur absorption process under simulated formation conditions, but also improves the safety performance of the overall experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a structural schematic diagram of the lower half of the high-temperature and high-pressure visualized elemental sulfur reaction device of the present invention;

[0020] Figure 2 It is a structural schematic diagram of the upper part of the high-temperature and high-pressure visualized elemental sulfur reaction device of the present invention;

[0021] Figure 3 It is a side view of the position of the observation window in the high-temperature and high-pressure visualized elemental sulfur reaction device of the present invention;

[0022] Figure 4 It is a schematic diagram of the structure of the elemental sulfur experimental device.

[0023] in:

[0024] 1. Reactor body; 2. Reactor head; 3. Seal; 4. Half ring; 5. Head fixing platform; 6. Glass; 7. Sapphire glass; 8. Flange; 9. Storage rack; 10. Reaction sample; 11. Heating element; 12. Constant temperature jacket; 13. Inlet needle stop valve; 14. Outlet needle stop valve; 15. Pressure sensor; 16. High-definition camera; 17. Flexible light source; 18. Drain port; 19. Light source wire; 20. Hexagon socket bolt; 21. Light source flange; 22. Temperature sensor; 23. Lower convex ring; 24. Upper convex ring; 25. Back pressure valve; 26. Recovery container; 27. Electronic balance; 28. Absorption container; 29. ​​Gas meter; 30. Weighing cup.

[0025] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0027] Example 1

[0028] like Figures 1 to 3 As shown, a high-temperature and high-pressure visualized elemental sulfur reaction device includes a reactor mechanism, a heating mechanism, a pressure control mechanism and a visualized monitoring mechanism;

[0029] The reactor structure comprises a reactor body 1, a reactor body cover 2, a glass cup 6 disposed inside the reactor body 1, and a storage rack 9 disposed inside the reactor body 1;

[0030] The reactor body 1 is composed of an upper cylindrical reactor body and a lower rectangular reactor body. The short sides of the rectangular reactor body form two observation windows symmetrically arranged at 180 degrees. The observation windows are connected to the inner cavity of the reactor body. Sapphire glass 7 is arranged in the observation windows. The sapphire glass 7 on one side is fixed to the reactor body 1 through a flange 8, and the sapphire glass 7 on the other side is fixed to the reactor body 1 through a light source flange 21.

[0031] The light source flange 21 and the flange 8 are fixed to the reactor body 1 by hexagon socket bolts 20 to achieve compression sealing, ensuring that the reactor is reliably sealed without leakage at high temperature 200°C and high pressure 100MPa;

[0032] The sapphire glass 7 is sealed with the observation window plane by a sealing gasket to ensure reliable sealing; the sapphire glass 7 has a diameter of 40 mm, is resistant to high temperature and high pressure, and has a transparency of more than 93%, ensuring clear observation;

[0033] The bottom of the reactor body 1 is provided with an emptying port 18;

[0034] The kettle body head 2 is formed with an inlet, a temperature detection port and an outlet, and the three interfaces are all sealed with an internal thread clamp ring structure; the temperature detection port is provided with a temperature sensor 22, which is used to monitor the actual temperature of the sample evolution in the reactor body, and is resistant to pressure, temperature and corrosion, with a temperature accuracy of 0.3 level;

[0035] The glass cup 6 is placed on the storage rack 9, and the glass cup 6 is used to hold the reaction sample 10;

[0036] The storage rack 9 includes a disc-shaped chassis and a vertical rod vertically connected to the chassis. A limiting groove is provided in the middle of the chassis. The glass 6 is placed in the limiting groove to achieve a limiting function to prevent the glass 6 from being miscentered and slipping off, thereby avoiding potential safety hazards. The storage rack 9 facilitates the removal and placement of the glass 6 in the reactor body.

[0037] The sealing of the elemental sulfur reactor is an important link that affects the success or failure of the experiment and the pollution of the laboratory environment. The reactor will often be opened to place test samples. In order to improve the use efficiency, the reactor body 1 and the reactor head 2 are fixed by a clamp ring, which is composed of two semicircular clamp half rings 4, and the inner wall of the clamp half ring 4 forms an annular groove;

[0038] The outer wall at the top of the reactor body 1 forms a lower convex ring 23, and the bottom surface of the lower convex ring 23 is a conical surface; the outer wall at the bottom of the reactor head 2 forms an upper convex ring 24, and the top surface of the upper convex ring 24 is a conical surface, and the taper of the bottom surface of the lower convex ring 23 and the top surface of the upper convex ring 24 are the same; the upper convex ring and the lower convex ring are embedded in the annular groove of the clamp half ring 4 to achieve the fixation between the reactor body 1 and the reactor head 2; a clamp quick-opening structure is formed between the clamp ring and the convex ring, which is convenient for operation and maintenance; a twisting fulcrum and a tightening screw sleeve are provided on the clamp half ring 4, and the reactor body can be clamped by hand torque to play a high-pressure sealing role;

[0039] The bottom surface of the kettle body cover 2 forms a boss, which is inserted into the reactor body 1. The outer diameter of the boss matches the inner diameter of the reactor body 1, so as to achieve positioning between the reactor body 1 and the kettle body cover 2.

[0040] A seal 3 is provided between the reactor body 1 and the reactor head 2. The seal 3 is provided in a seal groove on the top surface of the reactor body 1. The seal groove has a depth of 3 mm and the seal 3 protrudes by a compression amount of 0.5 mm.

[0041] The kettle head 2 is a stepped column structure with a small top and a large bottom, and a head fixing platform 5 is sleeved on the outside of the small diameter section; the head fixing platform 5 is fixed to the shoulder of the kettle head 2 by bolts; the fixing platform 5 is connected to the guide rod on the movable bracket to form a whole support;

[0042] The heating mechanism includes a heating element 11 and a thermostatic sleeve 12 which are sequentially sleeved on the outside of the reactor body 1 from the inside to the outside; the heating element 11 and the thermostatic sleeve 12 form a notch corresponding to the position of the observation window. The heating element 11 is used to heat the reactor and control the constant temperature. A high-temperature mica heating sheet is used to achieve step-by-step temperature control to reach the experimental temperature; the thermostatic sleeve 12 is used to keep the reactor body warm, ensuring that the heating temperature does not quickly diffuse outward, and providing a constant temperature environment for the test sample.

[0043] The pressure control mechanism includes an inlet needle stop valve 13 arranged at the inlet of the kettle head 2, an outlet needle stop valve 14 arranged at the outlet of the kettle head 2, and a pressure sensor 15 arranged inside the reactor body 1, and the pressure sensor is used to monitor the pressure inside the reactor body in real time.

[0044] The inlet needle stop valve 13 and the outlet needle stop valve 14 are both connected to the reactor body 1. The inlet needle stop valve 13 can inject a variety of high-pressure fluids, and the outlet needle stop valve 14 can achieve interception control of the size of the produced fluid and a closing effect.

[0045] The visual monitoring mechanism includes a high-definition camera 16 arranged outside the observation window on one side and a flexible light source 17 arranged outside the observation window on the other side. The flexible light source 17 is arranged between the sapphire glass 7 and the light source flange 21; the light source wire 19 of the flexible light source 17 extends out of the light source flange 21.

[0046] The high-definition camera 16 is used to monitor the chemical reaction and evolution of the sample in the kettle in real time and record the video with playback function. The high-definition camera is a high-resolution, color CCD camera with 10 million pixels and a maximum resolution of 1024*1024. It is equipped with an image acquisition board, a microcomputer, and software to observe and analyze the chemical reaction and evolution of the sample.

[0047] The flexible light source 17 is used to provide a white soft background light source for the reaction sample 10 in the reactor. The light source intensity is adjustable so that the sample evolution process can be clearly seen. The flexible light source 17 is arranged on the outside of the sapphire glass 8 on one side, with a diameter of about 50mm. It uses a high-temperature resistant LED lamp bead with a voltage of 12V and a power of 10W. A diffuser is provided on the front face of the lamp bead to improve the uniformity of the light source. The light source penetrates the sapphire glass to illuminate the sample.

[0048] A concave groove is arranged inside the light source flange 10, and the LED lamp beads are placed in the concave groove. A 5mm lead hole is arranged outside the light source flange 10 for leading out the light source wire 19. The light source wire 19 is wrapped with insulating material to ensure safety and reliability.

[0049] The setting of the visual observation window can observe the whole process of reaction evolution in the reaction chamber through the window. At the same time, with the visual monitoring mechanism, the whole process of reaction evolution in the reaction chamber can be observed online in real time through a high-definition camera, and video recording can be performed with a playback function, which improves the convenience and safety of the experiment and has a good guiding role in oil field production. The observation adopts the principle of pinhole imaging, and the reaction sample 10 in the glass cup 6 in the reactor body cavity can be observed.

[0050] In this embodiment, the reactor body 1 and the reactor head 2 are made of high temperature, high pressure and corrosion resistant materials, and are processed and formed by a variety of chip cutting machines. The shape and size of the internal reaction chamber of the reactor body 1 are designed according to the needs of the elemental sulfur reaction. The reactor body 1 and the reactor head 2 form a carrier that provides a high pressure and visual working environment for the experiment.

[0051] Example 2

[0052] like Figure 4As shown, an elemental sulfur experimental device comprises the high-temperature and high-pressure visualized elemental sulfur reaction device described in Example 1, a piston-type sample preparation container connected to the inlet needle stop valve 13 of the high-temperature and high-pressure visualized elemental sulfur reaction device through a high-pressure metering pump, a recovery container 26 arranged below the exhaust port 18 of the high-temperature and high-pressure visualized elemental sulfur reaction device, a back pressure valve 25 connected to the outlet needle stop valve 14 of the high-temperature and high-pressure visualized elemental sulfur reaction device through a pipeline, an absorption container 28 connected to the outlet needle stop valve 14 of the high-temperature and high-pressure visualized elemental sulfur reaction device through a pipeline, a gas meter 29 connected to the top of the absorption container 28, and an electronic balance 27 arranged below the absorption container 28; a weighing cup 30 is arranged on the electronic balance 27; a valve between the outlet needle stop valve 14 of the high-temperature and high-pressure visualized elemental sulfur reaction device and the absorption container 28, and the valve is arranged in parallel with the back pressure valve 25.

[0053] The piston sample container provides subsequent experimental samples for the high-temperature and high-pressure visualized elemental sulfur reaction device. The high-pressure metering pump pressurizes the experimental samples in the piston sample container to the formation pressure.

[0054] Example 3

[0055] A high temperature and high pressure visual elemental sulfur analysis method based on the device of Example 2, such as Figure 4 As shown, the following steps are included:

[0056] (I) Sample transfer under simulated temperature and pressure conditions

[0057] (i) After the sample is prepared, it is transferred to the PVT analysis kettle;

[0058] (ii) Clean the PVT analysis kettle and connecting pipelines, and Figure 4 Connect the various devices as shown;

[0059] (iii) Keep the PVT analysis kettle and piston sample container at a constant temperature above the formation temperature for 4 hours;

[0060] (iv) The plunger pump of the PVT analysis kettle is pumped to the minimum volume, and the PVT analysis kettle and the external pipeline are evacuated to 200Pa and then continue to pump for 30 minutes;

[0061] (v) pressurizing the sample to the formation pressure using a high pressure metering pump, with a pressure fluctuation of less than 1%;

[0062] (vi) While maintaining the formation pressure, the connecting valves between the piston sample preparation container and the PVT analysis kettle are slowly opened in sequence, the high-pressure metering pump is pumped in, and the plunger pump of the PVT analysis kettle is pumped out at the same time, so as to transfer the required sample into the PVT analysis kettle;

[0063] (II) High temperature and high pressure visual elemental sulfur reaction device airtightness inspection

[0064] Open the inlet needle stop valve 13 of the high-temperature and high-pressure visualized elemental sulfur reaction device described in Example 1, transfer helium into the reactor body, close the inlet needle stop valve 13, maintain the gas pressure in the reactor body at 10 MPa, and keep the pressure fluctuation less than 1%, and the air tightness of the device is qualified; after passing the test, open the outlet needle stop valve 14 and release the helium to 0.1 MPa.

[0065] (III) Elemental sulfur measurement

[0066] (i) A certain amount of reaction sample (elemental sulfur) 10 is added into a glass cup 6 of a high-temperature and high-pressure visualized elemental sulfur reaction device. The amount of reaction sample (elemental sulfur) 10 added is 1 / 2 of the volume of the glass cup 6.

[0067] (ii) Transfer the test gas sample from the PVT reactor body through the inlet needle stop valve 13 into the reactor body of the high-temperature and high-pressure visual elemental sulfur reaction device, keep the pressure the same as the pressure at the sampling point, close the inlet needle stop valve 13, set the temperature and pressure of the sample reactor body, and require that the sample after transfer is within the range of ±0.1°C of the set temperature and within the range of ±0.1% of the set pressure, and it is considered that the sample has been fully transferred and reached equilibrium;

[0068] (iii) Record the ambient temperature and atmospheric pressure, and set the pressure of the back pressure valve 25. The pressure of the back pressure valve 25 should be 1MPa to 5MPa higher than the experimental pressure in the reactor body;

[0069] (iv) Open the back pressure valve 25 and the outlet needle stop valve 14, control the pressure fluctuation of the back pressure valve 25 to less than 0.5 MPa, release the gas in the sample kettle at 5 mL / min to 10 mL / min, and keep the temperature and pressure fluctuation in the sample kettle less than 0.1%;

[0070] When the temperature fluctuation and pressure fluctuation exceed the gas-liquid equilibrium index, the experiment is closed. When the temperature and pressure meet the requirements, continue to exhaust and collect and record the gas volume. When the collected gas volume reaches 10,000 ml, the experiment is stopped.

[0071] The change of the solution is observed by visualizing the elemental sulfur kettle, and the mass of the elemental sulfur adsorption solution is weighed in real time by an electronic balance 27 and the result is recorded until the experiment is completed, and the final dissolved weight change is controlled to be less than 1%;

[0072] The gas released from the sample kettle passes through the absorption tank, and the precipitated elemental sulfur is absorbed by carbon disulfide;

[0073] (v) If the experiment fails to detect the effective weight result of elemental sulfur, continue to discharge 10,000 ml of gas and repeat process (iv) until the end of the experiment;

[0074] (vi) Record the volume of released gas and the mass of elemental sulfur.

[0075] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high temperature and high pressure visualized elemental sulfur reaction device, characterized in that: The invention comprises a reactor mechanism, a heating mechanism, a pressure control mechanism and a visual monitoring mechanism; the reactor mechanism comprises a reactor body (1), a reactor body cover (2), a glass cup (6) arranged inside the reactor body (1) and a storage rack (9) arranged inside the reactor body (1); the glass cup (6) is placed on the storage rack (9); observation windows are symmetrically arranged on the reactor body (1), and sapphire glass (7) is arranged in the observation windows; the sapphire glass (7) on one side is fixed to the reactor body (1) through a flange (8), and the sapphire glass (7) on the other side is fixed to the reactor body (1) through a light source flange (21); an inlet, a temperature detection port and an outlet are formed on the reactor body cover (2), and a temperature sensor is arranged at the temperature detection port. (22); the reactor body (1) and the reactor body seal (2) are fixed by a clamping ring; the heating mechanism comprises a heating element (11) and a constant temperature sleeve (12) which are sequentially sleeved on the outside of the reactor body (1) from the inside to the outside; the pressure control mechanism comprises an inlet needle stop valve (13) arranged at the inlet of the reactor body seal (2), an outlet needle stop valve (14) arranged at the outlet of the reactor body seal (2), and a pressure sensor (15) arranged inside the reactor body (1); the visual monitoring mechanism comprises a high-definition camera (16) arranged outside the observation window on one side and a flexible light source (17) arranged outside the observation window on the other side, and the flexible light source (17) is arranged between the sapphire glass (7) and the light source flange (21).

2. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1 is characterized in that: The reactor body (1) is composed of an upper cylindrical reactor body and a lower rectangular reactor body. An observation window is arranged on the short side of the rectangular reactor body. The observation window is communicated with the inner cavity of the reactor body. An emptying port (18) is arranged at the bottom of the reactor body (1).

3. The high temperature and high pressure visualized elemental sulfur reaction device according to claim 1, characterized in that: The sapphire glass (7) on one side is fixed to the reactor body (1) via a flange (8), and the sapphire glass (7) on the other side is fixed to the reactor body (1) via a light source flange (21).

4. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1 is characterized in that: The storage rack (9) comprises a disc-shaped chassis and a vertical rod vertically connected to the chassis. A limiting groove is arranged in the middle of the chassis, and the glass (6) is placed in the limiting groove.

5. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1 is characterized in that: The clamping ring is composed of two semicircular clamping half rings (4), and the inner wall of the clamping half ring (4) forms an annular groove.

6. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1, characterized in that: The top outer wall of the reactor body (1) forms a lower convex ring (23), the bottom surface of which is a conical surface; the bottom outer wall of the reactor body head (2) forms an upper convex ring (24), the top surface of which is a conical surface, and the bottom surface of the lower convex ring (23) and the top surface of the upper convex ring (24) have the same taper; the upper convex ring and the lower convex ring are embedded in the annular groove of the clamping half ring (4).

7. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1, characterized in that: A sealing member (3) is provided between the reactor body (1) and the reactor body cover (2).

8. The high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 1, characterized in that: A concave groove is arranged inside the light source flange (10), the LED lamp beads of the flexible light source (17) are placed in the concave groove, and the light source wire (19) of the flexible light source (17) extends out of the light source flange (8).

9. A method for analyzing elemental sulfur using the high-temperature and high-pressure visualized elemental sulfur reaction device according to any one of claims 1 to 8, characterized in that: The following steps are involved: (I) Sample transfer under simulated temperature and pressure conditions; (II) High temperature and high pressure visual elemental sulfur reaction device air tightness inspection; (III) Elemental sulfur measurement.

10. The elemental sulfur analysis method of the high-temperature and high-pressure visualized elemental sulfur reaction device according to claim 9, characterized in that: The method for checking the air tightness of the high-temperature and high-pressure visualized elemental sulfur reaction device in step (II) is specifically as follows: open the inlet needle stop valve, transfer helium into the reactor body, close the inlet needle stop valve, maintain the gas pressure in the reactor body at 10 MPa, and the pressure fluctuation is less than 1%, and the device is qualified for air tightness; after passing the test, open the outlet needle stop valve 14 and release the helium to 0.1 MPa.

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