1. About the basic requirements of the production process of storage tanks: Vacuum workers should be familiar with the basic knowledge required in vacuum and be able to correctly operate vacuum equipment, master the correct connection method of vacuum pipes and valves, and be familiar with the method of measuring the vacuum degree of vacuum instruments by vacuum instruments. General process requirements for vacuum leak detection.

2. Before the leak detection of the container, the operator should confirm that the container has been completely welded, has passed the corresponding non-destructive testing and air pressure test, and passed the test.

3. Preparation: Use a vacuum unit or vacuum pump to evacuate the container. The vacuum unit and pipeline should be leak-tested and the ultimate vacuum of the vacuum unit or vacuum pump can reach 1pa before opening the connecting valve and vacuum pipeline. It should have a bypass diaphragm valve and can be used for helium mass spectrometry vacuum leak detection.

4. Evacuate the inner cylinder: When evacuating, pay attention to opening the vacuum valve slightly before exhausting the atmosphere, and then slowly open the large vacuum valve after the exhaust sound of the vacuum pump becomes smaller to prevent the vacuum pump from jamming due to excessive air flow. When pumping out, pay attention to observe that the cooling water must be normal, the water temperature must not be too high, must not exceed 60°C, and the water flow must not be too small. When pumping down, the front pump (slide valve pump) should be turned on to exhaust the atmosphere, and the roots pump should be started when the vacuum reaches 20-30pa.

5. Operation method of helium mass spectrometry leak detection: For vacuum vessels, vacuum leak detection should be carried out when it is evacuated to 1pa~6pa. Before leak detection, the leak detector should be calibrated with standard leaks. Leak detection should be based on the size and The corresponding leak rate is judged whether it is qualified (according to the technical requirements of the drawing). If the leak rate exceeds the requirements on the drawing, it is judged that the leakage of the storage tank exceeds the standard. At this time, the specific leakage location of the container should be determined and can be used in conjunction with the pressure test process. Determine the leak location, and then formulate a repair process to repair the leak location with argon arc welding. After repairing, use a vacuum leak detector to check the leak again and confirm that it is qualified before entering the next process.