Vacuum equipment is required to achieve and maintain a vacuum state. If there is a leakage problem, it will become a major defect. At the same time, no vacuum equipment has absolute tightness, there is a certain degree of leakage problems.
The phenomenon of gas passing through solid is called gas permeability, especially the hydrogen and helium gas passing through the sealing with rubber material can not be ignored. But the nature of air permeability is different from that of air leakage. Leakage is defined as the phenomenon of mechanical intrusion from the high-pressure side to the low-pressure side of a gap or hole.
2. Reasons for Leakage
The main cause of air leakage is the defect of the material itself, and the other is the bad sealing part. Another situation is that there is no leakage at room temperature, but when the temperature changes, there will be leakage. The main reason for this is the difference of thermal expansion coefficient.
3. Admissible range of air leakage
Strictly speaking, air leakage exists in any equipment. The problem is whether the air leakage has an effect on the vacuum equipment and the purpose of use. The effect of air leakage is that it may affect the pressure reached or the purity of the experimental production. If such adverse effects can not be caused, a certain amount of leakage can be allowed in a certain range. Generally speaking, the air leakage shown in the table below is acceptable.
Helium-Mass-Spectrometer-leak-detector-for-Large-production-line
High-precision-electronics-helium-mass-spectrometer-leak-detector
China-lighting-helium-testing-mass-spectrometer-leak-detector-equipment
Helium-mass-spectrometer-leak-detector-device-for-china-aerospace
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