After a vacuum equipment is put into use, there may be leakage. Therefore, the vacuum equipment should have detailed operation records in order to find out the cause of air leakage.

① In the use of vacuum equipment, it is sometimes necessary to open some flanges for cleaning or placing test pieces. If air leakage is found after reassembly, it is necessary to check the seal.

② Leak detection shall be carried out for the replaced parts.

③ If it is found that the vacuum degree of the running vacuum equipment deteriorates, it should be considered whether it is caused by air leakage, which can be judged by static boost test.