When evacuating the vacuum chamber, the vacuum chamber must be clean to achieve the desired pressure as quickly as possible. Typical contaminants in vacuum systems include

1. Production of residue from vacuum system Surface, grease and grease on seals
2. Application-related contaminants Process reaction products, dust and particles
3. Environment-related contaminants Condensing steam, especially moisture adsorbed on the walls of containers.
     
Therefore, it is necessary to ensure that the components are as clean as possible when installing vacuum equipment. All parts installed in the vacuum chamber must be clean and free of grease. All seals installed must be dry. If vacuum grease cannot be avoided and it is an auxiliary installation rather than a sealant, it must be used with great care. If high vacuum or ultra-high vacuum is to be produced, clean, lint-free, powder-free gloves must be worn during assembly.