The compressed air contains a certain amount of water, bacteria, impurities, residual oil (except for water-lubricated air compressor), with the release of compressed air capacity, the system will appear a certain amount of condensate water and even residual oil. For those industries where the quality of the process is relatively high, such as painting, pneumatic control systems, electronic components production, food processing, pharmaceuticals, etc., if the air source is not clean,it may cause chemical materials to react with water, short circuit of electronic products, or packing material is identified as defective because of residual oil and then cause double loss of corporate reputation and economy.