The complete set of air separation unit can meet the various production needs of enterprises. It usually includes air compressor, air precooling system, purification system, booster turbo expander unit, fractionator system, oxygen compression system, nitrogen compression system, liquid storage system, instrument control system and electric control system. Each system of the complete set of air separation unit is closely connected and interacted. In order to ensure the safe and efficient operation of the equipment, every component should be attached great importance.