Abstract: The corrosion and operation of overhead recycle system in atmospheric distillation column were introduced, including the inside of the overhead recycle system of the column, the pipelines of heat exchange system and the high temperature part at the bottom of the column. The corrosion mechanism and causes of H₂S+HCl+H₂O corrosion at low temperature part and sulfur + naphthenic acid corrosion at high temperature part were analyzed, respectively. Some anticorrosion measures were put forward, such as reasonable selection of equipment materials, quality control of crude oil, optimization of “one removal and three injections”, and addition of desalting drum for overhead recycle system.

Key words: atmospheric distillation column, corrosion, desalting