The causes leading to corrosive perforation of condenser’s copper tubes for units no.3 and no.4 in Yunfu Power Plant have been carried out. Based on analysis results of copper tubes’ composition

corrosion formation

corrosive products

and quality of the circulating water

it is determined that the corrosion type to be pitting attack

and the causes to be residual carbon film existing on inner surface of the copper tubes

as well as the chemical oxygen dissipation (COD) and sulphide content in the water to be over standard. After adopting ferrous sulphate for single filming

and adding suitable amount of antiscalant into the circulating water

the said problem has been solved.