Abstract: The electrochemical corrosion in the wind girder of insulated oil tank produced due to the accumulated sour rainwater. In the light of the corrosion and perforation of wind girder in a 1000 m³ fuel tank, a technical reform and precaution measure program are worked out. The implement result indicates that the rainwater coming from the insulating layer (made with insulating brick or blanket)can be effectively drained off from the modified wind girder.the electrochemical corrosion in the wind girder is avoided.