Hi forum Our naphtha storage tank had a floating roof and during the T&I the inspection finding revealed that the floating roof stuck at some legs and not reach the normal level . The floating roof sleeve found internally corroded and this is the main reason for this problem. Any how could you explained why corrosion is happened inside the floating roof sleeve is that because the sleeve at the top of floating roof is opened to atmosphere is their any possibility the corrosion is due when the floating roof go down with the product the water goes between the legs and their sleeve. Air condensation inside the sleeve combined with vapor from the naphtha emission. Your input as usual will be valued. Nothe that: the gap between the sleeve and legs is to narrow may be about 1 mm is their any problem form corrosion side if we recommended to increase the size more best regard to all

hlep :)

Thanks for your support and really our refinery forum gains a corrosion specialist like you. You know I am thinking about the metallic cups that will be installed at the top of the sleeve to prevent the humid air ingress to the sleeve during the floating roof float up or down.