Abstract: Failure analysis is made through investigation for an amported floating deck in aluminium alloy. During the investgation, senile lingual sealing belt and electro-chemically corroded cover are found. The reason for the accidental failure lies in the unduely designed inlet pipe to the tank. The following suggestions are given correspondingly: ① Attention shall be paid to the quality when selecting lingual sealing belt among domestic suppliers. And the suppliers shall carry out material and formula optimization, as well as technology improvement so as 10 guarantee product quality. ② The tank shall be internally protected in such manner that no rust falls down to the surface of cover plate to cause electro-chemical corrosion; in addition, the service life of cover plate shall be designed with the consideration of other parts in aluminium alloy. ③ Proper types of support legs shall be selected according to production requirement; and the inlet diffusing pipe shall be duely chosen in respect of its structure, size, and installation location.