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Considering the corrosion issues associated with the acidic water tanks in refining units mentioned earlier, the areas most prone to corrosion are as follows: the bottom part of the tank, from 0 to 300 mm deep, as well as the tank walls and bottom plate. In these areas, sedimentary water containing high concentrations of sulfides and chloride ions accumulates over time, resulting in extremely high corrosivity; these areas thus represent the main sites of internal corrosion. Additionally, the outer wall of the tank bottom is susceptible to hidden electrochemical corrosion due to the intrusion of groundwater. At the gas-liquid interface where the liquid level fluctuates, a concentration difference of oxygen leads to the formation of corrosion cells. Meanwhile, acidic gases condense in the gas phase area at the top of the tank, creating highly corrosive liquid films that accelerate the corrosion of the tank top and the surrounding tank walls. In welds and heat-affected zones, 70% of the corrosion perforations occur near the weld bead; welding residual stresses, in combination with substances such as H₂S and CN⁻, easily lead to stress corrosion cracking. Piping attached to the tank roof and weak structural elements: The acid gas connection pipes and water seal pipes on the tank roof are in constant contact with sulfur-containing gas phases, which can lead to localized pitting. Additionally, areas where water tends to accumulate, such as recesses on the tank roof and the joints of the wind-resistant rings, can also suffer from localized corrosion.