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This post was last edited by Wang Wei2 on 2020-6-24 at 14:16. 1. Coating protection – this is the most practical and cost-effective protection measure for light hydrocarbon storage tanks. Under normal circumstances, liquid storage tanks can be protected using a combination of coating and cathodic protection, but light hydrocarbon storage tanks can only be protected by coatings, as cathodic protection currents are unsafe – and even extremely dangerous – for such tanks. The key to coating protection is the selection of paint. Once the coating is damaged, it will accelerate the corrosion of the tank wall. The reasons for coating damage are mostly poor adhesion of the paint, pinholes in the coating, poor solvent resistance, and weak resistance to the penetration of light hydrocarbon liquids. Therefore, the following principles should be followed when selecting coatings: 1) Excellent adhesion ； 2) Excellent impermeability ； 3) Stable solvent resistance (light hydrocarbon liquids) ； 4) Good flexibility and impact resistance ； 5) Good workability, namely good leveling properties, no sagging, and a moderate surface drying time. To this end, an epoxy glass flake coating can be used at the base layer; the extremely thin glass flakes in this coating can arrange themselves in dense layers parallel to the surface of the metal substrate, just like fish scales. For liquids and gases to reach the metal surface, they must navigate around these layers of flakes, similar to navigating through a maze, which gives this coating an excellent isolating and blocking effect. This type of paint is very popular in countries such as Europe and the United States, and it is also considered a high-quality paint recommended in China. It is recommended to use antistatic coating for the surface layer, in order to discharge the charges generated inside the tank promptly and ensure the safety of the storage tank. 2. Thermal spraying of aluminum + anti-corrosion coating + antistatic coating. This method involves first applying a layer of aluminum to the tank wall via thermal spraying, before carrying out the first method. This method has two major advantages; the first is that the adhesion between thermally sprayed aluminum and the base metal is better than that of organic coatings ； Secondly, aluminum provides cathodic protection for the steel tank walls. 3. Adding a corrosion inhibitor on top of coating protection: Practice has shown that the proper use of corrosion inhibitors is a simple and effective way to prevent steel from corroding. In light hydrocarbon storage tanks, since they contain a certain amount of water and H2S, it is even more important to add corrosion inhibitors. The key to adding a corrosion inhibitor lies in its proper selection. Adsorptive membrane corrosion inhibitors are commonly used in light hydrocarbon liquids containing water and H2S, as these inhibitors contain polar groups that allow them to adsorb onto the metal surface to form a film; the hydrophobic groups in these molecules then prevent water and depolarizing agents from reaching the metal surface, thereby protecting it.