Crude oil tank: In the cargo tank loaded with crude oil, the thick crude oil film has a certain protective effect on the steel plate. However, if the sulfur content in crude oil is high, the inorganic sulfides, mercaptans and thiophene and other organic sulfides are more corrosive. Crude oil is generally mixed with oilfield saltwater, which contains magnesium chloride. In addition to the corrosion of the oil itself, there is often a tank that is used for both oil and ballast. The ever-used empty tank has a certain protective effect on the steel plate due to a layer of oil film on the surface, but once ballast water is loaded, the steel plate will be severely corroded. The painting parts of the product oil tanks of crude oil are generally the bilge and the roof, and the bulkheads are usually not painted. The selected coatings are tar epoxy and high build pure epoxy coatings.
Generally, the fuel tank is not necessary protected by paint. In order to prevent the bulkhead from rusting during the construction process, a layer of anti-rust oil is often applied during the section coating to provide temporary protection. After the fuel tank is filled with oil, the anti-rust oil will dissolve in the fuel and will not affect the quality of the oil. The bulkhead is directly protected by fuel and will not corrode. The fuel oil/ballast dual-purpose tanks with fuel oil loading time of less than 10% of the number of sailing days each year are treated as ballast water tanks.
The lubricating oil compartment can be protected with anti-rust oil or pure epoxy paint. The surface treatment should reach ISO St3 or be sandblasted, and dust and other debris should be completely removed.