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The principle by which the coating protects pipelines is to prevent direct contact between the pipeline’s metal matrix and the surrounding corrosive agents. This requires the coating itself to have certain mechanical strength, chemical stability, and density (the ability to resist penetration by corrosive substances), as well as a good adhesion to the metal substrate. In addition to meeting the aforementioned basic requirements, some coatings must also fulfill specific requirements depending on their application, such as decorative properties, environmental friendliness, electrical conductivity, high-temperature resistance, and the presence of metallic components with anodic properties. Corrosion-resistant coatings have a significant effect on uniform corrosion in long-distance pipelines, and can greatly reduce the rate of such corrosion. However, coating corrosion protection also carries certain risks at times; for example, in certain environmental conditions, the damaged areas of the coating can become anodic points relative to the surrounding pipeline substrate, resulting in a situation where there is a large cathode and a small anode, which accelerates the development of pitting at that point. Sometimes this situation is addressed by applying external cathodic protection. There are various methods for classifying pipeline coatings; based on the state of the coating material and the coating process, they can be roughly divided into three categories: liquid coatings, sintered epoxy coatings, and polyolefin anti-corrosion coatings.