Ductile iron pipes usually have an external coating made of protective materials like zinc or asphalt. These coatings are applied to the pipe's surface to prevent corrosion and shield the iron from its surroundings. Zinc coatings, like hot-dip galvanizing, are widely employed because of their exceptional resistance to corrosion. Conversely, asphalt coatings offer a resilient and adaptable shield against corrosion and abrasion. The selection of the coating relies on factors such as the intended use, environmental circumstances, and project-specific requirements.
The external coating used in ductile iron pipes is typically made of a protective material such as zinc or asphalt. These coatings are applied to the surface of the pipe to provide corrosion resistance and protect the iron from the surrounding environment. Zinc coatings, such as hot-dip galvanizing, are commonly used due to their excellent corrosion resistance properties. Asphalt coatings, on the other hand, provide a durable and flexible barrier against corrosion and abrasion. The choice of coating depends on factors such as the intended application, environmental conditions, and the specific requirements of the project.
The external coating commonly used in ductile iron pipes is a protective layer made of either cement mortar or polyethylene.