Which of the following materials is commonly used for external corrosion protection on pipes?

Bituminous coatings are widely recognized for their effectiveness in providing external corrosion protection on pipes. These coatings are made from a combination of asphalt and various additives that create a thick, durable barrier. This barrier protects the metal surfaces of pipes from moisture, chemicals, and other environmental factors that can lead to corrosion. The resilience of bituminous coatings allows them to adhere well to metal surfaces, creating a protective layer that is both waterproof and resistant to many corrosive substances.

Moreover, bituminous coatings are often applied to underground or submerged pipes, making them particularly valuable in utility maintenance. Their ability to withstand exposure to water and soil conditions helps to prolong the lifespan of the pipes and reduce maintenance costs related to corrosion damage.

The other materials mentioned, while they have their own applications, are typically not as suitable for external corrosion protection in this context. Copper coatings may offer some corrosion resistance due to copper's inherent properties, but they are less commonly used for large-scale pipe protection. Polymer compounds can provide a level of protection but may not be as robust as bituminous coatings in harsh environments. Fiberglass wraps are often used for reinforcement or repair rather than as a primary method for corrosion protection on pipes.