Which type of coating is often used to help pipes sink underwater?

Concrete coating is a type of coating that is often applied to pipes to provide additional weight, which helps them sink when placed underwater. This weighting effect is particularly beneficial for underwater infrastructure applications, such as oil and gas pipelines, where maintaining the position of the pipe on the seabed is critical for safety and functionality.

Concrete coatings help counteract buoyancy in water, making them a practical choice for pipelines that must remain submerged and stable. They also provide physical protection to the pipes from marine organisms and potential abrasion from the seabed.

While fusion bonded epoxy, coal tar enamel, and asphalt coatings are useful in various protective applications for pipes, they primarily focus on corrosion resistance and surface protection rather than providing the necessary weight to ensure that pipes remain submerged. Therefore, concrete coatings stand out as the most suitable option for this specific purpose.