Which type of pipe is typically used in the construction of very large water mains?

Steel pipes are typically used in the construction of very large water mains due to their strength, durability, and ability to withstand high pressures associated with large-volume water distribution systems. Steel can handle the stresses of being buried underground and the weight of the surrounding soil, making it an ideal choice for large diameter and long-span applications where structural integrity is critical.

Moreover, steel pipes can be welded or joined together in various ways, providing flexibility in installation and maintenance. They also have a long lifespan when properly coated and maintained, reducing the frequency of replacements compared to some other materials. The properties of steel allow for effective handling of temperature fluctuations and external environmental conditions, making it a reliable choice for municipal infrastructure.

While plastic, PVC, and polyethylene pipes can be used for other applications and smaller water systems, they generally do not have the physical strength required for the very large water mains that steel pipes can support.