Which type of pipe material is often used for residential water supply lines?

The correct answer encompasses all mentioned materials because each has specific advantages that make them suitable for residential water supply lines.

PVC is widely used in plumbing primarily for drainage and venting systems, but it is not typically approved for hot water applications, which can limit its use for water supply lines. CPVC is an extension of PVC that has been treated to withstand higher temperatures, making it a viable option for hot and cold water supply.

PEX has gained immense popularity in residential plumbing due to its flexibility, resistance to scale and chlorine, and ease of installation. It can be snaked into walls and around corners without the use of fittings, which reduces the potential for leaks.

Since all three materials—PVC, CPVC, and PEX—serve different purposes and have specific applications within residential plumbing, the most comprehensive choice is that they can all be used in various capacities for residential water supply lines.