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

Copper tubing is commonly used for residential water supply lines due to its excellent durability and resistance to corrosion. It has been a traditional material in plumbing for many years and is known for its ability to handle high temperatures and pressures, making it suitable for both hot and cold water supply. Copper also has the added benefit of being antimicrobial, which helps reduce the likelihood of bacteria growth within the plumbing system.

While options like PVC and ABS piping are often used for drainage systems and not primarily for water supply, and galvanized steel can corrode and lead to water quality issues over time, copper's longevity and reliability make it the preferred choice for delivering potable water in homes. This characteristic is vital for ensuring safe and efficient water supply throughout a residential plumbing system.