Which of the following materials is commonly used for hot water supply lines?

CPVC, or chlorinated polyvinyl chloride, is a widely used material for hot water supply lines due to its ability to withstand higher temperatures compared to other types of plastic piping. CPVC has a maximum temperature rating of about 200°F (93°C), making it suitable for hot water applications. Additionally, it is resistant to corrosion and scale buildup, which are common issues in plumbing systems. Its lighter weight and ease of installation compared to metal piping materials further enhance its popularity for residential and commercial plumbing.

In contrast, while steel can be used for hot water supply lines, it is more prone to corrosion and may require additional insulation. Polyethylene, typically used for cold water applications and underground installations, does not have the same temperature resistance as CPVC and is not suitable for hot water supply lines. Concrete is not a viable option for plumbing lines due to its rigidity and inability to withstand the necessary pressure and thermal dynamics associated with hot water supply. These characteristics highlight why CPVC is the preferred choice in this context.