Which of the following is NOT a common material for plumbing pipes?

Glass is not a common material used for plumbing pipes due to several practical limitations. While glass can be used in specific applications, such as for laboratory or specialized uses, it lacks the durability and flexibility required for general plumbing needs. Plumbing systems need materials that can withstand pressure, thermal expansion, and potential impacts, which glass does not adequately provide.

In contrast, copper is widely used for its excellent corrosion resistance and thermal properties, making it ideal for hot and cold water supply lines. PVC is favored for its lightweight and resistance to corrosion, often used in drainage and venting systems. Galvanized steel, though less common than its alternatives today, was historically used for its strength and long lifespan, particularly in older buildings. Each of these materials has valuable attributes that make them suitable for various plumbing applications, while glass is limited by its fragility and lack of reliability in typical plumbing contexts.