Arizona Plumbing Practice Exam

Which of the following types of pipes is commonly used in residential water systems?

1. PVC

2. Steel

3. Copper

4. Cast iron

The correct answer is: Copper

Copper pipes are commonly used in residential water systems due to their durability, resistance to corrosion, and ability to handle high temperatures. Copper also has inherent antimicrobial properties, which helps in preventing bacteria growth in water supply lines. Additionally, it is flexible enough to be easily manipulated and installed, making it a preferred choice for plumbing applications in homes. While PVC is widely used for drain, waste, and vent applications, it is not typically approved for potable water systems in many areas. Steel pipes, although strong and used in some plumbing situations, are prone to rust and corrosion, especially in a water-saturated environment. Cast iron pipes, while sturdy and effective for drainage systems, are heavy and often used for waste systems rather than for supplying drinking water. Hence, copper stands out as the most suitable option for residential water plumbing.