Which type of pipe has the lowest normal maximum working pressure?

Polyvinyl chloride (PVC) is known for its specific properties that affect its use in water distribution systems. Among the materials listed, PVC typically has the lowest normal maximum working pressure due to its physical characteristics and how it is designed for use in various applications.

PVC is a lightweight, rigid plastic that is resistant to corrosion and chemical damage, making it popular for a variety of plumbing applications. However, compared to materials like ductile iron, which has a high tensile strength and can withstand high internal pressures, PVC generally cannot bear as much pressure. Similarly, reinforced concrete and high-density polyethylene (HDPE) are engineered to handle higher pressures due to their structural integrity and design, particularly in constructing water mains and waste systems.

The material's susceptibility to factors such as temperature and impact can also limit its maximum working pressure. While PVC can be suitable for low to moderate pressure applications, it is not designed for the high-pressure environments that other materials can handle, which is why it has the lowest maximum normal working pressure among the choices given. This understanding is crucial for ensuring that the correct type of pipe is selected based on the requirements of the water distribution system being designed or maintained.