What material is commonly used to construct backflow preventers?

Brass or plastic is commonly used to construct backflow preventers due to their advantageous properties. Brass is a durable material that resists corrosion and can withstand high water pressures, making it ideal for plumbing applications. It also provides a reliable seal that is essential for preventing backflow. On the other hand, plastic is used in some applications because it is lightweight, easy to manufacture, and resistant to deterioration from chemicals found in some water supplies. The combination of these materials ensures that backflow preventers remain effective and reliable over time.

Using aluminum, copper, steel, or concrete may not provide the same level of performance or reliability in a backflow preventer, which is why these materials are less common in their construction.