Backflow Prevention Practice Exam

Which type of backflow preventer is most commonly used in irrigation systems?

1. Atmospheric vacuum breaker

2. Reduced pressure zone device

3. Dual check valve

4. Pressure vacuum breaker

The correct answer is: Atmospheric vacuum breaker

The most commonly used backflow preventer in irrigation systems is the atmospheric vacuum breaker. This type of device is specifically designed to protect against back siphonage, which can occur when there is a drop in water pressure in the system, potentially allowing contaminants from the irrigation system to enter the potable water supply. Atmospheric vacuum breakers operate by allowing air into the system when a drop in water pressure is detected, thus breaking the vacuum and preventing backflow. They are relatively simple in design, cost-effective, and easy to install, which contributes to their popularity in irrigation applications. This simplicity makes them suitable for many residential and commercial irrigation systems, where the primary concern is back siphonage from the landscape irrigation system. While other types of backflow preventers, such as reduced pressure zone devices, dual check valves, and pressure vacuum breakers, serve important roles and are used in various situations, they may not be as universally applicable or as commonly found in typical irrigation settings as the atmospheric vacuum breaker. Reduced pressure zone devices, for example, provide a higher level of protection against backpressure and back siphonage but are more complex and costly, making them less common for basic irrigation needs.