What type of backflow prevention device is primarily used in irrigation systems?

The use of an anti-siphon valve or a reduced pressure zone valve is essential in irrigation systems to prevent backflow, thereby safeguarding the potable water supply. An anti-siphon valve is designed to prevent the backflow of contaminated water into the drinking water system by creating a break in the vacuum, which effectively stops any siphoning action. These valves are positioned above the highest point of the irrigation system, allowing them to function properly even when there is a drop in pressure.

A reduced pressure zone valve serves a similar purpose but is typically used in more complex or high-risk applications where the potential for contamination is greater. This type of valve creates a pressure differential that prevents backflow while also allowing for the safe discharge of any backflow contamination into the environment rather than into the potable water supply.

Both of these devices ensure compliance with safety standards and regulations set forth by plumbing codes, making them suitable choices for use in irrigation systems. Other devices offered in the choices, such as check valves, backwater valves, and atmospheric vacuum breakers, have specific applications that may not adequately address the unique requirements of irrigation systems for backflow prevention.