Backflow Prevention Practice Exam

Where must an air-gap separation be maintained in a reduced pressure principle assembly?

1. Build drain

2. Domestic Supply

3. Indirect drain outlet

4. Relief valve discharge

The correct answer is: Relief valve discharge

An air-gap separation is crucial in maintaining a safe distance between a potential contaminant and the water supply, thus preventing backflow. In the context of a reduced pressure principle assembly, the relief valve discharge is the correct location for the air gap. The relief valve discharges water in situations where the internal pressure of the assembly drops below atmospheric pressure. If this water were to backflow into the potable water supply without an air gap, it could introduce contaminants. Maintaining an air gap at the relief valve discharge ensures that any discharged water cannot siphon back into the system, thus protecting the integrity of the drinking water supply. Other locations referenced, such as a building drain or domestic supply, do not provide the same level of risk for backflow from the assembly as the relief valve discharge. An indirect drain outlet typically has a separate drainage system and may not pose the same immediate risk of contamination to the potable water supply as the relief valve. Therefore, ensuring an air-gap separation at the relief valve discharge is essential for maintaining safety and compliance with backflow prevention standards.