Backflow Prevention Practice Exam

In the event of system pressure reduction, what must the check valves do?

1. Open fully

2. Close securely

3. Stay partially opened

4. Alternate opening and closing

The correct answer is: Close securely

In the event of system pressure reduction, the check valves must close securely to prevent backflow from occurring. These valves are designed to allow water to flow in one direction only, thereby preventing contaminants from entering the clean water supply when there is a drop in pressure. If the check valves were to open or remain partially opened, it could create a pathway for potentially polluted water to flow back into the potable water system, which poses a significant health risk. The secure closure of the check valves is a critical safety feature in backflow prevention systems, ensuring that the integrity of the water supply is maintained even during pressure fluctuations. This mechanism is especially important in protecting against backpressure and backsiphonage, both of which could lead to hazardous cross-connections and contamination.