Backflow Prevention Practice Exam

In double check valves, what role does the spring play?

1. Regulates water pressure

2. Prevents reverse flow

3. Acts as a safety mechanism

4. Controls flow rate

The correct answer is: Prevents reverse flow

In double check valves, the spring plays a crucial role in preventing reverse flow. The valve comprises two check mechanisms that function together. When water flows in the intended direction, the spring allows the valve to open, permitting water to pass through. However, if there is a decrease in pressure or a tendency for water to flow back in the opposite direction, the spring ensures that the check valve closes. This closing action effectively blocks any backflow, protecting the potable water supply from potential contamination. Thus, the spring's function is essential for maintaining a one-way flow of water, which is a fundamental aspect of backflow prevention systems.