Cross Connection Practice Exam

What type of backflow prevention device contains two force biased, soft seated check valves?

1. Single Check Valve

2. Dual Check Valve

3. Reduced Pressure Principle Valve

4. Double Check Valve

The correct answer is: Dual Check Valve

The dual check valve is designed specifically with two force-biased, soft seated check valves to prevent backflow in various applications. This design allows it to effectively isolate the drinking water supply from potential contaminants by utilizing two independent check mechanisms. If one check valve were to fail for some reason, the second provides an additional layer of protection, thereby enhancing the reliability of the system. This type of valve is often used in lower hazard situations where the risk of contamination is minimal, yet a dependable protective measure is still necessary. Its construction and functionality are tailored for conditions where a high degree of backflow prevention is required with a relatively compact design, making it suitable for both residential and commercial applications. In contrast, other options have different functions and designs. For example, the single check valve operates with only one check mechanism, providing less redundancy. The reduced pressure principle valve incorporates a more complex system that includes an atmospheric vent, designed for high hazard applications, while the double check valve, although it features two check valves, is distinct from the dual check valve in terms of design and application focus.