Cross Connection Practice Exam

If a reduced pressure principle assembly starts discharging continuously after the number 1 shutoff valve is opened, what could be the cause?

1. A clogged relief valve

2. A fouled number one check valve

3. Low water pressure

4. A defective relief valve

The correct answer is: A fouled number one check valve

If a reduced pressure principle assembly is discharging continuously after the number 1 shutoff valve is opened, it indicates that there is an issue with the system that is preventing proper operation. When the number one check valve is fouled, it can fail to close effectively, which allows water to flow in reverse or creates conditions that result in continuous discharge. The check valves in a reduced pressure principle assembly serve a critical role in preventing backflow into the supply line. A fouled check valve can lead to a failure in maintaining the necessary pressure differential, which is vital for the assembly to function as intended. Therefore, when the system opens and the check valve does not seal properly due to fouling, it creates a situation where water continuously discharges. Understanding the configurations and potential issues of check valves within the assembly is essential for maintaining a functional and safe plumbing system. This knowledge helps identify not just the symptoms of malfunction but also directs maintenance efforts effectively.