Cross Connection Practice Exam

In test #2 of a Double Check Valve Assembly, what does a receding water level in the sight tube suggest?

1. Check valve #1 is leaking

2. Shutoff valve #2 is leaking

3. Test cock #3 is malfunctioning

4. There is no downstream pressure

The correct answer is: Shutoff valve #2 is leaking

In test #2 of a Double Check Valve Assembly, a receding water level in the sight tube typically indicates that there is a leak in the shutoff valve downstream of the assembly, which is why the water level is dropping. The function of the sight tube is to provide a visual indication of the pressure in the system. When the water level falls, it suggests that fluid is escaping from the system, and if the shutoff valve #2 is not sealing properly, it can lead to a decrease in the pressure and thus result in the receding water level. Understanding the role of the components is crucial here. During the testing process of the Double Check Valve Assembly, each element must function correctly to prevent backflow and ensure the integrity of the water supply. The shutoff valve's sealing capability directly impacts the performance of the assembly, and a failure in this area becomes evident through the behavior observed in the sight tube. While other components, such as check valves or test cocks, may also have operational effects, the specific situation described aligns best with a fault in the downstream shutoff valve, indicating it is likely leaking if the water level is receding.