Cross Connection Practice Exam

If water continuously flows from the open test cock #3 during a field test on a Double Check Valve Assembly, what could be the issue?

1. The air inlet valve is blocked

2. The shutoff valve #1 is leaking

3. The gauge is faulty

4. The test cock is damaged

The correct answer is: The shutoff valve #1 is leaking

When water continuously flows from the open test cock #3 during a field test on a Double Check Valve Assembly, it indicates a potential issue with the shutoff valve that precedes the assembly. The role of the shutoff valves in this setup is to create a pressure differential that allows for accurate testing of the backflow prevention device. If shutoff valve #1 is leaking, it would not maintain the necessary pressure and could allow water to bypass the assembly, resulting in continuous flow from the test cock. In contrast, a blocked air inlet valve or a faulty gauge typically wouldn’t lead to this specific symptom of water flow from the test cock. A damaged test cock could result in leaks or incorrect readings, but it wouldn't inherently cause continuous flow unless there is a direct path for water to escape, which suggests a different set of problems unrelated to the shutoff valve’s integrity. Thus, understanding the function of each component of the Double Check Valve Assembly is crucial in diagnosing the reason for the continuous flow from test cock #3, reinforcing the idea that a leaking shutoff valve is likely the source of the issue in this scenario.