Cross Connection Practice Exam

What is a likely cause if water continues to run from open test cock #3 during the first test of a Double Check Valve Assembly?

1. The shutoff valve #1 is leaking

2. Shutoff valve #2 and check valve #2 are leaking with backpressure

3. The test cock is malfunctioning

4. The assembly is improperly installed

The correct answer is: Shutoff valve #2 and check valve #2 are leaking with backpressure

When water continues to run from open test cock #3 during the first test of a Double Check Valve Assembly, this typically indicates an issue with the integrity of the valves and the presence of backpressure. In this scenario, if shutoff valve #2 and check valve #2 are leaking, backpressure could lead to the backflow of water, allowing water to escape from test cock #3. The purpose of the Double Check Valve Assembly is to prevent backflow, and if one of the check valves is malfunctioning, it would not seal properly. This failure could cause water to flow through the assembly in a direction it should not, thus creating a constant discharge from the test cock. Understanding how backpressure affects the system is important. In a properly functioning assembly, water flow would be contained within the designated pathways. A leak in shutoff valve #2 or check valve #2 could compromise that containment, leading to an undesired discharge at the test cock. In contrast, the other options suggest other issues that might not specifically account for the continuous flow observed. For instance, while a leaking shutoff valve #1 could potentially cause issues, it would not directly lead to water running from test cock #3 unless it creates a similar backflow situation