Cross Connection Practice Exam

What is the proper method for opening shut off valves when restoring water service to a customer after testing a Double Check Valve Assembly?

1. Open both shut off valves simultaneously

2. Slowly open number one shut off valve

3. Slowly open number two shut off valve

4. Open the valves in a rapid manner

The correct answer is: Slowly open number two shut off valve

The appropriate method for opening shut-off valves when restoring water service after testing a Double Check Valve Assembly is to slowly open the second shut-off valve. This approach is crucial because it allows for the gradual reintroduction of water into the system, helping to prevent sudden pressure surges that could potentially lead to water hammer, leaks, or other water supply issues. When you open the second valve slowly, it ensures that any air trapped in the system can escape safely, and it allows the pipes to adjust to the pressure of the flowing water gradually. This method is important for maintaining system integrity and safeguarding against damage that could occur if the valves were opened too quickly. In contrast, opening both shut-off valves simultaneously would create an abrupt change in pressure throughout the system. Rapidly opening the valves can also cause similar issues, including potential stress on the infrastructure of the plumbing system. The method of slowly opening the first shut-off valve is not the preferred approach because it may not effectively manage the restoration of service in a controlled manner as the second valve would.