Which of the following is NOT a method of supervising valves in a fire protection system?

In fire protection systems, supervising valves are essential for maintaining the integrity and functionality of the system. Each of the methods used to supervise valves has specific roles in monitoring and ensuring proper operation.

Choosing automatic fire suppression as a method of supervising valves is inaccurate because automatic fire suppression systems are primarily designed to extinguish fires and not to monitor or supervise the operational status of valves. While they play a vital role in fire safety, they do not provide the continuous oversight or indication of valve status needed for supervision.

On the other hand, central-station monitoring involves real-time supervision by a monitoring service that can alert personnel to any valve issues. Local signaling service provides immediate alerts within the facility about valve status changes, and locking valves in an open position is a protective measure to ensure that a valve will not inadvertently close, which is, in its way, a method of supervision to maintain system readiness.