What is the pressure increase that indicates when high air is monitored at the airline PRV?

The correct choice, 5 psi over high air alarm pressure, is significant because it establishes a standard threshold for when the airline Pressure Relief Valve (PRV) should activate in response to increased pressure levels within the system. Monitoring the air pressure at this threshold ensures the safety and functionality of the system. If the pressure rises by this amount above the alarm level, it indicates a potential issue that may require immediate attention to prevent over-pressurization.

This specific metric of 5 psi serves as a balanced approach, providing an adequate warning without being too sensitive to fluctuations in pressure that could lead to unnecessary alarms. By utilizing this level, sprinkler systems can be more effectively managed, reducing the risk of equipment failure and ensuring more reliable operation. Understanding this makes it clear why this pressure increment is a standard practice in maintaining sprinkler systems.