In a dry-pipe sprinkler system, the off-normal signal initiation requirement shall be triggered when the pressure increases or decreases by how many psi?

In a dry-pipe sprinkler system, maintaining the correct pressure is crucial for the system to function reliably. The initiation of an off-normal signal is intended to alert the system operator of a potential issue with the integrity of the sprinkler system, such as water leaks or system failures.

The requirement for triggering the off-normal signal when the pressure changes by 10 psi is established as a safety and operational measure. This threshold helps ensure that any significant deviation from normal operating conditions is promptly communicated for further investigation or corrective action. It is a balance between sensitivity and practicality, allowing for some minor fluctuations that could occur during normal operation while still providing a timely alert for more serious issues.

The choice of 10 psi as the trigger point is based on industry standards and practices, which aim to provide a reliable means of monitoring pressure changes without generating excessive false alarms from minor variations. By understanding this requirement, one can appreciate the importance of maintaining the integrity of the piping and the overall performance of the fire protection system.