The pressure supervisory signal-initiating device for the drypipe sprinkler system indicates both high- and low pressure conditions. The off-normal signal shall be initiated when the pressure increases or decreases by _____________ psi.

In a dry pipe sprinkler system, the pressure supervisory signal-initiating device is crucial for monitoring the system's air and water pressure. This device ensures that both high and low pressure conditions are identified promptly to maintain system integrity and to ensure reliable operation.

When the pressure increases or decreases by 10 psi, this threshold triggers an off-normal signal to alert that the system is not functioning within its designated operational parameters. The significance of the 10 psi threshold is rooted in industry standards which have been developed to balance safety and operational responsiveness. It ensures that deviations from normal pressure levels, which could affect the system's performance and effectiveness in the event of a fire, are detected early.

Establishing a 10 psi margin specifically helps to prevent false alarms while still being sensitive enough to detect actual changes that may indicate a potential issue with the dry pipe system. This tolerance is critical because larger changes might represent a serious malfunction, such as a rupture or a significant leak, while minor fluctuations could present no immediate threat.

Understanding these operational parameters is vital for fire safety professionals, as they directly impact how effectively a fire alarm system can respond to emergencies, ensuring that any potential hazards are addressed promptly and efficiently.