A reduction in full flow pressure must be corrected if it exceeds which percentage compared to the original acceptance test?

A reduction in full flow pressure must be corrected if it exceeds 10% compared to the original acceptance test. This standard is in place to ensure that the fire protection system can function effectively during an emergency by maintaining adequate pressure.

Full flow pressure is critical because it directly affects the system's ability to deliver enough water to suppress a fire. If the pressure drops significantly, the system may not be able to extinguish a fire effectively, potentially putting lives and property at risk. The 10% threshold is established to prompt timely corrective actions, such as checking for leaks or blockages or assessing the condition of pumps and water supplies.

This focus on maintaining pressure helps to ensure operational reliability and effectiveness in firefighting efforts, adhering to NFPA 25 standards for the inspection, testing, and maintenance of water-based fire protection systems.