The Problem
A 200,000 sq ft warehouse had 5 PSI/hour pressure loss in the fire suppression system. Discharging for testing would trigger a $50K recharge.
Detection Method
Pressure decay analysis + acoustic correlation on underground fire loop. Identified a flange joint leak 60m from pump house. GPR confirmed depth and position.
Results
2m x 1.5m patch. Flange gasket replaced. System restored to full pressure. No sprinkler discharge. Insurer accepted report as corrective action.
“If we'd discharged to find it, the recharge would have cost $50K. The survey found it without touching a single head.”