Fire Protection
Hydrant Flow Testing: Pitot, Static, and Residual Pressure
A practical explanation of the three readings used in hydrant flow analysis.
PSI to GPM Editorial Team ·
A hydrant test combines a static pressure, a residual pressure while flowing, and a measured test flow. These readings describe one operating point on the water-supply curve.
Pitot flow
Pitot pressure estimates discharge from the flowing outlet when the outlet diameter and coefficient are known.
Available flow projection
The measured point may be projected to a target residual pressure. Test quality, simultaneous readings, and a meaningful pressure drop are essential. Official work must follow current procedures and qualified review.