How to Conduct Hydrant Flow Testing

photo by Jens Knudsen

NFPA 25, Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, requires all fire hydrants to be tested and inspected at least annually, and flow tested every 5 years. This applies to all fire hydrants that are on, and within, private property (shopping centers, mall property, parking lots, etc.).

NFPA 25, Table - frequency of inspections for hydrant components

These testing and inspection requirements are the responsibility of the “property owner or designated representative” and must be performed by “qualified personnel”.

NFPA 291, Recommended Practice for Fire Flow Testing and Marking of Hydrants, outlines the proper procedure required to perform the flow test, and the information to be documented.

The required equipment needed for this test is:
  • Flow test kit
  • (2) Hydrant wrenches
  • Hydrant flow test documentation
  • Hydrant number/location map

The flow testing procedure should be conducted, as follows:
  • Position one personnel at the test hydrant, and one at the flow hydrant.
    • Flow hydrant should be located downstream from the test hydrant, or next in line in direction of flow.
  • Attach gauge to test hydrant.
  • Open hydrant; record static pressure reading.
  • Record outlet coefficient size of flow hydrant.
  • Attach pitot gauge to flow hydrant.
  • Open hydrant; record pitot/flow gauge reading (flow for 2 minutes).
  • At test hydrant, record residual pressure reading (should not be less than 20% of flow)
  • Shut down flow hydrant.
  • Shut down test hydrant.
  • Disassemble gauges from hydrant.
  • Hydrant test is now complete.

Document all gauge readings and complete report.