Hydrant flow test calculator.
Enter the static and residual pressures at the residual hydrant and the pitot readings at the flow hydrant. The available flow at 20 psi, the NFPA 291 class and the flow curve update as you type.
Calculate the available flow at 20 psi
Flow during the test is the pitot formula, 29.83 × c × d² × √p, summed over the outlets flowed. The flow available at 20 psi is projected from the residual hydrant's pressure drop with the 0.54 exponent of NFPA 291.
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Need a complete hydrant flow test report?
This calculator gives you quick numbers in the field. When you need a shareable record of the test, use the free companion site HydrantFlowTestReport.com: place the residual and flow hydrants on a map, enter the readings for a single or two-hydrant test, including Hose Monster measurements, and generate a PDF report with a location map, the test data and the projected flow curve, ready to download or email.
Built by the team behind FireInspection360
This calculator is one small piece of what we do. FireInspection360 is fire prevention software for fire marshals and fire districts: hydrant maintenance and flow test records, required fire flow compared with what the hydrants can deliver, inspections, permits, plan review, ITM reports and pre-incident planning, all in one record system.
See the whole platform with your own hydrant records.
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