Tools / Fire Pump Curve & Annual Test
Fire Pump Curve & Annual Test Checker
Enter the pump’s published curve points, then your churn, 100 % and 150 % test readings. The tool corrects for suction pressure and driver speed, plots the results on the curve, and tells you whether each point reaches the 95 % of the reference that NFPA 25 expects.
1 · Reference curve (nameplate or acceptance test)
Use the pump’s certified performance curve or the original unadjusted acceptance-test curve. NFPA 25 compares annual results with the acceptance curve.
Rated driver speed (variable-speed or diesel)
When you enter a measured rpm on a test row, flow is scaled by rated ÷ measured and pressure by its square (affinity laws) before comparing with the curve.
Flow from pitot readings (optional)
Enter a pitot reading — add nozzles together for the row flow.
2 · Field test readings
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Net pressure = discharge − suction. Variable-speed pumps are tested at churn, 25, 50, 75, 100, 125 and 150 % — add a point for each.
What the limits mean
- Churn (shutoff): no more than 140 % of rated pressure (NFPA 20).
- 150 % of rated flow: at least 65 % of rated pressure (NFPA 20). Many pumps sit well above this; 65 % is the floor, not the target.
- Annual test (NFPA 25 §8.3.3): churn, 100 % and 150 % evaluated at no less than 95 % of the flow and pressure on the original unadjusted field test curve or the nameplate (2017 edition and later). Engine speed may not be raised above rated to reach a point, and if the supply cannot support 150 % the pump is tested to the maximum allowable discharge. See NFPA 25 §8.3.3.
Reference tool: the curve between the three entered points is a smooth fit for drawing — it is not the manufacturer’s curve, and this tool does not apply velocity-pressure or elevation corrections. Record results on the manufacturer’s curve sheet, and follow NFPA 20/25 as adopted by your AHJ. The test report remains the responsibility of the qualified person who ran the test.