Inspection and Testing of Water Supplies and Fire Pumps
This domain tests your ability to verify that water is available and that fire pumps will deliver it under real demand. Expect questions on flow tests, pump churn runs, annual performance tests, controllers, and suction conditions.
Core rules and concepts
- Water supply flow tests establish static, residual, and flow readings; NFPA 25 calls for periodic flow testing, commonly on a five-year cycle for many systems, plus hydrant and flow-meter checks.
- Fire pumps require a weekly no-flow run: electric pumps typically 10 minutes and diesel pumps 30 minutes, with diesel checks for fuel, oil, battery, cooling, and controller conditions.
- An annual pump flow test compares churn, rated, and peak points against the certified curve and prior baseline.
- Record suction and discharge pressures, driver speed, voltage or fuel readings, and valve positions.
- Test headers, hose streams, and drain capacity must handle the test flow without unsafe discharge.
Worked example
A 750 gpm pump rated at 100 psi produces 720 gpm at 100 psi and 108 psi at churn. The flow is about 96 percent of rated flow, so it deserves investigation rather than automatic acceptance. Check gauge calibration, suction pressure, driver speed, test valve position, and the last baseline test. If the drop is real, notify the owner and recommend service. The reasoning matters: the pump is close to rating, but a downward trend can indicate impeller wear, a partly closed valve, or a suction problem.
Traps that cost marks
- Treating the weekly churn run as an annual flow test.
- Failing to record suction pressure or static readings.
- Testing without confirming drain capacity or hose stream safety.
- Ignoring a diesel pump's battery and fuel readings because the engine started.