In this guide 6 sections
Store raw readings, not just the curve. Keep flow, head, power and NPSH values together with the instruments used, their calibration dates, the test standard and grade, speed and fluid. Add every signature, all against the pump serial. Then a warranty dispute is settled from data.
Why a curve on paper is not enough
Months after a pump ships, a customer says it delivers less flow than promised, so you pull the test certificate and find a printed curve with a stamp. The readings behind it are long gone.
Without them you cannot say whether the pump met its duty point, which bay ran the test, or whether the flow meter was in calibration that day. The certificate becomes an opinion.
Raw readings turn it back into evidence.
The readings every test should keep
The bay runs the pump from shut-off to beyond the duty point and records, at each flow point, discharge flow, suction pressure, discharge pressure, power and speed. From those come total head, hydraulic power and efficiency.
Store both the measured inputs and the calculated results, along with the formula version used and any correction applied for shaft speed. Add vibration and noise when ordered.
- Flow at each test point
- Suction and discharge pressure
- Motor input power and speed
- Water temperature and density
- Calculated head and efficiency
NPSH tests and the setup around them
A net positive suction head test is a separate run in which suction pressure is lowered in steps until total head drops by the amount the standard sets. Record each step, the flow at which cavitation begins and the resulting required value, since a later suction problem at site will be judged against them.
Record the setup as well: pump model and serial, impeller diameter, wear ring clearance, seal type, and the test standard with its grade. A pump tested with a trimmed impeller will not match the one you ship at full diameter, so a missing trim figure makes the curve unusable as evidence.
Store the revision of the test procedure used.
Instruments and people behind the numbers
Every reading depends on an instrument. For each test, store the tag of the flow meter, the pressure transmitters and the power analyser, with the calibration certificate number and expiry date of every one.
If a certificate has expired, the system should warn before the test starts, not afterwards, and the record should name the operator, any witness and the approving engineer. Attach the signed witness page to the serial.
- Instrument tag and calibration expiry
- Operator and approving engineer
- Customer witness and sign-off copy
- Test standard, grade and tolerance band
Using the records when a claim arrives
When a complaint comes, open the serial. Compare the test curve with the contracted duty point and the tolerance, then overlay any field readings the customer can supply from site.
Often the pump passes and the system curve at site is the issue, such as a throttled valve or a clogged strainer. Sometimes the records show a real shortfall.
Next step: pick one pump model, list the fields from this guide that its current test sheet lacks, and add the missing ones to the next test run.
Pump test record sheet
The sheet opens with a header for serial, model, impeller trim, speed and test standard, then a readings grid for flow, pressures, power and speed at each point. The footer holds tags, expiries and signatures.
Open a blank worksheet to printQuestions owners ask
How long should test records be kept?
Keep them for the whole warranty period plus any retention clause in the contract, and many makers hold them for the pump’s expected working life.
Is a PDF certificate enough?
It helps as proof of what was issued, but store the readings as data too, because a PDF cannot be searched, compared across serials or recalculated.
Should failed tests be kept?
Yes, because a failed run followed by a trim and a pass explains why the shipped impeller has its final diameter, which matters when a later claim asks.