A Factory Acceptance Test (FAT) is often described in commercial terms — a milestone, a payment trigger, a box to check before shipment. On the shop floor, it’s something more specific: a structured sequence of measurements designed to answer one question — does this pump actually do what its datasheet says it does?
This is a walk-through of what that sequence typically looks like, based on a recent pump FAT carried out on behalf of a confidential international client, at the facility of a European rotating-equipment manufacturer.
Before the visit: reviewing the scope
A FAT witness assignment doesn’t start on-site — it starts with document review. Before mobilizing an inspector, the applicable Inspection & Test Plan (ITP), the approved FAT procedure, and the pump’s datasheet are reviewed against the purchase order and applicable project specification. This defines the acceptance criteria in advance: what flow, head, power, and efficiency values are expected, what the NPSH margin should be, and what vibration and noise levels are acceptable.
On-site: what gets measured
The test itself typically runs through several stages:
- Visual and dimensional checks — confirming nameplate data, dimensions, and general workmanship match the approved drawings before any test starts.
- Performance testing — running the pump across its specified operating range while recording flow rate, differential head, power draw, and calculated efficiency, then comparing the resulting curve against the guaranteed performance curve.
- NPSH testing, where specified — verifying the pump performs within its net positive suction head margin, which is critical for avoiding cavitation in service.
- Vibration and noise measurement — recorded at multiple points and operating conditions, checked against the applicable standard’s velocity or displacement limits.
- Bearing temperature and running checks — monitoring temperature rise over a sustained run to catch early signs of misalignment or lubrication issues.
- Leakage and alignment checks, closing out the mechanical verification before sign-off.
Where things get interesting: the open points
Not every FAT closes without a finding. In this case, the initial vibration reading at one operating point sat just above the alert threshold defined in the applicable standard — not a failure, but a flag worth investigating before acceptance. The finding was documented as an open point, the vendor rebalanced the impeller, and a re-test confirmed the value was brought within limits. That sequence — flag, document, retest, close — is exactly what a structured FAT is meant to produce: not just a pass/fail stamp, but an evidence trail showing how any deviation was identified and resolved.
The report that comes out the other end
The final FAT report doesn’t just state “accepted.” It includes the measured performance curve against the guaranteed curve, vibration and noise readings against their limits, photographic evidence of the nameplate and setup, the open point raised during testing, and the corrective action taken before final sign-off. That level of detail is what allows a client — often not present at the test themselves — to make an informed acceptance decision rather than relying on a vendor’s own self-certification.
Why this matters beyond one pump
A single pump FAT is a small event in the life of a project. But multiplied across dozens of packages on a plant expansion or a new build, consistent, independently witnessed testing is what turns “the vendor says it’s fine” into a documented, traceable basis for acceptance — which is the entire point of third-party inspection in the first place.