State the questions the test must answer
List the construction, function and performance matters the purchase requires to be verified. Distinguish dimensional inspection, ratio or direction checks, selector functions and the outcomes that depend on load or thermal conditions. A single FAT label can cover very different work between suppliers. Agree the test scope before fabrication or commercial award, with each required result associated with an appropriate method and a clear record rather than a generic certificate of satisfactory operation.
Identify the actual test configuration
Request the setup drawing and the supplied equipment included in the demonstration. State the prime-mover arrangement, connected auxiliaries, lubricant and other conditions relevant to the test. A gearbox tested without its final cooling or control arrangement may provide useful evidence, but the limits must be recorded. The acceptance plan should identify differences from the delivered installation instead of letting the site team assume the whole ordered package has been demonstrated together.
Distinguish no-load checks from load-dependent outcomes
Ask which requested outcomes can be established by the proposed no-load run and which require other evidence. A smooth rotation demonstration does not by itself prove the required transmitted-load or continuous thermal duty. Have the responsible designers determine the verification needed for the project. If a load test is proposed, define the supported load cases, ratios, speeds and duration through the agreed procedure rather than accepting an unspecified claim that the gearbox was fully tested.
Define measurements and acceptance criteria
Agree measurement locations, instruments, recording and the criteria established by the responsible project team. Keep noise, temperature and vibration conditions traceable to the actual test setup. Results from different locations or load states may not be directly comparable. Identify witness and review points, calibration evidence and the form of the final report. A pass statement without the relevant conditions and recorded values can leave the purchaser unable to interpret what was accepted.
Close deviations without overstating the evidence
Set a process for recording unresolved findings, corrective work and any required repeat checks. Identify which factory limitations are addressed by design documents, additional tests or installed verification. Align release, delivery and site-acceptance milestones with those responsibilities. The objective is a proportionate evidence package for the ordered transmission, not an unrealistic promise that one factory test reproduces every rig condition or removes the need to assess the completed drive train at the destination.
Price comparable test scopes before ranking bids
Separate inspection, no-load running, any load demonstration, third-party attendance and report deliverables in the commercial schedule. A more extensive test arrangement may require different resources and lead time. Ask bidders to explain exclusions rather than treating every FAT price as the same work. Retain the accepted procedure revision and setup limitations with the final report so future service or warranty discussions do not depend on incompatible interpretations of what the factory evidence established.
Put these items side by side in the bid review
| Purchase item | Question to resolve | Evidence to request |
|---|---|---|
| Scope | Which requirement is each check verifying? | Accepted test matrix |
| Conditions | What load and auxiliaries are present? | Setup and operating record |
| Limitations | What remains for other evidence or site checks? | Closed verification responsibility list |
Suggested wording for the quotation request
Propose the gearbox inspection and FAT scope with test configuration, actual load, speed, ratios and measurements. Distinguish no-load evidence from load-dependent outcomes, state setup limitations and identify additional design or installed verification. Price witnessing and reports separately where applicable.
Assess each option within the complete gearbox drive train: prime mover, transmission, couplings, driven equipment, mounting and supporting oil system. Preserve the accepted load schedule and interface drawings when comparing suppliers or approving changes. A component rating should not be treated as proof of the complete installed arrangement. Obtain configuration-specific documents from the responsible designers, and retain the agreed exclusions and verification records with the equipment order. Installation, shifting, testing and maintenance must follow approved equipment instructions and site procedures rather than a procurement comparison.
For the wider equipment scope, consult the Oilfield Transmission Box: FAT Checklist. Use the RFQ checklist to collect the supporting documents before requesting a configuration-specific quotation.
Buyer questions
Does a successful no-load run prove rated continuous-duty performance?
No. Identify the load and thermal outcomes that need other agreed evidence.
Should test conditions accompany a pass statement?
Yes. Retain the setup, cases, measurements and applicable acceptance criteria in the report.
Background and supplier contact
Power transmission standards and technical publications offers related background, not certification of the equipment in a quotation. Applicability must be checked for the project and destination.
Explore the oilfield transmission box, browse all technical resources, or visit Vance Petroleum for company information. Request a gearbox proposal with the load schedule, interface drawings and required shaft speeds.