Inspection, Testing and Quality Assurance
Domain 5: Inspection, testing and quality assurance
This domain tests how inspection is planned and evidenced, not just how a single test is performed. The exam expects you to link the inspection and test plan (ITP) to specification requirements, hold points and records.
ITP and inspection points
An ITP lists operations, the characteristic to be checked, the method, the acceptance criterion, the frequency, and who performs or witnesses it. Hold points stop work until inspection is released; witness points require notification but do not stop work; review points require documents to be examined. Typical welding ITPs cover consumable control, joint preparation, fit-up, preheat, root and fill checks, final visual inspection, NDT and post-weld heat treatment.
QA evidence
Quality assurance depends on traceability, calibrated equipment, qualified personnel, approved procedures and control of nonconformities. ISO 3834 provides the framework. Destructive tests such as tensile, bend, impact and hardness testing are mainly qualification or verification tools; production NDT is not a substitute for procedure qualification. Calibration records, material certificates and NDT reports must be retrievable.
Worked example
A pressure-retaining weld will be partly inaccessible after closure. The ITP should place a hold point before closure for root inspection and any required NDT of the internal side, with the acceptance level stated. If the hold point is signed off after closure, the record shows that the required inspection could not have been performed; that is a documentation and quality failure even if the weld later passes external NDT.
Traps
Confusing hold, witness and review points. Using NDT as a substitute for welder qualification. Accepting verbal release without a signature. Forgetting the calibration status of NDT equipment and gauges.