Practical visual inspection and reporting
This domain tests whether you can inspect a weld properly and record what you found. Expect inspection stages, illumination and access conditions, gauges, the main visual discontinuities, acceptance levels to EN ISO 5817, and the content of a usable inspection report.
Conditions and stages
Visual inspection follows ISO 17637. Illumination at the inspection surface should be at least 500 lux, viewing distance no more than about 600 mm, and the viewing angle to the surface at least 30 degrees. Inspection occurs before welding (fit-up, edge preparation, cleanliness), during welding (root, interpass, preheat), and after welding (final). Aids include a fillet weld gauge, undercut gauge, hi-lo gauge, reinforcement gauge, mirror and borescope.
Discontinuities and acceptance
Typical visual findings are cracks, porosity, undercut, overlap, excessive reinforcement, spatter, arc strikes, linear misalignment and incomplete fusion at the toe. EN ISO 5817 defines quality levels B, C and D, with B the most stringent. Acceptance limits depend on the quality level and must be stated before inspection. Cracks are generally unacceptable at any level.
Worked example
Final visual inspection of a fillet weld finds a 3 mm toe crack. The weld is rejected regardless of whether level B, C or D applies. Reasoning: a crack is planar and will propagate under cyclic loading, so no quality level permits it. The inspector marks and records the location and size, requests surface or volumetric NDT to establish the extent, and the weld is repaired to an approved procedure and re-inspected.
Report content
A report should identify the project, drawing and weld number, the standard and acceptance level, inspection stage, conditions and instruments, findings with location and size, and a clear pass, fail or re-inspection status, with date and inspector signature.
Traps that cost marks
- Inspecting without a stated acceptance level.
- Recording a defect without location, size or extent.
- Skipping root inspection before capping.
- Passing a weld without checking illumination and access.