Overview
ISO 17637:2016 - "Non-destructive testing of welds - Visual testing of fusion-welded joints" defines requirements and guidance for visual testing (VT) of fusion welds in metallic materials. The standard covers visual inspection before, during and after welding, and applies to finished and repaired welds. It is intended for use alongside application or product standards that specify the extent of inspection and acceptance criteria.
Key topics and technical requirements
- Scope and purpose: Visual testing of fusion-welded joints and, where required, inspection of the joint prior to welding.
- Illumination and viewing conditions: Minimum surface illuminance of 350 lx (wearing tinted goggles increases the minimum); 500 lx recommended. For direct inspection the eye should be within 600 mm of the surface at an angle of at least 30°. Remote inspection (mirrors, boroscopes, fibre optics, cameras) is allowed when direct access is not possible.
- Personnel qualification: Examinations and acceptance decisions must be performed by qualified personnel; indirect VT personnel are recommended to be qualified to ISO 9712 or an equivalent industry scheme.
- Inspection stages:
- Pre-weld: verify weld preparation, cleanliness and correct assembly.
- During welding: check cleanliness between runs, look for visible imperfections, and ensure correct transitions and gouging.
- Post-weld (finished weld): assess cleaning/dressing, profile and dimensions, weld root and surfaces, and compliance with acceptance criteria (e.g., ISO 5817, ISO 10042 where applicable). Final testing after any post‑weld heat treatment.
- Repaired welds: Requirements for visual inspection of partially or completely removed and re-welded joints, ensuring excavations are adequate for removal of imperfections and that final welds meet original criteria.
- Test records: Minimum reporting information includes component and testing body identity, material, joint type and thickness, welding process, acceptance criteria, detected imperfections and locations, extent of inspection, devices used, result, tester name and date. Permanent visual records (photos or sketches) recommended if required.
Applications and who uses it
ISO 17637 is used by:
- Welding engineers and quality managers for weld acceptance and inspection planning.
- NDT technicians and inspectors performing visual weld inspection in fabrication, construction, pressure vessels, pipelines, shipbuilding and structural steel.
- Fabricators and procurement/specification writers to define inspection requirements in welding procedure specifications (WPS) and contracts.
- Training and certification bodies referencing VT scope and competency requirements.
Related standards
- ISO 9712 (personnel qualification for NDT)
- ISO 5817, ISO 10042 (examples of acceptance criteria referenced for finished welds)
- Application/product standards that define specific inspection extent and acceptance criteria
Keywords: ISO 17637, visual testing, non-destructive testing, weld inspection, fusion-welded joints, visual weld inspection, NDT of welds.