Weld Inspection: The “Four-Check” Approach
The inspection of weld quality for embedded parts follows a “four-check” protocol: visual inspection (surface defects), dimensional verification (weld leg size), non-destructive testing (internal defects), and documentation verification (reports/welder qualifications).
Industry experts note that the inspection process—covering appearance (cracks/undercut), dimensions (weld leg), non-destructive testing (UT/MT), and documentation (reports)—forms a closed-loop system, culminating in the verification of test reports.
The Four-Check Process
- Visual Inspection: Cracks/undercut (surface)—checked by the naked eye;
- Dimensional Verification: Weld leg size (dimensions)—checked via measurement;
- Non-Destructive Testing: Internal defects (NDT)—UT/MT methods;
- Documentation Verification: Reports/qualifications (records)—verified against standards;
- Re-inspection & Confirmation: Rework for non-compliant items (re-inspection)—closing the loop.
Key Inspection Points
First, visual inspection.
Check for cracks and undercut (surface defects) to ensure nothing is missed by the naked eye.
Second, dimensional measurement.
Measure weld leg sizes (against design specifications) to prevent undersized welds.
Third, non-destructive testing.
Conduct UT/MT to detect internal flaws.
Fourth, documentation verification.
Check test reports and welder qualifications to ensure compliance and valid certification.
Common Pitfalls to Avoid
First, “visual-only inspection.”
Relying solely on appearance risks missing internal defects; non-destructive testing is essential.
Second, “insufficient dimensions.”
Undersized weld legs compromise structural strength; precise measurement is required.
Third, “missing reports.”
No inspection report available (traceability impossible);
document verification required.
Trends and Reminders
Weld acceptance is moving towards digitalization, characterized by the digitization of non-destructive testing (electronic reports) and the intelligentization of welding (robotic welding).
For purchasers, the recommended approach is to verify appearance, measure dimensions, conduct non-destructive testing, and review documentation.
Strict weld acceptance ensures the safety of embedded components.
