Here are the key updates every welding engineer and quality manager should know.
1. New tolerance rule (QW-100 subparagraph f)
Dimensions and parameters without explicit tolerances are treated as nominal values. Reasonable deviations may be accepted based on engineering judgment. A 500mm test piece with ±5mm deviation is acceptable if weld quality is not affected.
2. Essential variables refined for automated welding
Current/voltage fluctuation up to 10% and heat input variation up to ±15% are now explicitly permitted within a qualified WPS, provided the allowable range is documented.
3. NDT digital transformation
Real-time monitoring and data traceability are now integrated into the qualification framework. Welders and NDT personnel must pass ASME-recognized assessments under the new edition, particularly for RT and UT.
4. Additive manufacturing mandated
Electron beam melting is now explicitly covered. Additive materials require pre-verification through the ASME MatDB database.
What stays the same:
• Essential variable change beyond qualified range still requires new PQR
• Supplementary essential variables apply when impact testing is required
• PWHT temperature field uniformity per QW-407.1
Deadline: Any new welding qualification issued on or after January 1, 2026 must comply. Existing qualifications remain valid, but quality documents should be updated.
Review your WPS tolerance statements and NDT traceability now.
Source: LongMa (Jan 2026); Inspenet (Jan 2026); Therness.com; ASME BPVC Section IX 2025