UNI EN ISO 3834
Quality requirements for fusion welding of metallic materials
The common denominator. EN 1090-2 requires it at every execution class — the level rising with the class (EXC1 → ISO 3834-4, EXC2 → 3834-3, EXC3/4 → 3834-2) — the pressure world adopts it as the welding quality system, and ASME Section IX is its qualification counterpart outside Europe.
Why this one comes first
Almost every other welding regime leans on ISO 3834. EN 1090-2 references it for all structural work, with the ISO 3834 level rising with the execution class (EXC1 → 3834-4, EXC2 → 3834-3, EXC3/4 → 3834-2); pressure equipment manufacturers use it as the welding quality system behind PED; and outside Europe the qualification role is played by ASME Section IX, with the quality-system role carried by the ASME BPVC QC/QA programme behind the stamp.
That is why the product has one backbone and not four: the evidence a welding shop must produce is largely the same, and only the regime on top changes.
The three levels
The standard comes in comprehensive, standard and elementary requirements. The level is not a grade of quality — it is a match to the work being done. Choosing a level higher than the work needs buys audit burden, not confidence.
What it asks you to be able to show
- Which procedure covered this joint, in the revision that was current when it was welded
- Which welder made it, qualified in a range that actually contains this joint
- That the consumables and parent material were the ones specified, traceable to a heat
- That inspection happened at the extent required, by someone qualified to perform it
- That deviations were dispositioned, not quietly absorbed
Where it's used in Worgify
This standard is wired into these parts of the product — not just described here.