[PUBLISHED]
European industrial procurement routinely asks for ISO 3834-2 up front. Most welding subcontractors list it on their capability sheet without explaining what it proves. For a procurement manager at a main contractor or end operator, here is the working translation.
What ISO 3834 is, structurally
ISO 3834 is a quality-requirements framework for fusion welding of metallic materials. It is not a welding procedure or a welder qualification — both of those live in separate standards (ISO 15614-1 and ISO 9606-1 respectively). ISO 3834 is about whether the welding organisation is set up to consistently produce welds that meet the specification the customer gave them.
The standard is structured in three tiers of rigour:
- ISO 3834-4 — elementary quality requirements
- ISO 3834-3 — standard quality requirements
- ISO 3834-2 — comprehensive quality requirements
The tiers are progressive. If a subcontractor is certified to -2, the -3 and -4 requirements are covered by definition.
What -2 actually requires
Comprehensive-level certification is audited against ten-ish process domains. The ones that matter most when you are comparing subcontractors:
- Contract review and design review — the welding organisation reviews the contract, identifies applicable standards, flags technical gaps before accepting the work. This is why you can hand us an isometric package and expect a competent pushback if the WPS coverage does not match what you have drawn.
- Welding coordination — there is a named welding coordinator with authority (typically EN ISO 14731 qualification) and documented tasks mapped to every project. Not “someone in the office handles welding” — a named person with the credential and the budget to stop the work if something is not right.
- Welder and operator qualifications — welders qualified to EN ISO 9606-1 (or equivalent) for the process, material group, thickness, and position range of the work. Records kept, revalidation dates tracked.
- WPS and procedure qualification — Welding Procedure Specifications available for every process used. WPQR (Welding Procedure Qualification Records) per EN ISO 15614-1 underneath each WPS. We do not guess which electrode to use on the job — the WPS tells us and the WPQR proves it works.
- Heat treatment and consumables control — storage, handling, and traceability of filler metals and heat treatment procedures where the material demands it.
- Inspection and testing — visual, dimensional, and NDT coordinated with qualified personnel and approved partners.
- Non-conformance and corrective action — documented process for when a weld fails inspection, including root-cause and re-weld procedure.
What -2 does not prove
This matters as much as what it does prove.
- It does not mean the subcontractor has delivered to your specific standard before. If your project needs ASME B31.3 and the subcontractor has only worked to EN 13480, the welding-quality framework transfers but the code-specific WPS coverage needs to be verified separately.
- It does not mean posting compliance is handled. Cross-border posting (A1, ID06, SOKA-BAU, SIPSI, Limosa, etc.) is outside the scope of ISO 3834 entirely. If the welders cannot legally cross the border, the welding quality system is academic.
- It does not mean crews are available on your timeline. Capability is not the same as capacity.
How we treat it
We treat ISO 3834-2 as the baseline to operate in European industrial work — not a differentiator. The certification is active with UDT (Urząd Dozoru Technicznego, Polish notified body). It is audited annually.
The differentiators on top of the baseline: the welder qualification matrix we carry, the WPS library we have built, the welding coordinator assigned to each project (named, with EN ISO 14731 credentials), and the test-pack discipline that means your QA team can accept our output without re-inspecting everything.
For procurement screening, the list of certifications is on /certifications/. For the full document pack, /procurement/.