A WPQR proves that a welding procedure produces a sound weld, while IACS approval proves that a specific welder can execute that procedure reliably in production. A fabricator needs both to produce structural welds that class societies will accept.
What WPQR and IACS welder approval actually mean
A WPQR, welding procedure qualification record, is documented proof that a specific combination of materials, joint design, welding process and parameters produces a weld with the mechanical properties required for the job, established by welding and testing a sample joint before it is used in production. IACS approval for a welder is a separate but related qualification: practical testing, overseen by a recognised body under the International Association of Classification Societies framework, that confirms an individual welder can consistently produce a sound weld in the specific process, material and position they will actually work in.
Together the two answer different questions. The WPQR proves the procedure itself is sound on paper and in a test piece; the welder's approval proves the person applying that procedure in production can execute it reliably, which is why a shipyard or fabricator needs both a qualified procedure and an approved welder to produce class accepted structural welds, not one or the other.
How a welding procedure gets qualified
Qualifying a procedure starts with a written specification, the WPS or welding procedure specification, that sets out every variable expected to affect the weld's properties: base material grade, filler material, joint geometry, welding position, current and voltage range, travel speed and preheat or interpass temperature where relevant. A test piece is welded exactly to this specification, usually witnessed by an inspector or class surveyor, and then subjected to destructive and non destructive testing, tensile and bend tests, and often impact testing, to confirm the weld meets the required mechanical properties.
If the test piece passes, the WPS becomes qualified and the results are recorded as the WPQR, which then defines the acceptable range for each variable in future production welds, not just the exact values used in the test. A change outside that qualified range, a different material thickness band, a different position, generally requires a new qualification before it can be used.
How a welder becomes IACS approved
A welder seeking approval welds a test piece under examination, in the process, material, thickness range and position they need to be certified for, following a qualified procedure. The test piece is then checked visually and, depending on the scope, by radiographic or ultrasonic examination and by bend testing, to confirm the welder produced a sound joint without relying on conditions more favourable than they will meet in production.
Approval is scoped rather than universal: a welder certified for flat position butt welds on carbon steel plate of a certain thickness is not automatically approved for overhead welding, for aluminium, or for a different thickness range outside what was tested, and approvals are typically time limited, requiring periodic renewal to confirm the welder's skill has not lapsed. This scoping is deliberate, since welding skill in one position or material does not reliably transfer to another, and a fabricator working across steel, stainless and aluminium needs a correspondingly broader roster of approvals to cover the work.
Why this matters for a finished structure
For a customer ordering a gangway, pontoon or custom steel structure, WPQR qualified procedures and IACS approved welders are the practical mechanism behind a claim of weld quality, not a marketing phrase. A fabricator such as Yeke Denizcilik, working under Bureau Veritas certified production with WPQR qualified procedures and IACS approved welders, can trace any structural weld back to the exact procedure and the specific welder who made it, which matters if a question about that weld ever comes up during a class survey or years into the structure's service life.
The alternative, welding without qualified procedures or verified welder competence, may still produce joints that look acceptable on the surface, but there is no documented basis for trusting their mechanical properties under load, which is precisely the risk these qualifications exist to remove from marine structural work.
What to ask a fabricator for
A straightforward way to check a fabricator's welding credentials is simply to ask for copies of the relevant WPQR and welder approval certificates for the joints in the order, rather than accepting a general statement that the work is qualified. A fabricator with proper documentation will produce these without difficulty, since they already exist as part of normal quality records.
It is also reasonable to ask which body issued the welder approvals and what scope, process, material, thickness and position, they cover, since a certificate that does not match the actual joints being welded on the order provides no real assurance. This kind of question costs nothing to ask and gives a clear, verifiable answer rather than a general reassurance.
For a repeat customer working with the same fabricator on multiple orders, keeping a simple log of which WPQR and which welder approval applied to each past delivery makes any future audit faster and removes any doubt about which records belong to which structure.