Shipbuilding and marine fabrication
Weld monitoring for shipbuilding
High-volume welding under classification-society rules. The codes that apply, the four monitoring pain points that cost yards most, and which Therness signal addresses each.
ISO standard · reference card
ISO 3834-3: standard quality requirements and where it fits
Is the standard-level part of ISO 3834 the right fit? Decision flow against the comprehensive and elementary tiers, the codes it sits beside, and the records a Part 3 declaration depends on.
- Designation
- ISO 3834-3
- Issued by
- ISO
- Title
- Quality requirements for fusion welding of metallic materials — Part 3: Standard quality requirements
- Edition
- Confirm the edition your certification body works to.
Part 3 sits in the middle of the ISO 3834 series, and that middle position is exactly where misclassification happens. A manufacturer moving up from simpler work reads Part 3 as “3834 without the heavy parts of Part 2” and treats its clauses as optional; a manufacturer moving down from comprehensive certification reads it as “3834 minus the paperwork” and drops records the standard still requires. Both readings miss that Part 3 is a complete quality-requirements standard in its own right — it carries the same clause categories as ISO 3834-2 at a reduced depth, proportionate to the work Part 1’s criteria route here, not a shorter list.
The clauses most often under-scoped at this level are inspection and testing, and identification and traceability — the same two clauses that matter most for ISO 5817 acceptance downstream. A Part 3 declaration still requires evidence that inspection happened during production, not only that a finished part looked acceptable, and still requires each weld identifiable to its welder and procedure. What differs from Part 2 is the extent expected, not whether the categories apply at all.
ISO 3834-5 then lists the further documents a Part 3 declaration has to satisfy — personnel qualification, procedure qualification, quality-management evidence — at the depth this part sets. Therness equipment produces the same shape of evidence whichever part governs: continuous per-weld records that satisfy Part 3’s inspection and traceability clauses without adding inspection headcount to a shop whose whole reason for choosing this tier was that comprehensive controls were not proportionate to the work.
Scope: does it apply to your job?
Applies to
- Manufacturers whose product range, process complexity and consequence of a defect sit between the comprehensive and elementary tiers
- Fusion welding of metallic materials under a certification scheme or contract that permits the standard level
Does not apply to
- Safety-critical or metallurgically demanding work, where Part 2's comprehensive requirements are the expected route
- The simplest, lowest-consequence production Part 4's elementary requirements are intended for
- Choosing the level for you — that selection is made against the criteria in Part 1
Applicability decision flow
| Question | If yes | If no |
|---|---|---|
| Does an application standard or contract already name Part 3? | Work to Part 3; the selection question is already closed. | Apply the Part 1 selection criteria before assuming Part 3 fits. |
| Does the work involve wide material ranges, thick sections or safety-critical service? | Part 2's comprehensive requirements are the more defensible route. | Part 3 may be proportionate to the actual product and process range. |
| Is the manufacturing scope simple enough that Part 4's elementary requirements would also be considered? | Compare against the Part 1 criteria directly — the two tiers are adjacent, not interchangeable by preference. | Stay with the standard requirements of Part 3. |
| Is structural steelwork under EN 1090-2 in scope? | The execution class named there drives the part; check the current mapping before defaulting to Part 3. | Continue applying the Part 1 criteria on their own terms. |
What proves conformity, and what only supports it
Conformity is decided by inspection and testing against the criteria the standard and the contract set. The records below are evidence that the process was held where it was qualified; they support an inspection result, they never replace one.
| Requirement | Record produced | Source |
|---|---|---|
| Inspection and testing evidence proportionate to Part 3's lighter but still real testing clause | In-process thermal and parameter records attached to the job, without adding a separate manual inspection step | HeatCore AI |
| Identification and traceability of welds and welders, required at every ISO 3834 level | Weld identifier, operator, timestamp and process record joined in one export | WeldTrace |
Evidence the process, not just the paperwork
Therness records what the machine actually delivered on every weld — parameters, thermal signature and a per-weld trail — so a conformity argument rests on measurements instead of recollection.
