ISO standard · reference card
ISO 17637: scope of visual testing for fusion welds
Does ISO 17637 cover your inspection stage? Scope decision flow for the visual-testing procedure standard, the acceptance standard it pairs with, and the records that support a visual-testing report.
- Designation
- ISO 17637
- Issued by
- ISO
- Title
- Non-destructive testing of welds — Visual testing of fusion-welded joints
- Edition
- Confirm the edition your certification body works to.
ISO 17637 is a procedure standard for looking at a weld, not an acceptance standard for judging one. It sets how visual testing is carried out — at which stages, under what conditions, by whom — and leaves the pass/reject decision to whichever quality-level or application standard the contract names.
The recurring gap is treating a clean-looking weld as inspected when only the post-weld stage was checked. The standard’s value sits largely in the stages before the bead is finished: joint fit-up, root condition and interpass cleanliness catch problems a finished-weld look alone will not reveal once the joint is complete. The second gap is assuming visual testing has done the job only a volumetric method can — it sees the surface, and nothing behind it.
Therness equipment does not perform visual testing. It captures a continuous per-weld record of the surface and the process, so the inspector’s visual result sits alongside evidence of what actually happened at every stage, not just at the moment the inspector looked.
Scope: does it apply to your job?
Applies to
- Visual testing of fusion-welded joints in metallic materials, before, during and after welding
- Written visual-testing procedures, and requiring the operator carrying them out to be qualified
- Direct viewing and aided viewing methods such as mirrors, borescopes and cameras
Does not apply to
- Setting the accept/reject levels themselves, which come from a quality-level or application standard such as ISO 5817
- Other NDT methods — radiographic, ultrasonic, penetrant and magnetic particle testing — each covered by its own standard
- The certification scheme itself — issuing or maintaining a qualification — which ISO 9712 governs
Applicability decision flow
| Question | If yes | If no |
|---|---|---|
| Is the joint a fusion weld in a metallic material? | ISO 17637 is the applicable visual-testing procedure standard. | A different NDT or inspection standard applies to the joining process. |
| Does the job need pre-weld and in-process checks, not only a look at the finished bead? | ISO 17637 covers all three stages — build the inspection plan around before, during and after welding. | Post-weld visual testing alone may satisfy a lighter contract; confirm against the application standard. |
| Does the contract or application standard already name the acceptance level? | Apply that level's criteria at the visual-testing stage; ISO 17637 supplies the procedure, not the level. | The level has to come from elsewhere, commonly ISO 5817, before a pass/fail decision can be made. |
| Is viewing done remotely or through a camera rather than direct line of sight? | Aided visual testing is permitted where the standard's conditions for it are met — record the method and equipment used. | Direct visual testing applies under normal lighting and access conditions. |
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 |
|---|---|---|
| Continuous coverage of the weld surface across a shift, not a periodic spot check | Per-weld thermal and visual record captured inline as each seam is made | HeatCam IR-C |
| Flagging which welds carry a visible anomaly ahead of the inspector's pass | AI-scored anomaly flag per weld, tied to the weld identifier | HeatCore AI |
| A recorded trail of when and how each weld was made, to accompany the inspection report | Per-weld operator, timestamp and parameter record exported alongside the visual result | 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.
