Industry
Welding and fabrication quality
From machine frames to process skids, fabrication quality depends on welding control. We verify it before, during and after welding.
01Fabrication is welding plus geometry
Fabricated products combine cutting, forming, welding, machining, surface treatment and assembly. Welding is the special process at the centre: it must be qualified, executed by qualified welders and inspected at the right stages.
Geometry is the second challenge. Distortion, fit-up errors and inadequate fixturing produce weldments that are structurally sound but cannot be assembled. QUALITAS TR covers both: welding quality to ISO 3834 principles and dimensional control of welded assemblies.
02Typical quality risks we see
- Welding outside qualified ranges
- Expired or unsuitable welder qualifications
- Lack of fusion and incomplete penetration
- Excessive distortion
- Uncontrolled consumables
- Missing traceability and weld maps
- Repairs without procedure
03How QUALITAS TR supports welding and fabrication buyers
| Service | What we do in this sector |
|---|---|
| Welding Inspection | Before, during and after welding inspection to the specified quality level. |
| WPS, PQR and Welder Qualification Review | Welding documentation review and qualification witnessing. |
| NDT Coordination and Witnessing | NDT planning and review. |
| Dimensional and Geometrical Inspection | Dimensional and geometrical inspection of weldments. |
| Manufacturing and Special Process Audits | Welding process audits against ISO 3834 requirements. |
04Key inspection points
- WPS coverage per joint
- Welder certificates and continuity
- Consumable storage and baking
- Fit-up and root gap
- Preheat and interpass temperature
- Visual inspection to ISO 5817 level
- NDT extent and results
- Dimensions after welding and stress relief
- Weld map and traceability
- Surface preparation before coating
Inspection and Test Plan: hold, witness and review points
A typical ITP sequence for a fabricated and machined assembly.
| # | Activity | Reference | Supplier | Third party | Record |
|---|---|---|---|---|---|
| 1 | Pre-inspection meeting, ITP and drawing revision check | PO, specification | P | H | Minutes |
| 2 | Material certificate review and identification | EN 10204 3.1 | P | R | MTC log |
| 3 | WPS, PQR and welder qualification review | ISO 15614, ISO 9606 | P | R | Review sheet |
| 4 | Fit-up and in-process weld visual inspection | ISO 17637, ISO 5817 | P | W | Weld map |
| 5 | NDT after final heat treatment | Project NDT procedure | P | W | NDT reports |
| 6 | Final dimensional inspection | Drawing, GD&T | P | H | Dimensional report |
| 7 | Pressure or functional test | Test procedure | P | H | Test certificate |
| 8 | Coating DFT, marking, packing and release | Coating spec, packing spec | P | H | Release note |
05Standards and requirements
Welding quality requirements are defined in ISO 3834 (comprehensive, standard or elementary). The appropriate part is chosen according to product criticality, often by the design code.
06The sector in Turkey
Turkey has a very large fabrication sector serving construction, energy, process industries and machinery, concentrated in Kocaeli, İstanbul, İzmir, Ankara and the steel producing regions.
Many fabricators hold ISO 3834 and EN 1090 certification; actual implementation varies, which audits reveal.