Structural Weld Examination

Structural weld examination applies magnetic particle inspection to the welds joining structural steelwork — bridges, gantries, supports, frames and fabricated assemblies. It concentrates on the weld toe and the surrounding heat-affected zone, which is where fatigue cracking in structures characteristically begins.

Why structural weld examination matters

Structures accumulate damage slowly under cyclic load, and structural failures are rarely sudden material failures; they usually start as a small crack at a weld toe that grows over years. Because the critical region is at the surface, magnetic particle inspection is very well matched to the problem: it is sensitive, quick over large areas of weld, and shows the crack directly. Catching a toe crack early is the difference between a local repair and a structural replacement.

What it detects

Weld toe cracking and fatigue cracking
Surface-breaking cracks in the heat-affected zone
Undercut and surface porosity
Lack of fusion breaking the surface
Cracking around attachments and stiffeners

Where it is applied

  • Bridges, gantries and support structures
  • Fabricated steelwork and frames
  • In-service structural inspection programmes
  • Weld quality verification after fabrication or repair

DELIVERED USING MAGNETIC PARTICLE (MT)

Applicable Standards

SANS 3577-3, ASTM E709

Professional Equipment

Magnaflux Yokes, UV Lamps, Fluorescent Particle Systems

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Common questions

Can the structure stay in service during inspection?

Generally yes. The method is non-destructive and applied locally to accessible welds; what usually governs is safe access to the weld rather than the inspection itself.

How much of the weld gets inspected?

That is set by the specification. Some programmes examine all welds of a given class, others target the locations where fatigue is predicted or where earlier inspection raised a concern.

Does surface coating need to be removed?

Yes, locally. Paint or coating over the weld must be removed for particles to indicate properly, and the surface is prepared before inspection.

Where we deliver it

MPIA Services is based in Durban (also known as eMkhomazi), KwaZulu-Natal, and carries out structural weld examination on site across all nine South African provinces. Mobile field units travel to the asset, so the work happens in place — on live rail corridors, in yards and depots, and at industrial sites — rather than requiring components to be sent away. See where we work.

Need structural weld examination?

Tell us the asset, the standard you need to satisfy and where the work is. We will come back with scope, timing and a quotation.

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