Eddy Current Testing in Fabrication & Welding: What It Finds, What It Misses, and What Governs It
What ET is actually used for in fabrication & welding
Material verification and sorting — mixed stock, heat-treat condition checks — bring eddy current into fabrication QA alongside dedicated weld techniques.
How ET works
Eddy current testing induces circulating currents in a conductive material and reads the impedance change a discontinuity causes. It needs no couplant and no contact, which makes it the fastest surface and near-surface method available — and, in tube form, the only practical way to screen thousands of heat-exchanger tubes inside a shutdown window.
What ET will not do
What ET will not do: examine non-conductive material, penetrate deeply (the effect is confined near the surface, more so as frequency rises), or produce results anyone can interpret without training — signal interpretation is the whole skill, and lift-off, edge effects and permeability variation all masquerade as indications.
The fabrication & welding assets this applies to
Structural steel, pressure vessels and pipe spools, skids and modules — everything examined before it ever enters service.
The damage mechanisms driving the examination
Construction defects rather than degradation: lack of fusion and penetration, porosity and slag, cracking from restraint or hydrogen, and dimensional non-conformance.
What governs acceptance
AWS D1.1 for structural steel, ASME Section VIII and IX for pressure equipment and procedure qualification, B31.3 for process piping, plus customer specifications that routinely tighten all three. On the method side: ASME Section V Article 8 for tubing; ASTM E243 and E571 for specific product forms; aerospace surface examination runs under NAS 410 with OEM technique requirements. An examination that is technically sound but performed outside the governing regime is not an examination anyone will accept, which is why the code family matters as much as the technique.
How Atlantis delivers ET in this sector
Atlantis mobilises examination teams to your site under Atlantis procedures with ASNT Level III oversight — we do not claim a depot or laboratory in every market, and say so plainly. What you receive is the examination performed to a qualified procedure, findings evaluated against the acceptance criteria your contract names, and records structured to survive a client audit years later.
Eddy Current Testing services · ET training and certification · Fabrication & Welding NDT training · scope a ET examination.
ET in other sectors
Refining · Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding.