Eddy Current Testing in LNG: What It Finds, What It Misses, and What Governs It
What ET is actually used for in lng
LNG plant exchangers and the fin-fan fleet supporting liquefaction take eddy current examination between runs, where tube failure means capacity loss on a scheduled cargo.
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 lng assets this applies to
Liquefaction trains, cryogenic storage tanks, loading lines and jetties, boil-off handling, and the marine interface.
The damage mechanisms driving the examination
Cryogenic service changes the question: brittle fracture risk drives material and toughness concerns, thermal cycling fatigues connections, and external corrosion under cryogenic insulation is difficult to detect precisely because access is difficult.
What governs acceptance
API 625 and 620 for cryogenic tanks, ASME for pressure equipment, plus jurisdictional and marine-terminal requirements at the interface. 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 · LNG programme consulting · LNG NDT training · scope a ET examination.
ET in other sectors
Refining · Petrochemical · Offshore · Pipeline · Marine & Shipbuilding · Aviation & Aerospace.