Magnetic Particle Testing in Refining: What It Finds, What It Misses, and What Governs It
What MT is actually used for in refining
MT is the workhorse for surface cracking on refinery equipment — nozzle welds, skirt attachments and internally on vessels during turnaround entry, particularly where wet H2S service makes surface breaking cracks credible.
How MT works
MT magnetises a ferromagnetic component and applies iron particles, which gather at the flux leakage a surface-breaking or near-surface discontinuity creates. It is fast, inexpensive per square metre, and unusually good at what it does: finding cracks in steel that a visual examination would miss.
What MT will not do
What MT will not do: work on non-magnetic material at all — no stainless austenitics, no aluminium, no nickel alloys — and it finds nothing meaningfully below the surface. Coatings degrade sensitivity, and flaws parallel to the flux direction are invisible, which is why examination in two directions is standard practice rather than diligence.
The refining assets this applies to
Crude and vacuum units, cokers, reformers, hydrotreaters, the piping circuits between them, fired heaters, exchanger trains, and the tank farm at the end of it.
The damage mechanisms driving the examination
Corrosion is the governing story — sulphidic and naphthenic attack on hot circuits, aqueous corrosion in overheads, corrosion under insulation everywhere insulation exists — with wet H2S cracking, high-temperature hydrogen attack and creep in specific services.
What governs acceptance
API 510 (vessels), 570 (piping) and 653 (tanks) govern in-service inspection, with ASME Section V supplying method rules and Section VIII / B31.3 the acceptance criteria. Operator contractor-approval gates site access above the codes. On the method side: ASME Section V Article 7; AWS D1.1 for structural work; ASTM E1444 in aerospace and general industry; ASTM E709 as the practice reference. 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 MT 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.
Magnetic Particle Testing services · MT training and certification · Refining programme consulting · Refining NDT training · scope a MT examination.
MT in other sectors
Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding · Aviation & Aerospace.