Radiographic Testing in Refining: What It Finds, What It Misses, and What Governs It
What RT is actually used for in refining
Refinery turnarounds pull radiography for weld acceptance on piping tie-ins and vessel repairs, where a permanent image is required before insulation and fireproofing close the work.
How RT works
Radiography passes X-rays or gamma radiation through the component onto film or a digital detector. Density differences in the image reveal what the material contains — porosity, slag, lack of fusion, and the internal geometry of a weld — producing the one thing no other method gives: a permanent, reviewable image of the volume examined.
What RT will not do
What RT will not do reliably: find tight planar defects lying perpendicular to the beam, because a crack with no measurable width casts almost no shadow. It also requires access to both sides, controlled radiation areas that shut down surrounding work, and licensed sources — which is why RT is scheduled around the plant rather than the plant around RT.
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 Articles 2 and 22 for technique; ASME Section VIII and B31.3 for acceptance; API 1104 for pipeline girth welds; ISO 17636 in international scopes. 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 RT 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.
Radiographic Testing services · RT training and certification · Refining programme consulting · Refining NDT training · scope a RT examination.
RT in other sectors
Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding · Aviation & Aerospace.