Radiographic Testing in Fabrication & Welding: What It Finds, What It Misses, and What Governs It
What RT is actually used for in fabrication & welding
Shop radiography remains the reference for coded vessel and spool fabrication — the image travels with the data book the client audits.
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 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 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 · Fabrication & Welding NDT training · scope a RT examination.
RT in other sectors
Refining · Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding.