Visual Testing in Fabrication & Welding: What It Finds, What It Misses, and What Governs It
What VT is actually used for in fabrication & welding
CWI-style visual acceptance is the first gate on every production weld: profile, undercut and reinforcement checked before any volumetric method is spent.
How VT works
Visual testing is the examination every other method is deployed against: direct or remote observation under controlled lighting and access, judged against written acceptance criteria. It finds the majority of reportable conditions in most programmes — weld profile, corrosion, mechanical damage, coating breakdown, leakage evidence — and it decides where volumetric examination is worth performing.
What VT will not do
What VT will not do: see beneath the surface, quantify wall loss, or substitute for a volumetric method where the code requires one. Its weakness is human rather than physical — inconsistent lighting, inadequate access, and acceptance criteria applied from memory rather than from the document.
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 9; AWS D1.1 for structural acceptance; API 510/570/653 for in-service external and internal examination; ASME B31.3 for process piping. 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 VT 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.
Visual Testing services · VT training and certification · Fabrication & Welding NDT training · scope a VT examination.
VT in other sectors
Refining · Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding.