Visual testing, the examination of joints before, during and after welding for size, profile, undercut, porosity, cracks, spatter and arc strikes, using fillet gauges, rulers, lights, mirrors and borescopes. It catches most fabrication problems at the lowest cost, and a weld must pass VT before other NDE is worth paying for. Codes give acceptance criteria, and inspectors must meet vision requirements.
VT first, if it doesn't pass visual there's no point paying for UT.
Also heard as
- visual testing
- visual inspection
- visual
Related terms
CWI
Certified Welding Inspector: the AWS inspection credential, and the usual job title for the person checking welds.
Discontinuity
Any break in the normal makeup of a weld, such as a pore or inclusion, that becomes a defect only when it exceeds code limits.
Undercut
A notch the arc melts into the base metal beside the weld toe that the weld metal never fills back in.
Arc strike
A spot where the arc touched base metal outside the weld, leaving a small melted or hardened scar.