VT · Conventional NDT
Visual Testing
The Method
How VT works.
Visual testing (VT) is examination of a surface by eye, directly or with aids such as magnifiers, mirrors, borescopes, and video equipment. Findings are evaluated against the acceptance criteria in the governing code, specification, or drawing.
On welded fabrications, VT is applied before, during, and after welding. Gauges and calibrated measuring tools turn observation into recorded, repeatable results.
Applications
Where VT is used
- Fit-up and joint preparation before welding
- In-process and final weld inspection
- Weld size, length, and profile verification
- Remote visual inspection of internal or restricted-access areas
- Pre-coating and pre-installation surface inspection
Detection capability
What VT can detect
- Surface cracks large enough to resolve visually
- Undercut, overlap, and underfill
- Surface porosity and craters
- Excessive reinforcement, concavity, or convexity
- Undersized or missing welds, misalignment, and arc strikes
- Corrosion, erosion, and mechanical damage
Methods & Equipment
Typical equipment
- Fillet, butt-weld, Hi-Lo, and undercut gauges
- Calibrated rules and measuring tools
- Inspection lighting and light meters
- Magnifiers, mirrors, and borescopes or video probes
Technical Considerations
Limits and requirements to plan for.
Lighting and access
Codes set minimum light intensity and limits on viewing distance and angle. Remote equipment must show equivalent resolution.
Surface condition
Scale, slag, and coatings can hide discontinuities. Surfaces must be clean enough for the required examination.
Surface only
VT sees only the surface. Subsurface and internal discontinuities need MT, UT, or PAUT.
Vision requirements
Inspectors maintain current near-vision and color-perception examinations.
In Practice
VT in industry.
Shipbuilding
Visual examination of structural, piping, and component welds as part of a multi-method plan.
Structural steel
Weld size, profile, and workmanship on fabricated members.
In-service equipment
Condition assessment of vessels, piping, and supports.
Industries that benefit
How TCI Supports You
What you get from TCI.
- VT performed to your procedures and acceptance criteria
- Inspection timed to fabrication hold points
- Clear, traceable inspection records
Let's discuss your inspection requirements.
Tell us about your project, schedule, and the specifications you work to. A member of our leadership team will respond directly.