Visual Inspection(VT)
Definition
The most fundamental NDE method, involving direct or remote visual examination of equipment surfaces for signs of degradation, damage, leakage, misalignment, or other anomalies. Visual inspection detects surface conditions including corrosion, coating breakdown, distortion, discoloration, leakage staining, insulation damage, and mechanical damage. It may be performed directly, with magnification aids, or remotely using cameras, borescopes, or drones.
Context
Visual inspection is the first-line inspection method and often the most cost-effective for identifying external degradation. It is a required element of all inspection programs per API 510, 570, and 653. In Reliatic, visual inspection findings are recorded as inspection records linked to assets and may trigger more detailed NDE if anomalies are found.
Examples
- External visual inspection identifies bulging and cracking of insulation jacketing on a hot pipe, indicating potential CUI underneath requiring further investigation with UT.
- Internal visual inspection during turnaround reveals hydrogen blistering on the shell of an amine absorber, documented with photographs and mapped on the vessel sketch for monitoring.
Applicable Standards
- ASME V Article 9
- API 510
- API 570
- AWS D1.1
Related Terms
A group of analysis techniques used to evaluate the condition of materials, components, and assemblies without causing damage or altering their serviceability. NDE methods detect surface and subsurface flaws, measure wall thickness, characterize material properties, and assess the integrity of welds and joints. Common NDE methods include ultrasonic testing (UT), radiographic testing (RT), magnetic particle inspection (MPI/MT), liquid penetrant testing (PT), visual testing (VT), eddy current testing (ECT), and acoustic emission testing (AE).
Inspection EffectivenessA qualitative rating of the probability that an inspection activity will correctly identify and characterize the damage present in the inspected equipment. Inspection effectiveness is categorized from A (Highly Effective — high probability of detecting the damage) through E (Ineffective — virtually no chance of detection). The rating depends on the inspection technique used, the skill of the inspector, the coverage area, and the damage mechanism being sought.
Corrosion Under Insulation(CUI)External corrosion of piping and equipment that occurs beneath thermal insulation, fireproofing, or other external coatings where moisture becomes trapped against the metal surface. CUI is one of the most prevalent and damaging integrity threats in process industries because it is hidden from visual inspection, can progress rapidly, and is difficult to detect without removing insulation or using specialized inspection techniques.
Where this appears in Reliatic
This concept is used in the Inspections module.