Course Title

Day 1 — VT Fundamentals, Personnel Qualification, and Inspection Principles

1. Introduction to Visual Inspection

1.1 VT as an NDT Method

• Visual Testing — VT — is a formal NDT method per ISO 9712:2021 requiring trained and qualified personnel

• VT application scope — welds, pressure vessels, piping, structural steel, fabricated components, and in-service equipment

• Personnel qualification tiers per ISO 9712:2021 — Level I performs under supervision, Level II interprets and signs reports, Level III establishes procedures

• ASNT SNT-TC-1A employer-based qualification — training, experience, and examination requirements by level

• VT as the first NDT method — mandatory visual examination before applying other NDT methods per ASME Section V Article 9

1.2 The Human Visual System and Its Limitations

• Visual acuity requirement — Jaeger J1 or equivalent near vision acuity tested annually per ISO 9712:2021

• Colour vision — distinguishing relevant indications from background requires adequate colour discrimination

• Visual fatigue — inspection performance degrades significantly after 4 continuous hours without a break

• Perceptual set — the tendency to see what is expected rather than what is present — the most common VT failure mode

• Viewing angle — surface indications are most visible at 30–90° viewing angle to the surface

• Distance limitation — maximum 600 mm viewing distance for unaided direct visual examination per ASME Section V

2. Illumination and Examination Conditions

• Minimum illumination per ASTM E165 — 500 lux at the examination surface for general visual inspection

• Minimum illumination per ISO 17637:2016 — 1000 lux at the weld surface for weld visual inspection

• Illumination measurement — lux meter use, measurement location, and documentation requirement

• Natural versus artificial lighting — controlling glare, shadow, and reflection that obscure surface indications

• Surface preparation before VT — cleaning, scale removal, and contrast enhancement where permitted

• Contrast aids — chalk, developer, and contrast paint to enhance indication visibility on dark or rough surfaces

• Temperature conditions — surface temperature effects on indication visibility and inspector performance

• Illumination record — documenting lux level, measurement location, and instrument used in the inspection record

3. Direct and Indirect Visual Examination Methods

3.1 Direct Visual Examination

• Direct VT — unaided eye or optical aids with the eye within 600 mm and 30° minimum to the surface

• Systematic examination pattern — grid, strip, or zone scanning to ensure full surface coverage

• Magnification aids — hand lens 2–10×, loupe, and illuminated magnifier for indication characterization

• Mirrors — flat and angled mirrors for surface access in confined geometry

• Probes and picks — for tactile confirmation of suspected crack indications

3.2 Indirect and Remote Visual Examination

• Rigid borescope — for inaccessible internal surfaces including tubes, nozzles, and cavities

• Flexible fiberscope — for curved internal access paths where rigid borescope cannot reach

• Video borescope — RVI — Remote Visual Inspection — for recording and analysis of inaccessible surfaces

• Drone-mounted camera inspection — for elevated or hazardous external structure inspection

• Image resolution requirement — indirect VT images must demonstrate equivalent resolution to direct examination at the same surface

• RVI calibration — verifying image scale using reference wire or gauge on the inspection surface

Day 2 — Weld Inspection, Discontinuity Classification, and Equipment Inspection

4. Weld Visual Inspection

4.1 Weld Inspection Procedure per ISO 17637

• Pre-weld inspection — parent material condition, joint fit-up, and tack weld quality

• Inter-pass inspection — each weld pass before the next is deposited — mandatory for multi-pass welds

• Post-weld inspection — completed weld profile, surface condition, and dimensional check

• Weld inspection sequence per ISO 17637:2016: Non-Destructive Testing of Welds — Visual Testing of Fusion-Welded Joints

• Weld gauge use — fillet weld size, throat thickness, undercut depth, and reinforcement height measurement

• 1000 lux minimum illumination verification before commencing weld VT

4.2 Weld Discontinuity Classification

• Cracks — the most serious weld discontinuity — hot cracks, cold cracks, crater cracks, and longitudinal cracks

• Porosity — gas pores within the weld metal — uniform, clustered, and linear porosity types

• Undercut — groove melted into the parent material along the weld toe — measured in depth and length

• Lack of fusion — incomplete bonding between weld metal and parent metal or between passes

• Incomplete penetration — failure of the weld to extend through the full joint thickness

• Overlap — weld metal flowing over the parent material without fusion — a rejectable surface condition

• Excess reinforcement — weld bead height exceeding the permitted maximum for the applicable standard

• Spatter — metal particles ejected during welding — not a structural defect but indicates process control failure

5. Acceptance and Rejection Criteria

• Acceptance criteria source — always apply the criteria specified in the applicable code, standard, or contract document

• Weld acceptance criteria per ISO 5817: Welding — Fusion-Welded Joints — Quality Levels for Imperfections — Quality Levels B, C, and D

• Pressure vessel weld acceptance per ASME Section VIII and structural weld acceptance per AWS D1.1

• Crack — always rejectable regardless of size, location, or applicable standard

• Undercut acceptance — depth and length limits vary by quality level and service condition

• Porosity acceptance — individual pore size and cluster density limits per applicable standard

• Dimensional acceptance — weld size, throat, and reinforcement checked against drawing and specification tolerances

• Applying "as-found" versus "fit-for-purpose" assessment — Level II applies the standard, Level III may assess fitness for service

6. In-Service Equipment and Structural Inspection

6.1 Pressure Vessel and Piping VT

• Pressure vessel visual inspection per API 510: Pressure Vessel Inspection Code — internal and external examination scope

• Piping visual inspection per API 570: Piping Inspection Code — external corrosion, supports, and insulation condition

• Corrosion identification — general corrosion, pitting, crevice corrosion, and galvanic corrosion visual indicators

• Erosion identification — flow-induced erosion at bends, tees, and injection points

• External coating inspection — blistering, cracking, adhesion loss, and holiday identification

• Insulation damage inspection — wet insulation, mechanical damage, and CUI — Corrosion Under Insulation — risk areas

6.2 Structural and Fabrication VT

• Structural steel inspection — cracks at connections, corrosion at base plates, and deformation of primary members

• Bolt and fastener inspection — thread condition, washer presence, and torque indicator condition

• Coating and paint condition — rust bleeding, coating delamination, and impact damage

• Fabrication inspection — dimensional verification, surface finish, and identification marking check

• Casting and forging VT — surface crack identification, cold shuts, misruns, and shrinkage porosity

Day 3 — Reporting, HSE, Quality, and Practical Exercises

7. Inspection Measurement Tools and Gauges

• Weld gauge — measuring fillet size, throat, undercut depth, reinforcement height, and misalignment

• Depth gauge — measuring pit depth, undercut depth, and surface defect dimensions

• Straight edge and feeler gauge — measuring distortion, warpage, and joint gap

• Vernier caliper and tape measure — dimensional verification of weld sizes and component dimensions

• Lux meter — verifying illumination at the examination surface before and during inspection

• Comparators and reference standards — comparing surface roughness, coating thickness, and pit size to calibrated references

• Tool calibration — verifying gauge calibration status before use and documenting calibration reference in the inspection record

8. Inspection Documentation and Reporting

8.1 Inspection Record Requirements

• Inspection record mandatory content — item identification, inspection date, inspector name and qualification, procedure reference, illumination level, and findings

• Indication description — location, orientation, dimensions, and classification for each indication found

• Sketch or photograph — recording indication location on a dimensioned sketch or marked photograph

• Accept or reject disposition — clearly stating whether each indication is within or outside acceptance criteria

• Inspector signature and qualification level — Level I under Level II supervision, Level II signs independently

8.2 Nonconformance and Quality Records

• Nonconformance Report — NCR — for every rejected indication — initiated immediately on rejection

• NCR content per ISO 9001:2015 Clause 8.7 — description, location, disposition decision, and corrective action

• Disposition options — accept as-is with engineering authorization, repair, or reject and replace

• Re-inspection after repair — documenting the repair and re-inspection result on the original NCR

• Record retention per ISO 9001:2015 Clause 7.5 — retention period defined by applicable code and contract

• Applying RCA to recurring rejections — identifying the welding, fabrication, or maintenance root cause

9. Inspection Procedure Development

• Written inspection procedure requirement — per ASME Section V Article 9 and ISO 9712:2021

• Procedure content — scope, applicable standard, equipment, illumination requirement, surface preparation, examination method, and acceptance criteria

• Procedure qualification — demonstrating the procedure detects the required minimum indication size

• Procedure review and approval — Level III review and customer or third-party approval where required

• Procedure control per ISO 9001:2015 Clause 7.5 — version control and distribution management

10. HSE and Quality Management Integration

• Applying HIRARC to visual inspection activities — confined space access, working at height, and UV light exposure

• Confined space entry for internal vessel inspection — permit requirement, atmospheric testing, and attendant

• Working at height for elevated weld or structural inspection — fall arrest and scaffold compliance

• Eye protection — UV-rated safety glasses for inspections near welding operations or UV contrast aids

• HSE management of inspection activities per ISO 45001:2018 — risk assessment before each inspection task

• Quality management of the inspection program per ISO 9001:2015 — procedure control, calibration records, and audit schedule

• Inspector eye test records — annual near vision acuity test records retained per ISO 9712:2021

11. Practical Inspection Exercises

• Illumination verification exercise — measuring lux levels at presented inspection surfaces and comparing against ISO 17637 and ASTM E165 requirements

• Weld visual inspection practical — inspecting a presented weld specimen set for all discontinuity types, classifying each, and applying ISO 5817 acceptance criteria

• Remote visual inspection exercise — operating a borescope or RVI system to inspect a simulated inaccessible internal surface and document findings

• Weld gauge practical — measuring fillet size, undercut depth, and reinforcement height on presented weld specimens

• Inspection report completion — completing a full VT inspection report for a presented inspection scenario including sketch, lux record, indication log, and NCR for a rejected indication

12. Case Studies and Group Discussions

• Case studies from VT failures in Middle East oil and gas, construction, and petrochemical environments including uninspected weld cracks that propagated to pressure vessel failure, corrosion under insulation missed during periodic visual inspection, and structural connection cracks missed due to inadequate illumination — and the importance of proper visual inspection training in preventing asset failures and personnel injury

• Group discussion on visual inspection challenges in regional environments including maintaining inspection quality during high-volume fabrication programs, managing lux compliance in outdoor desert inspection environments, and developing consistent acceptance criteria application across multicultural inspection teams

• Integrated inspection scenario — teams inspect a presented multi-defect weld and equipment specimen set, complete the full inspection record including lux documentation, indication log, acceptance/rejection decision, and NCR — presented for peer and facilitator review against ISO 17637 and ASME Section V criteria