Visual Inspection Grade — What to Check
The visual inspection grade is the least intrusive of the three IEC 60079-17 inspection grades. It is carried out without opening or disturbing equipment and checks only for defects that are visible from the outside. Despite its simplicity, visual inspection can identify many serious deficiencies.
When Is Visual Inspection Used?
Visual inspection is appropriate for:
- Routine plant rounds — often monthly or quarterly
- Initial check before more detailed inspection
- Areas where opening equipment would require excessive disruption
- Zone 2 equipment where close inspection grade is not always required
What to Check During Visual Inspection
| Item | What to Look For | Potential Category |
|---|---|---|
| Enclosure body | Cracks, impact damage, corrosion penetrating body | A or X |
| Bolts and fasteners | Missing bolts — count all fastener positions | X if any missing on Ex d |
| Cable entries | Open entries, missing glands or stopping plugs | X |
| Cable sheath | Cuts, abrasion, mechanical damage to visible cable | A or X |
| Warning labels | Present, legible, correct | B or C |
| Earthing | External earth tag visible and uncorroded | A or B |
| Flamepath area | Paint overspray, obvious damage (without measuring) | A |
| Drainage plugs | Present and not blocked | A |
| IP gasket | Visible compression set, cracking, or extrusion | A or X |
Visual inspection cannot measure flamepath gaps, check thread engagement, or verify internal condition. If a visual inspection reveals concerns — possible damage, unusual appearance, evidence of overheating — escalate to a Close or Detailed Inspection grade. Never assume equipment is compliant based on visual inspection alone if there is doubt about internal condition.
Visual Inspection in the CompEx Assessment
The CompEx Ex03/Ex04 written assessment tests your ability to identify which deficiencies are detectable by visual inspection grade and which require close or detailed inspection. EX Academy's inspection simulator presents scenarios at each grade level — helping you understand the limits and capabilities of each inspection type.
Interactive inspection simulations, equipment selection decisions, and 1,185+ practice questions referenced to IEC 60079. Try free — no card required.
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