A gap in a coating that lets the electrolyte reach bare steel: pinholes, missed spots, very thin areas, mechanical damage or cracks. On buried and immersed structures, holidays are where corrosion and CP current concentrate, so coatings are tested 100 percent with holiday detectors before burial or service. Each holiday found is marked, repaired with a compatible patch material and retested.
Found six holidays on the field joints, mark them with chalk and get the repair kit out.
A coating with zero holidays on the skids can still gain dozens in the ditch. Rocky trench bottoms and careless lowering-in undo good inspection.
Also heard as
- coating holiday
- pinhole
- discontinuity
- jeep
Related terms
Holiday detector
Instrument that finds coating holidays by detecting current flow or sparks through flaws to the metal.
Jeep
Pipeline slang for the high-voltage holiday detector, and also for the coating flaws it finds.
DCVG
Direct current voltage gradient survey that locates and sizes coating holidays on buried pipe.
Cathodic protection
Shielding buried or submerged steel from corrosion with DC current from sacrificial anodes or a rectifier.
Same word, different worlds
A skip, void or pinhole in the coating where bare metal is exposed.
Sealants & WaterproofingA gap, pinhole or thin spot in a membrane or coating where it fails to cover the substrate.
Hydrography & ChartingA gap in survey coverage where no data was collected, which must be filled before the survey is complete.