Holiday (Coating Defect)

A holiday is a gap, pinhole, or discontinuity in a pipeline’s protective coating that exposes bare steel to the surrounding soil, creating a point where cathodic protection current concentrates and where corrosion is most likely to initiate if that current is inadequate. Holidays can originate during manufacturing, from handling and installation damage, or from age-related coating degradation, and detecting them is the specific purpose of techniques such as DCVG and holiday (jeep) testing. A coating with many small holidays but strong, uniform cathodic protection can still perform well; the risk concentrates where holidays coincide with weak or absent CP coverage.