NACE SP0274-2011

This standard practice involves testing all pipeline coatings, including coatings on in-service pipelines and new or replacement coatings. High-voltage electrical inspection of pipelines coatings is one commonly used method in the detection of defects. Presented in this standards are acknowledged techniques for the use of holiday detectors currently used on pipeline coatings. A table of minimum testing voltages for various coating thicknesses is provided, as well as guidance for testing voltages, grounding, condition of coating surfaces, and care of equipment.