As pipelines age, the applied protective coating systems also age and deteriorate. ACVG is an aboveground, non-intrusive survey method used to verify and assess the condition of buried pipeline coating systems and accurately locate coating defects using the voltage gradients created in the soil by the passage of AC current to/from a coating defect on the pipeline. With coating defects identified, the surveyor takes additional measurements to determine the severity of the defect and determine what remedial action is required. The ACVG survey technique determines the following:

• Accurate location of coating defects to within 10cm of the actual location
• Size and severity of coating defects

ACVG works on buried pipelines and pipework protected with impressed current cathodic protection systems, sacrificial (galvanic) anode systems even on unprotected pipework.

The ACVG technique is suitable for:

• Cross country pipelines 
• Urban pipelines
• Complex pipeline systems such as those within Petrochemical/Process Plants and Tank Farm Facilities  

Advantages of the ACVG technique are:

• It can be conducted off-set parallel to the pipeline, for example if the pipeline runs beneath a heavily trafficked road, then the survey can be conducted on a verge or road edge.
• It is not subject to DC interference
• It is ideal for use in HHVAC corridors

Can be conducted at the same time as an ACCA Survey