AC Voltage Gradient (ACVG)

AC Voltage Gradient (ACVG) is a survey technique used to detect coating failure in pipelines. It involves applying an alternating current (AC) signal to the pipeline and measuring the voltage drop along the pipe length. The ACVG technique utilizes the fact that coating failure on a pipeline reduces the electrical resistance of the metal, thus leading to an increase in the voltage gradient. By analyzing the voltage gradient, pipeline operators can detect the presence of coating failure and its location on the pipeline, allowing for timely repairs and maintenance to prevent further corrosion of the metal underneath. ACVG surveys can be performed using specialized equipment and are considered to be non-destructive and efficient methods of coating failure detection in pipelines.