AC interference testing is a non-destructive evaluation (NDE) method used to assess pipeline integrity and detect corrosion anomalies caused by external AC sources.

AC interference testing is a non-destructive evaluation (NDE) method used to assess pipeline integrity and detect metal loss, coating degradation, and corrosion anomalies caused by external AC sources. Pipelines located near high-voltage power lines, railway systems, or industrial facilities are particularly susceptible to AC-induced corrosion — a serious threat to pipeline safety.

During testing, an AC voltage is applied to the pipeline, and resulting current flows are measured to identify electromagnetic field changes that indicate material degradation. Results help pipeline operators assess corrosion risk, validate cathodic protection effectiveness, and prioritize maintenance in high-risk zones.

AC interference testing is a key component of pipeline integrity management and is often combined with ACVG surveys, DCVG surveys, and advanced techniques like Current Magnetometry Inspection (CMI) for comprehensive external corrosion assessment of both piggable and unpiggable pipelines.