Applicability of -850 mV (CSE) Cathodic Protection Potential Criterion under AC Interference Condition

Alternating currtnt(AC) would disrupt the normal operation of buried pipeline cathodic protection (CP) system.There are many interference factors for the complex situation of actual underground pipelines.The impact of AC interference on cathodic protection system was studied by using laboratory simulation device.The results of protection current density and the changes of protection potential under the AC interference show that the classic metal buried pipeline CP criterion,i.e.-850 mV(CSE),in the AC interference condition is not suitable.