L19714 HVDC and Pipeline Protection – A Laboratory Study and Field Tests

The reports presents the results of a laboratory and engineering study to define 1) the detrimental effects that earth currents of high voltage direct current (HDVC) origin have on a buried pipeline; 2) methods that may be used to mitigate these effects; and 3) representative costs for a reasonable protection system. The report also includes the results of a field demonstration of an automatically controlled rectifier arranged to provide corrosion or coating disbonding protection.The study concluded that the detrimental effects of HVDC on the pipeline simulated in these laboratory studies can be effectively mitigated by any one or a combination of the following methods: 1) longitudinal cable; 2) cable to HVDC electrode; 3) multiple rectifier stations; and 4) sacrificial anodes. The mode and related laboratory techniques developed for this study can be used as engineering tools to study and evaluate corrosion problems on buried structures and their alternative solutions to a resolution of about one mile.