Corrosion is a natural process where metal degrades into oxide as part of a reaction with the environment. To protect pipelines from corrosion, both external and atmospheric, we use pipeline coatings and cathodic protection (CP).
- Pipeline coatings are the most common anti-corrosion treatment. They work by providing a barrier of corrosion-resistant material between the damaging environment and the steel.
- CP is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" which acts as the anode. The sacrificial metal then corrodes instead of the protected metal. For long pipelines, where passive galvanic cathodic protection is not adequate, an external DC electrical power source is used to provide the current.
NMGC employees monitor all cathodically protected steel pipe every year to confirm the cathodic protection system is functioning properly.