General principles of cathodic protection of buried or immersed onshore metallic structures

This document describes the general principles for the implementation and management of a system of cathodic protection against corrosive attacks on structures which are buried or in contact with soils, surface fresh waters or underground waters, with and without the interference of external electrical sources. It specifies the protection criteria to be achieved to demonstrate the cathodic protection effectiveness. For structures that cannot be electrically isolated from neighbouring influencing structures, it may be impossible to use the criteria defined in the present document. In this case, EN 14505 will be applied (see 9.4 "Electrical continuity/discontinuity"). To assist in forming a decision whether or not to apply cathodic protection the corrosion likelihood can be evaluated using Annex A. Annex A summarizes the requirements of EN 12501-1 [2] and EN 12501-2 [3]. Cathodic protection of structures immersed in seawater is covered by EN 12473 and a series of standards more specific for various applications. Cathodic protection for reinforced concrete structures is covered by EN ISO 12696. This document is applicable in conjunction with: - EN ISO 15589-1 for application for buried or immersed cathodically pipelines, - EN 50162 to manage d.c. stray currents, - EN ISO 18086 to manage corrosion due to a.c. interference from high voltage power sources and a.c. traction systems, - EN 13509 for cathodic protection measurement techniques - EN 50443 to manage protection for touch and step voltage.