Cathodic protection British Standards

British Standards Institution, Code of Practice for Cathodic Protection, London 1973. 

Almost without exception all the accepted criteria for full cathodic protection of iron are based on a potential measurement. The various recommended practices published by the US National Association of Corrosion Engineers (NACE) give six criteria for full protection ". The current British Standard Code of Practice gives one. These are summarised in Table 10.3. Only the first three are useful the remainder are of dubious value or expressions of pious hope. 

Cathodic Protection of Buried and Submerged Structures, CP 1021 1973, British Standards Institution, London... 

The results of these experiments have been considered by the Joint Committee for the Co-ordination of the Cathodic Protection of Buried Structures and, in view of the various types of buried structures concerned and the circumstances in which field tests are conducted, the Committee decided not to amend its provisional recommendation that when cathodic protection is applied to a buried structure the maximum permissible potential change in the positive direction on a nearby pipe or cable should be 20 mV. If there is a history of corrosion on the unprotected installation no detectable positive change in structure/soil potential should be permitted. These criteria of interaction have been adopted in the British Standard Code of Practice for Cathodic Protection . 

Recent experience has confirmed that, by adopting the recommendations of the British Standards Institution or similar codes of practice operating in other countries, the likelihood of corrosion damage to buried structures adjacent to cathodically protected installations is negligible. This is because recently installed cathodically protected structures are usually coated with eflicient and durable insulating coverings such as epoxy resins and the protective current applied is consequently small. In many cases the small protective currents that can be applied by means of galvanic anodes is adequate. 

BS 7361 (1991). Cathodic protection part 1. Code of Practice for Land and Marine Applications. British Standards Institute. 

BSEN12696 (2000). Cathodic Protection of Steel in Concrete. British Standards Institute, London. 

In the case of steel structures with cathodic protection, the maximum potential should not be more negative than -1.1 V versus the CSE. Exceeding this value requires appropriate investigations and justification. More information on this subject is given by Hei-dersbach (1987), Heidersbach et al. (1987), Treseder et al. (1991) and British Standard BS7361 Part 1 (1991). 

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