CEN/TS 15280:2006

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 A.C. interference sources
5 Simplified description of a.c. corrosion process
6 Evaluation of a.c. corrosion likelihood
   6.1 Prerequisite
   6.2 General
   6.3 Installation/use of coupons
   6.4 Influence of a.c. voltage on the structure
   6.5 Off potential influence
   6.6 Influence of a.c. current density
   6.7 Influence of the on potential toward a.c. corrosion
        likelihood
   6.8 Influence of current ratio "I[a.c.]/I[d.c.]"
   6.9 Influence of soil characteristics on a.c. corrosion
        likelihood
   6.10 Assessment of the a.c. corrosion likelihood of the
        pipeline by using corrosion coupons
7 Design consideration
   7.1 General
   7.2 New interference cases (pipelines/power lines/traction
        systems in the design phase) - Condition for calculation
8 Interpretation of data, limits and relevant aspects
9 Mitigation measures
10 Monitoring
Annex A (informative) Assessment of the corrosion condition by
         using the electric resistance technique
Annex B (informative) Coulometric oxidation of corrosion products
         formed by a.c. corrosion
Bibliography

This Technical Specification is applicable to buried or immersed cathodically protected metallic structures and influenced by a.c. traction systems and/or a.c. power lines.In the presence of a.c. interference, the criteria given in EN 12954:2001, Table 1, are not sufficient to demonstrate that the steel is being protected against corrosion.This Technical Specification provides limits, measurements procedures and information to deal with long term a.c. interference and evaluating a.c. corrosion likelihood.Even though short term interference can cause damage to buried pipelines (e.g. arc fusion), this Technical Specification does not deal with short term interference.