EN ISO 18086:2017

European foreword
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Cathodic protection persons competence
5 Assessment of the AC influence
6 Evaluation of the AC corrosion likelihood
7 Acceptable interference levels
8 Measurement techniques
9 Mitigation measures
10 Commissioning
11 Monitoring and maintenance
Annex A (informative) - Simplified description of the AC
        corrosion phenomenon
Annex B (informative) - Coupons and probes
Annex C (informative) - Coulometric oxidation
Annex D (informative) - Influence of soil characteristics on the
        AC corrosion process
Annex E (informative) - Other criteria that have been used in the
        presence of AC influence
Annex F (informative) - Parameters to take into account to
        choose a DC decoupling device
Annex G (informative) - Method to determine the reference
        electrode location to remote earth
Annex H (informative) - Simultaneous measurement on
        coupon current densities with high rate
Bibliography

ISO 18086:2015 is applicable to buried cathodically-protected pipeline that is influenced by AC traction systems and/or AC power lines.In the presence of AC interference, the protection criteria given in ISO 15589 1 are not sufficient to demonstrate that the steel is being protected against corrosion.ISO 18086:2015 provides limits, measurement procedures, mitigation measures, and information to deal with long term AC interference for AC voltages at frequencies between 16,7 and 60 Hz and the evaluation of AC corrosion likelihood.It deals with the possibility of AC corrosion of metallic pipelines due to AC interferences caused by inductive, conductive or capacitive coupling with AC power systems and the maximum tolerable limits of these interference effects. It takes into account the fact that this is a long-term effect, which occurs during normal operating conditions of the AC power system.It does not cover the safety issues associated with AC voltages on pipelines. These are covered in national standards and regulations.