ISO 18086-2019 PDF

Full title and description

St ISO 18086-2019 — Corrosion of metals and alloys — Determination of AC corrosion — Protection criteria. This International Standard specifies protection criteria, measurement procedures, limits and mitigation measures for assessing and managing the risk of alternating‑current (AC) enhanced corrosion on cathodically protected metallic pipelines that are subject to AC interference from power or traction systems.

Abstract

ISO 18086:2019 defines protection criteria and practical procedures to determine the likelihood of AC corrosion on buried cathodically protected pipelines influenced by AC power or traction systems. It covers AC voltages and currents at power‑system frequencies (nominally between 16.7 Hz and 60 Hz), describes coupling mechanisms (conductive, inductive, capacitive), sets evaluation limits, and outlines measurement and mitigation approaches for long‑term AC interference. Safety aspects of AC voltages on pipelines (personnel safety and acute electrical hazards) are excluded and addressed by other standards and national regulations.

General information

• Status: Published (current edition).
• Publication date: 10 December 2019.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 77.060 — Corrosion of metals and alloys.
• Edition / version: Edition 2 (2019).
• Number of pages: 38 pages.

Scope

This standard applies to buried cathodically protected metallic pipelines exposed to AC interference from nearby AC power transmission systems and/or AC electric traction systems. It addresses assessment of AC corrosion risk and provides protection criteria, measurement methods, tolerable limits and mitigation options for AC voltages and currents at frequencies from about 16.7 Hz up to 60 Hz. The document is concerned with long‑term corrosion risk under normal operating conditions of the interfering AC system and does not cover electrical safety requirements for personnel or equipment, which are handled by other standards and regulations.

Key topics and requirements

• Definition of protection criteria and thresholds for AC corrosion on cathodically protected pipelines.
• Measurement procedures for AC potentials, AC current densities and related parameters at pipeline locations and coating defects.
• Evaluation methods to determine the likelihood of AC‑enhanced corrosion under long‑term interference.
• Identification and explanation of coupling mechanisms: conductive, inductive and capacitive coupling.
• Recommended mitigation and remedial measures (bonding, drainage, earthing, mitigation devices, routing and separation strategies).
• Applicability limits and exclusions (frequency range ~16.7 Hz–60 Hz; excludes safety limits and non‑corrosion electromagnetic interference issues).
• Guidance on interpreting results in conjunction with cathodic protection criteria (complements ISO 15589‑1 and similar documents).

Typical use and users

ISO 18086:2019 is used by pipeline owners and operators, cathodic protection engineers, corrosion consultants, pipeline designers, utility companies, railway infrastructure and traction engineers, regulatory authorities and testing laboratories. It supports design reviews, interference assessments, ongoing monitoring and development of mitigation plans where AC interference may threaten long‑term corrosion protection of metallic pipelines.

Related standards

Relevant companion and referenced documents include ISO 15589‑1 (cathodic protection of on‑land pipelines — protection criteria and CP practices), EN 50443 (limits and safety criteria for pipeline interference from AC traction and power systems), national and regional adoptions of ISO 18086 (EN ISO 18086 / DIN EN ISO 18086, UNE/ÖNORM versions), and other pipeline cathodic protection and corrosion standards used for safety and design.

Keywords

AC corrosion; alternating current interference; pipelines; cathodic protection; protection criteria; inductive coupling; capacitive coupling; conductive coupling; mitigation; measurement procedures; long‑term corrosion risk.

FAQ

Q: What is this standard?

A: ISO 18086:2019 provides protection criteria, measurement methods and mitigation guidance for assessing AC‑enhanced corrosion risk on cathodically protected buried metallic pipelines exposed to AC interference.

Q: What does it cover?

A: It covers evaluation of AC corrosion likelihood for AC voltages/currents at frequencies from about 16.7 Hz to 60 Hz, defines tolerable limits and describes measurement and mitigation procedures. It does not address electrical safety limits for people or acute fault scenarios, which are covered by other standards.

Q: Who typically uses it?

A: Pipeline operators, cathodic protection and corrosion engineers, utilities, railway infrastructure planners, consultants, testing laboratories and regulators use the standard for risk assessment, monitoring and designing mitigation for AC interference on pipelines.

Q: Is it current or superseded?

A: The 2019 edition (Edition 2) is the published, current international edition that replaced the 2015 edition. Users should check national adoptees or later revisions for updates; standards are subject to periodic review.

Q: Is it part of a series?

A: It complements other pipeline and cathodic protection standards (notably ISO 15589 series on cathodic protection of pipelines) and is often referenced alongside EN 50443 and other national/regional standards dealing with electromagnetic interference and safety.

Q: What are the key keywords?

A: Key keywords include AC corrosion, alternating current interference, cathodic protection, pipelines, protection criteria, inductive/capacitive/conductive coupling, measurement procedures and mitigation measures.