EN ISO 15589-1:2026

• Abstract:

  This document specifies requirements and gives recommendations for the pre-installation surveys, design, materials, equipment, installation, commissioning, operation, inspection, and maintenance of cathodic protection systems for the external surface of on-land pipelines.; This document is applicable to on-land pipelines and piping systems used in other industries and transporting other media such as industrial gases, waters, or slurries.; Throughout this document, on-land pipelines mean:; pipelines that are buried;; landfalls of offshore pipeline sections protected by onshore based cathodic protection installations;; immersed sections of on-land pipelines such as river or lake crossings.; This document is applicable to pipelines of carbon steel, stainless steel, cast iron, galvanized steel, and copper.; This document does not apply to pipelines made of reinforced concrete (see ISO 12696).

• Status: Published
• Publication Date: 21-Jul-2026
• ICS: 75.200 - Petroleum products and natural gas handling equipment
• Technical Committee: CEN/TC 219 - Cathodic protection (provisional)
• Drafting Committee: CEN/TC 219/WG 1 - Cathodic protection of buried and immersed metallic structures
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 22-Jul-2026
• Completion Date: 22-Jul-2026
• Ref Project: SIST EN ISO 15589-1:2026 - Oil and gas industries including lower carbon energy - Cathodic protection of pipeline transportation systems - Part 1: On-land pipelines (ISO 15589-1:2026)

• Replaces: EN ISO 15589-1:2017 - Petroleum, petrochemical and natural gas industries - Cathodic protection of pipeline systems - Part 1: On-land pipelines (ISO 15589-1:2015, Corrected version 2020-11)
• Effective Date: 26-Apr-2023
• Referred By: EN 1594:2024 - Gas infrastructure - Pipelines for maximum operating pressure over 16 bar - Functional requirements
• Effective Date: 29-Jul-2026
• Consolidated By: ISO 15589-1:2026 - Oil and gas industries including lower carbon energy — Cathodic protection of pipeline transportation systems — Part 1: On-land pipelines
• Effective Date: 12-Feb-2026

EN ISO 15589-1:2026 is a European Standard from CEN that adopts ISO 15589-1:2026 for cathodic protection of pipeline transportation systems, Part 1 for on-land pipelines. It specifies requirements and recommendations for the external cathodic protection of buried pipelines, landfalls of offshore sections protected from shore, and immersed river or lake crossings, for the people who design, install, commission, inspect, and maintain these systems.

What does EN ISO 15589-1:2026 specify?

EN ISO 15589-1:2026 specifies cathodic protection for the external surface of on-land pipelines and piping systems used in other industries and carrying media such as industrial gases, waters, or slurries. It applies to carbon steel, stainless steel, cast iron, galvanized steel, and copper, and it excludes reinforced concrete pipelines.

The document defines on-land pipelines broadly, so the same rules cover buried lines, landfalls of offshore sections protected by onshore cathodic protection installations, and immersed sections such as river or lake crossings. In practice, this matters because the standard is not limited to one installation style or one industry sector.

Its structure is straightforward:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 5 Competence
• Clause 6 Cathodic protection criteria
• Clauses 7 to 14 cover prerequisites, design, equipment, monitoring, commissioning, maintenance, and documentation
• Annexes A, B, D, E, F and G give measurement methods, interference guidance, survey methods, attenuation calculations, isolation-joint tests, and flange corrosion measures

Annex	What it covers
A	Measurement methods, potential measurements, current measurements, line current, coupons and probes
B	Electrical interference from DC and AC sources and mitigation principles
D	Specialized surveys such as ACVG, CIPS, DCVG and current injection tests
E	Attenuation calculations for drain points and worked examples
F	Electrical tests for isolation joints before installation
G	Internal corrosion at insulating flanges and protective measures

What are the key requirements of EN ISO 15589-1:2026?

EN ISO 15589-1:2026 combines design rules, operational criteria, and monitoring requirements so that the cathodic protection system can be proven effective over the pipeline life. The most important points are the competence of the people involved, the protection criteria, the electrical condition of the pipeline, the design basis, and the monitoring and maintenance plan.

Competence matters

Clause 5 requires the people who design, supervise installation, commission, monitor, and maintain cathodic protection systems to have the right competence for the task. The note points to certification such as ISO 15257 or an equivalent scheme under ISO/IEC 17024. In practice, this means the standard expects qualified specialists, not general maintenance staff, to make CP decisions.

Protection is judged by potential, not by guesswork

Clause 6 uses IR free potential and protection potential as the main criteria. For carbon steel and cast iron, the text links the criterion to a very low corrosion rate when AC and fluctuating DC interference are absent. The clause also warns that potentials that are too negative can damage coatings or create hydrogen-related risks for some metals.

The document gives different criteria for different metals and environments, including carbon steels, stainless steels, copper, and galvanized steel. It also states that coated structures should generally not be polarized beyond the stated negative limit for coated systems unless experience or data justify it. For users, this means the CP design has to balance corrosion protection against overprotection.

Alternative assessment methods are only for specific cases

Clause 6 allows a 100 mV cathodic potential shift method when the main criteria cannot be achieved, but it limits where that approach can be used. It is not for every pipeline environment, and the text excludes several situations such as elevated operating temperature, SRB-containing soils, and some interference conditions. In practice, that means the engineer must justify any use of alternative criteria and document the reason.

The pipeline must be prepared correctly before CP is applied

Clause 7 requires electrical continuity of the protected section and encourages electrical isolation from foreign structures and earthing systems unless a justification is documented. The standard also addresses coatings, trench backfill or padding, buried casings, and devices for AC and DC interference mitigation.

This matters because CP works best when the current can reach the pipe surface through coating defects and the electrolyte, without unwanted drains into adjacent structures. Clause 7 also points the reader to isolation joints, overvoltage protection, DC decoupling devices, and drainage or earthing measures where they are needed.

Design has to be based on real pipeline data

Clause 8 says the design basis should collect the pipeline dimensions, coating details, operating conditions, electrolyte conditions, crossings, adjacent structures, and interference sources. The detailed design report then documents sizing and layout, materials, single-line diagrams, temporary systems, installation details, commissioning, and operation and maintenance instructions.

For readers, this means the CP design is not just an anode count. It is a full engineering package that has to reflect the actual route, the coating system, nearby pipelines and cables, traction systems, and site-specific risks.

The choice between impressed current and galvanic anodes depends on demand and site conditions

Clause 9 covers impressed current stations, including location, power supply, control, enclosure protection, and remote monitoring. The document says voltages above 50 V DC at rectifier output should generally be avoided. Clause 10 covers galvanic anode systems and makes them suitable for low current demand, temporary protection, or places without practical power supply.

For galvanic systems, the document requires anode material selection, documentation, backfill, cable connections, and sizing based on current demand, design life, and utilization factor. Clause 10 also gives the design logic for anode mass, number of anodes, and end-of-life current output. In practice, the designer has to show that the anodes can still protect the pipeline at the end of life, not only at installation.

Monitoring, commissioning, and maintenance are part of the CP system

Clause 11 requires monitoring facilities along the pipeline route and sets test-station placement logic for rural, urban, and special locations. It also describes the use of coupons, probes, line current monitoring, bond points, cased crossings, isolation joints, and remote monitoring.

Clauses 12 to 14 require staged commissioning, routine inspection, documented monitoring plans, measurement equipment control, remedial action when criteria are not met, and formal records for design, commissioning, operation, and maintenance. In practice, the standard treats CP as a managed system that must be checked, adjusted, and recorded throughout the pipeline life.

What terms does EN ISO 15589-1:2026 define?

• Cathodic protection system - The complete impressed current or galvanic anode arrangement, including power supply, anodes, monitoring facilities, bonds, and cables, used to protect the pipeline.
• IR drop - The voltage loss caused by current flowing through resistance in the circuit, mainly the electrolyte and the pipeline.
• IR free potential - The true pipeline-to-electrolyte potential with the IR drop removed, used to judge protection accurately.
• Isolation joint - An electrically insulating component, such as a monobloc isolation joint or insulated flange, inserted to stop electrical continuity.
• Stray current - Current that flows outside the intended circuit and can interfere with CP performance or increase corrosion risk.
• Test station - A monitoring point that provides measuring and test facilities for potentials, currents, bonds, and related checks.
• Close interval potential survey (CIPS) - A close-spaced field survey used to measure pipe-to-electrolyte potential along a buried pipeline.
• Direct-current voltage gradient (DCVG) - A survey method used to help locate coating defects by measuring DC voltage gradients above the pipeline.

Who uses EN ISO 15589-1:2026?

EN ISO 15589-1:2026 is used by pipeline operators, corrosion engineers, CP designers, inspection teams, maintenance teams, installation contractors, and quality managers. It is relevant to oil and gas industries including lower carbon energy, and also to other industries that transport industrial gases, waters, or slurries in on-land pipelines.

People use it when they plan pre-installation surveys, choose CP systems, size anodes or rectifiers, place test stations, commission a system, run CIPS or other surveys, and decide whether interference or coating damage needs corrective action. Buyers and specifiers also use it to define what evidence a contractor has to provide at design, installation, and handover.

What changed in EN ISO 15589-1:2026 from the previous edition?

EN ISO 15589-1:2026 supersedes EN ISO 15589-1:2017. The European foreword states that the text of ISO 15589-1:2026 was approved by CEN without modification.

Which standards are used with EN ISO 15589-1:2026?

EN ISO 15589-1:2026 relies on several standards for vocabulary, pipeline design, coatings, interference, measurement control, and safety-related equipment:

• ISO 8044 - corrosion vocabulary used for the terms and definitions
• ISO 10012 - control of measuring processes and measuring equipment
• ISO 13623 - pipeline transportation systems basis
• ISO 13847 - welding of pipelines
• ISO 21809-3 - field joint coatings for buried or submerged pipelines
• ISO 21809-5 - external concrete coatings
• ISO 21857 - prevention of corrosion influenced by stray currents
• ISO 18086 - guidance for AC corrosion likelihood and criteria
• ISO 15257 - competence framework referenced for CP personnel
• ISO/IEC 17024 - certification body requirements for personnel certification
• IEC 60079-10-1 - hazardous area classification for CP equipment locations
• IEC 60529 - IP rating for enclosures
• IEC 62561-3 - isolating spark gaps for overvoltage protection
• IEC 62128-2 - reference used for DC power-source operator conformity in interference mitigation
• IEC 62305-1 - surge protection terminology for protective devices
• EN 1594 - gas infrastructure pipelines over 16 bar
• EN 12007-3 - steel gas pipelines up to and including 16 bar
• EN 14161 - petroleum and natural gas pipeline transportation systems
• EN 50122-1, EN 50122-2, EN 50122-3, EN 50162 - AC and DC railway-related interference and protection concepts
• EN 50443 - additional information on AC interference from power lines and rail systems

What does the EN ISO 15589-1:2026 document contain?

EN ISO 15589-1:2026 contains the design and operating framework for CP on on-land pipelines, plus the measurement and calculation material needed to apply it. Clause 6 includes protection criteria and a table of potentials for different metals and environments, while Clause 8 includes the data needed for design and the report contents.

The annexes add practical methods: Annex A covers potential measurement, current measurement, line current and coupon or probe use; Annex D covers specialized surveys such as ACVG, CIPS and DCVG; Annex E gives attenuation equations and example calculations for drain points and pipeline sections; Annex F gives laboratory and field electrical tests for isolation joints; and Annex G explains internal corrosion at insulating flanges and protective measures.

For day-to-day work, this means the document supports engineering design, field testing, commissioning, troubleshooting, and long-term monitoring rather than only one stage of a pipeline project.

SLOVENSKI STANDARD
01-september-2026
Naftna in plinska industrija, vključno z nizkoogljično energijo - Katodna zaščita
cevovodov - 1. del: Cevovodi na kopnem (ISO 15589-1:2026)
Oil and gas industries including lower carbon energy - Cathodic protection of pipeline
transportation systems - Part 1: On-land pipelines (ISO 15589-1:2026)
Öl- und Gasindustrie einschließlich kohlenstoffarmer Energieträger - Kathodischer
Korrosionsschutz für Rohrleitungssysteme - Teil 1: Rohrleitungen an Land (ISO 15589-
1:2026)
Industries du pétrole et du gaz y compris les énergies à faible teneur en carbone -
Protection cathodique des systèmes de transport par conduites - Partie 1: Conduites
terrestres (ISO 15589-1:2026)
Ta slovenski standard je istoveten z: EN ISO 15589-1:2026
ICS:
75.200 Oprema za skladiščenje Petroleum products and
nafte, naftnih proizvodov in natural gas handling
zemeljskega plina equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 15589-1
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2026
EUROPÄISCHE NORM
ICS 75.200 Supersedes EN ISO 15589-1:2017
English Version
Oil and gas industries including lower carbon energy -
Cathodic protection of pipeline transportation systems -
Part 1: On-land pipelines (ISO 15589-1:2026)
Industries du pétrole et du gaz y compris les énergies à Öl- und Gasindustrie einschließlich kohlenstoffarmer
faible teneur en carbone - Protection cathodique des Energieträger - Kathodischer Korrosionsschutz für
systèmes de transport par conduites - Partie 1: Rohrleitungssysteme - Teil 1: Rohrleitungen an Land
Conduites terrestres (ISO 15589-1:2026) (ISO 15589-1:2026)
This European Standard was approved by CEN on 6 June 2026.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15589-1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 15589-1:2026) has been prepared by Technical Committee ISO/TC 67 "Oil and
gas industries including lower carbon energy" in collaboration with Technical Committee CEN/TC 219
“Cathodic protection” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2027, and conflicting national standards shall
be withdrawn at the latest by January 2027.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 15589-1:2017.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 15589-1:2026 has been approved by CEN as EN ISO 15589-1:2026 without any
modification.
International
Standard
ISO 15589-1
Third edition
Oil and gas industries including
2026-07
lower carbon energy —
Cathodic protection of pipeline
transportation systems —
Part 1:
On-land pipelines
Industries du pétrole et du gaz y compris les énergies à faible
teneur en carbone — Protection cathodique des systèmes de
transport par conduites —
Partie 1: Conduites terrestres
Reference number
ISO 15589-1:2026(en) © ISO 2026

ISO 15589-1:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 15589-1:2026(en)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms. 5
4.1 Symbols .5
4.2 Abbreviated terms .6
5 Competence . 6
6 Cathodic protection criteria . 7
6.1 General .7
6.2 Protection potentials .7
6.3 Alternative assessment methods .9
6.3.1 100 mV cathodic potential shift .9
6.3.2 Current density and reference potential consideration .9
6.3.3 Other assessment methods .9
6.4 Criteria in the presence of AC interference .9
6.5 Criteria in the presence of fluctuating DC interference .9
7 Prerequisites for the application of cathodic protection . 9
7.1 General .9
7.2 Electrical continuity .10
7.3 Electrical isolation .10
7.3.1 General .10
7.3.2 Locations .11
7.3.3 Isolation joints .11
7.3.4 Internal corrosion risks at isolation joints and insulated flanges . 12
7.3.5 Contacts between metallic structures. 12
7.3.6 Electrical earthing systems . . 12
7.3.7 Lightning and overvoltage protection . 13
7.3.8 Overvoltage protection devices for DC isolation .14
7.4 Coating . 15
7.4.1 General . 15
7.4.2 Factory-applied coatings . 15
7.4.3 Field joint coatings . 15
7.4.4 Coating for trenchless pipelines .16
7.4.5 Air to electrolyte interface .16
7.4.6 Compatibility of coatings and wraps with cathodic protection .16
7.4.7 Thermal insulation .16
7.4.8 Reinforced concrete weight coating .17
7.5 Selection of pipe trench backfill material.17
7.6 Buried casings for pipelines .17
7.6.1 General .17
7.6.2 Casings that shield cathodic protection current .18
7.6.3 Casings that pass cathodic protection current .18
7.7 Equipment for the reduction of AC interference .18
7.8 Equipment for the mitigation of DC interference .19
8 Basic requirements and guidance for cathodic protection design . 19
8.1 General .19
8.2 Basic information for cathodic protection design .19
8.3 Contents of cathodic protection design report . 20
8.4 Cathodic protection current demand .21
8.4.1 Calculation of the theoretical total current demand .21

iii
ISO 15589-1:2026(en)
8.4.2 Current demand based on current density values for coated pipelines . 22
8.5 Cathodic protection equipment . 23
8.5.1 Cathodic protection cables . 23
8.5.2 Cable connection to pipeline .24
8.5.3 Distribution boxes and test stations . 25
8.6 Temporary protection . 26
8.7 Specific case of existing pipelines . 26
8.7.1 General . 26
8.7.2 Parallel pipelines . 26
8.7.3 Parallelism or crossing with AC power systems .27
8.8 Trenchless installation methods .27
9 Impressed current stations .28
9.1 General . 28
9.2 Power supply . 28
9.3 Ground beds . 29
9.3.1 General . 29
9.3.2 Deep-well ground beds . 29
9.3.3 Shallow ground beds . 30
9.3.4 Impressed-current anodes and conductive backfill . 30
9.4 Output control .32
9.4.1 General .32
9.4.2 Current distribution for multiple pipelines .32
9.4.3 Potential control .32
10 Galvanic anode systems .33
10.1 General . 33
10.2 Design requirements . 33
10.3 Zinc anodes . 34
10.4 Magnesium anodes . 35
10.5 Design of the anode system. 35
10.6 Anode backfill.37
10.7 Cables and cable connections .37
10.8 Anode installation .37
11 Monitoring facilities .37
11.1 General .37
11.2 Locations of test stations .37
11.3 Description of test stations . 38
11.4 Use of probes and coupons . 38
11.5 Bonding to other pipelines . 39
11.6 Test facilities at metallic cased crossings . 39
11.7 Test facilities at isolation joints . 39
11.8 Line current monitoring test stations . 39
11.9 Drain-point test facilities . 39
11.10 Miscellaneous monitoring facilities . 40
12 Commissioning.40
12.1 General . 40
12.2 Preliminary tests . . 40
12.3 Start-up .41
12.3.1 Impressed current stations .41
12.3.2 Galvanic anodes .42
12.3.3 Drainage stations .42
12.3.4 Test stations.42
12.4 Verification of cathodic protection effectiveness .43
12.4.1 General .43
12.4.2 Measurements of DC potential and AC voltage .43
12.4.3 Current measurements .43
12.4.4 Adjustments .43
12.5 Commissioning report . 44

iv
ISO 15589-1:2026(en)
12.5.1 Installation documentation . 44
12.5.2 Commissioning data and information . 44
13 Monitoring, inspection and maintenance .45
13.1 General .45
13.2 Implementation of inspection .45
13.3 Inspection intervals . 46
13.4 Remote monitoring . 48
13.5 Specialized surveys . 48
13.6 Monitoring plan . 48
13.7 Measuring equipment . 49
13.8 Maintenance and repair . 49
14 Documentation .50
14.1 Design documentation . 50
14.1.1 General . 50
14.1.2 Construction details and installation procedures . 50
14.2 Commissioning documentation . .51
14.3 Operating and maintenance documentation .51
14.3.1 General .51
14.3.2 Inspection and monitoring data .52
14.3.3 Maintenance records .52
Annex A (normative) Cathodic protection measurements .53
Annex B (normative) Electrical interference . 61
Annex C (informative) Fault detection of impressed-current systems during operation .65
Annex D (informative) Description of specialized surveys . 67
Annex E (informative) Calculation of the CP potential attenuation . 74
Annex F (informative) Electrical tests for isolation joints before installation .79
Annex G (informative) Internal corrosion at insulating flange .80
Bibliography .83

v
ISO 15589-1:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon
energy, Subcommittee SC 2, Pipeline transportation systems, in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 219, Cathodic protection, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 15589-1:2015), which has been technically
revised.
The main changes are as follows:
— cathodic protection criteria have been extended with further clarification on the application of the
criteria;
— requirements for design have been more detailed; periodicities for inspection of cathodic equipment
have been enlarged; and the option for remote monitoring has been added;
— requirements for measurements and testing during commissioning have been further detailed.
A list of all parts in the ISO 15589 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

vi
ISO 15589-1:2026(en)
Introduction
Pipeline cathodic protection is achieved by the supply of sufficient direct current to the external pipe
surface, so that the steel-to-electrolyte potential is lowered to values at which external corrosion is reduced
to an insignificant rate.
Cathodic protection is normally used in combination with a suitable protective coating system to protect
the external surfaces of steel pipelines from corrosion.

vii
International Standard ISO 15589-1:2026(en)
Oil and gas industries including lower carbon energy —
Cathodic protection of pipeline transportation systems —
Part 1:
On-land pipelines
1 Scope
This document specifies requirements and gives recommendations for the pre-installation surveys, design,
materials, equipment, installation, commissioning, operation, inspection, and maintenance of cathodic
protection systems for the external surface of on-land pipelines.
This document is applicable to on-land pipelines and piping systems used in other industries and
transporting other media such as industrial gases, waters, or slurries.
Throughout this document, on-land pipelines mean:
— pipelines that are buried;
— landfalls of offshore pipeline sections protected by onshore based cathodic protection installations;
— immersed sections of on-land pipelines such as river or lake crossings.
This document is applicable to pipelines of carbon steel, stainless steel, cast iron, galvanized steel, and
copper.
This document does not apply to pipelines made of reinforced concrete (see ISO 12696).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 8044, Corrosion of metals and alloys — Vocabulary
ISO 10012, Measurement management systems — Requirements for measurement processes and measuring
equipment
ISO 13623, Petroleum and natural gas industries — Pipeline transportation systems
ISO 13847, Petroleum and natural gas industries — Pipeline transportation systems — Welding of pipelines
ISO 21809-3, Oil and gas industries including lower carbon energy — External coatings for buried or submerged
pipelines used in pipeline transportation systems — Part 3: Field joint coatings
ISO 21809-5, Oil and gas industries including lower carbon energy — External coatings for buried or submerged
pipelines used in pipeline transportation systems — Part 5: External concrete coatings
ISO 21857, Petroleum, petrochemical and natural gas industries — Prevention of corrosion on pipeline systems
influenced by stray currents
IEC 60079-10-1, Explosive atmospheres — Part 10-1: Classification of areas — Explosive gas atmospheres

ISO 15589-1:2026(en)
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 62561-3, Lightning protection system components (LPSC) - Part 3: Requirements for isolating spark gaps
(ISGs)
EN 1594, Gas infrastructure — Pipelines for maximum operating pressure over 16 bar — Functional
requirements
EN 12007-3, Gas infrastructure — Pipelines for maximum operating pressure up to and including 16 bar – Part
3: Specific functional recommendations for steel
EN 14161, Petroleum and natural gas industries — Pipeline transportation systems from 2011+A1 from 2015
(ISO 13623:2017)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8044 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
anode backfill
added material immediately surrounding a buried anode
3.2
bond
conductor connecting two points on the same structure or between different structures
3.3
cathodic protection system
impressed current and galvanic anode system consisting of all the equipment necessary for the application
of cathodic protection, such as impressed current installations, power supplies, impressed current anodes
(3.12), galvanic anodes, monitoring facilities, bonds (3.2) and cables
3.4
coupon
metal sample of defined surface area and thickness made of a metal equivalent to the metal of the pipeline
3.5
coating defect
anomaly in the coating that results in the steel surface making direct contact with the surrounding
electrolyte
3.6
DC decoupling device
direct current decoupling device
equipment that provides a low-impedance path for alternating current and high resistance for direct current
EXAMPLE Polarization cells, capacitors, or diode assemblies.
3.7
drain point
location of the cable connection to the protected pipeline through which the protective current returns to
its source
ISO 15589-1:2026(en)
3.8
drainage
transfer of stray current (3.24) between structures by means of a deliberate bond (3.2)
Note 1 to entry: See ISO 21857 for drainage devices (direct drainage bond, resistance drainage bond, unidirectional
drainage bond and forced drainage bond).
3.9
drainage station
equipment and materials required to provide drainage (3.8) of stray currents (3.24) from affected systems
3.10
galvanic anode station
equipment and materials required to provide cathodic protection by the use of galvanic anodes
Note 1 to entry: Such materials and equipment include galvanic anodes and cables.
3.11
ground bed
system of buried or immersed anodes
3.12
impressed current anode
electrode that delivers cathodic protection current in combination with an impressed current station (3.13)
3.13
impressed current station
equipment and materials required to provide cathodic protection by impressed current
Note 1 to entry: Such materials and equipment include impressed current anodes (3.12), cables, and a DC source.
3.14
IR drop
voltage that is the product of all currents flowing through the cathodic protection circuit and the resistance
of the current path (mainly the electrolyte and the pipeline)
Note 1 to entry: This is derived from Ohm’s law (U = I × R).
3.15
IR free potential
polarized potential
coating defect (3.5) or coupon (3.4) to electrolyte potential without the voltage error caused by the IR drop
(3.14) due to the protection current or any other current
3.16
isolation joint
electrically insulating component inserted between two lengths of pipe to prevent electrical continuity
between them
EXAMPLE Monobloc isolation joint, insulated flange.
3.17
spark gap
component with discharge distance for isolating electrically conductive installation sections
Note 1 to entry: In the event of lightning strike, the installation sections are temporarily connected conductively as
the result of response of the discharge.
3.18
local earth
conductive mass of the electrolyte, whose voltage between two reference electrodes at any point is not equal
to zero
ISO 15589-1:2026(en)
3.19
measuring point
location where the actual potential measurement takes place
Note 1 to entry: In the case of pipe-to-electrolyte potential measurement, th
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