EN ISO 12747:2025

SLOVENSKI STANDARD
oSIST prEN ISO 12747:2024
01-maj-2024
Naftna in plinska industrija, vključno z nizkoogljično energijo - Transportni
cevovodni sistemi - Priporočene prakse za podaljšanje življenjske dobe
cevovodov (ISO/DIS 12747:2024)
Oil and gas industries including lower carbon energy - Pipeline transportation systems -
Recommended practice for pipeline life extension (ISO/DIS 12747:2024)
Erdöl- und Erdgasindustrie - Rohrleitungstransportsysteme - Empfohlene Maßnahmen
zur Verlängerung der Lebensdauer einer Rohrleitung (ISO/DIS 12747:2024)
Industries du pétrole et du gaz y compris les énergies à faible teneur en carbone -
Systèmes de transport par conduites - Pratique recommandée pour prolonger la durée
de vie des conduites (ISO/DIS 12747:2024)
Ta slovenski standard je istoveten z: prEN ISO 12747
ICS:
23.040.01 Deli cevovodov in cevovodi Pipeline components and
na splošno pipelines in general
75.200 Oprema za skladiščenje Petroleum products and
nafte, naftnih proizvodov in natural gas handling
zemeljskega plina equipment
oSIST prEN ISO 12747:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 12747:2024
oSIST prEN ISO 12747:2024
DRAFT
International
Standard
ISO/DIS 12747
ISO/TC 67/SC 2
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Pipeline
Voting begins on:
transportation systems —
2024-03-15
Recommended practice for pipeline
Voting terminates on:
life extension
2024-06-07
ICS: 75.200
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 12747:2024(en)
oSIST prEN ISO 12747:2024
DRAFT
ISO/DIS 12747:2024(en)
International
Standard
ISO/DIS 12747
ISO/TC 67/SC 2
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Pipeline
Voting begins on:
transportation systems —
Recommended practice for pipeline
Voting terminates on:
life extension
ICS: 75.200
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 12747:2024(en)
ii
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 3
3 Terms and definitions . 3
4 Abbreviated terms . 6
5 Life extension overview . 7
5.1 General .7
5.2 Assessment process .7
5.3 Assessment requirements .8
5.4 Limitations on life extension .10
5.5 Pipeline system availability .11
5.5.1 General .11
5.5.2 Pipeline ancillary components .11
5.5.3 Threats . 12
6 Data compilation .12
7 Structural integrity of the pipeline system .13
7.1 General . 13
7.2 Structural integrity assessment . 13
7.3 PIMS review .14
7.4 Remediation requirements.14
8 Future threat identification . 14
9 Life extension assessment . 14
9.1 Risk assessment .14
9.1.1 Process .14
9.1.2 Use of risk assessment in life extension . 15
9.1.3 Risk management . 15
9.2 Pipeline system design review .16
9.2.1 Design standards .16
9.2.2 Changes to the design basis . .16
9.2.3 Additional data requirements .17
9.3 Assessment of remnant life .17
9.3.1 General .17
9.3.2 Corrosion assessment .18
9.3.3 Fatigue and flaw assessment .19
9.3.4 Remediation. 20
9.4 Integrity management during extended life . 20
9.4.1 PIMS . 20
9.4.2 Inspection and monitoring .21
9.4.3 Integrity of risers within caissons and j-tubes .21
9.5 Regulatory requirements. 22
9.6 Update of systems and procedures . 22
9.6.1 General . 22
9.6.2 Emergency response procedures . 22
9.6.3 Operations and safety systems . 22
10 Life extension report .22
Annex A (informative) Considerations for lifetime extension of unbonded flexible pipe .24
Annex B (normative) Change of fluid .26
Annex C (informative) Typical data requirements .28

iii
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Annex D (informative) Defect and anomaly assessment guidance .32
Annex E (informative) Common threats to rigid pipelines .33
Annex F (informative) Inspection, testing, monitoring and sampling techniques .34
Bibliography .36

iv
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
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, Materials, equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 2, Pipeline transportation systems.
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.

v
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Introduction
Within ISO/TC 67/SC 2 there has been a series of discussions concerning both the needs and level of
prescription required to address pipeline life extension issues. These have highlighted that:
— operators are applying differing approaches, which leads to inefficient use of both operator and authority
resources.
— the assessment and upgrading of existing facilities have been based on probabilistic or reliability-based
methods.
— the level of detail delivered varies.
The purpose of this document is to address the above concerns by providing a consistent approach to
pipeline life extension assessment that can be applied by operators (or parties acting on their behalf) across
the industry.
This document is concerned with the proof of structurall integrity of the pipeline system for the justification
of extended operation. Integrity management is not covered in detail. However, the interface between a
PIMS and the life extension process is considered because
— a PIMS, where present, forms an integral part of the integrity assessment of the pipeline system.
— a PIMS of some form is required for operation in extended life.
Factors affecting the future operability of the system but not the structural integrity, such as the loss of a
control umbilical, are flagged as requiring assessment but are not addressed in full in this document.
Whilst this document is aimed primarily at the pipeline operators, it can also be of interest to other
stakeholders such as
— regulators approving the life extension application.
— members of the public affected by the life extension application, such as other users of maritime waters,
landowners and developers.
Considering this, an overview of the life extension process and the key principles involved is given in
Clause 5. The remainder of the document is intended to provide detailed guidance to those performing
the life extension assessments. Case studies are also provided to illustrate the application of the lifetime
extension process described in this standard, along with lessons learned that may aid the user in the
performance of similar studies. All guidance is provided for use in conjunction with sound engineering
practice and judgment.
This document is not intended for use as a design standard.

vi
oSIST prEN ISO 12747:2024
DRAFT International Standard ISO/DIS 12747:2024(en)
Oil and gas industries including lower carbon energy —
Pipeline transportation systems — Recommended practice
for pipeline life extension
1 Scope
This document gives guidance on how to assess the feasibility of extending the service life of a pipeline
system, as defined in ISO 13623, beyond its specified design life. Pump stations, compressor stations,
pressure-reduction stations and depots are not specifically addressed in this document, as shown in
Figure 1.
This document applies to both onshore and offshore rigid metallic pipelines and risers (including SCRs). It is
not directly applicable to the following:
— flexible pipelines;
— pipelines constructed from other materials, such as glass reinforced plastics or polymers;
— umbilicals (control and / or chemical conveyance service);
— topsides equipment and piping (outside of pipeline system limits defined in accordance with local
regulatory requirements);
— pipeline protection and support structures and components.
NOTE 1 The assessment process defined in clause 5.3 can be applied in the lifetime extension assessment of the
above at the discretion of the user. As an example, guidance on use of the process for lifetime extension of unbonded
flexible pipe is provided in Annex A.
NOTE 2 Further guidance on the lifetime extension of subsea systems, including umbilicals and topsides equipment,
is provided in NORSOK U-009.
NOTE 3 Although the life extension of structures and structural elements is not addressed in this standard, the
continued fitness-for-service of structures having a direct impact on the structural integrity of the pipeline system
shall be considered throughout any period of extended operation. This shall include assessment of the implications of
structural degradation on pipeline system integrity. Further guidance can be found in NORSOK N-006.
This document addresses life extension, which is a change to the original design premise. It is also applicable
to other changes to the design premise, such as MAOP re-ratings or a change to the conveyed fluids, at the
discretion of the user. Guidance on the latter is provided in Annex B, given the potential for extension to
operating life of a pipeline system being solely dependent on a change in operating fluids (such as when
considering re-use of a pipeline for CCUS or for hydrogen transportation).

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Key
pipeline systems covered by ISO 12747
connection with other facilities
pipeline not covered by ISO 12747
station/plant area or offshore installation not covered by ISO 12747

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Figure 1 — Extent of pipeline systems covered
2 Normative references
The following referenced documents are indispensable for the application 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 13623, Petroleum and natural gas industries — Pipeline transportation systems
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
acceptance criteria
specified indicators or measures employed in assessing the ability of a component, or system to perform its
intended function.
3.2
ancillary equipment
components attached to pipe or piping within the pipeline system with additional functions to the conveyance
of fluid, such as to monitor pipeline parameters or control pipeline conditions / flow. This includes valves,
pressure indicators, temperature gauges, corrosion probes, SCR flex joints etc.
3.3
anomaly
discrepancy or deviation of an element of the pipeline system from the established rules and limits
3.4
anomaly limits
criteria set as part of the design and PIMS processes to enable determination of anomalies.
3.5
design life
period for which the design basis is planned to remain valid.
[SOURCE: ISO 13623]
3.6
failure
event in which a component or system does not perform according to its operational requirements.
3.7
flow assurance
ensuring successful and economical flow of fluid through the pipeline system
3.8
high integrity pressure protection system
mechanical overpressure protection system that rapidly isolates the pipeline if there is a risk of exceeding
the maximum allowable operating pressure (MAOP)
3.9
life extension
additional period beyond the original service life for which the pipeline system can be operated safely.
Note 1 to entry: Life extension is considered as a modification to the design premise.

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
3.10
location class
geographic area classified according to criteria based on population density and human activity.
[SOURCE: ISO 13623]
3.11
maximum allowable operating pressure
maximum pressure at which the pipeline system, or parts thereof, is allowed to be operated.
[SOURCE: Adapted from ISO 13623]
3.12
operation
activities involved with running and maintaining the pipeline system in accordance with the design premise.
3.13
operator
party ultimately responsible for the operation and integrity of the pipeline system.
3.14
pipeline integrity management system
management system designed to ensure the safe operation of a pipeline system in accordance with the
design intent, by control of the physical condition of a pipeline, the operating conditions within the system
and any changes made to the system.
3.15
pipeline
those facilities through which fluids are conveyed, including pipe, pig traps (where present), components
and appurtenances, up to and including the isolating valves.
[SOURCE: Adapted from ISO 13623]
Note 1 to entry: The definition of pipeline limits can vary by design standard, geographical region, and operator
designation under PIMS. However, the definition above applies within this standard. Examples of selected facilities are
provided below.
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Key
1 drain 5 process 9 pipeline 13 onshore facility
2 pipeline limit 6 pipeline limit if there is no pig trap 10 isolation valve
3 pig trap 7 offshore installation 11 fenceline
4 vent 8 subsea xmas tree 12 pipeline limit if entering facility
Figure 2 — Definition of pipeline limits at selected facilities
3.16
pipeline
〈offshore〉 pipeline laid in maritime waters and estuaries seaward of the ordinary high-water mark.
[SOURCE: ISO 13623]
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
3.17
pipeline
〈onshore〉 pipeline laid on or in land, including lines laid under inland water courses, up to the ordinary high-
water mark when connected to an offshore pipeline.
[SOURCE: ISO 13623]
3.18
pipeline system
pipelines, stations, supervisory control and data acquisition system (SCADA), safety systems, corrosion
protection systems, and any other equipment, facility or building used in the transportation of fluids.
[SOURCE: ISO 13623]
Note 1 to entry: The extent of the pipeline system covered by this standard is defined in clause 1.
3.19
remnant life
assessed period (irrespective of the defined design life) for which a pipeline system can be operated safely,
based on time-dependent degradation mechanisms such as corrosion and fatigue.
3.20
required life
desired operational life of the pipeline, accounting for continued operation beyond the original pipeline
design life
3.21
risk
qualitative or quantitative likelihood of an event occurring, considered in conjunction with the consequence
of the event.
3.22
risk management
policies, procedures and practices involved in the identification, assessment, control and mitigation of risks.
3.23
service life
period of time during which the pipeline is assessed to fulfil all specified performance requirements.
3.24
threat
any activity or condition that can adversely affect pipeline system integrity.
3.25
topsides
structures and equipment placed on a supporting structure (fixed or floating) to provide some or all of a
platform’s functions.
4 Abbreviated terms
CCUS Carbon capture, utilization and storage
CP Cathodic protection
ECA Engineering critical assessment
ESD Emergency shut-down
ESDV Emergency shut-down valve

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
HIC Hydrogen-induced cracking
HIPPS High integrity pressure protection system
ILI In-line inspection
MAOP Maximum allowable operating pressure
NDE Non-destructive examination
PIMS Pipeline integrity management system
QRA Quantitative risk assessment
ROW Right of way
SCADA Supervisory control and data acquisition
SCC Stress corrosion cracking
SCR Steel catenary riser
SSC Sulfide stress cracking
VIV Vortex-induced vibration
5 Life extension overview
5.1 General
The design life of a pipeline is derived to prevent failure during operation due to time-dependent degradation
mechanisms such as corrosion and fatigue. However, the expiry of the design life does not mean that the
pipeline system is not fit-for-service because
— corrosion rates determined during the design process could have been conservative and/or corrosion
defects could have been repaired;
— the anticipated operational fatigue damage could have been overestimated.
Extended operation beyond the pipeline design life can be desirable when recoverable oil and gas remain,
where additional operational assets are tied (or will be tied) into the pipeline system, or where an
opportunity for change in service has been identified (e.g. changing a production line into a water injection
line or converting an existing production line for hydrogen or carbon dioxide transportation).
In all cases, if the intention is to operate a pipeline system beyond its specified design life, a life extension
assessment should be performed. The aim of this assessment is to demonstrate that the operator is not
exposing society to unacceptable risk by continuing to operate the pipeline beyond the design life. In addition
to the to time-dependent degradation mechanisms mentioned above, obsolescence of components within
the system, changes in regulatory requirements and modifications to the system, the way it is operated, and
the organisation operating the pipeline should also be considered.
NOTE For a change of service, it is possible that the original design life of the pipeline will not be exceeded,
particularly when changing from hydrocarbon transportation to water injection. However, the assessment process
defined within this standard can still be utilised to justify fitness for service over the remaining operating life
following the change.
5.2 Assessment process
Figure 3 illustrates the pipeline system life extension assessment process. The dashed boxes highlight the
distinct stages of the assessment and cross-reference the applicable clause of this document.

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
The process begins with a requirement for pipeline extension (item 1). Future service needs are then
defined (item 2), considering anticipated cessation of production, any changes to operating regime or fluids
conveyed. The assessment of current pipeline system integrity (item 3) shall be performed considering the
future service requirement, before definition of threats to the pipeline system in any period of extended
operation (item 4) and commencement of the life extension assessment (item 5).
The life extension assessment shall consider conditions found during the normal operational life that
were not considered in the design. Examples are time-dependent cracking mechanisms (e.g. SCC) and
manufacturing flaws that can grow under the effect of cyclic loading. The requirements of the life extension
assessment are discussed in more detail in 5.3.
Once an acceptable life extension has been determined, the assessment process shall be fully documented
(item 6). If life extension is not possible, the pipeline should be decommissioned at the end of the service life
as originally planned.
5.3 Assessment requirements
The assessment process illustrated in Figure 3 involves an assessment of the current pipeline system
integrity and an assessment to determine the suitability of the pipeline system for the future life needs.
Data requirements, and actions to be taken if insufficient data is available to complete the assessments, are
detailed in clause 6.
The assessment of the current integrity (item 3) shall include, but not be limited to:
— review of the pipeline system operational history;
— detailed assessment of the current structural integrity of the pipeline system (considering fitness-for-
service in terms of the future service needs defined in item 2)
The life extension assessment (item 5) shall include, but not be limited to:
— risk assessment for extended or modified operation;
— review of the pipeline system design, including a gap analysis to identify the additional requirements of
the current design standards;
— assessment of the remnant life of the system, including:
— corrosion assessment, accounting for accumulated and future corrosion in combination with defect
assessment;
— fatigue assessment, accounting for both accumulated and future fatigue damage;
— coating breakdown and CP system degradation assessment;
— identification and assessment of other time-dependent degradation mechanisms active in the pipeline;

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Figure 3 — Pipeline system life extension process
— revision or introduction of the PIMS for the future operating period, including update of the anomaly
limits;
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
— identification of any tenure issue (e.g. expiry of permit to occupy land) or statutory requirements (e.g.
pipeline license renewal), including a gap analysis to identify any additional regulatory requirements
introduced during the pipeline design life;
— review of the adequacy of the safety and operating systems;
— review of the adequacy of the operating and maintenance, emergency response and safety and
environmental procedures.
Additional studies shall be performed as required to determine the need for remedial measures to mitigate
the threats to the pipeline system anticipated during any extended operational period.
5.4 Limitations on life extension
The allowable life extension is governed by the assessed remnant life of the pipeline system, as illustrated in
Figure 4.
Figure 4 — Life extension and remnant life
NOTE Whilst Figure 4 illustrates lifetime extension assessment commencing prior to expiry of the original design
life, this is not mandatory. Many scenarios exist, such as when a pipeline has been taken out of service and preserved,
which could result in commencement of the assessment post expiry of the design life.
If the required life of the pipeline system exceeds the remnant life, the remnant life assessment may be
repeated, considering:
— the potential to gather further information to facilitate refined assessment (such as through NDE)
— reduction of degradation rates to increase remnant life (if applicable);
— replacement of pipeline components;
— reassessment of anomaly limits and rectification of any anomalies;
— derating of the pipeline system.

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Alternatively, it is possible to define conditional life extensions. This is illustrated by the following examples.
EXAMPLE 1 A life extension of 20 years is required for a pipeline system, following the tie-in of a new asset, but
the remnant life of the pipeline system is only 5 years due to excessive riser corrosion. In this case, an initial 5-year
life extension can be made, followed by a further extension of 15 years upon replacement of the riser at the end of its
remnant life.
EXAMPLE 2 A life extension of 20 years is required for a pipeline system, but due to the predicted corrosion rates, a
reduction in MAOP will be required in 2 years. In a fashion similar to Example 1 above, an initial 2-year life extension
can be made, with a further extension of 18 years subject to favourable results from an in-line inspection (ILI) run.
If the ILI run confirmed the predicted corrosion rate, reduction in MAOP or rectification of the unacceptable defects
would still be required after 2 years in order to achieve the required 20-year life extension.
The lifetime extension process is intended to be based on conservative assumptions to account for
degradation caused by future operation. As such, future assessments (based on now known operating
conditions) can lead to the justification of further life extensions as conservatism is removed. This is
acceptable and the number of successive assessments and associated extensions to operation is not intended
to be limited.
5.5 Pipeline system availability
5.5.1 General
The guidance given in this document is concerned with the proof of structural integrity of the pipeline
system. However, the availability of the pipeline system during the life extension is also of critical
importance. As such, a separate assessment of the integrity of the following should be carried out as part of
the life extension process, as applicable:
— pipeline system facilities, such as:
— platform topsides;
— manifolds and termination structures;
— pump stations;
— compressor stations;
— processing plants and terminals;
— Leak detection systems
— Chemical injection systems
— Safeguarding systems (ESDV’s, SSIV’s)
— instrumentation;
— control systems, including SCADA;
— umbilicals for control, power and chemical injection (including terminations).
Obsolescence of the above should also be considered.
5.5.2 Pipeline ancillary components
In addition to the above, additional ancillary components that are part of the pipeline system shall be
considered in the life extension process. Ancillary components might have been:
— installed with the pipeline, or
— retro-fitted to the pipeline.

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
Where the stated design life of ancillary components is inadequate for the required extended service
duration, the life extension may consider:
— consultation with the original equipment manufacturer
— appropriate ongoing integrity management activities to ensure ongoing performance.
5.5.3 Threats
The following threats to pipeline integrity and availability shall be considered:
— external corrosion of metallic protection and support structures
— deterioration of non-metallic sealing components e.g., static and dynamic seals, environmental ingress
seals on actuators
— damage to, or deterioration of, pipeline coatings, insulation and fire protection;
— corrosion or fouling of internal components due to environmental ingress e.g. valve yokes, actuator cans
— obsolescence and continued suitability of safeguarding, control, monitoring, and leak detection systems
— integrity of wear and tear components (e.g. valve internals specifically if performing an isolation function
related to safety, pig trap quick opening closures where cumulative wear takes place resulting in closure
misalignment)
NOTE A change of fluid conveyed by a pipeline will require a chemical compatibility check of all materials that are
in contact with the new service fluid.
6 Data compilation
Typical data required for a life extension assessment of a pipeline system are listed in Annex C. This
comprises:
— data relating to the original design of the pipeline, including safety case requirements;
— operations data over life to date;
— inspection and monitoring data;
— integrity management documentation, including:
— PIMS and associated performance indicators;
— integrity statements and reports;
— anomaly assessment results;
— risk assessments.
— maintenance and repair data;
— external data, relating to external stakeholder interfaces with the operation or integrity of the pipeline.
The use of accurate data is vital and the level of confidence in the data source shall be considered as part of
the assessment.
When performing the life extension assessment, the degree of missing data shall be assessed and mitigation,
such as additional pipeline inspections or risk assessments, shall be identified where appropriate.
NOTE 1 When considering aging pipelines, data are often missing, especially if the operatorship has passed through
several organizations. The impact of missing data is addressed in clause 9.2.3.

oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
It is likely that inspections, such as CP surveys, will have been performed numerous times over the life of a
pipeline. In such cases, comparison of successive inspection results should be performed wherever possible
to identify trends of decreasing performance or deteriorating integrity that will impact remnant life.
7 Structural integrity of the pipeline system
7.1 General
The integrity of the pipeline system can have deteriorated since installation. The level of information
available to characterize the deterioration experienced depends on the monitoring and management
systems implemented by the operator.
To determine whether the current structural integrity of the pipeline system is acceptable for life extension
(considering future service requirements), an integrity assessment shall be performed based on the data and
documentation detailed in Clause 6. There are numerous standards that cover the assessment of pipeline
integrity (see Annex D), and these should be consulted for further guidance.
NOTE Integrity management practice varies with different operators in different parts of the world. Consequently,
the level of assessment required to justify life extension varies from that performed continuously as part of a robust
PIMS to the need (or desire) for a standalone assessment as part of the lifetime extension process.
7.2 Structural integrity assessment
The structural integrity assessment shall evaluate:
a) the internal and external pipeline condition;
b) the effects of any repairs or modifications to the structural integrity of the pipeline system;
c) the status of external pipeline coatings and the CP system;
d) the impact of any operational excursions from the design envelope;
e) the effect of any defects or anomalies on the structural integrity of the pipeline system and the
requirement for remediation;
f) the status and condition of the safety systems;
g) the fitness-for-service of the pipeline system .
NOTE Guidance on the assessment of rigid pipe defects and anomalies is provided in Annex D
The installation and commissioning of the pipeline system should also be considered, paying particular
attention to:
a) any new or non-standard construction methods that were used;
b) the presence of components (such as mitred bends) that are no longer accepted by current design
standards;
c) any difficulties or unforeseen events that occurred (e.g. the presence of hydrotest water in the pipeline
for longer than anticipated);
d) deviations from the original design of the pipeline system.
If sufficient data are not available to determine the structural integrity of the pipeline, further inspection,
testing or analysis shall be carried out.
NOTE In practice, this generally involves ILI, hydrotest or direct assessment. Selection of the most appropriate
approach will depend on pipeline configuration (for instance not all pipelines are piggable or suitable for direct
assessment) and the risks to the pipeline from performing the inspection (or test) as well as the quality and extent of
the data obtained.
oSIST prEN ISO 12747:2024
ISO/DIS 12747:2024(en)
7.3 PIMS review
If the integrity of a pipeline system is governed by a PIMS, the information provided should form the basis of
...