EN ISO 24817:2026
(Main)Oil and gas industries including lower carbon energy - Composite repairs for piping - Qualification and design, installation, testing and integrity management (ISO 24817:2026)
- Abstract
This document specifies requirements and gives recommendations for the qualification and design, installation, testing and integrity management for the external application of composite repair systems to corroded or damaged piping and pipelines, tanks and vessels.
- Status
- Published
- Publication Date
- 29-Sep-2026
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 30-Sep-2026
- Completion Date
- 30-Sep-2026
EN ISO 24817:2026 is a CEN standard for composite repairs on pipework, pipelines, tanks and vessels in oil, petrochemical and natural gas service. It specifies requirements and recommendations for the qualification, design, installation, testing and integrity management of external composite repair systems for corroded or damaged equipment, for owners, repair system suppliers and installers.
What does EN ISO 24817:2026 specify?
EN ISO 24817:2026 specifies how to qualify and use external composite repair systems for damaged or corroded piping and similar equipment in the petroleum, petrochemical and natural gas industries. The document is aimed at repairs that are already considered suitable as a remedy, so the reader can focus on how to design, install, test and manage the repair.
The scope covers pipework and pipelines, and also tanks and vessels. The document is organized into clauses for scope, references, terms, applications, key issues, qualification, feasibility assessment, design methodology, installation, ongoing integrity management, system testing and decommissioning, with supporting annexes A to M.
| Annex | What it covers |
|---|---|
| A | Design data sheet |
| B | Qualification data and summary test reports |
| C | Short-term pipe spool survival test |
| D | Measurement of the interface toughness parameter for through-wall defects |
| E | Performance testing for long-term allowable strain |
| F | Impact performance testing |
| G | Degradation factor measurement |
| H | Qualification for other defect types assessed by substrate stress |
| I | Guidance on selecting defect size and geometry for through-wall defects |
| J | Training and approval of installers and supervisors |
| K | Installation requirements and guidance |
| L | Design considerations, including worked examples |
| M | Integrity management of composite repair systems |
What are the key requirements of EN ISO 24817:2026?
EN ISO 24817:2026 is built around a repair workflow: assess the defect, qualify the repair system, design the repair, install it under controlled conditions, and manage it in service. The most important point is that the standard is not itself a defect assessment code - it assumes the defect has already been judged repairable and uses that assessment as an input.
Qualification and feasibility
Clause 5 states that EN ISO 24817:2026 is not a defect assessment standard. That matters because the standard does not decide whether a defect is acceptable or rejectable; it starts after that decision has been made and uses outputs such as minimum remaining wall thickness or MAWP (maximum allowable working pressure) in the repair design.
Clause 6 defines the repair system as a combination of material family, surface preparation, filler, primer, repair laminate and curing procedure. In practice, this means the supplier cannot change one of those elements without re-qualifying what is being offered, and the owner has to check that the qualified system matches the site conditions.
Clause 6 and Section 7 require the owner and supplier to exchange the right data early: design pressures and temperatures, corrosion mechanism, inspection data, installation conditions, upset conditions and any working limits. This is what lets the supplier design for the real site, rather than for an idealized case.
Section 7 requires qualification data for the chosen repair class and the specified substrate and surface preparation procedure. That matters because qualification is tied to the actual material family and surface-prep method used on site, not just to a generic composite product.
Section 8 requires a repair feasibility assessment before design starts. The assessment looks at defect type and location, reliability of inspection data, operating and design conditions, fluid chemistry, extra loads, geometry, maintenance actions, hazards, personnel skills, installation practicality, extreme events and likely failure modes. The practical effect is that composite repair is only chosen when it can be installed, inspected and managed safely for the required life.
Section 8 also assigns repairs to Class 1, Class 2 or Class 3. Class selection matters because it sets the service envelope: Class 1 for low-spec utility duties, Class 2 for fire water and other safety-related service excluding hydrocarbons, and Class 3 for produced fluids, hydrocarbons and more demanding applications.
Design and installation
Section 9 requires the owner to specify the repair design lifetime and initial service life. The design lifetime shall be at least two years, and the document sets maximum lifetime limits by repair type and class; for longer lifetimes, performance testing in Annex E and the associated service factor are needed.
Section 9.2 and 9.3 control environmental and temperature suitability. The repair system has to be shown compatible with the service environment, and the allowable temperature is based on glass transition temperature (Tg) or heat distortion temperature (HDT), with cure history taken into account. In practice, the supplier has to demonstrate that the resin system will still perform at the actual operating and installation temperatures.
Section 9.4 to 9.6 set out the load basis for design. Cyclic loading is only factored when needed, design strains are taken from default values or from performance testing, and the design uses equivalent loads and equivalent pressure. This is the bridge between pipe loads, pressure and the composite laminate design.
Section 9.7 to 9.15 set the thickness and extent of repair for Type A and Type B defects, external loads, other defect types and other components. The document requires the designer to consider worst-case defect size, component geometry, axial extent, taper, repair thickness, component-specific increase factors and debonding risk. For the reader, this means the repair is not sized just by wall loss - it is sized by the actual loaded area and by how the repair will transfer load into the substrate.
Section 10 covers storage, documentation, installer and supervisor competence, application procedure and completion records. The repair must be applied using the qualified procedure, with the same surface preparation used in qualification, and QA records, photographs and design documents retained by the owner and installer. This is important because surface preparation and cure control are key to long-term bond performance.
Section 10.6 allows live repairs only if the hazards are assessed and managed, including stop-gap leak sealing where needed. Section 12 then requires curing before pressure testing, and gives a hydrotest approach that the owner may specify for the repaired system.
Integrity management and end of life
Section 11 requires an ongoing integrity management plan, including record keeping, inspection, allowable defects, maintenance options and review of repair lifetime. A baseline inspection after installation is recommended so later changes can be compared with the original condition.
Section 11 also requires action at the end of the repair life: remove and replace the component, remove and replace the repair, or revalidate the repair design lifetime. Section 13 covers decommissioning and removal of repair material.
What terms does EN ISO 24817:2026 define?
- Composite - a thermoset resin system reinforced by fibres.
- Cure schedule - the qualified time-temperature profile used to achieve the required T or HDT.
- Design lifetime / repair design lifetime - the period used in design calculations and typically the maximum period for which the repair is expected to be needed.
- Closed free end piping - pipework free to move laterally and strain axially, also called unrestrained piping.
- Barcol hardness - a measure of surface hardness using a surface impresser.
- MAWP (maximum allowable working pressure) - the pressure limit used as an input to repair design.
- NDT (non-destructive testing) - inspection methods used to examine the repair laminate, bond and substrate without removing the repair.
Who uses EN ISO 24817:2026?
EN ISO 24817:2026 is used by asset owners, operators, repair system suppliers, design engineers, integrity engineers, quality managers, installers, supervisors and inspection teams. It is relevant in oil, petrochemical and natural gas facilities, and also in utility piping, pipelines, tanks and vessels where external composite repair is considered.
In practice, owners use it to define the repair scope, check qualification evidence and manage inspection and lifetime decisions. Suppliers use it to qualify materials and provide design data. Installers and supervisors use it to follow the qualified procedure, document QA and prove competence.
Which standards are used with EN ISO 24817:2026?
EN ISO 24817:2026 relies on material tests, surface preparation references and defect-assessment standards to support repair qualification and design.
| Standard(s) | Contribution |
|---|---|
| ISO 75-3, ISO 527-1, ISO 527-4, ISO 868, ISO 11357-2, ISO 11359-2, ASTM D696, ASTM D5379 | Test methods for thermal, tensile, hardness, glass-transition, thermal-expansion and shear properties of the repair materials |
| ISO 10952, ASTM C581, ASTM D543 | Chemical resistance and environmental compatibility testing |
| ISO 14692 | GRP piping reference, including cyclic loading and trench/back-fill guidance used in the document |
| ISO 8501-1, ISO 8502-4, ISO 8503, ISO 8504 | Surface cleanliness, condensation and preparation guidance |
| ISO 45001 | Suggested safety management framework for implementation |
| ISO 15649, ISO 13623, ASME B31.1, ASME B31.3, ASME B31.4, ASME B31.8, BS 8010 | Examples of original piping design standards that repaired systems may have been built to |
| ASME B31G, API RP 579-1 / ASME FFS-1, BS 7910, PDAM | Defect assessment methods used before deciding on repair |
| ASME PCC-2 Part 5 Article 501, AWWA M45, ASTM D1598, ASTM D1599 | Supporting guidance for pressure testing and related load/installation practice |
What does the EN ISO 24817:2026 document contain?
EN ISO 24817:2026 contains a design data sheet, qualification data requirements, test methods and worked examples. Annexes B to H provide the test set-ups and reporting needs for laminate properties, adhesion, Type A and Type B defects, impact, degradation and other defect types.
The main body contains formulas and tables for repair class selection, design lifetime, environmental compatibility, temperature limits, cyclic loading, design strain, equivalent loads, thickness, axial extent, taper length and debonding checks. These are the calculations a designer uses to turn defect data and service conditions into a repair build-up.
Annex J and Annex K cover installer and supervisor training and site installation practice. Annex L explains the design path with worked examples, and Annex M describes how to manage the repair through service life and decommissioning.
Relations
- Effective Date
- 02-Jul-2025
- Effective Date
- 12-Feb-2026
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Frequently Asked Questions
EN ISO 24817:2026 is a draft published by the European Committee for Standardization (CEN). Its full title is "Oil and gas industries including lower carbon energy - Composite repairs for piping - Qualification and design, installation, testing and integrity management (ISO 24817:2026)". This standard covers: This document specifies requirements and gives recommendations for the qualification and design, installation, testing and integrity management for the external application of composite repair systems to corroded or damaged piping and pipelines, tanks and vessels.
This document specifies requirements and gives recommendations for the qualification and design, installation, testing and integrity management for the external application of composite repair systems to corroded or damaged piping and pipelines, tanks and vessels.
EN ISO 24817:2026 is classified under the following ICS (International Classification for Standards) categories: 75.180.20 - Processing equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 24817:2026 has the following relationships with other standards: It is inter standard links to EN ISO 24817:2017, ISO 24817:2026. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 24817:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 24817:2025
01-december-2025
Petrokemična industrija ter industrija za predelavo nafte in zemeljskega plina -
Popravila cevovodov s kompozitnimi materiali - Kvalifikacija in načrtovanje,
montaža, preskušanje in upravljanje celovitosti (ISO/DIS 24817:2025)
Petroleum, petrochemical and natural gas industries - Composite repairs for pipework -
Qualification and design, installation, testing and integrity management (ISO/DIS
24817:2025)
Erdöl-, petrochemische und Erdgasindustrie - Reparatur von Rohrleitungen mit
Verbundwerkstoffen - Qualifizierung und Auslegung, Montage, Prüfung und Inspektion
(ISO/DIS 24817:2025)
Industries du pétrole, de la pétrochimie et du gaz naturel - Réparations en matériau
composite pour tuyauteries - Qualification et conception, installation, essai et gestion de
l'intégrité (ISO/DIS 24817:2025)
Ta slovenski standard je istoveten z: prEN ISO 24817
ICS:
75.180.20 Predelovalna oprema Processing equipment
oSIST prEN ISO 24817:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN ISO 24817:2025
oSIST prEN ISO 24817:2025
DRAFT
International
Standard
ISO/DIS 24817
ISO/TC 67/SC 6
Petroleum, petrochemical
Secretariat: AFNOR
and natural gas industries —
Voting begins on:
Composite repairs for pipework
2025-09-01
— Qualification and design,
Voting terminates on:
installation, testing and integrity
2025-11-24
management
Industries du petrole, de la petrochimies et du gaz natruel —
Reparations en materiau composite pour canalisations —
Conformite aux exigences de performance et conception,
installation, essai et gestion de l’intégrité
ICS: 75.180.20
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 has not been edited by the ISO Central 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 24817:2025(en)
oSIST prEN ISO 24817:2025
DRAFT
ISO/DIS 24817:2025(en)
International
Standard
ISO/DIS 24817
ISO/TC 67/SC 6
Petroleum, petrochemical
Secretariat: AFNOR
and natural gas industries —
Voting begins on:
Composite repairs for pipework
— Qualification and design,
Voting terminates on:
installation, testing and integrity
management
Industries du petrole, de la petrochimies et du gaz natruel —
Reparations en materiau composite pour canalisations —
Conformite aux exigences de performance et conception,
installation, essai et gestion de l’intégrité
ICS: 75.180.20
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 has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
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
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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 24817:2025(en)
ii
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms. 7
4.1 Units .7
4.2 Symbols .7
4.3 Abbreviated terms .11
5 Applications .11
6 Summary of key issues .13
6.1 Repair system qualification .14
6.2 Enquiry stage .14
6.3 Design of repair.14
6.3.1 Type A and Type B design cases .14
6.4 Installer training .17
6.5 Installation of repair .17
6.6 Ongoing integrity management of the repaired system .17
7 Qualification . 17
7.1 Repair system qualification data .17
7.2 Re-qualification of the repair system .19
7.2.1 Overview .19
7.2.2 For Type A defect repairs .19
7.2.3 For Type B defect repairs .19
8 Repair feasibility assessment . 19
8.1 Repair class .21
8.2 Required data .21
8.2.1 Background .21
8.2.2 Original equipment design data .21
8.2.3 Maintenance and operational histories . 22
8.2.4 Service condition data . 22
9 Design methodology .22
9.1 Repair design lifetime and initial service life . 22
9.2 Environmental compatibility . 23
9.3 Design temperature effects. 23
9.4 Cyclic loading . 25
9.5 Determination of design strains . 25
9.5.1 Design strains based on default allowable strains . 25
9.5.2 Design strains based on performance testing . 26
9.6 Determination of equivalent load and equivalent pressure . 26
9.7 Design of repairs for Type A defects .27
9.7.1 Substrate load sharing, limited by substrate allowable stress .27
9.7.2 Substrate load sharing, limited by repair laminate design strain .27
9.7.3 Repair laminate carries all loads . 28
9.8 Design of repairs for Type B defects . 28
9.8.1 Determination of service factor, f . 29
leak
9.8.2 Circular or near-circular defects . 29
9.8.3 Slot-type defects in the circumferential direction . 30
9.8.4 Slot-type defects in the axial direction . 30
9.9 External loads . 30
9.10 Other defects (with assessments based on substrate stress) .31
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ISO/DIS 24817:2025(en)
9.11 Repair of other components .31
9.12 Axial extent of repair .32
9.12.1 Patches . 33
9.13 Calculation of the repair design thickness, t . 34
design
9.14 Confirmation that repair design thickness is within acceptable limits . 34
9.14.1 Maximum acceptable value of t . 34
calc
9.14.2 Maximum allowable design pressure for tees or nozzles . 34
9.14.3 Potential for repair debonding . 34
9.15 Calculation of total repair length . 35
9.16 Design output. 36
9.17 Optional design considerations . 36
9.17.1 Fire performance . 36
9.17.2 Cathodic disbondment. 36
9.17.3 Electrical conductivity .37
9.17.4 Fretting type defects .37
9.17.5 Delamination or blister type defects.37
9.17.6 Clamps and other repair systems . .37
10 Installation .37
10.1 Storage conditions .37
10.2 Documentation prior to repair application . 38
10.2.1 Method statement . 38
10.2.2 Work pack . 38
10.3 Installer and supervisor qualifications . 40
10.4 Installation procedure . 40
10.5 Repair completion documentation . 40
10.6 Live repairs .42
10.7 Repair of clamps, piping components, tanks, or vessels.42
10.8 Environmental considerations .42
10.9 Repair of defects within the repair system .42
11 Ongoing integrity management .43
11.1 General .43
11.2 Record keeping .43
11.3 In-service inspection .43
11.4 Allowable defects for the repair system .45
11.5 Repair system maintenance and remedial options .47
11.5.1 Overview .47
11.5.2 Substrate adjacent to the repair . 48
11.5.3 Repairs to Type A defects . 48
11.5.4 Repairs to Type B defects . 48
11.5.5 Repair system . 48
11.6 Repair lifetime considerations . 49
11.6.1 Periodic review . 49
11.6.2 Lifetime reduction . 50
11.6.3 Lifetime extension . 50
11.7 Future modifications . 50
12 System testing .50
13 Decommissioning . 51
Annex A (normative) Design data sheet .52
Annex B (normative) Qualification data .55
Annex C (normative) Short-term pipe spool survival test .60
Annex D (normative) Measurement of γ for through-wall defect calculation .62
LCL
Annex E (normative) Measurement of performance test data . 67
Annex F (normative) Measurement of impact performance .69
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oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
Annex G (normative) Measurement of the degradation factor .70
Annex H (normative) Qualification of repair systems for other defects (with assessments based
on substrate stress) .72
Annex I (Informative) Guidance on the selection of the appropriate defect size and geometry
for through-wall defects (Type B defect) .75
Annex J (normative) Installer qualification .84
Annex K (informative) Installation requirements and guidance .87
Annex L (informative) Design considerations.89
Annex M (informative) Management of the integrity of composite repair systems to pipework
and vessels .96
Bibliography .99
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oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(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 on 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 the following URL:
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 6, Processing equipment
and systems.
This third edition cancels and replaces the second edition (ISO 24817:2017E), which has been technically
revised.
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oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
Introduction
The objective of this document is to ensure that pipework, pipelines, tanks and vessels repaired using
composite systems that are qualified, designed, installed and managed using this document will meet
the specified performance requirements. Repair systems are designed for use within the petroleum,
petrochemical and natural gas industries, and also within utility service applications. The main users of this
document will be plant and equipment owners of the pipework and vessels, design contractors, suppliers
contracted to provide the repair system, certifying authorities, installation, maintenance and inspection
contractors.
vii
oSIST prEN ISO 24817:2025
oSIST prEN ISO 24817:2025
DRAFT International Standard ISO/DIS 24817:2025(en)
Petroleum, petrochemical and natural gas industries —
Composite repairs for pipework — Qualification and design,
installation, testing and integrity management
1 Scope
This document gives requirements and recommendations for the qualification and design, installation,
testing and integrity management for the external application of composite repair systems to corroded or
damaged pipework and pipelines, tanks and vessels used in the petroleum, petrochemical and natural gas
industries.
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 75-3, Plastics — Determination of temperature of deflection under load — Part 3: High-strength
thermosetting laminates and long-fibre-reinforced plastics
ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles
ISO 527-4, Plastics — Determination of tensile properties — Part 4: Test conditions for isotropic and orthotropic
fibre-reinforced plastic composites
ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore
hardness)
ISO 10952, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — Determination of the resistance
to chemical attack for the inside of a section in a deflected condition
ISO 11357-2, Plastics — Differential scanning calorimetry (DSC) — Part 2: Determination of glass transition
temperature and step height
ISO 11359-2, Plastics — Thermomechanical analysis (TMA) — Part 2: Determination of coefficient of linear
thermal expansion and glass transition temperature
ISO 14692, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping
ASTM C581, Standard Practice for Determining Chemical Resistance of Thermosetting Resins Used in Glass-
Reinforced Structures Intended for Liquid Service
ASTM D543, Standard Practices for Evaluating the Resistance of Plastics to Chemical Reagents
ASTM D696, Standard Test Method for Coefficient of Linear Thermal Expansion of Plastics Between Minus 30 °C
and 30 °C with a Vitreous Silica Dilatometer
ASTM D1598, Standard Test Method for Time-to-Failure of Plastic Pipe under Constant Internal Pressure
ASTM D1599, Standard Test Method for Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and
Fittings
ASTM D2583, Standard Test Method for Indentation Hardness of Rigid Plastics by Means of a Barcol Impressor
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
ASTM D2992, Standard Practice for Obtaining Hydrostatic or Pressure Design Basis for Fiberglass (Glass-Fiber-
Reinforced Thermosetting-Resin) Pipe and Fittings
ASTM D3039, Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials
ASTM D3165, Standard Test Method for Strength Properties of Adhesives in Shear by Tension Loading of Single-
Lap-Joint Laminated Assemblies
ASTM D3681, Standard Test Method for Chemical Resistance of Fiberglass (Glass-Fiber-Reinforced Thermosetting
Resin) Pipe in a Deflected Condition
ASTM D5379, Standard Test Method for Shear Properties of Composite Materials by the V-Notched Beam Method
ASTM D6604, Standard Practice for Glass Transition Temperatures of Hydrocarbon Resins by Differential
Scanning Calorimetry
ASTM E831, Standard Test Method for Linear Thermal Expansion of Solid Materials by Thermomechanical
Analysis
ASTM E1640, Standard Test Method for Assignment of the Glass Transition Temperature by Dynamic Mechanical
Analysis
ASTM E2092, Standard Test Method for Distortion Temperature in Three-Point Bending by Thermomechanical
Analysis
ASTM G8, Standard Test Methods for Cathodic Disbonding of Pipeline Coatings
EN 59, Methods of testing plastics — Glass reinforced plastics — Measurement of hardness by means of a Barcol
impressor (BS 2782-10, Method 1001, Measurement of hardness by means of a Barcol impresser)
EN 1465, Adhesives — Determination of tensile lap shear strength of rigid-to-rigid bonded assemblies
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological 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
anisotropic
exhibiting different physical properties in different directions
3.2
Barcol hardness
measure of surface hardness using a surface impresser
3.3
blister
air void between layers within the laminate visible on the surface as a raised area
3.4
closed free end piping
pipework that is free to displace laterally and to strain axially
Note 1 to entry: This may include aboveground pipework that is configured to accommodate thermal expansion
or support movement, field bends and adjacent pipe buried in soft or unconsolidated soil, an un-backfilled section
of buried pipeline that is free to displace laterally or which contains a bend and unanchored sections of pipe. Also
referred to as “Unrestrained” piping.
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
3.5
composite
thermoset resin system that is reinforced by fibres
3.6
crack
split in the repair laminate extending perpendicular to the surface such that there is actual separation with
opposite surfaces
3.7
cure
curing
setting of a thermosetting resin system, such as polyester or epoxy, by an irreversible chemical reaction
3.8
cure schedule
time-temperature profile qualified to generate a specified T or HDT
g
3.9
delamination
an area of separation between layers in the repair laminate
3.10
design lifetime
repair design lifetime
the period of time used in the design calculations and typically the maximum period for which the repair is
expected to be required
Note 1 to entry: The design lifetime shall not be interpreted as the achievable service life of the repaired system.
3.11
design temperature
the temperature for which the repair is designed
3.12
differential scanning calorimetry
DSC
method of determining the glass transition temperature of a thermosetting resin
3.13
disbond
an area between the repair laminate and the substrate which should be bonded but where no bond exists
(also referred to as interfacial delamination)
3.14
dry spot or un-impregnated/dry fibre
area of fibre not impregnated with resin, with bare, exposed fibre visible
3.15
engineered repair
repair which has been designed and applied under a specified, controlled process so that under the design
conditions, there is a high degree of confidence that the repair will maintain its integrity over the design
lifetime
3.16
exposed fibre
area of fibre not impregnated with resin that projects from the body of the repair
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
3.17
fixed piping
includes sections of buried pipe, sections of aboveground pipework attached to closely spaced rigid supports,
anchored at each end and at changes in direction and field bends and adjacent pipework buried in stiff or
consolidated soil
Note 1 to entry: Also referred to as “Restrained” piping.
3.18
foreign matter
any substance other than the reinforcing fibre or other materials that form part of the repair system
3.19
finishing materials
final layer of material to help compact the repair laminate, typically a polymeric film or a fabric
Note 1 to entry: They should be fully removed after the repair has hardened and before the repair is inspected or
painted.
3.20
glass transition temperature
temperature at which a resin undergoes a marked change in physical properties
3.21
hardener
component added to a thermosetting resin to effect cure
3.22
heat distortion temperature
HDT
temperature at which a standard test bar deflects by a specified amount under a given load
3.23
inspection authority
the entity responsible for verifying the repair complies with the requirements
3.24
installer
person who is qualified to apply a composite repair system
3.25
installation temperature
expected substrate (component) surface temperature at time of repair installation
3.26
filler material
material used to repair external surface imperfections prior to the application of the composite laminate
3.27
laminate
repair laminate
composite laminate
part of a repair system that is the composite
Note 1 to entry: Most composites considered in this document are composed of discrete lamina or layers which are
wrapped or stacked, one on top of the other. This stacked construction is the laminate.
3.28
layer
single, individual ply of the composite laminate
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
3.29
leak
perforation in the substrate with loss of containment
3.30
material family
substrate family
material group or metallurgical alloy class whose members have similar chemical compositions, for example
cast irons, carbon steels, austenitic stainless steels, glass reinforced epoxy resin (GRE), glass reinforced
vinyl ester (GRVE) and glass reinforced unsaturated polyester (GRuP)
3.31
maximum initial service life
the minimum of the repair design lifetime or 20 years, as specified in Table 5
3.32
maximum repair design lifetime
the maximum value that may be selected for the repair design lifetime, as specified in Table 5
3.33
occasional load
load that occurs rarely and during a short time
Note 1 to entry: Occasional loads typically occur less than 10 times in the life of the component and each load duration
is less than 30 min.
3.34
operating temperature
expected repair operating temperature
3.35
owner
organization that owns or operates the component to be repaired
3.36
pin hole
pin-prick hole in the resin rich surface, not extending into the laminate
3.37
pipeline
pipe with components subject to the same design conditions used to transport fluids between plants
Note 1 to entry: Components include fittings, flanges and valves.
3.38
piping
piping system
pipework
assemblies of piping components used to convey fluids within a plant
Note 1 to entry: Components include pipe, fittings, flanges and valves. A piping system is often above ground but
sometimes buried.
3.39
pit
depression in the surface of the repair laminate
3.40
ply
single wrap or layer (lamina) of a repair laminate
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
3.41
post cure
additional elevated-temperature cure applied after resin has hardened to ensure the required glass
transition temperature is achieved
3.42
qualified application procedure
application procedure used for the qualification tests and subsequently used to install repairs
3.43
qualification test temperature
temperature at which qualification testing of the repair system is performed
3.44
reinforcement
fibre embedded in the resin system
Note 1 to entry: Possible fibre materials include aramid, carbon, glass, polyester, or similar materials. Reinforcement
results in mechanical properties superior to those of the base resin.
3.45
repair system
system comprised of the substrate, composite material (repair or composite laminate), filler material,
adhesive and including surface preparation and installation methods
3.46
repair system installer
company that installs the repair system
3.47
repair system supplier
company that designs and supplies the repair system
3.48
resin system
all of the components that make up the matrix portion of a composite
Note 1 to entry: Often this includes a resin, filler(s), pigment, mechanical property modifiers and catalyst or hardener.
3.49
risk
event encompassing what can happen (scenario), its likelihood (probability) and its level or degree of
damage (consequences)
3.50
service life
defined lifetime
the period of time for which the repair is intended to be retained in service by the owner
Note 1 to entry: This shall not exceed the design lifetime. An appropriate maintenance strategy shall be defined and
implemented to enable the required service life, see Section 11.5.
3.51
stop gap
temporary solutions applied to stop live leaks and so enable a composite repair to be installed
Note 1 to entry: Stop-gaps do not restore the integrity of the component and have expected service lives in the order
of days to weeks.
3.52
substrate
surface to which a repair is applied
oSIST prEN ISO 24817:2025
ISO/DIS 24817:2025(en)
3.53
supervisor
experienced installer who is qualified by successfully completing the supervisor training course
3.54
Shore hardness
measure of surface hardness using a surface impresser or durometer
3.55
thermoset resin system
resin system that cannot be melted or remoulded following polymerization
3.56
Type A defect
defect within the substrate where, at the end of design lifetime, the remaining wall thickness will be ≥ 1 mm,
see Section 6.3.1
3.57
Type B defect
through-wall defect or a defect within the substrate where, at the end of design lifetime, the remaining wall
thickness will be < 1 mm, see Section 6.3.1
3.58
wrinkle
wavy surface or distinct ridge in the laminate where the reinforcing fabric has creased during application
4 Symbols and abbreviated terms
4.1 Units
°C degree Celsius
h hours
mm millimetre
MPa megapascal
N Newton
4.2 Symbols
A pressurised cross-sectional area as defined in Formula (9) mm
-1
α thermal expansion coefficient of substrate °C
s
-1
α thermal expansion coefficient of the repair laminate in the axial direction °C
a
-1
α thermal expansion coefficient of the repair laminate in the circumferential direction °C
c
B dimensionless regression gradient in Annex G.3
D original external diameter mm
D original external branch or nozzle diameter mm
b
d defect diameter (or diameter of the equivalent circle) mm
d peak wall loss due to corrosion in pipeline defect, equal to t-t mm
peak s
...