SIST EN 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
• Public Enquiry End Date: 16-Nov-2025
• Publication Date: 13-Oct-2026
• ICS: 75.180.20 - Processing equipment
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 12-Oct-2026
• Due Date: 17-Dec-2026
• Completion Date: 14-Oct-2026
• Ref Project: EN ISO 24817:2026 - Oil and gas industries including lower carbon energy - Composite repairs for piping - Qualification and design, installation, testing and integrity management (ISO 24817:2026)

• Revises: SIST EN ISO 24817:2017 - Petroleum, petrochemical and natural gas industries - Composite repairs for pipework - Qualification and design, installation, testing and inspection (ISO 24817:2017, Corrected version 2018-01-01)
• Effective Date: 02-Jul-2025

SIST EN ISO 24817:2026 is the SIST adoption of ISO 24817 for composite repairs for pipework in the oil and gas industries, including lower carbon energy. It specifies requirements and recommendations for the qualification, design, installation, testing and integrity management of external composite repair systems for corroded or damaged piping, pipelines, tanks and vessels.

What does SIST EN ISO 24817:2026 specify?

SIST EN ISO 24817:2026 applies to external composite repair systems used on corroded or damaged pipework, pipelines, tanks and vessels in the petroleum, petrochemical and natural gas industries. It is written for repair planning and execution after a defect has already been assessed and a decision to repair has been made.

The document is not a defect assessment standard. In practice, that means the user must first establish the defect condition and remaining wall or allowable pressure by another assessment method, then use this document for the repair design, installation and in-service management.

The document is organized into clauses 1 to 13, followed by annexes A to M.

Annex	What it covers
A	Design data sheet for the owner to complete
B	Qualification data and summary test reports
C	Short-term pipe spool survival test for Type A defects
D	Measurement of the interface toughness parameter, γ
E	Performance testing for long-term allowable strain, ε
F	Impact performance testing
G	Measurement of the degradation factor
H	Qualification for other defects based on substrate stress
I	Guidance for selecting defect size and geometry for Type B defects
J	Training, qualification and approval of installers and supervisors
K	Installation requirements and guidance
L	Design considerations and worked examples
M	Management of the integrity of composite repair systems

What are the key requirements of SIST EN ISO 24817:2026?

SIST EN ISO 24817:2026 treats a composite repair system as a combination of material family, surface preparation, filler, primer, repair laminate and curing procedure. Clause 6 matters because qualification, design and installation only work when those elements are controlled together, not as separate products.

Clause 6 places the owner and repair system supplier in a shared information flow. The owner passes design conditions, corrosion mechanism, inspection data, operating limits, upset conditions and site constraints to the supplier, using the design data sheet in Annex A. In practice, this prevents a repair from being designed on incomplete pressure, temperature or access information.

Clause 8 requires a feasibility assessment before design starts. The assessment looks at defect location and reliability of inspection data, pressure and temperature, internal contents and chemical compatibility, loads from supports or connections, repair lifetime, geometry, maintenance operations, safety hazards, personnel skills, installability, and failure consequences. This matters because some repairs are technically possible but too difficult, too risky or too hard to inspect over time.

Clause 8 also assigns the repair to a class. Class 1 covers lower-demand utility duties, Class 2 covers fire-water or deluge-type service without hydrocarbons, and Class 3 covers produced fluids and more onerous service. The class drives the design basis, qualification depth and the expected level of testing.

Clause 7 requires repair system qualification data from the supplier. The document requires material documentation, surface preparation documentation, short-term test data, and for Classes 2 and 3 long-term lap shear durability data. For the reader, this means the supplier has to prove the repair system is not just a material claim but a qualified process for a specific substrate and surface preparation method.

Clause 9 sets the design basis. The owner specifies the repair design lifetime and service life, the environmental compatibility is checked, and the maximum allowable temperature is tied to glass transition temperature (Tg) or heat distortion temperature (HDT). Cyclic loading is handled through a cyclic loading factor, and equivalent loads and equivalent pressure are calculated from the acting axial, shear and moment loads. In practice, the designer must convert the real operating case into a repair thickness and length, not just a nominal pressure rating.

Clause 9 separates defect design into Type A and Type B cases. Type A covers non-through-wall defects and uses load-sharing methods. Type B covers through-wall defects and uses defect size, repair laminate properties and interface toughness data, including the current defect, expected end-of-life defect, stop-gaps, filler and unprepared areas. Annex I helps choose the defect shape and size used in those calculations.

Clause 9 also covers other defect types and other components. Repairs for dents, gouges and crack-like features rely on substrate stress methods and, for qualifying life extension on similar defects, Annex H requires demonstration on the relevant defect type. For bends, tees, reducers, flanges, nozzles and tank or vessel features, the document applies thickness increase factors because geometry changes the local stresses.

Clause 10 controls installation. The repair has to be installed using the qualified procedure, with storage control, labeling, shelf-life control, suitable humidity and dew-point conditions, and the same surface preparation used in qualification. QA measurements, photographs and cure status records must be retained. This is important because adhesion and cure are the main field-controlled factors that determine whether the design assumptions remain valid.

Clause 11 defines ongoing integrity management. The owner must keep records, identify the repair, inspect the repair and substrate in service, define allowable defects, review repair lifetime, and revalidate, remove or replace the repair at the end of its life. Clause 12 then covers system testing, including hydro-testing after cure, with leakage treated as a rejection condition.

What terms does SIST EN ISO 24817:2026 define?

Composite - a thermoset resin system reinforced by fibres, used here as the structural repair material.

Repair system - the full combination of material family and application steps that form the repair, not just the laminate.

Design lifetime / repair design lifetime - the period used in design calculations and typically the maximum period the repair is expected to be needed.

Type A defect - a non-through-wall defect repaired by methods that share load between substrate and repair or let the repair carry the load.

Type B defect - a through-wall defect where the repair design is based on the pressurised area and interface toughness.

Closed free end piping - pipework that can move laterally and strain axially, also called unrestrained piping.

MAWP - maximum allowable working pressure, used as an input to repair design and defect assessment.

Barcol hardness - a surface hardness measure used as part of qualification and cure checking.

Who uses SIST EN ISO 24817:2026?

SIST EN ISO 24817:2026 is used by owners of piping, pipelines, tanks and vessels; repair system suppliers; installers; supervisors; and integrity, inspection and QA/QC personnel. It is relevant in petroleum, petrochemical and natural gas service, and also in utility piping systems where composite repairs are used.

Engineers use it to size the repair and choose the design route. Buyers and quality managers use it to check that a supplier has the right qualification data, training records, installation controls and inspection plan.

What changed in SIST EN ISO 24817:2026 from the previous edition?

SIST EN ISO 24817:2026 is shown on the page as corresponding to prEN ISO 24817 and to the ISO/DIS 24817:2025 draft designation in the document package.

Which standards are used with SIST EN ISO 24817:2026?

The document builds on several test and application standards.

• ISO 75-3, ISO 11357-2 and ISO 11359-2 - used for temperature, Tg/HDT and thermal expansion data for the repair system.
• ISO 527-1 and ISO 527-4 - used for tensile property testing of plastics and fibre-reinforced composites.
• ISO 868 - used for indentation hardness.
• ISO 10952 - used for chemical attack resistance testing.
• ISO 14692 - used for GRP piping context and cyclic loading treatment.
• ASTM C581, ASTM D543 and ASTM D696 - used in environmental compatibility and thermal expansion-related testing.
• ASTM D1599 and ASTM D1598 - used in pressure and survival testing within the annex methods.
• ISO 8501-1, ISO 8502 and ISO 8503 - used in surface condition and preparation guidance.
• ASME B31G, API RP 579, API 579-1 / ASME FFS-1 and PDAM - used as external defect assessment methods before the repair design starts.
• ASME PCC-2 Part 5 Article 501 - used as additional guidance for system pressure testing.

What does the SIST EN ISO 24817:2026 document contain?

SIST EN ISO 24817:2026 contains a design data sheet, qualification data tables, qualification test reports and detailed annex methods for Type A and Type B repairs. It also includes test setups for pipe spool survival, interface toughness, long-term strain, impact resistance, degradation factor and life-extension qualification for other defect types.

The document also provides installation checklists, storage and cure guidance, in-service inspection topics, allowable defect concepts and repair lifetime review steps. Annex L adds design flow guidance and worked examples, which are useful when turning defect data into repair thickness, axial extent, layer count and cure schedule.

SLOVENSKI STANDARD
01-december-2026
Naftna in plinska industrija, vključno z nizkoogljično energijo - Popravila
cevovodov s kompozitnimi materiali - Kvalifikacija in načrtovanje, montaža,
preskušanje in upravljanje celovitosti (ISO 24817:2026)
Oil and gas industries including lower carbon energy - Composite repairs for piping -
Qualification and design, installation, testing and integrity management (ISO
24817:2026)
Erdöl-, petrochemische und Erdgasindustrie - Reparatur von Rohrleitungen mit
Verbundwerkstoffen - Qualifizierung und Auslegung, Montage, Prüfung und Inspektion
(ISO 24817:2026)
Industries du petrole et du gaz, y compris les énergies à faible teneur en carbone -
Reparations en materiau composite pour tuyauterie - Conformite aux exigences de
performance et conception, installation, essai et gestion de l’intégrité (ISO 24817:2026)
Ta slovenski standard je istoveten z: EN ISO 24817:2026
ICS:
75.180.20 Predelovalna oprema Processing equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 24817
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2026
EUROPÄISCHE NORM
ICS 75.180.20 Supersedes EN ISO 24817:2017
English Version
Oil and gas industries including lower carbon energy -
Composite repairs for piping - Qualification and design,
installation, testing and integrity management (ISO
24817:2026)
Industries du petrole et du gaz, y compris les énergies Erdöl-, petrochemische und Erdgasindustrie -
à faible teneur en carbone - Reparations en materiau Reparatur von Rohrleitungen mit Verbundwerkstoffen
composite pour tuyauterie - Conformite aux exigences - Qualifizierung und Auslegung, Montage, Prüfung und
de performance et conception, installation, essai et Inspektion (ISO 24817:2026)
gestion de l'intégrité (ISO 24817:2026)
This European Standard was approved by CEN on 17 August 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 24817:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 24817:2026) has been prepared by Technical Committee ISO/TC 67 "Oil and
gas industries including lower carbon energy" in collaboration with Technical Committee CEN/TC 12
“Oil and gas industries including lower carbon energy” the secretariat of which is held by NEN.
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 March 2027, and conflicting national standards shall
be withdrawn at the latest by March 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 24817:2017.
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 24817:2026 has been approved by CEN as EN ISO 24817:2026 without any modification.

International
Standard
ISO 24817
Third edition
Oil and gas industries including
2026-09
lower carbon energy — Composite
repairs for piping — Qualification
and design, installation, testing and
integrity management
Industries du petrole et du gaz, y compris les énergies à faible
teneur en carbone — Reparations en materiau composite pour
tuyauterie — Conformite aux exigences de performance et
conception, installation, essai et gestion de l’intégrité
Reference number
ISO 24817:2026(en) © ISO 2026
ISO 24817:2026(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 24817:2026(en)
Contents Page
Foreword .vi
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms. 7
4.1 Symbols .7
4.2 Abbreviated terms .10
5 Applications .11
6 Summary of key issues .13
6.1 General . 13
6.2 Repair system qualification . 13
6.3 Enquiry stage . 13
6.4 Design of repair. 13
6.4.1 General . 13
6.4.2 Type A and Type B design cases .14
6.5 Installer training . 15
6.6 Installation of repair .16
6.7 Ongoing integrity management of the repaired system .16
7 Qualification . 16
7.1 Repair system qualification data .16
7.2 Re-qualification of the repair system .18
7.2.1 Overview .18
7.2.2 For Type A defect repairs .18
7.2.3 For Type B defect repairs .18
8 Repair feasibility assessment .18
8.1 General .18
8.2 Repair class . 20
8.3 Required data . 20
8.3.1 Background . 20
8.3.2 Original equipment design data . 20
8.3.3 Maintenance and operational histories .21
8.3.4 Service condition data .21
9 Design methodology .21
9.1 Design lifetime and initial service life .21
9.2 Environmental compatibility . 22
9.3 Design temperature effects. 23
9.4 Cyclic loading .24
9.5 Determination of design strains .24
9.5.1 General .24
9.5.2 Design strains based on default allowable strains . 25
9.5.3 Design strains based on performance testing . 25
9.6 Determination of equivalent load and equivalent pressure . 25
9.7 Design of repairs for Type A defects . 26
9.7.1 General . 26
9.7.2 Design limited by substrate allowable stress. 26
9.7.3 Design limited by composite laminate design strain, substrate shares loads .27
9.7.4 Design limited by composite laminate design strain, composite laminate carries
all loads . 28
9.8 Design of repairs for Type B defects . 28
9.8.1 General . 28

iii
ISO 24817:2026(en)
9.8.2 Determination of service factor, f . 29
leak
9.8.3 Circular or near-circular defects . 29
9.8.4 Slot-type defects in the circumferential direction . 29
9.8.5 Slot-type defects in the axial direction . 30
9.9 External loads .31
9.10 Other defects (with assessments based on substrate stress) .31
9.11 Repair of other components .32
9.12 Axial extent of repair . 33
9.12.1 General . 33
9.12.2 Patches . 34
9.13 Calculation of the composite laminate thickness, t . 34
d
9.14 Confirmation that composite laminate thickness is within acceptable limits . 34
9.14.1 General . 34
9.14.2 Maximum acceptable value of t . 35
d
9.14.3 Maximum allowable design pressure for tees or nozzles . 35
9.14.4 Potential for repair disbonding . 35
9.15 Calculation of total repair length . 36
9.16 Design output. 36
9.17 Optional design considerations . 36
9.17.1 Fire performance . 36
9.17.2 Cathodic disbonding .37
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 .38
10.1 Storage conditions . 38
10.2 Documentation prior to repair application . 38
10.2.1 Method statement . 38
10.2.2 Work pack . 39
10.3 Installer and supervisor qualifications . 40
10.4 Installation procedure . 40
10.5 Repair completion documentation .41
10.6 Live repairs .42
10.7 Repair of clamps, piping components, tanks, or vessels.43
10.8 Environmental considerations .43
10.9 Repair of defects within the repair system .43
11 Ongoing integrity management .43
11.1 General .43
11.2 Record keeping . 44
11.3 In-service inspection . 44
11.4 Allowable defects for the repair system .45
11.5 Repair system maintenance and remedial options . 48
11.5.1 Overview . 48
11.5.2 Substrate adjacent to the repair . 49
11.5.3 Repairs to Type A defects . 49
11.5.4 Repairs to Type B defects . 49
11.5.5 Repair system . 49
11.6 Repair lifetime considerations . 50
11.6.1 Periodic review . 50
11.6.2 Lifetime reduction .51
11.6.3 Lifetime extension .51
11.7 Modifications .51
12 System testing . 51
13 Decommissioning .52
Annex A (informative) Design data sheet.53

iv
ISO 24817:2026(en)
Annex B (normative) Qualification data .56
Annex C (normative) Short-term pipe spool survival test . 61
Annex D (normative) Measurement of γ for through-wall defect calculation .63
LCL
Annex E (normative) Measurement of performance test data .68
Annex F (normative) Measurement of impact performance .70
Annex G (normative) Measurement of the degradation factor .71
Annex H (normative) Qualification of repair systems for other defects (with assessments based
on substrate stress) .73
Annex I (informative) Guidance on the selection of the appropriate defect size and geometry
for through-wall defects (Type B defect) . 76
Annex J (normative) Installer qualification .89
Annex K (normative) Installation requirements and guidance .92
Annex L (informative) Design considerations.95
Annex M (informative) Management of the integrity of composite repair systems to piping and
vessels .102
Bibliography .106

v
ISO 24817:2026(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 6, Process equipment, piping, systems, and related safety, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 12, Oil and gas industries
including lower carbon energy, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 24817:2017), which has been technically
revised.
The main changes are as follows:
— Clause 7 has been split into three separate Clauses: 7 (Qualification), 8 (Repair feasibility assessment)
and 9 (Design methodology) to enable clear referencing;
— in Clause 9, the individual design stages have been reorganised so that they are now presented in the
sequence they are used to make it easier to follow and review;
— where multiple options for design are presented, clarification has been added to guide on when each
should be selected;
— design lifetimes of up to 50 years can now be considered and the guidance on managing them in service
has been reinforced;
— requirements for considering temperature effects have been clarified;
— assessment of cyclic loading has been updated to maintain equivalence with guidance in ISO 14692;
— Poisson’s effects have been reviewed and updated;
— Type A design formulae have been re-arranged so that they can be calculated rather than some requiring
iteration;
— considerations of installing repairs on live lines (under pressure) have been revised;

vi
ISO 24817:2026(en)
— guidance on using composite materials to reinforce defects such as crack-like-flaws has been added;
— the test method for determining the value of design strain specified in Annex E has been revised to
remove the influence of the substrate in testing;
— units for variables has been standardised throughout. The main change is for the value of energy release
-2
rate, γ , which will now be in N mm rather than J m ;
LCL
— Annex I has been added to provide guidance on how to assess requirements for applying repairs to Type
B defects.
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.

vii
ISO 24817:2026(en)
Introduction
The objective of this document is to ensure that piping, pipelines, tanks and vessels repaired using
composite systems that are qualified, designed, installed and managed using this document meet the
specified performance requirements. The main users of this document are plant and equipment owners,
design contractors, suppliers contracted to provide the repair system, certifying authorities, installation,
maintenance and inspection contractors.

viii
International Standard ISO 24817:2026(en)
Oil and gas industries including lower carbon energy —
Composite repairs for piping — Qualification and design,
installation, testing and integrity management
1 Scope
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.
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 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and extrusion
plastics
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 8501 (all parts), Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness
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 D638, Standard Test Method for Tensile Properties of Plastics
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

ISO 24817:2026(en)
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
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, Glass reinforced plastics — Determination of indentation hardness by means of a Barcol hardness tester
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 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
Barcol hardness
measure of surface hardness using a surface impresser
3.2
blister
air void between layers (3.23) within the laminate (3.4) visible on the surface as a raised area
3.3
composite
thermoset resin system (3.49) that is reinforced by fibres

ISO 24817:2026(en)
3.4
composite laminate
laminate
repair laminate
part of a repair system (3.39) that is the composite (3.3)
Note 1 to entry: Most composites considered in this document are composed of discrete lamina or layers (3.23) which
are wrapped or stacked, one on top of the other. This stacked construction is the laminate.
3.5
crack
split in the composite laminate (3.4) extending perpendicular to the surface such that there is actual
separation with opposite surfaces
3.6
cure
setting of a thermoset resin system (3.49), such as polyester or epoxy, by an irreversible chemical reaction
3.7
cure schedule
time-temperature profile qualified to generate a specified glass transition temperature (3.17), T , or heat
g
distortion temperature (HDT) (3.19)
3.8
delamination
area of separation between layers (3.23) in the composite laminate (3.4)
3.9
design lifetime
period of time used in the design calculations that is 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 (3.44) of the repaired system.
3.10
design temperature
maximum temperature for which the repair is designed (the highest temperature the component to be
repaired is expected to experience in service)
3.11
differential scanning calorimetry
DSC
method of determining the glass transition temperature (3.17) of a thermosetting resin
3.12
disbond
interfacial delamination
area between the composite laminate (3.4) and the substrate (3.46) which should be bonded but where no
bond exists
3.13
exposed fibre
area of fibre not impregnated with resin that projects from the body of the repair
3.14
filler material
material used to repair external surface imperfections prior to the application of the composite laminate
(3.4)
3.15
foreign matter
any substance other than the reinforcing fibre or other materials that form part of the repair system (3.39)

ISO 24817:2026(en)
3.16
finishing materials
final layer of material to help compact the composite laminate (3.4), 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.
3.17
glass transition temperature
temperature at which a resin undergoes a marked change in physical properties
3.18
hardener
component added to a thermosetting resin to effect cure (3.6)
3.19
heat distortion temperature
HDT
temperature at which a standard test bar deflects by a specified amount under a given load
3.20
inspection authority
entity responsible for verifying the repair complies with the requirements
3.21
installer
person who is qualified to apply a repair system (3.39)
3.22
installation temperature
expected substrate (3.46) (component) surface temperature at the time of repair installation
3.23
layer
single, individual lamina of the composite laminate (3.4)
3.24
leak
perforation in the substrate (3.46) with loss of containment
3.25
material group
substrate family
class of metallurgical alloys or materials whose members have similar chemical compositions
EXAMPLE Cast irons, carbon steels, austenitic stainless steels, glass reinforced epoxy resin (GRE), glass
reinforced vinyl ester (GRVE) and glass reinforced u
...