SIST EN ISO 15741:2021

Paints and varnishes - Friction-reduction coatings for the interior of on- and offshore steel pipelines for non-corrosive gases (ISO 15741:2016)

This document specifies requirements and methods of test for liquid epoxy paints and internal coatings of such paints in steel pipes and fittings for the conveyance of non-corrosive gas. It also deals with the application of the paint. Other paints or paint systems are not excluded provided they comply with the requirements given in this document. The coating consists of one layer, which is normally shop-applied on blast-cleaned steel by airless spray or other suitable spraying techniques. The applied and cured paint film must be smooth to give the desired reduction in friction. Brush application is only used for small repair jobs.

Beschichtungsstoffe - Reibungsreduzierende Beschichtungen für das Innere von Stahlrohrleitungen im On- und Offshore-Bereich für nicht korrosive Gase (ISO 15741:2016)

Peintures et vernis – Revêtements réduisant le frottement pour l'intérieur de gazoducs en acier enterrés et immergés pour le transport de gaz non corrosifs (ISO 15741:2016)

Barve in laki - Premazi za zmanjšanje trenja v notranjosti jeklenih cevovodov na kopnem in na morju za nekorozivne pline (ISO 15741:2016)

General Information

• Status: Published
• Public Enquiry End Date: 02-Nov-2020
• Publication Date: 02-Mar-2021
• ICS: 87.020 - Paint coating processes
• ICS: 87.040 - Paints and varnishes
• Technical Committee: IBLP - Paints and varnishes
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 25-Feb-2021
• Due Date: 02-May-2021
• Completion Date: 03-Mar-2021
• Ref Project: EN ISO 15741:2021 - Paints and varnishes - Friction-reduction coatings for the interior of on- and offshore steel pipelines for non-corrosive gases (ISO 15741:2016)

Overview

EN ISO 15741:2021 (ISO 15741:2016 adopted by CEN) specifies requirements and test methods for friction‑reduction coatings - principally liquid epoxy paints - applied to the interior of on‑ and offshore steel pipelines used to transport non‑corrosive gases. The standard covers material qualification, application (normally shop‑applied), production control, testing of cured films and operational handling, including packaging, storage and repairs. The coating is typically a single, smooth, spray‑applied layer (airless spray or equivalent); brush application is restricted to small repairs.

Key topics and requirements

• Coating material specification
  • Qualification parameters: non‑volatile matter (mass/volume), viscosity, density, pot life, ash (residue on ignition), infrared spectrograms, appearance.
• Cured film properties and tests
  • Dry film thickness measurement, adhesion, Buchholz hardness, bend (conical mandrel) test, resistance to neutral salt spray, artificial ageing, water immersion, chemical resistance, resistance to gas pressure variations, hydraulic blistering.
  • Normative test methods and annexes: ash determination, porosity, curing test, wet‑sponge test, pressure and blistering procedures.
• Application and surface preparation
  • Surface preparation of blast‑cleaned steel, paint preparation, recommended application techniques (shop spray), and requirements to achieve a smooth cured film for friction reduction.
• Production control and quality assurance
  • On‑pipe and panel assessment (appearance, thickness, adhesion), batch test certificates, product data sheets, qualification and quality records.
• Handling and logistics
  • Storage, transportation, handling of coated pipes and guidance for loading and repair procedures.

Applications and users

• Practical uses:
  • Internal friction‑reduction coatings in transmission pipelines (onshore and offshore) conveying non‑corrosive gases where reduced hydraulic/friction losses are required.
  • Shop application during pipe fabrication to improve flow efficiency and protect against minor handling damage.
• Primary users:
  • Pipeline owners and operators, epoxy coating manufacturers, pipe fabricators, coatings applicators, QA/QC engineers, inspection bodies and procurement/specification writers involved in gas pipeline projects.

Related standards and committees

• Developed by ISO/TC 35 “Paints and varnishes” and adopted by CEN/TC 139 “Paints and varnishes”.
• EN ISO 15741:2021 aligns with ISO 15741:2016; users should coordinate with other industry standards for pipeline engineering, corrosion protection and project specifications.

Keywords: EN ISO 15741:2021, friction‑reduction coatings, epoxy paints, internal pipeline coatings, onshore offshore steel pipelines, non‑corrosive gases, dry film thickness, adhesion, surface preparation, production control.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2021
Barve in laki - Premazi za zmanjšanje trenja v notranjosti jeklenih cevovodov na
kopnem in na morju za nekorozivne pline (ISO 15741:2016)
Paints and varnishes - Friction-reduction coatings for the interior of on- and offshore
steel pipelines for non-corrosive gases (ISO 15741:2016)
Beschichtungsstoffe - Reibungsreduzierende Beschichtungen für das Innere von
Stahlrohrleitungen im On- und Offshore-Bereich für nicht korrosive Gase (ISO
15741:2016)
Peintures et vernis Revêtements réduisant le frottement pour l'intérieur de gazoducs en
acier enterrés et immergés pour le transport de gaz non corrosifs (ISO 15741:2016)
Ta slovenski standard je istoveten z: EN ISO 15741:2021
ICS:
87.040 Barve in laki Paints and varnishes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 15741
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2021
EUROPÄISCHE NORM
ICS 87.020
English Version
Paints and varnishes - Friction-reduction coatings for the
interior of on- and offshore steel pipelines for non-
corrosive gases (ISO 15741:2016)
Peintures et vernis - Revêtements réduisant le Beschichtungsstoffe - Reibungsreduzierende
frottement pour l'intérieur de gazoducs en acier Beschichtungen für das Innere von Stahlrohrleitungen
enterrés et immergés pour le transport de gaz non im On- und Offshore-Bereich für nicht korrosive Gase
corrosifs (ISO 15741:2016) (ISO 15741:2016)
This European Standard was approved by CEN on 18 January 2021.

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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15741:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 15741:2016 has been prepared by Technical Committee ISO/TC 35 "Paints and
varnishes” of the International Organization for Standardization (ISO) and has been taken over as
which is held by DIN.
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 August 2021, and conflicting national standards shall
be withdrawn at the latest by August 2021.
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.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 15741:2016 has been approved by CEN as EN ISO 15741:2021 without any modification.

INTERNATIONAL ISO
STANDARD 15741
Second edition
2016-11-15
Paints and varnishes — Friction-
reduction coatings for the interior of
on- and offshore steel pipelines for
non-corrosive gases
Peintures et vernis — Revêtements réduisant le frottement pour
l’intérieur de gazoducs en acier enterrés et immergés pour le
transport de gaz non corrosifs
Reference number
ISO 15741:2016(E)
©
ISO 2016
ISO 15741:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 15741:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Coating material . 2
4.1 General . 2
4.2 Particular requirements for qualification of the coating material . 3
4.2.1 General. 3
4.2.2 Non-volatile matter (by mass) . 3
4.2.3 Non-volatile matter (by volume) . 3
4.2.4 Viscosity . 3
4.2.5 Density . 3
4.2.6 Ash (residue on ignition) . 3
4.2.7 Pot life. 4
4.2.8 Infrared spectrograms . 4
4.2.9 Appearance . 4
4.3 Particular requirements for qualification of the cured paint film . 4
4.3.1 Preparation of test panels . 4
4.3.2 Conditioning of test panels . 4
4.3.3 Dry film thickness . 5
4.3.4 Adhesion . 5
4.3.5 Buchholz hardness . 5
4.3.6 Resistance to neutral salt spray . 5
4.3.7 Resistance to artificial ageing . 5
4.3.8 Bend test (conical mandrel) . 5
4.3.9 Resistance to gas pressure variations. 5
4.3.10 Resistance to water immersion . 6
4.3.11 Resistance to chemicals . 6
4.3.12 Resistance to hydraulic blistering . 6
4.4 Packaging, labelling and storing . 6
4.5 Quality assurance. 6
4.6 Product data sheet . 6
4.7 Qualification certificate . 7
4.8 Batch test certificate . 8
5 Application of the coating material . 9
5.1 General . 9
5.2 Surface preparation .10
5.3 Paint preparation .10
5.4 Paint application .10
6 Production control .11
6.1 Assessment of the coating on the pipes .11
6.1.1 Appearance .11
6.1.2 Dry film thickness .11
6.2 Assessment of the coating on steel panels .11
6.2.1 Preparation of test panels .11
6.2.2 Adhesion .11
6.2.3 Buchholz hardness .11
6.2.4 Bend test .11
6.2.5 Curing test .11
6.2.6 Porosity test .11
7 Repairs .12
ISO 15741:2016(E)
8 Handling, transportation and storage.12
8.1 Handling.12
8.2 Transportation to the storage area .12
8.3 Storage .12
8.4 Loading coated pipes for transportation .12
Annex A (normative) Determination of ash (refer to 4.2.5) .13
Annex B (normative) Dry film thickness (refer to 6.1.2) .14
Annex C (normative) Resistance to gas pressure variations (refer to 4.3.9) .15
Annex D (normative) Hydraulic-pressure blistering (refer to 4.3.12) .18
Annex E (normative) Porosity of a film of the coating material on a glass panel (refer to 6.2.6) .20
Annex F (normative) Curing test (refer to 6.2.5) .21
Annex G (normative) Wet-sponge test (refer to 6.2.6) .22
Bibliography .23
iv © ISO 2016 – All rights reserved

ISO 15741:2016(E)
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 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.
The committee responsible for this document is ISO/TC 35, Paints and varnishes, Subcommittee SC 14,
Protective paint systems for steel structures.
This second edition cancels and replaces the first edition (ISO 15741:2001), which has been technically
revised.
ISO 15741:2016(E)
Introduction
Internal coating of pipelines is used to reduce friction and improve the flow conditions when conveying
non-corrosive gases, and to offer sufficient corrosion protection during storage and transport of the
pipes. The reduction in friction depends on various parameters like the pressure and temperature of
the gas, and the diameter of the pipe. Therefore, it is not possible to give a single figure for this reduction
in friction.
In order to establish sufficient corrosion protection and to ensure optimum performance of the internal
coating in the steel pipes, it is necessary for owners of pipelines, planners, consultants, companies
carrying out the work, inspectors of protective coatings and manufacturers of coating materials to have
at their disposal state-of-the-art information in concise form including requirements for the coating.
Such information has to be as complete as possible, unambiguous and easily understandable to avoid
difficulties and misunderstandings between the parties concerned.
vi © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 15741:2016(E)
Paints and varnishes — Friction-reduction coatings for
the interior of on- and offshore steel pipelines for non-
corrosive gases
1 Scope
This document specifies requirements and methods of test for liquid epoxy paints and internal coatings
of such paints in steel pipes and fittings for the conveyance of non-corrosive gas. It also deals with the
application of the paint. Other paints or paint systems are not excluded provided they comply with the
requirements given in this document. The coating consists of one layer, which is normally shop-applied
on blast-cleaned steel by airless spray or other suitable spraying techniques. The applied and cured
paint film must be smooth to give the desired reduction in friction. Brush application is only used for
small repair jobs.
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 2409, Paints and varnishes — Cross-cut test
ISO 2811 (all parts), Paints and varnishes — Determination of density
ISO 2812-1:2007, Paints and varnishes — Determination of resistance to liquids — Part 1: Immersion in
liquids other than water
ISO 2812-2, Paints and varnishes — Determination of resistance to liquids — Part 2: Water immersion method
ISO 2815, Paints and varnishes — Buchholz indentation test
ISO 3233-1, Paints and varnishes — Determination of the percentage volume of non-volatile matter —
Part 1: Method using a coated test panel to determine non-volatile matter and to determine dry film density
by the Archimedes principle
ISO 3251, Paints, varnishes and plastics — Determination of non-volatile-matter content
ISO 6743-4, Lubricants, industrial oils and related products (class L) — Classification — Part 4: Family H
(Hydraulic systems)
ISO 6860, Paints and varnishes — Bend test (conical mandrel)
ISO 8501-1, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates
and of steel substrates after overall removal of previous coatings
ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO
surface profile comparators for the assessment of abrasive blast-cleaned surfaces
ISO 8503-2, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 2: Method for the grading of surface
profile of abrasive blast-cleaned steel — Comparator procedure
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 15741:2016(E)
ISO 19840:2012, Paints and varnishes — Corrosion protection of steel structures by protective paint
systems — Measurement of, and acceptance criteria for, the thickness of dry films on rough surfaces
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
coater
company which is responsible for application of the coating material in accordance with the provisions
of this document
3.2
coating material manufacturer
supplier of the coating material
3.3
dry film thickness
DFT
thickness of a coating remaining on the surface when the coating has hardened/cured
[SOURCE: ISO 12944-5:2007, 3.10]
3.4
natural gas
complex gaseous mixture of hydrocarbons, primarily methane, but generally also including ethane,
propane and higher hydrocarbons in much smaller amounts and some non-combustible gases, such as
nitrogen and carbon dioxide
[SOURCE: ISO 14532:2014, 2.1.1.1]
3.5
nominal dry film thickness
NDFT
dry film thickness specified for each coat or for the whole paint system
[SOURCE: ISO 12944-5:2007, 3.11]
3.6
pinhole
film defect characterized by small pore-like flaws in a coating which extend entirely through the
applied film and have the general appearance of pinpricks when viewed by reflected light
3.7
purchaser
organization or individual that buys the coated pipes and fittings
4 Coating material
4.1 General
The coating material shall typically be a two-pack epoxy paint. It shall not contain any substances which
will be released from the paint film after it has cured and are proven to be detrimental to the operation
of the pipeline and the quality of the gas.
2 © ISO 2016 – All rights reserved

ISO 15741:2016(E)
Unless otherwise agreed, the coating material shall be qualified in accordance with 4.2 and 4.3 and
shall not be changed after qualification.
The manufacturer of the coating material shall provide on request infrared spectrograms of the base
component and the curing agent component (see 4.2.8).
In addition, the manufacturer shall provide a product data sheet (see 4.6), a health and safety data sheet
and a certificate stating the test results obtained in accordance with 4.2 and 4.3, respectively, and, if
applicable, deviating test conditions.
The manufacturer shall also provide with every batch of the coating material a batch test certificate
stating the information as given in 4.8.
Unless otherwise agreed, the applied coating shall provide corrosion protection during storage and
transport for a minimum period of one year without significant breakdown of the coating.
The typical operating-temperature range for this type of coating is between −20 °C and 110 °C.
Where, subsequently, external coatings have to be applied, care shall be taken not to allow the internal
coating to be damaged by the elevated temperatures which may occur.
4.2 Particular requirements for qualification of the coating material
4.2.1 General
The following subclauses describe the laboratory test methods which are required for qualification of
the coating material.
4.2.2 Non-volatile matter (by mass)
When determined in accordance with ISO 3251, the non-volatile matter (by mass) of the coating
material shall comply with the value specified by the coating material manufacturer in the qualification
certificate (Table 2).
4.2.3 Non-volatile matter (by volume)
When determined in accordance with ISO 3233-1, the non-volatile matter (by volume) of the coating
material shall comply with the value specified by the coating material manufacturer in the product
data sheet (Table 1).
4.2.4 Viscosity
When determined by the method specified by the manufacturer, the viscosity of the ready-mixed
coating material shall comply with the value specified by the coating material manufacturer in the
qualification certificate (Table 2).
4.2.5 Density
When determined in accordance with one of the parts of the ISO 2811 series, the density of the coating
material shall comply with the value specified by the coating material manufacturer in the product
data sheet (Table 1).
4.2.6 Ash (residue on ignition)
When determined in accordance with the method described in Annex A, the ash (residue on ignition) of
the coating material shall comply with the value specified by the coating material manufacturer in the
qualification certificate (Table 2).
ISO 15741:2016(E)
4.2.7 Pot life
The pot life is considered to be the time taken by the ready-mixed coating material to reach a condition
at which it can no longer be applied satisfactorily. The pot life shall be specified in the product data
sheet (see 4.6).
4.2.8 Infrared spectrograms
Infrared spectrograms of the base component and the curing agent component shall be submitted on
request.
4.2.9 Appearance
The appearance and continuity of the coating shall be inspected visually without any magnification.
4.3 Particular requirements for qualification of the cured paint film
4.3.1 Preparation of test panels
Perform the tests specified in 4.3.3 to 4.3.12 on coatings applied to the required dry film thickness
specified in 4.3.3 by spraying on to test panels (steel or glass). Prepare steel test panels as specified in
5.2 and glass panels as specified in Annex E. Apply the paint in accordance with the instructions of the
coating material manufacturer. Perform each test at least in duplicate.
4.3.2 Conditioning of test panels
If specified, condition the coated test panels using one of the following cycles, depending on the
substrate and on the individual test. Cycle B and cycle C are optional and the choice of the conditioning
cycle depends on the time available to perform the test procedure.
Cycle A
Substrate: steel or glass
— condition at 18 °C to 25 °C and ≤80 % relative humidity until the coating is at least tack-free;
— dry for 30 min in a circulating-air oven at (75 ± 2) °C;
— condition for a minimum of 30 min at 18 °C to 25 °C and ≤80 % relative humidity before testing.
Cycle B
Substrate: steel or glass
— condition at 18 °C to 25 °C and ≤80 % relative humidity until the coating is at least tack-free;
— dry for 30 min in a circulating-air oven at (150 ± 2) °C;
— condition for a minimum of 30 min at 18 °C to 25 °C and ≤80 % relative humidity before testing.
Cycle C
Substrate: steel or glass
— condition at 18 °C to 25 °C and ≤ 80 % relative humidity until the coating is at least tack-free;
— dry for 30 min in a circulating-air oven at (40 ± 2) °C;
— condition for a minimum of 30 min at 18 °C to 25 °C and ≤80 % relative humidity before testing.
4 © ISO 2016 – All rights reserved

ISO 15741:2016(E)
4.3.3 Dry film thickness
Unless otherwise agreed, the dry film thickness of the coating, applied on a glass or steel panel, shall be
between 60 µm and 100 µm except for the test described in 4.3.6 (resistance to neutral salt spray).
Unless otherwise agreed, the dry film thickness shall be measured in accordance with ISO 19840.
4.3.4 Adhesion
When determined in accordance with ISO 2409, the cross-cut classification of the coating applied on
steel panels and conditioned using cycle B or C (see 4.3.2) shall be equal to or lower than 1.
4.3.5 Buchholz hardness
When determined in accordance with ISO 2815, the Buchholz hardness of the coating, applied on glass
or steel panels and conditioned using cycle B or C (see 4.3.2) shall have a value of 94 or more.
4.3.6 Resistance to neutral salt spray
The coating, applied on steel panels with a dry film thickness of 60 µm to 75 µm, conditioned using
cycle B or C (see 4.3.2), and with an X-cut down to the substrate located at least 20 mm from any edge,
shall be tested in accordance with ISO 9227 for 480 h.
After the test, allow the test panels to dry for at least 30 min at 18 °C t
...