EN ISO 28721-4:2015
(Main)Vitreous and porcelain enamels - Glass-lined apparatus for process plants - Part 4: Quality requirements for glass-lined flanged steel pipes and flanged steel fittings (ISO 28721-4:2015)
General Information
- Abstract
ISO 28721-4:2015 specifies the quality requirements for glass-lined flanged steel pipes and flanged steel fittings used for process plants.
- Status
- Published
- Publication Date
- 17-Nov-2015
- Withdrawal Date
- 30-May-2016
- Technical Committee
- CEN/TC 262 - Metallic and other inorganic coatings
- Drafting Committee
- CEN/TC 262 - Metallic and other inorganic coatings
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 18-Nov-2015
- Completion Date
- 18-Nov-2015
Overview
EN ISO 28721-4:2015 specifies the quality requirements for glass-lined flanged steel pipes and flanged steel fittings used in process plants. This part of the ISO 28721 series focuses on vitreous and porcelain enamels applied to steel components, ensuring these glass-lined apparatus meet stringent standards suitable for various industrial processes. Developed by ISO/TC 107 and endorsed by CEN, this standard supports manufacturers and purchasers in achieving consistent, high-quality glass-lined steel products optimized for chemical resistance, durability, and mechanical integrity.
Key Topics
Scope and Application: Defines the quality criteria for flanged steel pipes and fittings within glass-lined apparatus used in chemical, pharmaceutical, food processing, and other process plant industrial applications.
Materials Requirements: Specifies the suitable steel substrate materials, which must comply with EN 13480-2, ensuring compatibility and suitability for enamelling processes.
Welding Specifications: Details requirements for welded joints on pipes and fittings, mandating full penetration welds compliant with ISO 5817 quality class B and EN 1708-1. Emphasizes monitoring and testing weld quality, ensuring local repair procedures maintain integrity.
Surface and Enamel Quality: Sets standards for surface preparation, enamel coating thickness, and tolerance levels. Enamel defects and foreign matter inclusion limits are defined to maintain corrosion resistance and long-term durability.
Testing and Certification: Describes testing protocols for substrate materials and enamel coatings, including chemical resistance tests aligned with other ISO references (ISO 2746, ISO 28706 series).
Marking and Documentation: Requires proper marking of products for traceability and insists on provision of material testing certificates per EN 10204.
Applications
Chemical Process Plants: Glass-lined flanged steel pipes and fittings are used in pipelines and reactor connections where resistance to aggressive chemicals and harsh environments is crucial.
Pharmaceutical Industry: Ensures hygienic, corrosion-resistant piping systems that comply with strict purity and quality standards.
Food and Beverage Sector: Suitable for process piping requiring durable, easy-to-clean, corrosion-resistant linings to maintain product integrity.
Water Treatment and Environmental Engineering: Supports durable infrastructure resistant to corrosion and chemical attack, extending plant lifecycle.
The standard serves as a benchmark for manufacturers, fabricators, and end-users who require reliable specifications for glass-lined steel components that reduce maintenance, enhance safety, and ensure longevity in demanding operational conditions.
Related Standards
ISO 28721 Series: Other parts in this series cover general quality requirements (Part 1), thermal and chemical resistance (Parts 2 and 3), and defect characterization (Part 5).
EN 13480 (Parts 2 and 3): Industrial piping standards detailing material selection, design, and calculation methods relevant for pipes and fittings subjected to pressure.
ISO 5817: Standard for welding quality levels applied to fusion-welded joints, essential for ensuring joint integrity.
ISO 2746: High voltage test methods to verify enamel coating quality and resistance.
EN 1708-1: Defines basic welded joint details for pressurized steel components, complementing welding requirements for glass-lined parts.
EN 10204: Specifies types of inspection certificates providing traceability for metallic products.
Utilizing EN ISO 28721-4:2015 ensures that glass-lined flanged steel pipes and fittings delivered for process plants meet international benchmarks for quality, durability, and safety-crucial for optimizing industrial plant performance and compliance.
Relations
- Effective Date
- 25-Nov-2015
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Refers
EN 1708-1:2010 - Welding - Basic welded joint details in steel - Part 1: Pressurized components - Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Get Certified
Connect with accredited certification bodies for this standard
DVS-ZERT GmbH
German welding certification society.
Institut za varilstvo d.o.o. (Welding Institute)
Slovenia's leading welding institute since 1952. ISO 3834, EN 1090, pressure equipment certification, NDT personnel, welder qualification. Only IIW Au
CARES (UK Certification Authority for Reinforcing Steels)
UK certification for reinforcing steels and construction.
Sponsored listings
Frequently Asked Questions
EN ISO 28721-4:2015 is a standard published by the European Committee for Standardization (CEN). Its full title is "Vitreous and porcelain enamels - Glass-lined apparatus for process plants - Part 4: Quality requirements for glass-lined flanged steel pipes and flanged steel fittings (ISO 28721-4:2015)". This standard covers: ISO 28721-4:2015 specifies the quality requirements for glass-lined flanged steel pipes and flanged steel fittings used for process plants.
ISO 28721-4:2015 specifies the quality requirements for glass-lined flanged steel pipes and flanged steel fittings used for process plants.
EN ISO 28721-4:2015 is classified under the following ICS (International Classification for Standards) categories: 23.040.60 - Flanges, couplings and joints; 25.220.50 - Enamels. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 28721-4:2015 has the following relationships with other standards: It is inter standard links to EN ISO 28721-4:2012, ISO 12944-5:2007, ISO 2746:2015, ISO 5817:2014, ISO 28706-2:2008, ISO 28706-4:2008, ISO 28706-5:2010, ISO 8501-1:2007, EN ISO 11691:2020, EN ISO 4628-7:2016, EN ISO 19496-1:2017, EN 10204:2004, EN 13480-3:2002, EN 1708-1:2010, EN 13480-2:2024. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 28721-4:2015 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
01-februar-2016
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Vitreous and porcelain enamels - Glass-lined apparatus for process plants - Part 4:
Quality requirements for glass-lined flanged steel pipes and flanged steel fittings (ISO
28721-4:2015)
Emails und Emaillierungen - Emaillierte Apparate für verfahrenstechnische Anlagen - Teil
4: Qualitätsanforderungen an Flansch-Rohre und Flansch-Formstücke aus Stahl mit
Emaillierung (ISO 28721-4:2015)
Émaux vitrifiés - Appareils émaillés pour les installations industrielles - Partie 4:
Exigences de qualité pour les tubes et raccords à brides en acier émaillé (ISO 28721-
4:2015)
Ta slovenski standard je istoveten z: EN ISO 28721-4:2015
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
25.220.50 Emajlne prevleke Enamels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 28721-4
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2015
EUROPÄISCHE NORM
ICS 25.220.50 Supersedes EN ISO 28721-4:2012
English Version
Vitreous and porcelain enamels - Glass-lined apparatus for
process plants - Part 4: Quality requirements for glass-
lined flanged steel pipes and flanged steel fittings (ISO
28721-4:2015)
Émaux vitrifiés - Appareils émaillés pour les Emails und Emaillierungen - Emaillierte Apparate für
installations industrielles - Partie 4: Exigences de verfahrenstechnische Anlagen - Teil 4:
qualité pour les tubes et raccords à brides en acier Qualitätsanforderungen an Flansch-Rohre und
émaillé (ISO 28721-4:2015) Flansch-Formstücke aus Stahl mit Emaillierung (ISO
28721-4:2015)
This European Standard was approved by CEN on 1 November 2015.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 28721-4:2015 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 27821-4:2015) has been prepared by Technical Committee ISO/TC 107
"Metallic and other inorganic coatings" in collaboration with Technical Committee CEN/TC 262
“Metallic and other inorganic coatings” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2016, and conflicting national standards shall be
withdrawn at the latest by May 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 28721-4:2012.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 28721-4:2015 has been approved by CEN as EN ISO 28721-4:2015 without any
modification.
INTERNATIONAL ISO
STANDARD 28721-4
Second edition
2015-11-01
Vitreous and porcelain enamels —
Glass-lined apparatus for process
plants —
Part 4:
Quality requirements for glass-lined
flanged steel pipes and flanged steel
fittings
Émaux vitrifiés — Appareils émaillés pour les installations
industrielles —
Partie 4: Exigences de qualité pour les tubes et raccords à brides en
acier émaillé
Reference number
ISO 28721-4:2015(E)
©
ISO 2015
ISO 28721-4:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2015 – All rights reserved
ISO 28721-4:2015(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Materials for steel parts . 2
5 Information to be supplied by the purchaser. 2
6 Requirements . 2
6.1 Requirements for the steel parts . 2
6.1.1 Welding . 2
6.1.2 Material properties . 2
6.1.3 Surface characteristics . 3
6.1.4 Exterior protection . 3
6.2 Requirements for the glass-lined components . 3
6.2.1 Surfaces . 3
6.2.2 Enamel defects . 3
6.2.3 Foreign matter in the enamel . . 3
6.2.4 Enamel coating thickness . 4
6.2.5 Dimensions and tolerances . 4
6.2.6 Other requirements . 4
7 Tests and certificates. 4
7.1 General . 4
7.2 Place of testing . 4
7.3 Testing of the substrate . 4
7.4 Testing of the glass-lined components . 4
8 Marking . 5
ISO 28721-4:2015(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
...