EN 14728:2019
(Main)Imperfections in thermoplastic welds - Classification
Imperfections in thermoplastic welds - Classification
This document specifies a system for classifying imperfections that may be encountered in thermoplastic welded joints during manufacture and provides examples of imperfections for the following welding processes:
- heated tool butt welding;
- heated tool socket welding;
- electrofusion socket welding;
- hot gas welding;
- extrusion welding;
- solvent socket welding.
This document does not describe imperfections that may be generated during service or imperfections present before welding, which are due to poor preparation or assembly of components (e.g. fit up). The correct preparation and assembly of components (e.g. fit up) are described in the relevant welding procedure specification (WPS).
This document is also not concerned with the search for the possible influence of these imperfections on the behaviour of joints in relation to the different types of stress to which the latter may be subjected or on methods for preventing such imperfections.
This document can be used in conjunction with EN 16296 [1] to determine the acceptance of welds.
Only imperfections giving rise to discontinuities of materials or changes in shape are taken into consideration in this document, specifying their type, their shape and their positions. This classification can be used to determine the possible origin or causes of the imperfections.
Unregelmäßigkeiten an Schweißverbindungen von thermoplastischen Kunststoffen - Einteilung
Dieses Dokument legt ein System zur Einteilung von Unregelmäßigkeiten, die während der Herstellung in Schweißverbindungen von thermoplastischen Kunststoffen auftreten können, fest und enthält Beispiele von Unregelmäßigkeiten für die folgenden Schweißverfahren:
- Heizelementstumpfschweißen;
- Heizelementmuffenschweißen;
- Heizwendelmuffenschweißen (E-Muffenschweißen);
- Warmgasschweißen;
- Extrusionsschweißen;
- Klebemuffenschweißen (Diffusionskleben).
Dieses Dokument beschreibt keine Unregelmäßigkeiten, die während des Betriebs entstehen können oder vor dem Schweißen vorhanden sind, die auf mangelhafte Vorbereitung oder Zusammensetzung der Bestand¬teile (z. B. mangelhafte Passung) zurückzuführen sind. Die ordnungsgemäße Vorbereitung und Zusammen¬setzung der Komponenten (z. B. Passung) ist in der entsprechenden Schweißanweisung (WPS, en: Welding Procedure Specification) beschrieben.
Dieses Dokument befasst sich auch nicht mit der Suche nach möglichen Auswirkungen dieser Unregel-mäßigkeiten auf das Verhalten von Verbindungen in Bezug auf die unterschiedlichen Belastungen, denen diese Verbindungen ausgesetzt sein können, oder mit Verfahren zur Vermeidung solcher Unregelmäßig-keiten.
Dieses Dokument kann im Zusammenhang mit EN 16296 [1] für die Bewertung von Schweißnähten ver-wendet werden.
Nur Unregelmäßigkeiten, die Inhomogenitäten der Werkstoffe oder Formveränderungen zur Folge haben, sind in diesem Dokument berücksichtigt und zwar unter Angabe ihrer Art, ihrer Form und ihrer Lage. Diese Einteilung kann zur Bestimmung des möglichen Ursprungs oder der Ursachen von Unregelmäßigkeiten ver¬wendet werden.
Défauts dans les assemblages soudés en thermoplastiques - Classification
Le présent document spécifie un système de classification des défauts susceptibles d’être rencontrés dans les assemblages soudés en thermoplastiques lors de la fabrication et fournit des exemples de défauts pour les procédés de soudage suivants :
- soudage bout à bout par élément chauffant ;
- soudage d’emboîture par élément chauffant ;
- soudage d’emboîture par électrofusion ;
- soudage au gaz chaud ;
- soudage par extrusion ;
- soudage d’emboîture par adhésif.
Le présent document ne décrit pas les défauts qui pourraient être générés au cours du service ni les défauts présent avant le soudage, qui sont causés par une mauvaise préparation ou un mauvais assemblage des composants (par exemple, l'ajustement). La bonne préparation et le bon assemblage des composants (par exemple, l’ajustement) sont décrits dans la spécification des modes opératoires de soudage (WPS) correspondante.
Le présent document ne traite également pas de la recherche de l’éventuelle influence de ces défauts sur le comportement des assemblages en fonction des différents types de contraintes auxquels ces derniers peuvent être soumis ni sur les méthodes pour éviter de tels défauts.
Le présent document peut être utilisé conjointement avec l'EN 16296 [1] pour déterminer l’acceptation des soudures.
Seuls les défauts donnant lieu à des discontinuités de matériau ou à des modifications de forme sont pris en compte dans le présent document, en spécifiant leur type, leur forme et leurs positions. Cette classification peut être utilisée pour déterminer les possibles origines ou causes des défauts.
Napake v plastomernih zvarih - Razvrstitev
Ta evropski standard določa sistem za razvrstitev napak, ki se lahko pojavijo v plastomernih zvarnih spojih med izdelavo, in podaja primere napak pri naslednjih postopkih varjenja:
– soležno varjenje z ogrevanim orodjem;
– obojno varjenje z ogrevanim orodjem;
– elektrofuzijsko obojno varjenje;
– varjenje z vročim plinom;
– ekstrudersko varjenje;
– obojno varjenje s topilom.
Ta dokument ne opisuje napak, ki se lahko pojavijo med uporabo, ali napak, ki so prisotne pred varjenjem, kot je npr. slabo prileganje. Pravilna priprava (npr. prileganje) je opisana v ustrezni specifikaciji varilnega postopka (WPS). Ta dokument prav tako ne obravnava iskanja morebitnega vpliva teh napak na obnašanje spojev v povezavi z različnimi vrstami obremenitev, ki so jim spoji lahko podvrženi, ali metod za preprečevanje takšnih napak.
Zato tega dokumenta ni mogoče uporabiti za določevanje sprejemljivosti zvarov, kar je opredeljeno v standardu EN 16296 [1].
Ta dokument obravnava samo napake, ki povzročajo nehomogenost materialov ali spremembe oblike, in sicer določa njihovo vrsto, obliko ter položaj. Ta razvrstitev se lahko uporabi za določanje možnega izvora ali vzrokov napak.
General Information
Relations
Overview
EN 14728:2019 - Imperfections in thermoplastic welds: Classification defines a uniform system for classifying imperfections that can occur in thermoplastic welded joints during manufacture. The standard lists and codes imperfections (using a numbering/character system given in Annex A) and provides illustrative examples for six common welding processes:
- heated tool butt and socket welding,
- electrofusion socket welding,
- hot gas welding,
- extrusion welding,
- solvent socket welding.
EN 14728:2019 covers only imperfections that produce material discontinuities or changes in shape during manufacture. It does not address defects generated during service, nor defects caused by poor preparation or fit-up prior to welding, nor the effects of imperfections on joint performance or methods for preventing them.
Key Topics
- Classification system: a standardized numbering and character scheme (explained in Annex A) to identify imperfection type, shape and position.
- Process-specific examples: tables listing typical imperfections for each welding method (Tables 1–6), e.g. gas cavities, shrinkage cavities, lack of fusion, cold fusion, inclusions, undercut, excessive penetration, irregular bead profile.
- Scope limitations: excludes pre-weld preparation faults, service-induced defects and behavioural/strength assessments.
- Normative references: includes referenced documents such as EN 12201-3 (for fittings) and is intended to be used in conjunction with EN 16296 for weld acceptance criteria.
Practical Applications
- Quality control & inspection: provides a common language for inspectors to record and report imperfections in thermoplastic welds.
- Welding documentation: used in weld records, non‑destructive testing reports and manufacturing quality systems.
- Training & procedure development: helps trainers and welding procedure authors identify and describe typical manufacturing defects.
- Root-cause analysis: classification assists in tracing likely origins of imperfections by type, shape and position.
- Acceptance decision support: when used together with EN 16296, the classification aids in determining weld acceptance or rejection.
Who should use this standard
- Welding quality inspectors and technicians
- Plastic piping and fabrication manufacturers
- Pipeline operators and utilities using thermoplastic systems
- Welding engineers, procedure writers and test laboratories
- Standards organizations and certification bodies
Related standards
- EN 16296 - for determining weld acceptance criteria (use in conjunction with EN 14728:2019)
- EN 12201-3 - fittings for polyethylene piping systems (referenced in EN 14728)
EN 14728:2019 establishes consistent terminology and visual examples for imperfections in thermoplastic welds, improving communication, inspection consistency and traceability across manufacturing and inspection activities.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Napake v plastomernih zvarih - RazvrstitevUnregelmäßigkeiten an Schweißverbindungen von thermoplastischen Kunststoffen - EinteilungDéfauts dans les assemblages soudés en thermoplastiques - ClassificationImperfections in thermoplastic welds - Classification83.080.01Polimerni materiali na splošnoPlastics in general25.160.40Varjeni spoji in variWelded joints and weldsICS:Ta slovenski standard je istoveten z:EN 14728:2019SIST EN 14728:2019en,fr,de01-maj-2019SIST EN 14728:2019SLOVENSKI
STANDARDSIST EN 14728:20051DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14728
February
t r s { ICS
t wä s x rä v r Supersedes EN
s v y t zã t r r wEnglish Version
Imperfections in thermoplastic welds æ Classification Dßfauts dans les assemblages soudßs en thermoplastiques æ Classification
Unregelmäßigkeiten an Schweißverbindungen von thermoplastischen Kunststoffen æ Einteilung This European Standard was approved by CEN on
s v December
t r s zä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Rue de la Science 23,
B-1040 Brussels
t r s { CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v y t zã t r s { ESIST EN 14728:2019
Explanations for each character .29 Bibliography .33
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp SIST EN 14728:2019
2CAAI Shrinkage cavity Cavity due to shrinkage of weld during solidification. This cavity may be distinguishable by evidence of ductility or stress whitening.
2MAAA
Surface bubble On weld bead.
Particulate inclusion Foreign material trapped at weld interface. Foreign material on surface of weld beads.
3JAAI Parent material inclusion Inclusion of parts of parent material at weld interface.
3KAAI 3KAAF
Degraded polymer Inclusion of decomposition products at weld interface. Inclusion of decomposition products on surface of weld beads.
4BAAA Lack of fusion No fusion across weld interface.
4QBAF Groove in upset or reinforcement Excessive groove depth at centre of weld bead.
4WAAA Cold fusion Incomplete fusion across weld interface.
5EIAAa Linear misalignment Deviation from specified tolerances in coplanarity between two welded pieces.
5EJAAa Angular misalignment Deviation from specified angle between two welded pieces.
5GAAAa Irregular width Excessive variation in weld or bead width.
6DAAAa Excessive width Width of the weld bead greater than specified.
6HAAAa Excessive asymmetry of welds Asymmetric weld bead.
6MAAAa Insufficient upset material Upset material smaller than the specified value.
7VAAAa Excessive toe in Deviation between the outside diameter at the end of the pipe and the outside diameter remote from the pipe end.
9CAAA Tool mark Local damage due to clamping.
Key
good fusion at interface
cold fusion at interface
lack of fusion at interface a Not applicable to fabricated fittings according to EN 12201-3:2011+A1:2012, Annex B. SIST EN 14728:2019
2MAAA Surface bubble On weld bead.
3AAAF 3AAAI Particulate inclusion Foreign material trapped in the weld and/or on the surface of the weld bead.
4BAAA Lack of fusion Area of no fusion between pipe and fitting.
4CAAA
Incomplete penetration Insufficient penetration of the pipe(s) into the socket.
4PAAA Material extrusion Extrusion of material from the joint (sheeting).
4WAAA Cold
fusion Incomplete fusion around the circumference of
joint.
5EJAA
Angular misalignment Deviation of alignment between pipe and fitting.
5GAEF Irregular width Excessive variation of the width of the weld bead.
6DAAA Excessive width Excessive weld bead dimension.
Excessive asymmetry Deviation from specified weld bead shape.
6MAAA Insufficient upset material Weld bead smaller than the specified value.
7BAAA Thermal damage Surface alteration resulting from the accidental action of a source of heat.
9CAAA Tool mark Local damage due to weld preparation tool.
Key
cold fusion at interface
good fusion at interface NOTE All imperfections can occur on one or both sides of the joi
...
Frequently Asked Questions
EN 14728:2019 is a standard published by the European Committee for Standardization (CEN). Its full title is "Imperfections in thermoplastic welds - Classification". This standard covers: This document specifies a system for classifying imperfections that may be encountered in thermoplastic welded joints during manufacture and provides examples of imperfections for the following welding processes: - heated tool butt welding; - heated tool socket welding; - electrofusion socket welding; - hot gas welding; - extrusion welding; - solvent socket welding. This document does not describe imperfections that may be generated during service or imperfections present before welding, which are due to poor preparation or assembly of components (e.g. fit up). The correct preparation and assembly of components (e.g. fit up) are described in the relevant welding procedure specification (WPS). This document is also not concerned with the search for the possible influence of these imperfections on the behaviour of joints in relation to the different types of stress to which the latter may be subjected or on methods for preventing such imperfections. This document can be used in conjunction with EN 16296 [1] to determine the acceptance of welds. Only imperfections giving rise to discontinuities of materials or changes in shape are taken into consideration in this document, specifying their type, their shape and their positions. This classification can be used to determine the possible origin or causes of the imperfections.
This document specifies a system for classifying imperfections that may be encountered in thermoplastic welded joints during manufacture and provides examples of imperfections for the following welding processes: - heated tool butt welding; - heated tool socket welding; - electrofusion socket welding; - hot gas welding; - extrusion welding; - solvent socket welding. This document does not describe imperfections that may be generated during service or imperfections present before welding, which are due to poor preparation or assembly of components (e.g. fit up). The correct preparation and assembly of components (e.g. fit up) are described in the relevant welding procedure specification (WPS). This document is also not concerned with the search for the possible influence of these imperfections on the behaviour of joints in relation to the different types of stress to which the latter may be subjected or on methods for preventing such imperfections. This document can be used in conjunction with EN 16296 [1] to determine the acceptance of welds. Only imperfections giving rise to discontinuities of materials or changes in shape are taken into consideration in this document, specifying their type, their shape and their positions. This classification can be used to determine the possible origin or causes of the imperfections.
EN 14728:2019 is classified under the following ICS (International Classification for Standards) categories: 25.160.40 - Welded joints and welds. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 14728:2019 has the following relationships with other standards: It is inter standard links to EN 14728:2005, EN 14118-2:2003. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase EN 14728:2019 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CEN standards.
La norme SIST EN 14728:2019 se distingue par son approche systématique dans la classification des imperfections rencontrées dans les joints soudés en thermoplastique. Son champ d'application est précis, se concentrant exclusivement sur les imperfections identifiables lors de la fabrication, notamment concernant des processus tels que le soudage par outil chauffé à emboîtement, le soudage par électrofusion, et d'autres techniques pertinentes. Cette spécificité permet aux professionnels de l’industrie d’évaluer et de comprendre les défauts qui peuvent survenir pendant les opérations de soudage, ciblant ainsi les besoins pratiques du secteur. Un des points forts de cette norme réside dans sa capacité à fournir des exemples concrets d'imperfections, structurés par type, forme et position. Cela facilite non seulement l’identification des défauts mais aussi leur classification, un élément essentiel pour le contrôle qualité dans la fabrication des joints thermoplastiques. En explicitant que seules les imperfections engendrant des discontinuités matérielles ou des modifications de forme sont prises en compte, la norme assure une clarté qui peut réduire les ambiguïtés lors de l'évaluation des soudures. En outre, la norme ne se laisse pas distraire par des considérations hors sujet. Elle ne couvre pas les imperfections pouvant être générées durant le service, ni celles résultant de préparations ou d'assemblages inadéquats des composants. Cela garantit que les utilisateurs s'orientent vers les procédures appropriées pour la préparation des éléments et respectent les spécifications du processus de soudage (WPS). L'interaction de SIST EN 14728:2019 avec la norme EN 16296 est également significative, offrant une orientation structurée pour déterminer l'acceptabilité des soudures. Bien que la norme se limite à la classification des défauts, son apport en termes de compréhension des causes possibles de ces imperfections enrichit sa pertinence dans le domaine du soudage en thermoplastique. En somme, la norme SIST EN 14728:2019 représente un outil essentiel pour les professionnels impliqués dans le soudage de matériaux thermoplastiques, fournissant une méthodologie claire et des critères précis pour l'identification et la classification des imperfections, ce qui améliore la fiabilité et la qualité des produits finis.
SIST EN 14728:2019 표준 문서는 열가소성 용접에서 발생할 수 있는 불완전성을 분류하는 체계를 명확하게 제시하고 있습니다. 이 표준의 범위는 다양한 용접 공정, 즉 열 도구 맞대기 용접, 열 도구 소켓 용접, 전기 융합 소켓 용접, 열가스 용접, 압출 용접 및 용매 소켓 용접과 관련된 불완전성을 포함하여, 제조 중에 마주칠 수 있는 불완전성의 분류 시스템을 제공합니다. 표준의 강점 중 하나는 불완전성의 유형, 모양 및 위치를 명확하게 규정하고 있어, 불완전성의 가능성 있는 기원이나 원인을 파악하는 데 유용하다는 것입니다. 그러나 이 문서는 서비스 도중 발생할 수 있는 불완전성이나 용접 전 준비 부족 또는 조립 불량으로 인한 불완전성에 대해서는 다루지 않으며, 이러한 사항은 관련 용접 절차 사양(WPS)에서 설명됩니다. 이러한 면에서, 표준은 특정한 제조 과정에 중점을 두고, 정확한 용접 작업을 위한 필요조건을 제시하고 있습니다. 또한, SIST EN 14728:2019는 EN 16296과 함께 사용될 수 있는 점에서 용접에 대한 수용성을 결정하는 데 유용성을 더합니다. 문서가 다루는 불완전성은 물질의 불연속성이나 형태의 변화를 초래하는 경우에 한정되어 있으며, 따라서 이것은 품질 보증 및 안전성을 높이는 데 기여할 수 있습니다. 결론적으로, SIST EN 14728:2019 표준은 열가소성 용접의 불완전성을 효과적으로 분류하고 이를 통해 제조 과정의 품질을 향상시킬 수 있는 강력한 도구임을 보여줍니다.
EN 14728:2019標準は、熱可塑性溶接継手における不具合の分類に関する重要な文書です。このドキュメントは、製造過程で遭遇する可能性のある不具合の体系的なクラス分類システムを提供します。特に、加熱工具バット溶接、加熱工具ソケット溶接、エレクトロフュージョンソケット溶接、熱ガス溶接、押出溶接、溶剤ソケット溶接といったさまざまな溶接プロセスに焦点を当てています。 この標準の強みは、溶接不具合の具体的な種類、形状、及び位置を明確に特定することにあります。これは、製品の品質を保証するために不可欠な要素であり、製造過程における不具合を特定しやすくしています。また、EN 16296と組み合わせて使用することで、溶接の受け入れ基準を判断するための信頼性の高い指針も提供します。 さらに、EN 14728:2019は、サービス中に発生する不具合や、溶接前に悪い準備やコンポーネントの組み立てに起因する不具合については取り扱っていません。この点で、正確な準備と組み立ての重要性を強調しており、関連する溶接手続き仕様書（WPS）で詳細に説明されています。 全体的に、EN 14728:2019は、熱可塑性溶接における不具合の理解と管理を体系的に進めるために非常に重要な標準であり、業界内での適用性が高いといえます。
Das Dokument SIST EN 14728:2019 bietet ein umfassendes System zur Klassifizierung von Imperfektionen, die bei thermoplastischen Schweißverbindungen während der Herstellung auftreten können. Es konzentriert sich auf verschiedene Schweißverfahren, darunter heated tool butt welding, heated tool socket welding, elektrofusion socket welding, hot gas welding, extrusion welding und solvent socket welding. Diese spezifische Fokussierung auf gängige Schweißmethoden macht die Norm besonders relevant für Fachleute in der Schweißindustrie, die an der Qualitätssicherung und der Konformität von Schweißverbindungen interessiert sind. Ein herausragendes Merkmal der Norm ist die klare Definition und Kategorisierung von Imperfektionen, die in thermoplastischen Schweißnähten auftreten können. Es werden verschiedene Typen, Formen und Positionen der Imperfektionen berücksichtigt, was eine präzise Diagnostik und eine verbesserte Fehleranalyse ermöglicht. Diese Klassifizierung unterstützt die Benutzer dabei, die möglichen Ursachen der Imperfektionen besser zu verstehen und zu identifizieren. Die Norm schließt jedoch Imperfektionen aus, die durch mangelhafte Vorbereitung oder Montage der Komponenten entstehen, wie zum Beispiel unzureichendes Fit-Up. Dies verdeutlicht den spezifischen Anwendungsbereich der Norm und den Fokus auf die Fertigungsphase, wodurch eine klare Abgrenzung zu anderen Aspekten des Schweißprozesses erfolgt. Eine weitere Stärke der SIST EN 14728:2019 liegt in ihrer Anwendbarkeit in Verbindung mit EN 16296, um die Akzeptanz von Schweißverbindungen zu bestimmen. Diese Kombination bietet eine wertvolle Grundlage für die Qualitätssicherung und die Bewertung von Schweißverbindungen, wodurch die Relevanz der Norm in der gesamten Branche unterstrichen wird. Insgesamt stellt die SIST EN 14728:2019 eine essentielle Referenz für Fachkräfte in der Schweißtechnik dar, indem sie klare Richtlinien zur Identifikation und Klassifizierung von Imperfektionen in thermoplastischen Schweißnähten bereitstellt und somit zur Verbesserung der Qualitätssicherung beiträgt.
The standard EN 14728:2019, titled "Imperfections in thermoplastic welds - Classification," presents a comprehensive framework for classifying imperfections found in thermoplastic welded joints. Its scope is well-defined as it specifically addresses imperfections that arise during various welding processes, including heated tool butt welding, heated tool socket welding, electrofusion socket welding, hot gas welding, extrusion welding, and solvent socket welding. This targeted focus allows manufacturers and quality control professionals to systematically identify and categorize the types of imperfections that may affect the integrity of welded joints. One of the strengths of this standard is its clear delineation between imperfections occurring during the welding process and those resulting from poor preparation or pre-existing conditions. By excluding imperfections from prior stages, such as fit-up issues, the standard helps in ensuring that practitioners concentrate on the weld integrity itself rather than being distracted by underlying assembly problems. This ensures that users adopt a more rigorous approach in terms of quality assurance of welded products. Additionally, the standard emphasizes the significance of defining the type, shape, and positioning of imperfections, which is pivotal in understanding the potential origins and causes of each imperfection. This classification system is essential for manufacturers, as it equips them with the necessary information to analyze defects and improve manufacturing processes effectively. The relevance of EN 14728:2019 extends to its use alongside EN 16296, which provides a dual framework for determining the acceptance of welds. This integration fosters a robust quality management system that can lead to enhanced performance and reliability in thermoplastic welding applications. In summary, EN 14728:2019 serves as an invaluable resource for professionals involved in thermoplastic welding. Its focused scope, strong classification methodology, and compatibility with other standards highlight its importance in achieving high-quality welding outcomes and advancing industry best practices.
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