EN ISO 20238:2019

Conveyor belts - Drum friction testing (ISO 20238:2018)

ISO 20238:2018 specifies a method of testing to determine the propensity of a conveyor belt to generate heat flame or glow when held stationary, under a given tension, in surface contact around a rotating driven steel drum.
ISO 20238:2018 describes means of varying the conveyor belt tension.
NOTE       For conveyor belts containing steel reinforcement, it may not be possible to conduct this test in full due to the inability of the conveyor belt to comply with the requirements of 7.2. In this case, premature termination according to 7.3 can be necessary.

Fördergurte - Prüfung der Trommelreibung (ISO 20238:2018)

Diese Internationale Norm legt ein Prüfverfahren fest, mit denen die Tendenz eines Fördergurts zum Entflammen oder zum Glühen beurteilt werden kann, wenn er bei einer vorgegebenen Spannung in Kontakt mit einer umlaufenden Stahltrommel gehalten wird.
Methoden zur Veränderung der Spannung des Fördergurts werden beschrieben.
ANMERKUNG   Für Fördergurte mit Stahl-Verstärkung lässt sich diese Prüfung möglicherweise nicht in vollem Umfang durchführen, weil die Anforderungen von 6.2. nicht erfüllt werden. In diesem Fall kann eine vorzeitige Beendigung nach 6.3 erforderlich sein.

Courroies transporteuses - Essais de frottement au tambour (ISO 20238:2018)

ISO 20238:2018 spécifie une méthode d'essai permettant de déterminer la propension d'une courroie transporteuse à générer de la chaleur, une flamme ou une incandescence lorsqu'elle est maintenue immobile, sous une tension donnée, au contact de la surface d'un tambour en acier entraîné en rotation.
ISO 20238:2018 décrit les moyens pour faire varier la tension de la courroie transporteuse.
NOTE       Pour les courroies transporteuses pourvues d'une armature en acier, il peut s'avérer impossible d'effectuer cet essai dans son intégralité en raison de l'incapacité de la courroie transporteuse à satisfaire aux exigences du 7.2. Dans ce cas, un arrêt prématuré selon le 7.3 peut être nécessaire.

Naprave za kontinuirni transport - Trakovi tračnih transporterjev - Preskušanje trenja na pogonskem bobnu (ISO 20238:2018)

Ta evropski standard opisuje preskusno metodo, s katero se ugotavlja nagnjenost traka tračnega transporterja k nastanku toplote, plamena ali žarenja, kadar se drži pri miru pod določeno napetostjo pri površinskem stiku okrog vrtečega se gnanega jeklenega bobna.
Opisani so načini spreminjanja napetosti traku.
OPOMBA: Pri nekaterih vrstah trakov zaradi njihove zgradbe morda ne bo mogoče izvesti tega preskusa, ker trak ni v skladu z zahtevami iz točke 6.2.3.

General Information

• Status: Published
• Publication Date: 26-Feb-2019
• Withdrawal Date: 30-Aug-2019
• ICS: 53.040.20 - Components for conveyors
• Technical Committee: CEN/TC 188 - Conveyor belts
• Drafting Committee: CEN/TC 188/WG 3 - Safety requirements for conveyor belting
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 27-Feb-2019
• Completion Date: 27-Feb-2019
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: SIST EN ISO 20238:2019 - Conveyor belts - Drum friction testing (ISO 20238:2018)

Relations

• Replaces: EN 1554:2012 - Conveyor belts - Drum friction testing
• Effective Date: 06-Mar-2019

Overview - EN ISO 20238:2019 / ISO 20238:2018

EN ISO 20238:2019 (identical to ISO 20238:2018) specifies a laboratory drum friction testing method to determine the propensity of a conveyor belt to generate heat, flame or glow when held stationary in surface contact around a rotating driven steel drum under defined tension. The test simulates a stalled belt scenario to assess fire and thermal risk during conveyor operation. The standard describes apparatus, test-piece preparation, tensioning, test procedures in still air (Method A) and moving air (Method B), and reporting requirements.

Key topics and technical requirements

• Purpose: Assess risk of localized heating, flame or glowing when a belt is held against a driven drum.
• Test principle: A prepared belt specimen is wrapped partially around a rotating steel drum; tests run for specified tensions/time or until belt failure, recording presence/absence of flame/glow and drum temperature.
• Steel drum: Outer diameter (210 ± 1) mm; rotate at (200 ± 5) r/min; surface roughness Ra max 1.6 µm; shell specifications reference ISO 9329-1 / ISO 9330-1.
• Temperature measurement: Mineral-insulated stainless-steel thermocouple (max Ø 2 mm), tip ≤ 0.5 mm below drum surface, complying with EN 60584‑1.
• Air conditions: Still air or moving air at (2.0 ± 0.1) m/s measured 200 mm from drum; air supply pipe and perforation geometry specified.
• Test pieces: Cut ≥50 mm from belt edges, ≥100 mm from ends; width 150 mm, length ≥750 mm.
• Arc of contact: Preferred 180°; reduced arc (135°) allowed with adjusted load and considered equivalent in the standard.
• Special cases: For belts with steel reinforcement, full compliance with some test requirements may be impossible; premature termination (Clause 7.3) is allowed and must be reported.
• Reporting: Document presence/absence of flame or glow, maximum drum temperature, test conditions and any premature termination.

Applications - who uses this standard

• Conveyor belt manufacturers and material suppliers (product development and safety validation).
• Independent test laboratories performing conveyor belt fire/thermal testing.
• Safety engineers, compliance officers and OEMs in industries using belt conveyors (mining, ports, bulk material handling, recycling).
• Procurement teams and insurers evaluating fire risk and specifying belt acceptance criteria.
• Regulatory and standards bodies referencing belt safety performance.

Related standards and references

• Supersedes EN 1554:2012.
• Normative references included: ISO 65, ISO 7590, ISO 9329‑1, ISO 9330‑1, EN 60584‑1.

Keywords: conveyor belts, drum friction testing, ISO 20238:2018, EN ISO 20238:2019, conveyor belt testing, belt fire risk, drum friction, thermocouple, arc of contact.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2019
Nadomešča:
SIST EN 1554:2012
Naprave za kontinuirni transport - Trakovi tračnih transporterjev - Preskušanje
trenja na pogonskem bobnu (ISO 20238:2018)
Conveyor belts - Drum friction testing (ISO 20238:2018)
Fördergurte - Prüfung der Trommelreibung (ISO 20238:2018)
Courroies transporteuses - Essais de frottement au tambour (ISO 20238:2018)
Ta slovenski standard je istoveten z: EN ISO 20238:2019
ICS:
53.040.20 Deli za transporterje Components for conveyors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20238
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2019
EUROPÄISCHE NORM
ICS 53.040.20 Supersedes EN 1554:2012
English Version
Conveyor belts - Drum friction testing (ISO 20238:2018)
Courroies transporteuses - Essais de frottement au Fördergurte - Prüfung der Trommelreibung (ISO
tambour (ISO 20238:2018) 20238:2018)
This European Standard was approved by CEN on 21 February 2019.

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, 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20238:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20238:2019) has been prepared by Technical Committee ISO/TC 41 "Pulleys
and belts (including veebelts)" in collaboration with Technical Committee CEN/TC 188 “Conveyor belts”
the secretariat of which is held by SNV.
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 2019, and conflicting national standards shall
be withdrawn at the latest by August 2019.
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 1554:2012.
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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 20238:2018 has been approved by CEN as EN ISO 20238:2019 without any modification.

INTERNATIONAL ISO
STANDARD 20238
First edition
2018-01
Conveyor belts — Drum friction testing
Courroies transporteuses — Essais de frottement au tambour
Reference number
ISO 20238:2018(E)
©
ISO 2018
ISO 20238:2018(E)
© ISO 2018
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, Switzerland
Tel. [phone]
Fax [phone]
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Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 20238:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Test piece . 6
7 Procedure. 6
7.1 General . 6
7.2 Procedure and test . 6
7.2.1 Selection of test method . 6
7.2.2 Method A — Tests in still air. 6
7.2.3 Method B — Tests in moving air . 8
7.3 Premature termination . 9
8 Test report . 9
ISO 20238:2018(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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 41, Pulleys and belts (including veebelts),
Subcommittee SC 3, Conveyor belts.
iv © ISO 2018 – All rights reserved

ISO 20238:2018(E)
Introduction
The purpose of this document is to provide a method of testing that will assist conveyor belt users in
assessing the degree of risk which can be anticipated from the hazard caused when a conveyor belt
stalls and the drive mechanism of the conveyor system continues to operate, causing localized heating
of the conveyor belt through contact with the driving drum or other frictional heat source.
INTERNATIONAL STANDARD ISO 20238:2018(E)
Conveyor belts — Drum friction testing
1 Scope
This document specifies a method of testing to determine the propensity of a conveyor belt to generate
heat flame or glow when held stationary, under a given tension, in surface contact around a rotating
driven steel drum.
It describes means of varying the conveyor belt tension.
NOTE For conveyor belts containing steel reinforcement, it may not be possible to conduct this test in full due
to the inability of the conveyor belt to comply with the requirements of 7.2. In this case, premature termination
according to 7.3 can be necessary.
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 65, Carbon steel tubes suitable for screwing in accordance with ISO 7‑1
ISO 7590, Steel cord conveyor belts — Methods for the determination of total thickness and cover thickness
ISO 9329-1, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 1: Unalloyed
steels with specified room temperature properties
ISO 9330-1, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 1: Unalloyed
steel tubes with specified room temperature properties
EN 60584-1, Thermocouples — Part 1: EMF specifications and tolerances
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
A test piece of conveyor belt, suitably mounted and tensioned, is wrapped halfway around a rotating
steel drum, simulating a stalled belt. The test is continued at specified tensions for a given time period,
or until the belt parts or breaks. The presence, or absence, of flame or glow is noted and reported and
the maximum temperature of the drum is recorded. The test is conducted in still air and/or in moving
air. Two options on arc of contact are given. The reduced arc of contact test (135° of contact) with
increased initial load is considered equivalent to the 180° arc of contact test.
ISO 20238:2018(E)
5 Apparatus
5.1 Steel drum, of external diameter (210 ± 1) mm mounted on a horizontal axis and capable of being
rotated under all load conditions at (200 ± 5) r/min throughout the test. The outer shell of the drum shall
be manufactured from tube complying with ISO 9329-1 or ISO 9330-1. The surface roughness, Ra, of the
drum surface shall be a maximum of 1,6 μm.
NOTE Experience has shown that motors of between 7,5 kW and 15 kW have proven suitable for maintaining
these conditions, although for smaller motors, a “soft start” can be necessary.
Basic dimensions of the drum, shown in Figure 3, ar
...