EN ISO 7326:2016

Rubber and plastics hoses - Assessment of ozone resistance under static conditions (ISO 7326:2016)

ISO 7326:2016 specifies five methods for determining the ozone resistance of the outer covers of hoses:
-      method 1, for bore sizes up to and including 25 mm, carried out on the hose itself;
-      method 2, for bore sizes greater than 25 mm, carried out on a test piece from the hose wall;
-      method 3, for bore sizes greater than 25 mm, carried out on a test piece from the cover;
-      method 4, for all bore sizes, carried out on the hose itself;
-      method 5, for all bore sizes, carried out on hoses that are expandable, for example textile-reinforced hoses.
NOTE          For hoses with built-in fittings from which it is not possible to take test pieces, the ozone resistance can be assessed on slabs in accordance with ISO 1431‑1, using test sheets of the appropriate polymeric compound vulcanized to the same degree.

Gummi- und Kunststoffschläuche - Bestimmung der Ozonbeständigkeit unter statischen Bedingungen (ISO 7326:2016)

Tuyaux en caoutchouc et en plastique - Évaluation de la résistance à l'ozone dans des conditions statiques (ISO 7326:2016)

ISO 7326:2016 spécifie cinq méthodes pour la détermination de la résistance à l'ozone des revêtements extérieurs des tuyaux:
-      méthode 1, pour des dimensions d'alésage inférieures ou égales à 25 mm, réalisée sur le tuyau lui-même;
-      méthode 2, pour des dimensions d'alésage supérieures à 25 mm, réalisée sur une éprouvette prélevée dans la paroi du tuyau;
-      méthode 3, pour des dimensions d'alésage supérieures à 25 mm, réalisée sur une éprouvette prélevée dans le revêtement du tuyau;
-      méthode 4, pour toutes les dimensions d'alésage, réalisée sur le tuyau lui-même;
-      méthode 5, pour toutes les dimensions d'alésage, réalisée sur des tuyaux qui sont extensibles, par exemple des tuyaux renforcés textile.
NOTE          Pour des tuyaux ayant des raccords intégrés sur lesquels il n'est pas possible de prélever des éprouvettes, la résistance à l'ozone peut être évaluée sur des plaques conformément à l'ISO 1431‑1, en utilisant des plaques du mélange polymérique approprié, vulcanisées au même degré.

Gumene in polimerne cevi - Ocena odpornosti proti ozonu pri statičnih pogojih (ISO 7326:2016)

Ta dokument določa pet metod za ugotavljanje odpornosti proti ozonu zunanjih pokrovov cevi:
– metoda 1 za nominalne premere največ 25 mm, ki se izvaja na sami cevi;
– metoda 2 za nominalne premere več kot 25 mm, ki se izvaja na preskusnih kosih iz stene cevi;
– metoda 3 za nominalne premere več kot 25 mm, ki se izvaja na preskusnih kosih iz pokrova;
– metoda 4 za vse velikosti premerov, ki se izvaja na sami cevi;
– metoda 5 za vse velikosti premerov, ki se izvaja na razširljivih ceveh, na primer s tekstilom ojačenih
ceveh.
OPOMBA: Pri ceveh z vgrajenimi fitingi, pri katerih ni mogoče odvzeti preskusnega kosa, se lahko odpornost proti ozonu oceni na ploščah v skladu s standardom ISO 1431-1, ko se uporabijo preskusne plošče iz ustrezne polimerne zmesi, vulkanizirane na enako stopnjo.

General Information

• Status: Published
• Publication Date: 25-Oct-2016
• Withdrawal Date: 29-Apr-2017
• ICS: 23.040.70 - Hoses and hose assemblies
• Technical Committee: CEN/TC 218 - Rubber and plastics hoses and hose assemblies
• Drafting Committee: CEN/TC 218 - Rubber and plastics hoses and hose assemblies
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 26-Oct-2016
• Completion Date: 26-Oct-2016
• Ref Project: SIST EN ISO 7326:2016 - Rubber and plastics hoses - Assessment of ozone resistance under static conditions (ISO 7326:2016)

Relations

• Replaces: EN ISO 7326:2008 - Rubber and plastics hoses - Assessment of ozone resistance under static conditions (ISO 7326:2006)
• Effective Date: 08-Jun-2022

Overview - EN ISO 7326:2016 (Rubber and plastics hoses, ozone resistance)

EN ISO 7326:2016 specifies standardized laboratory methods to assess the ozone resistance of outer covers of rubber and plastics hoses under static conditions. The document defines five test methods (depending on hose bore and construction), required conditioning and test-piece preparation, test cabinet and fixture requirements, and reporting essentials. The standard is intended to determine susceptibility to ozone cracking that can occur during storage or service in ozone-containing atmospheres.

Key topics and technical requirements

• Five test methods for outer covers:
  • Method 1: test on the hose itself for bore ≤ 25 mm.
  • Method 2: strip from hose wall for bore > 25 mm.
  • Method 3: strip from cover for bore > 25 mm (remove reinforcement impressions).
  • Method 4: hose sample wound around a cylinder (all bore sizes).
  • Method 5: testing expandable hoses (e.g., textile‑reinforced) in the expanded state.
• Test conditions: default exposure to ozone concentration (50 ± 5) pphm at (40 ± 2) °C for 72 h (unless a product standard specifies otherwise).
• Test pieces and counts: three test pieces per evaluation; specified dimensions (e.g., 150 × 25 mm strip for Method 2; 25 mm width for cover strips in Method 3).
• Conditioning: no testing within 24 h of manufacture; mount and condition test pieces 48 h in substantially ozone‑free atmosphere at standard temperature.
• Apparatus: ozone cabinet with ozone generation and monitoring (per ISO 1431‑1), purpose‑made holders, cylinder or rods for specified methods; materials used inside the cabinet must not absorb or decompose ozone.
• Comparability note: results from different methods (e.g., Method 1 vs Method 2/3) may not be directly comparable; the product standard should specify which method to use.
• Alternative for hoses with fixed fittings: assess slabs/test sheets per ISO 1431‑1 when test pieces cannot be taken.

Applications - who uses EN ISO 7326:2016

• Hose manufacturers and compound formulators validating cover compounds for ozone resistance.
• Third‑party test laboratories performing conformity and warranty testing.
• Quality, R&D and materials engineers specifying hoses for outdoor, industrial or automotive applications where ozone exposure is a risk.
• Procurement and compliance teams requiring documented test evidence for product standards and certifications.

Related standards

• ISO 1431‑1: Resistance to ozone cracking - static and dynamic strain testing (referenced for ozone cabinet and alternative slab testing).
• ISO 23529: Conditioning and preparation of rubber test pieces.
• ISO 8330: Terms and definitions for rubber and plastics hoses and assemblies.

Keywords: EN ISO 7326:2016, ozone resistance, rubber and plastics hoses, static conditions, hose testing, ISO 1431-1, hose cover assessment, ozone cracking.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2016
1DGRPHãþD
SIST EN ISO 7326:2008
*XPHQHLQSROLPHUQHFHYL2FHQDRGSRUQRVWLSURWLR]RQXSULVWDWLþQLKSRJRMLK
,62
Rubber and plastics hoses - Assessment of ozone resistance under static conditions
(ISO 7326:2016)
Gummi- und Kunststoffschläuche - Bestimmung der Ozonbeständigkeit unter statischen
Bedingungen (ISO 7326:2016)
Tuyaux en caoutchouc et en plastique - Évaluation de la résistance à l'ozone dans des
conditions statiques (ISO 7326:2016)
Ta slovenski standard je istoveten z: EN ISO 7326:2016
ICS:
23.040.70 Gumene cevi in armature Hoses and hose assemblies
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 7326
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2016
EUROPÄISCHE NORM
ICS 23.040.70 Supersedes EN ISO 7326:2008
English Version
Rubber and plastics hoses - Assessment of ozone
resistance under static conditions (ISO 7326:2016)
Tuyaux en caoutchouc et en plastique - Évaluation de la Gummi- und Kunststoffschläuche - Bestimmung der
résistance à l'ozone dans des conditions statiques (ISO Ozonbeständigkeit unter statischen Bedingungen (ISO
7326:2016) 7326:2016)
This European Standard was approved by CEN on 9 October 2016.

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
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7326:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 7326:2016) has been prepared by Technical Committee ISO/TC 45 "Rubber and
rubber products" in collaboration with Technical Committee CEN/TC 218 “Rubber and plastics hoses
and hose assemblies” 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 April 2017, and conflicting national standards shall be
withdrawn at the latest by April 2017.
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 7326:2008.
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 7326:2016 has been approved by CEN as EN ISO 7326:2016 without any modification.
INTERNATIONAL ISO
STANDARD 7326
Fourth edition
2016-10-15
Rubber and plastics hoses —
Assessment of ozone resistance under
static conditions
Tuyaux en caoutchouc et en plastique — Évaluation de la résistance à
l’ozone dans des conditions statiques
Reference number
ISO 7326:2016(E)
©
ISO 2016
ISO 7326:2016(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
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ii © ISO 2016 – All rights reserved

ISO 7326:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General considerations . 1
5 Apparatus . 2
6 Test pieces . 2
6.1 Type of test piece . 2
6.1.1 Method 1 . 2
6.1.2 Method 2 . 2
6.1.3 Method 3 . 2
6.1.4 Method 4 . 3
6.1.5 Method 5 . 3
6.2 Number of test pieces . 3
7 Conditioning of test pieces . 3
8 Test conditions . 3
9 Procedure. 3
9.1 Method 1. 3
9.2 Method 2. 4
9.3 Method 3. 4
9.4 Method 4. 5
9.5 Method 5. 6
10 Test report . 7
Bibliography . 8
ISO 7326:2016(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
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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,
...