1、BS EN ISO 7326:2016Rubber and plastics hoses Assessment of ozone resistanceunder static conditions(ISO 7326:2016)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 7326:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN
2、ISO 7326:2016.It supersedes BS EN ISO 7326:2008 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/66, Rubber and plastics tubing, hoses and hoseassemblies.A list of organizations represented on this committee can beobtained on request to its secretary
3、.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 89087 1ICS 23.040.70Compliance with a British Standard cannot confer
4、 immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7326 October 201
5、6 ICS 23.040.70 Supersedes EN ISO 7326:2008English Version Rubber and plastics hoses - Assessment of ozone resistance under static conditions (ISO 7326:2016) Tuyaux en caoutchouc et en plastique - valuation de la rsistance lozone dans des conditions statiques (ISO 7326:2016) Gummi- und Kunststoffsch
6、luche - Bestimmung der Ozonbestndigkeit unter statischen Bedingungen (ISO 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
7、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).
8、 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, Cy
9、prus, 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 K
10、ingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR 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 worldwide for CEN national Members. Ref. No. EN ISO
11、7326:2016 EBS EN ISO 7326:2016EN ISO 7326:2016 (E) 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
12、 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 p
13、ossibility 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 standa
14、rds 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, Lux
15、embourg, 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. BS EN ISO 7326:2016ISO 7326:2016(E)Forewo
16、rd ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 General considerations 15 Apparatus . 26 Test pieces . 26.1 Type of test piece 26.1.1 Method 1 . 26.1.2 Method 2 . 26.1.3 Method 3 . 26.1.4 Method 4 . 36.1.5 Method 5 . 36.2 Number of test pieces . 37 Conditioning of
17、test pieces . 38 Test conditions . 39 Procedure. 39.1 Method 1. 39.2 Method 2. 49.3 Method 3. 49.4 Method 4. 59.5 Method 5. 610 Test report . 7Bibliography 8 ISO 2016 All rights reserved iiiContents PageBS EN ISO 7326:2016ISO 7326:2016(E)ForewordISO (the International Organization for Standardizatio
18、n) 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 rep
19、resented 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 dev
20、elop 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 IS
21、O/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
22、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
23、 of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs 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 docum
24、ent is ISO/TC 45, Rubber and rubber products, Subcommittee SC 1, Rubber and plastics hoses and hose assemblies.This fourth edition cancels and replaces the third edition (ISO 7326:2006), which has been technically revised with the following changes: in Clause 2, the latest edition of ISO 1431-1 has
25、been cited; 5.5 and 9.4.1 have been amended; in 6.1.1, the formula has been amended.iv ISO 2016 All rights reservedBS EN ISO 7326:2016ISO 7326:2016(E)IntroductionThe methods described in this document provide a means of assessing the resistance of hoses to the deleterious effects of atmospheric ozon
26、e under static conditions. ISO 2016 All rights reserved vBS EN ISO 7326:2016BS EN ISO 7326:2016Rubber and plastics hoses Assessment of ozone resistance under static conditions1 ScopeThis document specifies five methods for determining the ozone resistance of the outer covers of hoses: method 1, for
27、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
28、 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
29、sheets of the appropriate polymeric compound vulcanized to the same degree.2 Normative referencesThe 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 un
30、dated references, the latest edition of the referenced document (including any amendments) applies.ISO 1431-1:2012, Rubber, vulcanized or thermoplastic Resistance to ozone cracking Part 1: Static and dynamic strain testingISO 23529, Rubber General procedures for preparing and conditioning test piece
31、s for physical test methods3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 8330 apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO O
32、nline browsing platform: available at http:/www.iso.org/obp4 General considerationsMethod 1 and method 2 are the methods normally used, method 3 being used only if it is not possible to carry out the test in accordance with method 2. Method 4 is suitable for all bore sizes. Method 5 is specifically
33、for testing expandable hoses in the expanded state.The results of tests carried out in accordance with method 1 may not be comparable with the results obtained when tests are carried out in accordance with method 2 or method 3, even if the cover compounds of the hoses under test are identical in com
34、position and are cured to the same degree. The test method to be used shall be as specified in the product standard.INTERNATIONAL STANDARD ISO 7326:2016(E) ISO 2016 All rights reserved 1BS EN ISO 7326:2016ISO 7326:2016(E)5 ApparatusAll apparatus placed in the test cabinet shall be fabricated from ma
35、terials which do not absorb or decompose ozone.5.1 Ozone cabinet, with apparatus for generating ozone, monitoring and controlling the ozone concentration, as described in ISO 1431-1.5.2 Test piece holder, as shown in Figure 1 (for method 1).5.3 Test piece holder, as shown in Figure 2, made, for exam
36、ple, of wood coated with paint or aluminium (for method 2).5.4 Jig, for elongation of test pieces (for method 3).Details given in ISO 1431-1:2012, 5.6 shall be followed.5.5 Cylinder, as shown in Figure 3, with an outside diameter 2 times that of the specified minimum bend radius for the hose being t
37、ested or, if not specified, 8 times the outside diameter (for method 4).5.6 Round rod, as shown in Figure 4, with an outside diameter 1,2 times the inside diameter of the hose being tested (for method 5).6 Test pieces6.1 Type of test piece6.1.1 Method 1The test piece shall consist of a hose sample.
38、The length shall be calculated by the following formula:Lrdd=+pibextext22whereL is the length of the test piece;rbis the bend radius of the hose under test, as specified in 9.1.1;dextis the outside diameter of the hose under test.6.1.2 Method 2The test piece shall consist of a strip cut longitudinal
39、ly from the hose. The strip shall be 150 mm long and 25 mm wide.6.1.3 Method 3The test piece shall consist of a strip of the hose cover, 25 mm in width, removed longitudinally from the hose. Lightly buff the underside of the strip in accordance with ISO 23529 to remove any reinforcement impressions
40、and thus ensure uniformity of strain along the length of the strip.2 ISO 2016 All rights reservedBS EN ISO 7326:2016ISO 7326:2016(E)6.1.4 Method 4The test piece shall consist of a hose sample long enough to be wound at least once round the cylinder which will be used for the test.6.1.5 Method 5The t
41、est piece shall consist of a straight length of hose approximately 50 mm long.6.2 Number of test piecesThree test pieces shall be tested.7 Conditioning of test piecesNo test shall be carried out within 24 h of manufacture.The time interval between manufacture and testing shall be as specified in ISO
42、 23529. For evaluations which are intended to be comparable, the test shall, as far as possible, be carried out after the same time interval after manufacture.The test pieces, mounted as described for the appropriate procedure, shall be conditioned for 48 h in a substantially ozone-free atmosphere a
43、t standard temperature (see ISO 23529), in darkness or subdued light.8 Test conditionsUnless other conditions are specified in the relevant hose specification, the test pieces shall be exposed in the ozone cabinet to an ozone concentration of (50 5) pphm (parts per hundred million) by volume at (40
44、2) C for ()7220h.NOTE It has been found that differences in atmospheric pressure can influence ozone cracking when test pieces are exposed to constant ozone concentrations expressed in parts per hundred million. This effect may be taken into account by expressing the ozone content in the ozonized ai
45、r in terms of the partial pressure, i.e. in millipascals, and making comparisons at constant ozone partial pressure. At standard conditions of atmospheric pressure and temperature (101 kPa, 273 K), a concentration of 1 pphm is equivalent to a partial pressure of 1,01 mPa.9 Procedure9.1 Method 19.1.1
46、 Mount each test piece on a test piece holder (5.2), as shown in Figure 1. The radius, rb, shall be equal to the specified minimum bend radius for the hose under test or, if not specified, 6 times the internal diameter.9.1.2 Seal the ends of the test pieces with caps to prevent absorption of ozone b
47、y the inner lining and reinforcement. ISO 2016 All rights reserved 3BS EN ISO 7326:2016ISO 7326:2016(E)9.1.3 After periods of exposure of 2 h, 4 h, 24 h, 48 h and 72 h, examine the test pieces, whilst still in the extended condition, under 2 magnification, ignoring the area adjacent to the fixing po
48、ints. If cracks are discovered, record their nature and the time at which they were first observed.12Key1 hose test piece Lrdd=+pibextext222 aluminium plug3 aluminium baseplateFigure 1 Arrangement for mounting hose for method 19.2 Method 29.2.1 Mount each test piece on a test piece holder (5.3), as
49、shown in Figure 2, so that the required elongation of the hose cover, measured over a distance of 20 mm, is reached. If not otherwise specified, the elongation of the cover shall be 20 %. Coat the edge and the lining of each test piece with an ozone-resistant lacquer.9.2.2 After periods of exposure of 2 h, 4 h, 24 h, 48 h and 72 h, examine the test pieces, whilst still in the extended condition, under 2 magnification, ignoring the area adjacent to the fixing points. If cracks are discovered, rec
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