1、BRITISH STANDARD BS EN 278:1991 Specification for Rubber materials for diaphragms in domestic appliances using combustible gases up to 200 mbar This European Standard EN278:1991 has the status of a British StandardBSEN278:1991 This British Standard was published under the authorityofthe Standards Bo
2、ardand comes intoeffecton 29November1991 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference GSE/22 Draft for comment 88/74021 DC ISBN 0 580 19959 2 Cooperating organizations The European Committee for Standardization, under whose supervision this Europe
3、an Standard was prepared, comprises the national standards organizations of the following Western European countries. Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association fra
4、naise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Ne
5、therlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Stand
6、ards Institution Amendments issued since publication Amd. No. Date CommentsBSEN278:1991 BSI 09-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of EN 278 3 National appendix NA Inside back cover National appendix NB Inside back coverBSEN278:1991
7、ii BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Gas Standards Policy Committee and is the English language version of EN278, “Rubber materials for diaphragms in domestic appliances using combustible gases up to200 mbar” published by the European Co
8、mmittee for Standardization (CEN). EN278 was produced as a result of international discussion in which the UK took an active part. National appendix NA gives the constitution of the committees for UK participation in the preparation of this standard. National appendix NB gives details of Internation
9、al Standards quoted in this standard for which there is an identical or technically equivalent British Standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Brit
10、ish Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may ha
11、ve had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 278 May 1991 UDC 678.4:620.1:62-416:641.534.06 Incorporates Corrigendum September 1991 Descriptors: Household appliances, gas appliances, membr
12、anes, rubber products, specifications, characteristics, tests English version Rubber materials for diaphragms in domestic appliances using combustible gases up to 200 mbar Matriaux base de caoutchouc pour membranes destines aux appareils domestiques utilisant les combustibles gazeux jusqu 200 mbar E
13、lastomer-Werkstoffe fr Membranen in Haushaltsgerten fr Brenngase bis 200 mbar This European Standard was approved by CEN on6May1991. 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 sta
14、ndard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other
15、language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ire
16、land, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1991 Copyright reserved to all
17、CEN members Ref. No. EN 278:1991 EEN278:1991 BSI 09-1999 2 Foreword This European Standard was prepared by CEN/TC108 on the basis of a document drawn up by MARCOGAZ, AFECI, AEGPL and AFECOGAZ Liaison Committee CL13 “Lubricant and Sealing Materials”. In accordance with the Common CEN/CENELEC Rules, t
18、he following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword 2 Introduction 3 1 Scope and fi
19、eld of application 3 2 Normative references 3 3 Definitions 3 4 Classification of materials 3 5 Requirements 3 6 Methods of test 4 Table 1 Classification by hardness 3 Table 2 Requirements for material 4 Table 3 Test methods 6EN278:1991 BSI 09-1999 3 Introduction This standard defines the quality of
20、 materials to be used for the manufacture of diaphragms. It specifies tests to be carried out on specified samples taken from sheet and fixes the test values to be met. It may be necessary to carry out supplementary tests on the diaphragms themselves. Tests on diaphragms mounted in the appliance. Th
21、ese are intended to confirm the functional suitability of the diaphragms and should be performed under the most severe service conditions envisaged in the appropriate standards. Tests on the diaphragm itself. These are intended to confirm that the material from which the diaphragm is manufactured is
22、 one that complies with this standard. The fact that most diaphragms are small in size does not in general, allow for the necessary standard samples to be prepared for the tests from them. The test methods shall be chosen from those specified in this standard but the test values will possibly be dif
23、ferent due to the dimensional differences of the sample. This can also be especially applicable to diaphragms manufactured from fabric reinforced materials. In the case of reinforced diaphragms, the gas resistance, and lubricant resistance tests should be carried out on “finished” material: no delam
24、ination should occur. 1 Scope and field of application This European standard specifies requirements and tests for rubber materials for diaphragms used in domestic gas appliances of all categories, and auxiliary equipment mounted on or intended to be mounted on such appliances, in contact with combu
25、stible gases, up to200 mbar. This standard deals with materials from which are manufactured diaphragms of two kinds: homogeneous; reinforced. The normal range of envisaged operating temperatures covered by this standard is0 C to60 C. Temperatures outside this range may be proposed by the manufacture
26、r with limits between 20 C and+80 C. 2 Normative references ISO 37:1977, Rubber, vulcanized Determination of tensile stress-strain properties. ISO 48:1979, Vulcanized rubbers Determination of hardness (Hardness between 30 and 85 IHRD). ISO 188:1982, Rubber, vulcanized Accelerated ageing or heat-resi
27、stance tests. ISO 815:1972, Vulcanized rubbers Determination of compression set under constant deflection at normal and high temperatures. ISO 1431-1:1989, Rubber, vulcanized or thermoplastic Resistance to ozone cracking Part 1: Static strain test. ISO 1653:1975, Vulcanized rubbers Determination of
28、compression set under constant deflection at low temperatures. ISO 1817:1985, Rubber vulcanized Determination of the effect of liquids. ISO 4648:1978, Rubber, vulcanized Determination of dimensions of test pieces and products for test purposes. 3 Definitions For the purposes of this standard the fol
29、lowing definitions apply. 3.1 diaphragm thin membrane of rubber, located in a fixture and serving as a flexible gas tight partition between two chambers 3.2 reinforcement woven or unwoven textile, arranged in or on the rubber diaphragm material, thus reinforcing certain of the properties of such a d
30、iaphragm, for example the bursting strength 4 Classification of materials There are three classes (1, 2 and3) which are defined by the range of hardness in accordance withTable 1. Table 1 Classification by hardness The class and temperature range shall be indicated by the diaphragm material manufact
31、urer. He shall also indicate if the diaphragm material is or is not resistant to ozone. 5 Requirements 5.1 Visual property The material shall be free from porosity, inclusions, blisters and surface imperfections visible to the naked eye. Class 1 2 3 Range of hardness (IRHD) 35 to 40 41 to 55 56 to 7
32、5EN278:1991 4 BSI 09-1999 Table 2 Requirements for material 5.2 Physical and chemical properties The material shall be in accordance with the requirements laid down inTable 2. 6 Methods of test In addition to the conditions below reference should be made toTable 3. 6.1 General conditions Test pieces
33、 shall be cut from a sheet of material() mm or (6,3 0,3) mm thickness according to the test. Measurement of thickness shall be carried out according to ISO4648. The material shall be from the same compound formulation used to make the components, and vulcanized under conditions which are comparable
34、to those used in production. 6.2 Hardness Test the hardness in accordance with one of the methods specified in ISO48, in the event of a disagreement the micro-test shall be used. Five measurements shall be carried out on each sample. 6.3 Tensile strength and elongation at fracture Test the tensile s
35、trength and elongation at fracture with the method specified in ISO37 and the following special conditions. Six dumb-bell test pieces, type2 is preferred. In the event of a disagreement, type2 shall be used. 6.4 Compression set 6.4.1 Test at high temperature and standard temperature Test the compres
36、sion set at high temperature in accordance with the method specified in ISO815 using three small test pieces. Place the loaded compression apparatus in an oven for a duration of () h at (23 2) C and then for a period of () h in an oven at (70 1) C. For envisaged operating temperatures above the norm
37、al limit of60 C, the test shall be carried out at10 C above the upper limit. Property Unit Class 1 2 3 Hardness a Tolerances on the values given by the supplier IRHD IRHD 35 to 40 5 41 to 55 5 56 to 75 5 Tensile strength Elongation at break MPa % U 5 U 500 U 7 U 300 U 10 U 200 Compression set bat lo
38、w temperature at standard temperature +23 C at high temperature % % % k 40 k 20 k 35 k 40 k 20 k 25 k 40 k 20 k 25 Resistance to ageing change in hardness change in tensile strength change in elongation at break IRHD % % 8 U 15 U 25 8 U 15 U 25 8 U 15 U 25 Resistance to gas change of mass after imme
39、rsion change of mass after drying % % 10 to + 10 15 to + 5 5 to + 10 10 to + 5 5 to + 10 8 to + 5 Resistance to lubricants change in volume change in hardness % IRHD 10 to + 15 10 10 to + 15 10 10 to + 15 10 Resistance to ozone c no cracks no cracks no cracks a The hardness of the material shall be
40、stated by the manufacturer. b The sample shall not be damaged by adhering to the surfaces. c Requirement for this test will be limited to material declared ozone resistant by the manufacturer. Due to the potential interruption of any surface, such as waxes, by the operation of the diaphragm such pro
41、tective methods shall not be used without some additional protective additive. 2 +0,2 0 72 0 2 24 0 0,5EN278:1991 BSI 09-1999 5 6.4.2 Test at low temperature Test the compression set at low temperature in accordance with the method specified in ISO1653 using three small test pieces. Place the loaded
42、 compression apparatus for a duration of () h in a low temperature cabinet at( 5 1) C. For envisaged operating temperatures below the normal limit of0 C, the test shall be carried out at5 C below the lower limit. 6.5 Resistance to ageing Test the resistance to ageing in accordance with the method sp
43、ecified in ISO188 in a normal oven using six dumb-bell testpieces, type2 (see6.3) and three separate test pieces for the hardness test (see6.2). Place the test pieces in the oven for a duration of() h at (70 1) C. If the envisaged operating temperature is above the normal limit of60 C, the test shal
44、l be carried out at10 C above the upper limit. 6.6 Resistance to gas Test the resistance to gas in accordance with ISO1817:1985 specifically8.2, and the following special conditions. Using three weighed test pieces each of dimensions50mm 20mm 2mm. Immerse all three samples for () h at (23 2) C in n-
45、pentane (98% min. normal pentane by mass, estimated by gas chromatography). After removal from the liquid, dry rapidly and weigh immediately. Determine the change in mass with reference to the initial mass of the sample. Dry for a period of () h in an oven at(40 1) C at atmospheric pressure. Determi
46、ne the new change in mass with reference to the initial mass of the sample by weighing. For the calculation, the arithmetic mean value of the three results both after immersion and after drying to be used. 6.7 Resistance to lubricant Test the resistance to lubricants in accordance with ISO1817:1985
47、“volumetric method” (8.2) and “hardness test” (11.2) and the following special conditions. Three test pieces each of50mm 20mm 2mm. Duration of immersion to be () h in oil no. 2 at the maximum envisaged working temperature of(60 1) C or upper declared limit if greater. Determine the change in volume
48、and the change in hardness. 6.8 Resistance to ozone Test the resistance to ozone in accordance with ISO1431-1 “Method A” and the following special conditions. Duration of the test: () h. Concentration of ozone (50 5) pphm by volume 1) . Test temperature: (30 2) C. Relative humidity: k 65%. Elongatio
49、n of sample: (20 2)%. 72 0 2 168 0 2 72 0 2 168 0 2 1) pphm = parts per hundred millions 168 0 +2 24 0 0,5EN278:1991 6 BSI 09-1999 Table 3 Test methods Property ISO Test pieces Test temperature ( C) Duration of test (h) Remarks Type Number Hardness 48 3 23 2 Micro-hardness test is mandatory for reference purposes Tensile strength and elongation at break 37 dump-bell type 2 6 23 2 Compression set at low temperature 1653 sma
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