1、BRITISH STANDARD BS EN 291:1992 Rubber seals Static seals in domestic appliances for combustible gas up to 200 mbar Specification for material The European Standard EN 291:1992 has the status of a British StandardBSEN291:1992 This British Standard, having been prepared under the directionof the Gas
2、Standards Policy Committee, was publishedunder the authority ofthe Standards Board and comesinto effect on 1 May 1992 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference GSE/22 Draft for comment 89/75928 DC ISBN 0 580 20482 0 Cooperating organizations Th
3、e European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries. Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraa
4、d Finland Suomen Standardisoimisliito, r.y. France Association franaise 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 Italian
5、o di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerlan
6、d Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN291:1992 BSI 09-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of EN 291 3 National appendix NA Ins
7、ide back cover National appendix NB Inside back coverBSEN291:1992 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 EN291 “Rubber seals Static seals in domestic appliances for comb
8、ustible gas up to 200mbar Specifications for material” published by the European Committee for Standardization (CEN). It partially supersedes BS6505. EN291 was produced as a result of international discussion in which the UK took an active part. National appendix NA gives the constitution of the com
9、mittees for UK participation in the preparation of this standard. National appendix NB gives details of International 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 provisi
10、ons of a contract. Users of British Standards are responsible for their correct application. Compliance with a British 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,
11、pages 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 291 February 1992 UDC: 62-76
12、2-036.4:64.06-843:620.1 Descriptors: Household appliances, gas appliances, seals: stoppers, rubber products, vulcanized rubber, classifications, characteristics, tests, specifications English version Rubber seals Static seals in domestic appliances for combustible gas up to 200 mbar Specifications f
13、or material Joints de caoutchouc Joints statiques dtanchit destins aux appareils domestiques utilisant les combustibles gazeux jusqu 200 mbar Spcifications pour le matriau Gummidichtungen Statische Dichtungen in Haushalts-Gerten fr gasfrmige Brennstoffe bis 200 mbar Anforderungen an den Werkstoff Th
14、is European Standard was approved by CEN on 1992-02-21. 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
15、 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 language made by translation under the responsibility of a CEN member into it
16、s 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, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switze
17、rland 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 1992 Copyright reserved to CEN members Ref. No. EN 291:1992 EEN291:1992 BSI 09-1999 2 Foreword This European Sta
18、ndard was prepared by CEN/TC108 “Sealing materials and lubricants for gas appliances and gas equipment”. In accordance with the Common CEN/CENELEC Rules, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Irela
19、nd, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. Contents Page Foreword 2 Introduction 3 1 Scope and field of application 3 2 Normative references 3 3 Definition 3 4 Classification of material 3 5 Requirements 3 6 Methods of test 4 Table 1 Classific
20、ation of material 3 Table 2 Requirements for material 4EN291:1992 BSI 09-1999 3 Introduction This standard defines only the quality of materials to be used for the manufacture of seals. It specifies tests to be carried out on specified samples taken from sheet and fixes the test values to be met. Th
21、ere is however, an urgent need for component testing and a standard is in preparation which will implement this in addition to the material testing as such. It may be necessary to carry out supplementary tests on the seals themselves. Test on seals mounted in the appliance. These tests are intended
22、to confirm the functional suitability of the seal and should be performed under the most severe service conditions envisaged in the appropriate standards for gas appliances and/or auxiliary equipment. Tests on the seal itself. These tests are intended to confirm that the material from which the seal
23、 is manufactured is one that complies with this standard. The fact that most seals are small in size does not, in general, allow for the necessary standard samples for the tests to be prepared from them. The test methods should be chosen from those specified in this standard but the test values will
24、 possibly be different due to the dimensional differences of the sample. 1 Scope and field of application This European Standard specifies requirements and test methods for homogeneous rubbers for static seals used in domestic gas appliances of all categories, and in auxiliary equipment mounted or i
25、ntended to be mounted on such appliances which are in contact with combustible gases up to200mbar (not including LPG in liquid phase). This standard does not specify the geometrical characteristics of the seals. The normal range of envisaged operating temperatures covered by this standard is0 C to 6
26、0 C. Temperatures outside this range can be proposed by the manufacturer with limits between 20 C and + 150 C. 2 Normative references ISO 37:1977, Rubber, vulcanized Determination of tensile stress-strain properties. ISO 48:1979, Vulcanized rubbers Determination of hardness (Hardness between30 and 8
27、5IRHD). ISO 188:1982, Rubber, vulcanized Accelerated ageing or heat-resistance tests. ISO 815:1972, Vulcanized rubbers Determination of compression set under constant deflection at normal and high temperatures. ISO 1653:1975, Vulcanized rubbers Determination of compression set under constant deflect
28、ion 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 Definition For the purposes of this standard the following definition applies: static seal
29、 a component which ensures a seal between two components which do not have relative movement NOTEThe term “static seal” in this standard applies also to those seals where the parts of the joint are able to be moved, e.g.by adjustment of the appliance by an expert, who should be able to check the sou
30、ndness of the joint. 4 Classification of material Ten classes (A1 up to E2) and two groups (/1 and /2) of material are specified according toTable 1. The classes are related to the working and test temperature. The groups are defined by their physical and chemical characteristics. The class and grou
31、p of the material shall be indicated by the manufacturer of the seal. 5 Requirements 5.1 Visual quality The test sample shall be homogeneous, free from porosity, inclusions, and surface imperfections visible to the naked eye, even after cutting. Table 1 Classification of material Range of operating
32、temperature ( C) from 0 0 0 0 0 20 20 20 20 20 to 60 80 100 125 150 60 80 100 125 150 Class/Group A1/1 B1/1 C1/1 D1/1 E1/1 A2/1 B2/1 C2/1 D2/1 E2/1 D2/2 E1/2 D2/2 E2/2EN291:1992 4 BSI 09-1999 5.2 Physical and chemical properties The material shall be in accordance with the requirements laid down inT
33、able 2. 6 Methods of test In addition to the conditions below reference should be made toTable 3. 6.1 General conditions Test pieces shall be cut from a sheet of material of (2) mm or (6,3 0,3) mm thickness according to the test. Measurements of thickness shall be carried out according to ISO4648. T
34、he material shall be from the same compound formulation used to make the seals, vulcanized under conditions which are comparable to those used in production. 6.2 Hardness Test the hardness in accordance with either of the methods specified in ISO48 but, in the event of disagreement the micro-test sh
35、all be used. Five measurements shall be carried out on each sample. 6.3 Tensile strength and elongation at break Test the tensile strength and elongation at break in accordance with the method specified in ISO37 using six dumb-bell test pieces, type2 being preferred. In the event of disagreement typ
36、e2 shall be used. 6.4 Compression set 6.4.1 Test at high temperature Test the compression 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 (168)h at a temperature related to th
37、e class of the material. Table 2 Requirements for material+0,2 0 0 2 Property Unit Group 1 Group 2 Hardness atolerances hardness 40 to 75 IRHD 5 5 hardness 76 to 84 IRHD 4 4 hardness 85 to 91 IRHD 3 3 Tensile strength MPa U 7 U 5 Elongation at break % U 125 U 125 Compression set at high temperature
38、b % k 40 k 40 at low temperature 0 C (A1 to E1) % k 40 k 40 20 C (A2 to E2) % k 50 k 50 Resistance to ageing change in hardness, max. IRHD 10 10 change in tensile strength, max. % k 50 k 50 change in elongation at break, max. % k 50 k 50 Gas resistance change in mass after immersion, max. % + 10 5 n
39、o requirement c change in mass after drying, max. % + 5 8 5 Lubricant resistance change in hardness, max. IRHD 10 15 change in volume, max. % + 15 10 + 10 10 a The hardness of the material shall be stated by the manufacturer of the seal. b The sample shall not be damaged by adhering to the surfaces
40、of the test apparatus. c The swelling after immersion in liquid n-pentane by some Group 2 materials may be substantial.EN291:1992 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.
41、Place the loaded compression apparatus in a low temperature cabinet for a duration of (72)h at a temperature related to the class of material. 6.5 Resistance to ageing Test the resistance to ageing in accordance with the method specified in ISO 188, in a normal oven, using six dumb-bell test pieces
42、type2 (see6.3) and3 separate test pieces for the hardness test (see6.2). Place the test pieces in the oven for a duration of (168)h at a temperature related to the class of the material. 6.6 Resistance to gas Test the resistance to gas in accordance with8.2 of ISO1817:1985 and the following conditio
43、ns. Use three previously weighed test pieces each of (50 20 2)min. Immerse all three samples for (72) h at (23 2) C in n-pentane (98% min. n-pentane by mass, estimated by gas chromatography). After removal from the liquid, dry rapidly by wiping and immediately weigh. Determine the change in mass wit
44、h reference to the initial mass of the sample. Dry for a period of (168) h in an oven at (40 1) C at atmospheric pressure. Determine by weighing the new change in mass with reference to the initial mass of the sample. For the calculation, the arithmetic mean value of the three results both after imm
45、ersion and after drying is used. 6.7 Resistance to lubricants Test the resistance to lubricants in accordance with ISO 1817:1985 volumetric method (8.2) and hardness test (11.2) and the following conditions. Use three test pieces each (50 20 2)mm. Duration of immersion to be (168)h in oil No.2 with
46、maximum envisaged working temperature corresponding to the material classification according toTable 1. Determine the change in volume and of the change in hardness. 02 02 02 02 02 EN291:1992 6 BSI 09-1999 Table 3 Test methods Property ISO Test pieces Test temperature ( C) Duration of test (h) Remar
47、ks Type Number Hardness 48 3 23 2 Micro-hardness test shall be used for reference purposes Tensile strength and elongation at break 37 dumb-bell type 2 6 23 2 Compression set at high temperature 815 small test pieces disc (13,0 0,5) mm (6,3 0,3) mm thickness 3 class A: 70 1 B: 100 1 C: 125 2 D: 150
48、2 E: 175 2 168 at low temperature 1653 small test pieces disc (13,0 0,5) mm (6,3 0,3) mm thickness 3 class A1 to E1: 0 1 A2 to E2: 20 1 72 Final measurement after (30 3) min at (0, 20) C at the end of the exposure period Resistance to ageing 188 hardness tensile strength and elongation at break dumb
49、 bell type 2 3 6 class A: 70 1 B: 100 1 C: 125 2 D:150 2 E: 175 2 168 Normal oven Resistance to gas immersion in n-pentane 8.2 of 1817:1985 (50 20 2) mm 3 23 2 72 Weigh and determine change in mass. Use the arithmetic mean value, both after immersion and after drying drying 40 2 168 Lubricant resistance 8.2 and 11.2 of 1817:1985 (50 20
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