1、BS 7531:2006Rubber bonded fibre jointing for industrial and aerospace purposes SpecificationICS 23.040.80NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDIncorporatingcorrigendum no. 1Publishing and copyright informationThe BSI copyright notice displayed in this
2、document indicates when the document was last issued. BSI 2006ISBN 0 580 49231 1The following BSI references relate to the work on this standard:Committee reference PSE/2Draft for comment 06/30144329 DCPublication historyFirst published 1992Amendments issued since publicationAmd. no. Date Text affec
3、ted16859Corrigendum No. 131 January 2007 Change to figure A.2BS 7531:2006 BSI 2007 iBS 7531:2006ContentsForeword ii1 Scope 12 Normative references 13 Terms and definitions 14 Information to be supplied by purchaser 25 Grades and materials 26 Finish 37 Thickness 38 Tests 49 Retest 510 Marking 611 Tes
4、t certificate 6AnnexesAnnex A (normative) Method of carrying out residual stress test 7Annex B (normative) Method of carrying out flexibility test 12Annex C (normative) Method of carrying out compressibility test 13Annex D (normative) Method of carrying out gas permeability test 14Annex E (normative
5、) Method of carrying out resistance to fluids tests 16Annex F Method of calibration of residual stress testing apparatus 18Annex G Method of test to determine maximum stress value 19List of figuresFigure A.1 General assembly of residual stress testing apparatus 7Figure A.2 Details of residual stress
6、 testing apparatus 8Figure A.3 Details of dynamometer for calibration of residual stress testing apparatus 9Figure A.4 Typical calibration curve for residual stress testing apparatus 10Figure D.1 Typical layout of test apparatus for gas permeability 15Figure F.1 Arrangement for calibration of dynamo
7、meter at increased temperatures 18Figure F.2 Dynamometer 19List of tablesTable 1 Tolerance for thickness of sheet 4Table 2 Resistance to fluids 5Table A.1 Residual stress: Test report 12Table E.1 Resistance to fluids test conditions 17Summary of pagesThis document comprises a front cover, an inside
8、front cover, pages i and ii, pages 1 to 20, an inside back cover and a back cover.BS 7531:2006ii BSI 2007ForewordPublishing informationThis British Standard was published by BSI and came into effect on 31 October 2006. It was prepared by Technical Committee PSE/2, Jointing materials and compounds. A
9、 list of organizations represented on this committee can be obtained on request to its secretary. SupersessionThis British Standard supersedes both BS 7531:1992 andBS F 130:1987, which are withdrawn.Information about this documentThis new edition represents a full revision of the standard, and intro
10、duces the following principal change:Expansion of the Scope and amendment to the text to include two grades for use in aerospace applications which were previously covered in BS F 130:1987.Hazard warningsWARNING. This British Standard calls for the use of substances and/or procedures that can be inj
11、urious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Its re
12、quirements are expressed in sentences in which the principal auxiliary verb is “shall”.Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.Contractual and legal considerationsThis publication does not purport to in
13、clude all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.The BSI copyright notice displayed in this document indicates when the document was last issued. BSI 2007 1BS 7531:2006
14、1 ScopeThis British Standard specifies the requirements for the manufacture, quality and finish, thickness and testing of elastomer bonded compressed fibre jointing materials.This British Standard provides for four grades as follows:a) Grades X and Y for general industrial use.b) Grades AX and AY fo
15、r use in aerospace applications.In addition to the definitive requirements, this standard also requires the items detailed in Clause 4 to be documented. For compliance with this standard, both the definitive requirements and the documented items have to be met.2 Normative referencesThe following ref
16、erenced documents are indispensable for the application 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.BS 6920-1, Suitability of non-metallic products for use in contact
17、with water intended for human consumption with regard to their effect on the quality of the water Part 1: SpecificationBS 870, External micrometersBS 907, Specification for dial gauges for linear measurementBS 3643-1, Specification for ISO metric screw threads Part 1: Principles and basic dataBS EN
18、10269, Steels and nickel alloys for fasteners with specified elevated and/or low temperature propertiesBS EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring systemDIN 3535
19、-6, Gaskets for gas supply Part 6: Gasket materials based on synthetic fibres, graphite or polytetrafluoroethylene (PTFE) for gas valves, gas appliances and gas mainsBS ISO 1817, Rubber, vulcanized Determination of the effect of liquids3 Terms and definitionsFor the purposes of this British Standard
20、, the following terms and definitions apply.3.1 jointing manufactured solid run single-ply material supplied in sheets, from which required shapes can be cut and used for the purpose of sealing mating faces of components from the ingress or egress of fluids3.2 manufacturing runamount of jointing all
21、 of one grade in units of a maximum of 5 tBS 7531:20062 BSI 20073.3 batch of materialsingle mix of ingredients that is uniquely identified and traceable4 Information to be supplied by purchaserThe following information to be supplied by the purchaser shall be fully documented. For compliance with th
22、e standard both the definitive requirements specified throughout the standard and the following documented items shall be satisfied.a) the number of this British Standard, i.e. BS 7531:2006 (see 10.1);b) for Grades AX and AY the fibre type (see 5.2);c) the grade of jointing required (see Scope);d) t
23、he thickness required (see 7.1);e) the dimensions of sheets required;f) the quantity of sheets required;g) if wire mesh reinforcement is required and, if so the wire material, diameter and mesh size (see 5.3);h) if the jointing will or is likely to come into contact with potable water (see 5.4);i) i
24、f the manufacturers identification mark is not required to be indelibly marked on the jointing (see 10.3);j) for Grades AX and AY if a test certificate is required (see 11.1);k) if one or both surfaces shall be treated with a suitable release agent, e.g. graphite (see Clause 6).5 Grades and material
25、s5.1 GradesFor grades AX and AY the binder shall be acrylonitrile-butadiene (NBR) elastomer.5.2 MaterialNOTE Examples of fibres that can be used (singly or in combination) are aramid, carbon and glass.The material shall consist of fibres and inorganic fillers bonded with a suitable elastomer or blen
26、d of elastomers, and shall be manufactured in the form of sheets. The fibres shall be uniformly dispersed throughout the jointing.For Grades AX and AY the purchaser shall state which fibre type is required.5.3 ReinforcementAll grades shall be available with or without wire mesh reinforcement.The pur
27、chaser shall state if wire mesh reinforcement is required and the wire material, diameter and mesh size should be specified. BSI 2007 3BS 7531:20065.4 Contact with potable waterWhen used under the conditions for which they are designated, non-metallic products in contact with or likely to come into
28、contact with potable water shall comply with the requirements of BS 6920-1.NOTE 1 Non-metallic products for installation and use in the United Kingdom which are verified and listed under the UK Water Fitting Byelaws Scheme are deemed to satisfy the requirements of this clause. Details of the Scheme
29、are obtainable from WRC plc, 660 Ajax Avenue, Slough SL1 4BG.NOTE 2 Non-metallic products approved by the Department of the Environment Committee on Chemicals and Materials of construction for use in Public Water Supply and Swimming Pools are considered free from adverse health effects for the purpo
30、ses of compliance with this clause.A list of approved chemicals and materials and details of the approvals scheme are available from the Secretary of the Committee at the Department of the Environment, Water Division, Romney House, 43 Marsham Street, London SW1P 3PY.The purchaser shall state whether
31、, when used under the conditions for which they are designated, non-metallic products come or are likely to come into contact with potable water.6FinishThe sheets of all grades of jointing shall be solid run (not laminated), of uniform texture, smooth on both sides and free from irregularities such
32、as blisters, tears and lumps.The purchaser shall state whether, and which, surfaces shall be treated with an acceptable release agent, e.g. graphite.7 Thickness7.1 Nominal thicknessThe nominal thickness of all grades of jointing shall be one of the following:a) 0.4 mm;b) 0.5 mm;c) 0.75 mm;d) 1.0 mm;
33、e) 1.5 mm;f) 2.0 mm.NOTE For any grade of material the compressive strength at elevated temperature decreases with increasing thickness.The purchaser shall state the thickness required.BS 7531:20064 BSI 20077.2 Thickness toleranceThe maximum variation of any sheet from the nominal thickness, and the
34、 maximum possible variation in thickness between any points not more than 250 mm apart on a sheet, shall be in accordance with Table 1.7.3 Thickness measurementThe thickness shall be measured with either:a) a ratchet micrometer complying with BS 870 and having an anvil of 6 mm to 16 mm in diameter.
35、The reading shall be taken after three clicks of the ratchet; orb) a dial type micrometer complying with BS 907, with a flat pressure foot of not less than 6 mm diameter and a flat anvil of diameter not less than that of the pressure foot.8Tests8.1 SamplesThe manufacturer shall select from each manu
36、facturing run for Grades X and Y and each batch for Grades AX and AY, a sample or samples including those treated with release agent, e.g. graphite, where appropriate sufficient to provide the test pieces for one complete series of tests as specified in this clause.The manufacturer shall carry out t
37、ests in accordance with 8.2 to 8.6 for each manufacturing run of each grade of jointing and additionally shall carry out tests in accordance with 8.2, 8.4 and 8.6 (Oil No. 3 only) for each batch of grades AX and AY.8.2 Residual stressThe residual stress when determined in accordance with Annex A sha
38、ll be not less than 25 MPa for grades X and AX or 22 MPa for grades Y and AY.8.3 FlexibilityWhen tested in accordance with Annex B in the as supplied condition all grades shall not crack or delaminate.Table 1 Tolerance for thickness of sheetNominal thickness of sheetmmMaximum permissible variation f
39、rom nominal thicknessmmMaximum permissible variation in thickness between points not more than 250 mm apartmm0.4 and 0.5 0.05 0.050.75 and 1.0 0.10 0.101.5 and 2.0 0.15 0.10 BSI 2007 5BS 7531:20068.4 CompressibilityNOTE Values for thicknesses of 0.4 and 0.5 mm have been omitted owing to the practica
40、l difficulty of making satisfactory measurements.When determined in accordance with Annex C jointing of 0.75 mm nominal thickness and above shall show a depth of the impression, expressed as a percentage of the original thickness under preload, of not less than 6% for all grades and not more than 14
41、% for grades AX and AY.8.5 Gas permeabilityNOTE Due to the nature of their construction wire reinforced materials are unable to meet this requirement and hence are excluded from this test.When determined in accordance with Annex D the leakage for non-wire reinforced material shall not exceed 1 ml/mi
42、n for all grades.8.6 Resistance to fluidsWhen tested in accordance with Annex E the materials shall meet the requirements shown in Table 2.After immersion the samples shall not crack or delaminate when tested in accordance with Annex B nor shall their surfaces show signs of tackiness but discolorati
43、on and surface blistering is permitted.9 RetestIf any sample fails to comply with the requirements related to any appropriate test, two further samples shall be selected from the same manufacturing run for retesting. If either of the retest samples fails the test the whole manufacturing run of mater
44、ial shall be deemed not to comply with this British Standard.Table 2 Resistance to fluidsFluid Oil No. 1 at 150 C Oil No. 3 at 150 CLiquid 101 at 150 C Liquid B at 23 C Water at 100 CGrade Thickness increase % maxMass increase % maxThickness increase % maxThickness increase % maxMass increase % maxT
45、hickness increase % maxMass increase % maxThickness increase % maxX and Y N/A N/A 20 up to 0.75 mm, 10 aboveN/A N/A N/A N/A 15AX and AY 12 15 20 up to 0.75 mm, 10 above12 15 12 15 N/ABS 7531:20066 BSI 200710 Marking10.1 Every sheet of jointing shall be indelibly marked with the number of this Britis
46、h Standard and the grade of material, e.g. BS 7531:20061)Grade X.10.2 Every sheet of jointing to Grades AX and AY shall additionally be marked with its batch number and month and year of manufacture.10.3 If the jointing is marked with the manufacturers identification mark this shall be indelibly mar
47、ked on every 300 mm 300 mm of the jointing.The purchaser shall state if the manufacturers identification mark is not required. 11 Test certificate11.1 For jointings to Grades AX and AY each batch of material shall be uniquely identified and supplied with a test certificate.11.2 Where a test certific
48、ate is to be provided it shall be worded as follows.We hereby certify that the jointing supplied complies in all respects with the requirements of BS 7531, Specification for rubber bonded fibre jointing for industrial and aerospace purposes.Grade The certificate shall also state the batch number and
49、 month and year of manufacture.NOTE Except in the case of Grades AX and AY a test certificate is not normally provided. The purchaser shall state whether a test certificate is required.1)Marking BS 7531:2006 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is solely the claimants responsibility. Such a dec
