1、BS ISO27996:2009ICS 49.080; 83.140.50NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAerospace fluidsystems Elastomerseals Storage andshelf lifeThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 March2009 BSI
2、 2009ISBN 978 0 580 57603 4Amendments/corrigenda issued since publicationDate CommentsBS ISO 27996:2009National forewordThis British Standard is the UK implementation of ISO 27996:2009.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/69, Aerospace hydraulic systems, fl
3、uids andcomponents.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot conf
4、er immunityfrom legal obligations.BS ISO 27996:2009Reference numberISO 27996:2009(E)ISO 2009INTERNATIONAL STANDARD ISO27996First edition2009-02-01Aerospace fluid systems Elastomer seals Storage and shelf life Systmes de fluides pour laronautique et lespace Joints lastomres Stockage et dure de conser
5、vation BS ISO 27996:2009ISO 27996:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performi
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8、etariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writ
9、ing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 279
10、96:2009ISO 27996:2009(E) ISO 2009 All rights reserved iiiForeword 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 committee
11、s. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Inter
12、national Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International St
13、andards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the sub
14、ject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 27996 was prepared by Technical Committee ISO/TC 20, Aircraft and Space Vehicles, Subcommittee SC 10, Aerospace fluid systems and components. BS ISO 27996:2009ISO 27996:2009(E) iv ISO 2009 All
15、 rights reservedIntroduction In fluid power systems, power is transmitted and controlled through a fluid (liquid or gas) under pressure within an enclosed circuit. Components are designed to meet these requirements under varying conditions. Testing of components to meet performance requirements prov
16、ides users a basis of assurance for determining design application and for checking component compliance with their stated requirements. BS ISO 27996:2009INTERNATIONAL STANDARD ISO 27996:2009(E) ISO 2009 All rights reserved 1Aerospace fluid systems Elastomer seals Storage and shelf life 1 Scope This
17、 International Standard is applicable to the general requirements for data recording procedures, packaging, and storing of elastomeric seals and seal assemblies which include an elastomeric element prior to the seal being assembled into hardware components. The requirements for packaging are an inte
18、gral part of the controlled storage procedure and provide a means of positive product identity from the time of manufacture to the time of assembly into a component. This International Standard does not establish limitations or storage times for assembled components nor the operating life of these c
19、omponents. The information contained in this International Standard is intended for use by those organizations that do not have specific requirements or recommendations already in place for the control of elastomeric seals and seal assemblies. This International Standard can be specified in control,
20、 storage and procurement documents. However, when the requirements of this International Standard are in conflict with the customers requirements or specifications, the requirements of the customers detailed specifications take precedence. 2 Normative references The following referenced documents ar
21、e 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. ISO 1629, Rubbers and lattices Nomenclature ISO 5598, Fluid power systems and componen
22、ts Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply. 3.1 date of vulcanization date on which the elastomer product was vulcanized NOTE Date of vulcanization is expressed in quarters (Q) of a year. EXAMPLE 4Q08 (
23、October to December, 2008). 3.2 elastomer material that possesses elastic properties and has undergone vulcanization and/or conversion into a finished product NOTE The basic building block of elastomer is the rubber polymer it contains. BS ISO 27996:2009ISO 27996:2009(E) 2 ISO 2009 All rights reserv
24、ed3.3 end user user carrying out the installation into a hardware component which can include an aircraft 3.4 extended storage life period for which an elastomer seal element moulded from class III material and properly packaged can be stored after the initial storage period and the successful reins
25、pection and testing of representative samples 3.5 hardware component unit in which the elastomeric seal element is installed 3.6 installation date date of the first installation into a hardware component 3.7 limited storage life period of time during which an elastomeric seal element which has not b
26、een properly packaged by the manufacturer in an expedient manner after vulcanization can be installed without first testing for product integrity 3.8 rubbers polymeric building blocks of an elastomers chemical composition NOTE Rubbers are further defined in ISO 1629. 3.9 seal elastomeric seal config
27、uration or an assembly with an elastomeric element which prevents the excursion of media on one side of the product from migrating to the other side 3.10 storage life period of time, in quarters of a year, from the date of vulcanization until installation into a hardware component NOTE The storage l
28、ife is counted from the quarter following the date of vulcanization. 3.11 storage life limit maximum period of time, starting from the quarter following vulcanization, that an elastomeric seal element, appropriately packaged, can be stored under specific conditions, after which time it is regarded a
29、s unserviceable for the purposes for which it was originally manufactured 4 General The life of elastomeric seal elements is reduced by the influence of environmental factors, e.g. ozone, heat and light. To extend life to the full storage life limit, the seal elements shall be properly packaged and
30、certified as such by the manufacturer as quickly as possible following vulcanization. If the seal elements are not properly packaged and certified as such by the manufacturer, then the limited storage life requirement is followed and package labels shall indicate this. BS ISO 27996:2009ISO 27996:200
31、9(E) ISO 2009 All rights reserved 35 Packaging 5.1 General Unless otherwise specified by the customer at the time of order, the elastomeric seal or seal assembly shall be packaged: a) in individually sealed envelopes by the manufacturer, or b) in individually sealed packets in multiple envelopes by
32、the manufacturer, provided that individually packaged elastomeric seals or assemblies can be removed without affecting the seal integrity of the other packets. The packaging shall be carried out in an atmosphere in which the relative humidity is not greater than 65 %. Contamination by oil, grease, e
33、tc. shall be avoided. Seal assemblies (all components) shall be packaged in the same sealed envelope so that all elements of the assembly are present when the package is opened. 5.2 Packaging materials All packaging materials shall be free of copper naphthenates or creosote preservatives which can d
34、egrade rubber. Suitable materials include kraft bags (polyethylene coated kraft paper) and polyethylene bags more than 0,075 mm thick and certified to be ultraviolet (UV) resistant. Opaque packaging is preferred, but certified UV resistant materials can be used if available. Metal foil bags can be u
35、sed provided they are salt free. 5.3 Labelling Each package or container shall be labelled with the following information, which shall be visible from the outside of the package without breaking the seal: a) manufacturers part number; b) specification number and revision level; c) customers part num
36、ber and/or contract number (if requested); d) quantity in package; e) manufacturers name and/or identity number e.g. commercial and government entity (CAGE) code; supplier number; f) quarter and year of cure or manufacturer of the rubber component e.g. 3Q08 (July to September 2008); g) manufacturers
37、 batch number; h) rubber class designation in accordance with ISO 1629; i) identity of packager and package date, if different than manufacturer. Expiration date is not required to be on the label and is added only when purchaser specifically requests the addition. BS ISO 27996:2009ISO 27996:2009(E)
38、 4 ISO 2009 All rights reserved6 Storage 6.1 Temperature The storage temperature should be in the range of 5 C to 30 C, except when higher or lower temperatures are caused by temporary climate changes. Articles shall be stored away from direct sources of heat such as boilers, radiators and direct su
39、nlight. NOTE If the storage temperature is below 10 C, it is important to take care during the handling of stored articles, as they might have stiffened and become susceptible to distortion if not handled carefully. The temperature of articles stored below 10 C shall be raised to approximately 20 C
40、throughout their mass before being installed into a component. 6.2 Humidity The relative humidity shall be such that, given the variations of temperature in storage, condensation does not occur. In any event, if the elastomers are not stored in sealed moisture-proof bags, the relative humidity of th
41、e atmosphere in storage should be between 40 % and 70 %, or if polyurethanes are being stored, the relative humidity should not exceed 65 %. 6.3 Light Elastomeric seals shall be protected from light sources, in particular direct sunlight or intense artificial light having an ultraviolet content. The
42、 individual kraft storage bags offer the best protection from light. NOTE It is advisable that windows of storage rooms where elastomers are stored in bulk be covered with a red or orange coating or screen. 6.4 Radiation Precautions shall be taken to protect stored articles from all sources of ioniz
43、ing radiation likely to cause damage to stored articles. 6.5 Atmosphere As ozone is particularly deleterious to some elastomeric seals, storage rooms shall not contain any equipment that is capable of generating ozone, such as mercury vapour lamps, high voltage electrical equipment giving rise to el
44、ectric sparks or silent electrical discharges. Combustion gases and organic vapour shall be excluded from storage rooms, as they may give rise to ozone via photochemical processes. 6.6 Deformation Elastomeric seals shall be stored free from superimposed tensions and compressive stresses, or other ca
45、uses of deformation. Where articles are packaged in a strain-free condition, they shall be stored in their original packaging. In case of doubt, the manufacturers advise shall be sought. Rings of large inside diameter shall be formed into three equal superimposed loops so as to avoid creasing or twi
46、sting. NOTE It is not possible to achieve this condition by forming just two loops. 6.7 Contact with liquid and semi-solid materials Elastomeric seals shall not be allowed to come into contact with liquid or semi-solid materials (e.g. gasoline, greases, acids, disinfectants, cleaning fluids) or thei
47、r vapours at any time during storage, unless these materials are by design an integral part of the component or the manufacturers packaging. When elastomeric seals are received coated with their operational media, they shall be stored in this condition. BS ISO 27996:2009ISO 27996:2009(E) ISO 2009 Al
48、l rights reserved 56.8 Contact with metals Certain metals and their alloys (in particular, copper, manganese, iron and cadmium) are known to have deleterious effects on elastomers. Elastomeric seals shall not be stored in contact with such metals (except when bonded to them), but shall be protected
49、by individual packaging. 6.9 Contact with dusting powder Dusting powders shall only be used for the packaging of elastomeric items in order to prevent sticking. In such instances, the minimum quantity of powder to prevent adhesion shall be used. 6.10 Contact between different elastomers Contact between different polymeric elastomers and elastomers of different seals shall be avoided. They shall not be packaged together in the same envelope. NOTE Contact between elastomers and polyvinyl chloride (PVC) is not
