《BS-ISO-2942-1994.pdf》由会员分享,可在线阅读,更多相关《BS-ISO-2942-1994.pdf(10页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD BS ISO 2942:1994 Implementation of ISO 2942:1994 Hydraulic fluid power Filter elements Verification of fabrication integrity and determination of the first bubble point ICS 23.100.30 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (
2、c) BSI BS ISO 2942:1994 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 October 1996 BSI 11-1998 The following BSI references relate to the work on this standard: Com
3、mittee reference MCE/18 Draft for comment 93/708001 DC ISBN 0 580 26074 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee MCE/18 upon which the following bodies were represented: Association of British Mining Equipment Co
4、mpanies British Compressed Air Society British Fluid Power Association British Hydrodynamics Research Association Department of Trade and Industry (National Engineering Laboratory) Ministry of Defence University of Bath The following bodies were also represented in the drafting of the standard throu
5、gh Subcommittee MCE/18/11: Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2942:1994 BSI 11-1998i Contents Page Committees res
6、ponsible Inside front cover National foreword ii Foreword ii 1Scope1 2Normative reference1 3Definitions1 4Graphic symbols1 5Apparatus and material1 6Test methods1 7Data presentation3 8Identification statement3 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontroll
7、ed Copy, (c) BSI BS ISO 2942:1994 ii BSI 11-1998 National foreword This British Standard reproduces verbatim ISO 2942:1994 and implements it as the UK national standard. This British Standard is published under the direction of the Engineering Sector Board whose Technical Committee MCE/18 has the re
8、sponsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational
9、 and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicatio
10、n. 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, the ISO title page, page ii, pages 1 to 3 and a back cover. This standard has been updated (see copyright da
11、te) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00
12、2006, Uncontrolled Copy, (c) BSI BS ISO 2942:1994 ii Foreword 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 committees. E
13、ach 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 Internati
14、onal Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards 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 bodie
15、s casting a vote. International Standard ISO 2942 was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 8, Product testing and contamination control. This third edition cancels and replaces the second edition (ISO 2942:1985), which has been technically revised and expa
16、nded to include the determination of the first bubble point. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2942:1994 BSI 11-19981 Introduction In hydraulic fluid power systems, power is transmitted and controlled through a liquid un
17、der pressure within an enclosed circuit. Filters maintain fluid cleanliness by removing insoluble contaminants. 1 Scope This International Standard specifies a bubble-point test method applicable to filter elements to be used in hydraulic fluid power systems. It can be used either to verify the fabr
18、ication integrity of a filter element (by checking the absence of bubbles) or to permit the localization of the largest pore of the filtering medium by determining the first bubble point. It therefore defines the acceptability of filter elements for further use or testing. The first bubble point is
19、under no circumstances a functional characteristic of a filter element; in particular, it cannot be used for extrapolation to the concepts of filtration rating, efficiency or retention capacity. 2 Normative references The following standards contain provisions which, through reference in this text,
20、constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition
21、s of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1219-1:1991, Fluid power systems and components Graphic symbols and circuit diagrams Part 1: Graphic symbols. ISO 5598:1985, Fluid power systems and components Vocabulary. 3
22、Definitions For the purposes of this International Standard, the definitions given in ISO 5598 and the following definitions apply. 3.1 filter element the component which ensures the retention of contaminant ISO 5598 in this International Standard, a filter element is a porous device which performs
23、the actual process of filtration 3.2 fabrication integrity the physical acceptability of a filter element relative to that designated by the filter manufacturer 3.3 first bubble point the pressure at which the first bubble appears when a filter element is tested using the method specified in this In
24、ternational Standard. In the absence of manufacturing defects, this value is related to the largest pore of the filtering medium 4 Graphic symbols Graphic symbols used are in accordance with ISO 1219-1. 5 Apparatus and material 5.1 Bubble-point testing apparatus, as shown in Figure 1, and mainly com
25、posed of the following. 5.1.1 Compressed-air supply, with filter(s) and pressure regulator(s), adjustable for values from the minimum up to 10 kPa (100 mbar). 5.1.2 Pressure-measuring device, with a relative accuracy of 3 %. 5.1.3 Leakproof container, for submerging the filter element under test, fi
26、tted with a thermometer and a built-in manual or automatic mechanism for rotating the filter element. 5.2 Reference liquid, clean isopropanol or an alternative liquid designated by the filter element manufacturer. Its cleanliness shall be consistent with subsequent test requirements. Its surface ten
27、sion shall be regularly checked if the liquid is used repeatedly. It is advisable to renew the liquid when its surface tension varies by 5 % with respect to fresh liquid. WARNING Isopropanol or other solvents used as the reference liquid may be hazardous to the individual and to the environment. Tak
28、e safety precautions appropriate to the liquid being used and consult local environmental regulations before disposal of any reference liquid. 6 Test methods 6.1 General procedure 6.1.1 Check that the filter element to be tested complies with the manufacturers drawing(s). 6.1.2 Install the clean fil
29、ter element in the bubble-point testing apparatus (5.1), with the major axis of the filter element parallel to the surface of the reference liquid (5.2). Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2942:1994 2 BSI 11-1998 6.1.3 Su
30、bmerge the element until it is covered by 12 mm 3 mm of the reference liquid at a temperature of 22 C 5 C. 6.1.4 Allow the filter element to remain submerged in the liquid for 5 min before proceeding. NOTE 1This arbitrary 5-min soak is to ensure that the filter element is wetted. Soaking may be perf
31、ormed in the tank, not necessarily whilst the filter is clamped in the rotating apparatus. 6.2 Verification of fabrication integrity (absence of air bubbles) 6.2.1 Apply air pressure to the inside of the filter element at the value designated by the filter manufacturer. After filling the test elemen
32、t with air, re-adjust the depth of liquid covering the element to 12 mm 3 mm. NOTE 2Air bubbles may be trapped on or within the outer structure of the filter element, resulting in a few spurious bubbles. These bubbles should be ignored. A steady stream of bubbles at the manufacturers designated valu
33、e is the only consideration. 6.2.2 Rotate the filter element through 360 about its major axis while applying the air pressure as indicated in 6.2.1 6.2.3 The acceptance criterion is that there shall be no evidence of bubbles at the pressure specified by the manufacturer. 6.3 Determination of the fir
34、st bubble point 6.3.1 Apply air pressure progressively to the inside of the filter element while rotating it about its axis (as indicated in 6.2.2). Increase the pressure by steps of 50 Pa (0,5 mbar) beginning at zero pressure. Stop the pressure rise as soon as the first bubble point appears as a re
35、gular flow. Record the corresponding pressure. CAUTION Air bubbles may be trapped on or within the outer structure, resulting in a few spurious bubbles. These bubbles should be ignored. The first bubbles appears in a regular flow as long as internal air pressure is maintained. Adequate lighting is r
36、equired for reliable observation. Increase air pressure slowly to allow the establishment of equilibrium and to prevent overshooting. Avoid mechanical vibration or jarring of the test element to prevent upsetting bubble equilibrium which causes erroneously low pressure readings. 6.3.2 Completely rel
37、ease the air pressure in the filter element to allow the pores to be flooded with liquid and repeat the procedures given in 6.3.1 6.3.3 Repeat the operation two more times and record the corresponding pressures. Figure 1 Typical bubble-point testing apparatus Licensed Copy: sheffieldun sheffieldun,
38、na, Sun Nov 26 06:46:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2942:1994 BSI 11-19983 7 Data presentation Record the result of the verification of fabrication integrity and the data for the determination of the first bubble point in accordance with the typical test report shown in Figure
39、2. 8 Identification statement (Reference to this International Standard) Use the following statement in test reports, catalogues and sales literature when electing to comply with this International Standard: “Filter element fabrication integrity verified and first bubble point determined in accordan
40、ce with ISO 2942:1994, Hydraulic fluid power Filter elements Verification of fabrication integrity and determination of the first bubble point.” Figure 2 Typical test report for fabrication integrity and first bubble point Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 06:46:49 GMT+00:00 200
41、6, Uncontrolled Copy, (c) BSI BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
42、 | | | | | | | | | | | | BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by
43、amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standa
44、rd would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest ed
45、itions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel: 020 8996 9001. Fax: 020 8996 7001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those t
46、hat have been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services a
47、re also available which give details on all its products and services. Contact the Information Centre. Tel: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details
48、of these and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyrig
49、ht, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is gra
链接地址:https://www.31doc.com/p-3747445.html