1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22952-8 SANS 4928:2009Edition 2ISO 4928:2006Edition 3SOUTH AFRICAN NATIONAL STANDARD Road vehicles Elastomeric cups and seals for cylinder
4、s for hydraulic braking systems using a non-petroleum base hydraulic brake fluid (Service temperature 120 C max.) This national standard is the identical implementation of ISO 4928:2006 and is adopted with the permission of the International Organization for Standardization. Published by SABS Standa
5、rds Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 4928:2009 Edition 2 ISO 4928:2006 Edition 3 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committ
6、ee SABS TC 45, Rubber and rubber products, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in October 2009. This SANS document supersedes SANS 4928:2003 (edition 1). Reference numberISO 4928:2006(E)IS
7、O 2006INTERNATIONAL STANDARD ISO4928Third edition2006-07-15Road vehicles Elastomeric cups and seals for cylinders for hydraulic braking systems using a non-petroleum base hydraulic brake fluid (Service temperature 120 C max.) Vhicules routiers Coupelles et joints en caoutchouc pour cylindres de disp
8、ositifs de freinage hydrauliques utilisant un liquide de frein base non ptrolire (Temprature maximale dutilisation 120 C) SANS 4928:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) PDF disclaimer This PDF file may contain
9、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 performing the editing. In downloading this file, parties accept therein the responsibility
10、 of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation paramet
11、ers were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2006 All rights reserved. Unless otherwise
12、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 writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright offi
13、ce 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 2006 All rights reservedSANS 4928:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .IS
14、O 4928:2006(E) ISO 2006 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 General requirements. 2 4.1 Workmanship and finish 2 4.2 Marking 2 4.3 Packaging 2 4.4 Sampling 2 5 Test requirements. 2 5.1 Resistance to fluid at elevated te
15、mperature 2 5.2 Precipitation 2 5.3 Wheel cylinder seals heat pressure stroking 2 5.4 Master cylinder seals heat pressure stroking . 3 5.5 Low-temperature performance 4 5.6 Oven ageing 4 5.7 Corrosion. 4 5.8 Storage corrosion test 5 6 Test procedures 5 6.1 Resistance to fluid at elevated temperature
16、 Dimensional test 5 6.2 Precipitation test. 7 6.3 Wheel cylinder seals heat pressure stroking 8 6.4 Master cylinder seals heat pressure stroking . 9 6.5 Low-temperature performance 11 6.6 Oven ageing 12 6.7 Hardness determination. 12 6.8 Corrosion test . 13 6.9 Storage corrosion test 14 SANS 4928:20
17、09This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). Th
18、e work of preparing International Standards is normally carried out through ISO technical committees. 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-gov
19、ernmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International 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.
20、The main task of technical committees is to prepare International Standards. 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 bodies casting a vo
21、te. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 40421 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Brakin
22、g and systems equipment. This third edition cancels and replaces the second edition (ISO 4928:1980), which has been technically revised. SANS 4928:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO 4928:2006(E) ISO
23、 2006 All rights reserved 1Road vehicles Elastomeric cups and seals for cylinders for hydraulic braking systems using a non-petroleum base hydraulic brake fluid (Service temperature 120 C max.) 1 Scope This International Standard specifies performance tests of brake cups and seals for hydraulic brak
24、ing systems for road vehicles; it does not include requirements relating to chemical composition, tensile strength and elongation of the rubber compound. Disc brake seals are not covered by this International Standard. This International Standard is applicable to moulded seals (cups or double-lipped
25、 type gland seals), 60 mm in diameter and smaller, compounded from high temperature-resistant rubber, for use in hydraulic actuating cylinders using road vehicle non-petroleum base hydraulic brake fluid conforming to the requirements of ISO 4925. 2 Normative references The following referenced docum
26、ents 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. ISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardness
27、 between 10 IRHD and 100 IRHD) ISO 188:1998, Rubber, vulcanized or thermoplastic Accelerated ageing and heat resistance tests ISO 1250, Mineral solvents for paints White spirits and related hydrocarbon solvents ISO 4925, Road vehicles Specification of non-petroleum-base brake fluids for hydraulic sy
28、stems ISO 4926, Road vehicles Hydraulic braking systems Non-petroleum base reference fluids 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 sloughing release of carbon black on the surface of the rubber 3.2 scoring formation of grooves in the
29、 rubber parallel to the direction of travel of the piston or seal 3.3 scuffing visible erosion of the outer surface of the rubber SANS 4928:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) 2 ISO 2006 All rights reserved4 G
30、eneral requirements 4.1 Workmanship and finish Seals shall be free from blisters, pin-holes, cracks, protuberances, embedded foreign material or other physical defects which can be detected by thorough inspection, and shall conform to the dimensions specified on the drawings. 4.2 Marking The identif
31、ication mark of the manufacturer and other details as specified on drawings shall be moulded into each seal. Each seal in conformity with this International Standard may also have the following mark: “ISO 4928”. 4.3 Packaging Seals shall be packaged to meet requirements specified by the purchaser. 4
32、.4 Sampling The minimum lot on which complete specification tests shall be conducted for quality control testing, or the frequency of any specific type test used to control production, shall be agreed upon by the manufacturer and the purchaser. 5 Test requirements 5.1 Resistance to fluid at elevated
33、 temperature After being subjected to the test for resistance to compatibility fluid at elevated temperature as prescribed in 6.1, the seals shall conform to the requirements specified in Table 1, and shall show no excessive disintegration as evidenced by blisters or sloughing. Table 1 Requirements
34、for fluid resistance at elevated temperature (120 C) Characteristics Permitted change Volume Outside diameter, lip Outside diameter, base Hardness From 0,0 % to + 20,0 % From 0,0 % to + 5,75 % From 0,0 % to + 5,75 % From 15 IRHD to 0 IRHD 5.2 Precipitation Not more than 0,3 % sediment by volume shal
35、l be formed in the centrifuge tube after the seals have been tested as specified in 6.2. 5.3 Wheel cylinder seals heat pressure stroking 5.3.1 General Wheel cylinder seals, when tested by the procedure specified in 6.3, shall meet the performance requirements specified in 5.3.2 to 5.3.6. SANS 4928:2
36、009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) ISO 2006 All rights reserved 35.3.2 Lip diameter change The minimum lip diameter of wheel cylinder seals after the stroking test shall be greater than the wheel cylinder bore
37、 by the minimum dimensions specified in Table 2. Table 2 Lip diameter change of wheel cylinder seals Dimensions in millimetres Diameter of wheel cylinder bore Minimum excess over bore u 19,05 19,05; u 25,4 25,4; u 38,1 38,1; u 60 0,40 0,50 0,65 0,75 5.3.3 Leakage No constant dampness past the seals
38、or fluid discoloration of the filter paper on two or more inspections shall occur. 5.3.4 Corrosion Pistons and cylinder bore shall not show corrosion as evidenced by pitting to an extent discernible to the naked eye, but staining or discoloration shall be permitted. 5.3.5 Change in hardness Rubber s
39、eals shall not decrease in hardness by more than 15 IRHD when tested in accordance with the procedure as specified in 6.7. 5.3.6 Condition of test seals Wheel cylinder seals shall not show excessive deterioration such as scoring, scuffing, blistering, cracking, chipping (heel abrasion) or change in
40、shape from original appearance. 5.4 Master cylinder seals heat pressure stroking 5.4.1 General Master cylinder seals, when tested by the procedure specified in 6.4, shall meet the performance requirements specified in 5.4.2 to 5.4.6. 5.4.2 Lip diameter change The minimum lip diameter of master cylin
41、der seals after the stroking test shall be greater than the master cylinder bore by the minimum dimensions specified in Table 3. Table 3 Lip diameter change of master cylinder seals Dimensions in millimetres Diameter of master cylinder bore Minimum excess over bore u 19,05 19,05; u 25,4 25,4; u 38,1
42、 38,1; u 60 0,30 0,40 0,50 0,65 SANS 4928:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) 4 ISO 2006 All rights reserved5.4.3 Leakage The same requirement as specified for wheel cylinder seals shall be applied (see 5.3.3)
43、. 5.4.4 Corrosion The same requirement as specified for wheel cylinder seals shall be applied (see 5.3.4). 5.4.5 Change in hardness The same requirement as specified for wheel cylinder seals shall be applied (see 5.3.5). 5.4.6 Condition of test seals The same requirement as specified for wheel cylin
44、der seals shall be applied (see 5.3.6). 5.5 Low-temperature performance 5.5.1 Leakage No leakage of fluid shall occur when seals are tested according to the procedure specified in 6.5.1. 5.5.2 Bend test The seal shall not crack and shall return to approximately its original shape within 1 min when t
45、ested according to the procedure specified in 6.5.2. 5.6 Oven ageing 5.6.1 General Seals, when tested according to the procedure specified in 6.6, shall meet the requirements specified in 5.6.2 and 5.6.3. 5.6.2 Change in hardness The change in hardness shall be within the limits of 5 IRHD. 5.6.3 Con
46、dition of test seals The seal shall show no evidence of deterioration, or change in shape from original appearance. 5.7 Corrosion 5.7.1 General Seals, when tested according to the procedure specified in 6.8, shall meet the requirements specified in 5.7.2 and 5.7.3. 5.7.2 Corrosion of metal strips Th
47、e seals shall not cause corrosion exceeding the limits shown in Table 4. The metal strips outside of the area where the strips are in contact shall be neither pitted nor roughened to the extent discernible to the naked eye, but staining or discoloration is permitted. SANS 4928:2009This s tandard may
48、 only be used and printed by approved subscription and freemailing clients of the SABS .ISO 4928:2006(E) ISO 2006 All rights reserved 5Table 4 Permissible change in mass of corrosion test strips Test strips Permissible change in mass mg/cm2of surface Tinned iron Steel Aluminium Cast iron Brass Coppe
49、r Zinc 0,2 0,2 0,1 0,2 0,4 0,4 0,4 5.7.3 Fluid-water mixture characteristics The fluid-water mixture at the end of the test shall show no jellying at 23 C 5 C. No crystalline type deposits shall form and adhere to either the glass wall or the surface of metal strips. The fluid-water mixture shall contain no more than 0,2 % sediment by volume. 5.8 Storage corrosion test After twelve cycles in the humidity cabinet when operated according to the procedure specified 6.9, there shall be no ev
