1、BSI Standards PublicationBS ISO 16908:2014Hydraulic filter elementtest methods Thermalconditioning and cold start-upsimulationBS ISO 16908:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 16908:2014.The UK participation in its preparation was entrusted to T
2、echnicalCommittee MCE/18/-/6, Contamination control.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British S
3、tandards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 78006 6ICS 23.100.60Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 20
4、14.Amendments issued since publicationDate Text affectedBS ISO 16908:2014 ISO 2014Hydraulic filter element test methods Thermal conditioning and cold start-up simulationMthodes dessai des lments filtrants hydrauliques Conditionnement thermique et simulation de dmarrage froidINTERNATIONAL STANDARDISO
5、16908First edition2014-09-01Reference numberISO 16908:2014(E)BS ISO 16908:2014ISO 16908:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by an
6、y means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Gen
7、eva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 16908:2014ISO 16908:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Symbols 25 Test equi
8、pment and materials . 26 Accuracy of measuring instruments and test conditions . 27 Summary of information required prior to testing 38 Thermal conditioning test 39 Cold start test . 49.1 Preliminary preparation . 49.2 Procedure 610 Pass/fail criteria . 711 Data reporting . 712 Identification statem
9、ent (reference to this International Standard) 7Annex A (informative) Cold start test equipment . 8Annex B (informative) Test data reporting form 12Bibliography .13BS ISO 16908:2014ISO 16908:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national
10、 standards bodies (ISO member bodies). The 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. Internationa
11、l organizations, governmental and non-governmental, 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.The procedures used to develop this document and those intended fo
12、r its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.or
13、g/directives). 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. Details of any patent rights identified during the development of the document will be
14、 in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions
15、 related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 131, Fluid power systems, Subcommittee SC 6,
16、Contamination control.iv ISO 2014 All rights reservedBS ISO 16908:2014ISO 16908:2014(E)IntroductionIn hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within a closed circuit. Filter elements maintain fluid cleanliness by removing insoluble contamina
17、nts.Filter elements, particularly those intended for mobile hydraulic applications, are designed to withstand a range of thermal stresses, such as low and high temperature extremes, and system demands at low temperature (cold starts) whereby hydraulic fluid passes through the element under test at a
18、 greatly increased viscosity. These cold starts test the ability of the filter element to withstand the high differential pressures without subsequent loss of integrity or performance.Stresses due to cold starts can be encountered within the lifetime of a filter element fitted in a mobile hydraulic
19、system. It is therefore necessary to check that, having been subjected to such conditions, the filter element shall continue to provide adequate filtration while also maintaining structural integrity.This International Standard provides a procedure by which to introduce stresses due to cold start an
20、d to condition a filter element prior to any subsequent performance qualification testing, such as multi-pass, collapse, flow fatigue, etc. This enables the purchaser of the filter element to be secure in the knowledge that the product can withstand cold starts and still maintain performance as inte
21、nded. ISO 2014 All rights reserved vBS ISO 16908:2014BS ISO 16908:2014Hydraulic filter element test methods Thermal conditioning and cold start-up simulation1 ScopeThis International Standard specifies a test procedure to thermally condition a hydraulic filter element and simulate cold start, such a
22、s that which can be encountered in mobile machinery applications. It is intended to provide a procedure that yields reproducible results and can be used prior to other filter element performance tests, such as those specified in ISO 11170.2 Normative referencesThe following documents, in whole or in
23、 part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 1219-1, Fluid power systems and components
24、Graphical symbols and circuit diagrams Part 1: Graphical symbols for conventional use and data-processing applicationsISO 2942, Hydraulic fluid power Filter elements Verification of fabrication integrity and determination of the first bubble pointISO 2943, Hydraulic fluid power Filter elements Verif
25、ication of material compatibility with fluidsISO 3968, Hydraulic fluid power Filters Evaluation of differential pressure versus flow characteristicsISO 4021, Hydraulic fluid power Particulate contamination analysis Extraction of fluid samples from lines of an operating systemISO 4406, Hydraulic flui
26、d power Fluids Method for coding the level of contamination by solid particlesISO 5598, Fluid power systems and components VocabularyISO 11500, Hydraulic fluid power Determination of the particulate contamination level of a liquid sample by automatic particle counting using the light-extinction prin
27、ciple3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.3.1cold soakprolonged immersion of a component or part in stationary fluid at 5 C below the stated minimum temperature of use3.2cold startapplication of a rapid increase
28、 in flow and differential pressure with cold fluid at a high viscosity3.3differential pressurepdifference between the tested component inlet and outlet pressure as measured under the specified conditionsINTERNATIONAL STANDARD ISO 16908:2014(E) ISO 2014 All rights reserved 1BS ISO 16908:2014ISO 16908
29、:2014(E)3.4hot soakprolonged immersion of a component or part in stationary fluid at a temperature 15 C above the manufacturers recommended operating temperature3.6material safety data sheet (MSDS)specification sheet defining physical aspects, characteristics, and health and safety data for a substa
30、nce4 SymbolsThe graphical symbols used in this International Standard are in accordance with ISO 1219-1.5 Test equipment and materials5.1 Soak test fluid, which shall be either the same as the system operating fluid or another compatible fluid agreed upon between the supplier and purchaser.5.2 Cold
31、start test fluid, which can be either the same as the soak test fluid or an alternative with a higher cold temperature viscosity to minimize the volume of fluid required to conduct the cold start test and to standardize the fluid required for testing of additional filters. If an alternative fluid is
32、 chosen, it shall be fully compatible with the filter element material and with the soak test fluid.5.3 Differential pressure transducer, which shall be positioned such that the upstream and downstream connections are close to the filter housing, with no bends or restrictions included in the measure
33、ment, and with pressure taps in accordance with ISO 3968 and connected to a calibrated data recording system.5.4 Temperature transducer, which shall be located so that the sensor part is located in the internal fluid volume, positioned so that it measures the temperature of the test fluid as close a
34、s possible upstream of the test element, connected to a calibrated data recording system, and positioned so that the sensor part does not touch the filter element or any part of the filter element container.5.5 Environmental chamber, which shall be capable of achieving and maintaining the required t
35、emperature within the stated limits and capable of containing the test equipment (see 5.6). The chamber shall have suitable thermal controls with a calibrated feedback loop to allow precise control of the chamber temperature.5.6 Cold start test equipment. See Annex A for a list of typical equipment
36、necessary to perform the cold start test.6 Accuracy of measuring instruments and test conditionsThe accuracy of measuring instruments used and variations in test conditions shall be maintained within the limits given in Table 1.2 ISO 2014 All rights reservedBS ISO 16908:2014ISO 16908:2014(E)Table 1
37、Accuracy of measuring instruments and test conditionsTest parameter SI unitInstrument accuracy (of actual value)Permitted variations in test conditions (of target value)Differential pressure kPa a2 % +5 % / -0 %Gauge pressure kPa a2 % 5 %Flow rate L/min 2 %Temperature C 0,1 C 5 Ca100 kPa = 1 bar7 Su
38、mmary of information required prior to testingPrior to applying the requirements of this International Standard to a particular hydraulic filter element, the following shall be established: fabrication integrity test pressure (see ISO 2942); required maximum element differential pressure for the col
39、d start test.NOTE 1 For filter elements protected by a bypass valve within the filter housing, the maximum test differential pressure is generally set as the maximum differential pressure across the bypass valve at maximum flow rate and viscosity at the minimum expected temperature. For filter eleme
40、nts without such bypass, the maximum test differential pressure is generally set as the maximum operating system pressure.NOTE 2 The maximum test differential pressure is normally limited to the maximum permissible collapse or burst pressure of the filter element. If this pressure is exceeded, it ca
41、n result in damage to the test filter element.8 Thermal conditioning test8.1 Visually inspect the filter element for any damage. If it is damaged, reject the filter element and start over with a new filter element.8.2 Carry out a fabrication integrity test on the element in accordance with ISO 2942.
42、 Reject the filter element if it is damaged as a result of testing or fails to meet the required minimum bubble point pressure. If either of these occurs, start over with a new filter element.8.3 Drain fluid and dry the filter element thoroughly.8.4 Conduct heat soak and cold soak tests as required
43、in accordance with ISO 2943. The following requirements enhance the safe conduct of these tests.a) If the material safety data sheet for the test fluid states that inhalation of its vapours is harmful, ensure that any vapour from the fluid is extracted externally from the workplace when testing with
44、 the fluid at above ambient temperatures.b) If external extraction of the vapour is unavailable, the test shall be conducted in an enclosed vessel or housing with suitable pressure rating. ISO 2014 All rights reserved 3BS ISO 16908:2014ISO 16908:2014(E)9 Cold start test9.1 Preliminary preparation9.1
45、.1 Housing9.1.1.1 Determine whether the designated housing for the filter element is fitted with a bypass valve. If a bypass valve is fitted as standard, then the bypass valve shall be disabled, or the cold start test procedure shall be conducted using an alternative housing that does not have a byp
46、ass valve. If the bypass valve is integral to the filter element, it shall be included in the test.9.1.1.2 If the designated housing is not available, fit the filter element within an alternative housing that has an internal diameter at least as large as that of the designated housing and either doe
47、s not have a bypass valve or whose bypass valve has been disabled.9.1.1.3 The alternative housing shall not be smaller in internal diameter than the designated housing, as this can cause bias to the flow direction, thereby causing an uneven distribution of pressure stress in the filter element mediu
48、m in the biased area.9.1.2 Cold test equipment9.1.2.1 A suggested test equipment and circuit are shown in Annex A.9.1.2.2 Shut all sampling valves.9.1.2.3 With a piece of pipe or test block replacing the test housing, run the hydraulic power circuit pump to empty test fluid from the transfer cylinde
49、rs at a suitable flow rate. Install the test housing onto the cold start test rig. If the test circuit was previously used with a different fluid, all components of the test circuit should be drained, flushed with a compatible solvent, and then flushed with a volume of the new test fluid being used in order to prevent cross-contamination of test fluids.9.1.2.4 Fill the test housing with test fluid. The clean-up filter element in the cold start test circuit should be replaced with a new filter element.
