1、BSI Standards PublicationBS ISO 14085-2:2015Aerospace series Hydraulicfilter elements Test methodsPart 2: ConditioningBS ISO 14085-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14085-2:2015.The UK participation in its preparation was entrusted to Techn
2、icalCommittee ACE/69, Aerospace hydraulic systems, fluids andcomponents.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 correctapplic
3、ation. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 80578 3ICS 49.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee o
4、n 31 March 2015.Amendments issued since publicationDate Text affectedBS ISO 14085-2:2015 ISO 2015Aerospace series Hydraulic filter elements Test methods Part 2: ConditioningSrie arospatiale Elments filtrants hydrauliques Mthode dessais Partie 2: Vieillissement acclrINTERNATIONAL STANDARDISO14085-2Fi
5、rst edition2015-03-01Reference numberISO 14085-2:2015(E)BS ISO 14085-2:2015ISO 14085-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any
6、 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 Gene
7、va 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 14085-2:2015ISO 14085-2:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Symbols 25 Test equipment and materials . 26 Accuracy of measur
8、ing instruments and test conditions . 37 Summary of information required prior to testing 48 Thermal conditioning test 48.1 Preliminary preparation . 48.2 Thermal conditioning test procedure . 49 Cold start test . 59.1 Preliminary preparation . 59.2 Cold start test procedure 710 Reporting 811 Identi
9、fication statement . 8Annex A (informative) Cold Start Test Equipment 9Annex B (informative) Test Results Sheet 12Bibliography .13 ISO 2015 All rights reserved iiiContents PageBS ISO 14085-2:2015ISO 14085-2:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federa
10、tion of national 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 committ
11、ee. International 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 t
12、hose intended for 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
13、 (see www.iso.org/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 d
14、ocument will be 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 a
15、nd expressions 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 information .The committee responsible for this document is ISO/TC 20, Aircraft and space vehicle
16、s, Subcommittee SC 10, Aerospace fluid systems and components.ISO 14085 consists of the following parts, under the general title Aerospace series Hydraulic filter elements Test methods : Part 1: Test sequence Part 2: Conditioning Part 3: Filtration efficiency and retention capacity Part 4: Verificat
17、ion of collapse/burst pressure rating Part 5: Resistance to flow fatigue Part 6: Initial cleanliness leveliv ISO 2015 All rights reservedBS ISO 14085-2:2015ISO 14085-2:2015(E)IntroductionIn aerospace hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure.
18、The liquid is both a lubricant and power-transmitting medium. The presence of solid contaminant particles in the liquid interferes with the ability of the hydraulic fluid to lubricate and causes wear and malfunction of the components. The extent of contamination in the fluid has a direct bearing on
19、the performance, reliability, and safety of the system, and needs to be controlled to levels that are considered appropriate for the system concerned.Different principles are used to control the contamination level of the fluid by removing solid contaminant particles; one of them uses a filter eleme
20、nt enclosed in a filter housing. The filter element is the porous device that performs the actual process of filtration. The complete assembly is designated as a filter.Filter elements are designed to withstand a range of thermal stresses, such as low and high temperature extremes, and system demand
21、s at low temperature (cold starts) whereby hydraulic fluid passes through the element at a greatly increased viscosity. These thermal stresses test both the chemical and thermal stability of the filter element. These cold starts test the ability of the filter element to withstand the high differenti
22、al pressures and potential weakness at low temperatures without subsequent loss of integrity or performance.These stresses will be encountered within the lifetime of any filter element fitted in an aerospace hydraulic system. It is, therefore, necessary to check that having been subjected to such co
23、nditions; the filter element continues to provide adequate filtration, while also maintaining structural integrity.This part of ISO 14085 provides a procedure by which to introduce such thermal stresses and to condition a filter element prior to any subsequent qualification testing. This enables the
24、 purchaser of the filter element to be secure in the knowledge that the product will withstand such thermal stresses in addition to other qualification requirements without failure. ISO 2015 All rights reserved vBS ISO 14085-2:2015BS ISO 14085-2:2015Aerospace series Hydraulic filter elements Test me
25、thods Part 2: Conditioning1 ScopeThis part of ISO 14085 specifies a procedure to thermally condition a hydraulic filter element to presumed aerospace hydraulic system stresses, a test procedure to complete cold soaks, hot soaks, and temperature variation in a combined manner, and a test procedure to
26、 simulate cold starts.This part of ISO 14085 is not intended to qualify a filter element under replicate conditions of service; this can only be done by a specific test protocol developed for the purpose, including actual conditions of use, for example the operating fluid or contamination.This part
27、of ISO 14085 is intended to provide a test procedure that yields reproducible thermal test conditioning of a hydraulic filter element, for simulation of the thermal stresses typically encountered in an aerospace hydraulic system.The conditioning test procedures defined in this part of ISO 14085 are
28、intended to be used prior to performance tests as specified in other parts of this International Standard.The tests data resulting from application of this part of ISO 14085 can be used to compare the performance of aerospace hydraulic filter elements.2 Normative referencesThe following documents, i
29、n whole or in 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 an
30、d components 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 4021, Hydraulic fluid power Particul
31、ate contamination analysis Extraction of fluid samples from lines of an operating systemISO 5598, Fluid power systems and components Vocabulary3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.INTERNATIONAL STANDARD ISO 1408
32、5-2:2015(E) ISO 2015 All rights reserved 1BS ISO 14085-2:2015ISO 14085-2:2015(E)3.1cold soakprolonged immersion of a filter element in stationary fluid at the lowest expected system fluid temperature3.2cold startapplication of a rapid increase in flow and differential pressure (3.3), followed by a b
33、rief maintaining of the differential pressure (3.3), with cold fluid at a high viscosity3.3differential pressurepdifference between the inlet and outlet pressures of the component under test, as measured under specified conditions3.4fabrication integrityphysical acceptability of a filter element to
34、meet the specification designated by the filter supplier3.5hot soakprolonged immersion of a filter element in stationary fluid at the highest expected system fluid temperature3.6material safety data sheetMSDSspecification sheet defining physical aspects, characteristics, and health and safety data f
35、or a substance4 SymbolsThe graphical symbols used in this part of ISO 14085 are in accordance with ISO 1219-1.5 Test equipment and materials5.1 Hot and cold soak test fluid, shall be the same as the system operating fluid, or shall be another compatible fluid agreed upon between the supplier and pur
36、chaser.5.2 Cold start test fluid, may be the same as the cold soak test fluid, but an alternative may also be selected with a higher cold temperature viscosity, if agreed upon between the supplier and purchaser.Using a higher viscosity can reduce the volume of fluid required to conduct the cold star
37、t test because a lower flow is required to achieve the required differential pressure. If an alternative fluid is chosen, it shall be fully compatible with the filter element and all materials to which it is exposed.5.3 Differential pressure transducer shall bea) positioned such that the upstream an
38、d downstream connections conform to ISO 3968, with no bends or restrictions included in the measurement. Pressure taps in accordance with ISO 3968, andb) connected to a data recording system.5.4 Temperature transducer shall bea) located such that the sensing part is located in the internal fluid vol
39、ume,b) positioned so that it measures the temperature of the test fluid as close as possible to the upstream part of the test element,2 ISO 2015 All rights reservedBS ISO 14085-2:2015ISO 14085-2:2015(E)c) positioned so that the sensor part does not touch the filter element or any part of the filter
40、element container,d) connected to a data recording system, ande) able to withstand the upstream pressure generated during the cold start test.5.5 Filter element container, used for thermal conditioning tests shalla) be large enough (in length and width, or diameter) to accommodate at least one test
41、filter element,If using an open container, the container shall be deep enough for fluid to fully cover the test filter element by a minimum of 10 mm.b) have a construction suitable for testing over the full temperature range,c) have a cover for the container, or shall be a sealed or unsealed housing
42、,If the container is sealed, it shall either be capable of withstanding any increase in pressure due to expansion of fluid as it heats up, or shall have a means of venting any increase in pressure.d) be compatible with all the fluids used in the process, ande) have a means for inserting a temperatur
43、e transducer into the test fluid.5.6 Environmental chamber, capable of achieving and maintaining the required temperatures within the stated limits and capable of holding the filter element containers (see 5.5). The chamber shall have suitable thermal controls with a calibrated feedback loop to allo
44、w precise control of the chamber temperature.Alternatively, the hot and cold soaks can be performed using separate oven and freezer units, but the same limits apply. If separate oven and freezer units are used, thermal shocks shall be avoided.NOTE The environmental chamber is the preferred option, a
45、s this reduces the possibility of thermal shocks and enables the thermal cycling tests to be performed more quickly as heating and cooling is more effective. It is also a safer option as it overcomes the need to transfer the thermal container and hence removes the possibility of fluid spillage or ph
46、ysical contact with the hot or cold surfaces.5.7 Cold start test equipment. See Annex A for a list of typical equipment necessary to perform the cold start test.6 Accuracy of measuring instruments and test conditionsUse and maintain measuring instrument accuracy and test condition variations within
47、the limits given in Table 1.Table 1 Accuracy of measuring instruments and allowed test conditions variationsTest 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 ra
48、te L/min 2 %Temperature C 0,1 C0 C/+4 C for max. temp -4 C/0 C for min. tempa100 kPa = 1 bar ISO 2015 All rights reserved 3BS ISO 14085-2:2015ISO 14085-2:2015(E)7 Summary of information required prior to testingPrior to applying the requirements of this part of ISO 14085 to a particular hydraulic fi
49、lter element, establish thea) fabrication integrity test pressure (see ISO 2942),b) required maximum element differential pressure for the cold start test agreed upon between purchaser and supplier, andc) required hot and cold test temperatures for the soak test agreed between purchaser and supplier.8 Thermal conditioning test8.1 Preliminary preparation8.1.1 Visually inspect the filter element for any obvious damage.8.1.2 Carry out a fabrication integrity test on each element in accordance with I
