1、BSI Standards PublicationBS ISO 14085-3:2015Aerospace series Hydraulicfilter elements Test methodsPart 3: Filtration efficiency and retentioncapacityBS ISO 14085-3:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14085-3:2015. The UK participation in its pr
2、eparation was entrusted to TechnicalCommittee ACE/69, Aerospace hydraulic systems, fluids and components.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users ar
3、e responsible for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 80579 0 ICS 49.080 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the S
4、tandards Policy and Strategy Committee on 31 March 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e d ISO 2015Aerospace series Hydraulic filter elements Test methods Part 3: Filtration efficiency and retention capacitySrie arospatiale Elments filtrants hydrauliques Mthod
5、e dessais Partie 3: Efficacit de filtration et capacit de rtentionINTERNATIONAL STANDARDISO 14085-3First edition 2015-03-01Reference number ISO 14085-3:2015(E)BS ISO 14085-3:2015ISO 14085-3:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwi
6、se specified, no part of this publication may be reproduced or utilized otherwise in any form or by any 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 bel
7、ow or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 14085-3:2015ISO 14085-3:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative r
8、eferences 13 Terms and definitions . 24 Symbols and abbreviated terms . 45 Test procedure overview 66 Test equipment and supplies. 67 Instrument accuracy and allowable test condition variation .108 Test equipment validation 109 Summary of information required prior to testing .1410 Preliminary test
9、preparation .1410.1 Test filter assembly 1410.2 Contaminant injection system 1410.3 Steady flow filter test system . 1510.4 Cyclic flow filter test system . 1711 Filter element efficiency test 1711.1 Steady flow test 1711.2 Cyclic flow test 1812 Calculation and data reporting .2012.1 Filtration rati
10、o and retention capacity 2012.2 Calculation of stabilized particle counts for cyclic flow test .2413 Identification statement (reference to this part of ISO 14085) 25Annex A (normative) Properties of test fluid to evaluate performance of hydraulic fluid systems filter elements .30Annex B (informativ
11、e) Test system design guide 32Bibliography .37 ISO 2015 All rights reserved iiiContents PageBS ISO 14085-3:2015ISO 14085-3:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Interna
12、tional 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-governmental, in liaison with
13、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 for its further maintenance are described in the ISO/IEC Directives, P
14、art 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.org/directives). Attention is drawn to the possibility that some of th
15、e 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 in the Introduction and/or on the ISO list of patent declarations r
16、eceived (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 related to conformity assessment, as well as information about ISOs
17、 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 20, Aircraft and space vehicles, Subcommittee SC 10, Aerospace fluid systems and components.ISO 14085 consists of
18、 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: Verification of collapse/burst pressure rating Part 5: Resistance to flow fatigue Part 6: In
19、itial cleanliness leveliv ISO 2015 All rights reservedBS ISO 14085-3:2015ISO 14085-3:2015(E)IntroductionIn aerospace hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure. The liquid is both a lubricant and power-transmitting medium. The presence of solid
20、 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 the performance, reliability, and safety of the system, and needs to be controlled
21、 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 element enclosed in a filter housing. The filter element is the porous device that perf
22、orms the actual process of filtration. The complete assembly is designated as a filter.The performance characteristics of a filter are a function of the element (its medium and geometry) and the housing (its general configuration and seal design). For a given filter, the actual performance is a func
23、tion of the characteristics of the liquid (viscosity, temperature, conductivity, etc.), the particles in suspension (size, shape, hardness, etc.), and the flow conditions.A standard multi-pass method for evaluating the performance of hydraulic fluid filter elements under steady state conditions has
24、been developed and used for several years, and is referred to in several aircraft hydraulic systems specifications.Most aircraft hydraulic systems are subjected to unsteady flow with flow cycles caused by such conditions as actuator movement. Such flow variations can have a significant impact on fil
25、ter performance. To enable the relative performance of hydraulic filters to be reliably compared so that the most appropriate filter can be selected, it is necessary to perform testing with the same standard operating conditions.This part of ISO 14085 describes two test methods and the equipment req
26、uired to measure hydraulic filter element performance with multi-pass flow in both steady and cyclic conditions.The influence of other stressful operating conditions, such as heat, cold, and vibration, are not measured with this procedure alone. The influence of such conditions is determined with pr
27、e-conditioning being performed on the test filter element prior to efficiency testing (refer to ISO 14085-1 for descriptions of such tests and when they are applied).The stabilized contamination level measured while testing with cyclic flow gives an indication of the average contamination level main
28、tained by the filter in a dynamic operating system. The average system contamination level is important in establishing wear rates and reliability levels.The measurements are made with precise control over the operating conditions in particular the test fluid and test contaminant, to ensure repeatab
29、ility and reproducibility. However, because the test parameters and test contaminant do not exactly replicate actual operating conditions which significantly differ from one system to another, the measurements cannot be expected to duplicate actual performance in an operating system. ISO 2015 All ri
30、ghts reserved vBS ISO 14085-3:2015BS ISO 14085-3:2015Aerospace series Hydraulic filter elements Test methods Part 3: Filtration efficiency and retention capacity1 ScopeThis part of ISO 14085 describes two methods to measure in repeatable conditions the filtration efficiency of filter elements used i
31、n aviation and aerospace hydraulic fluid systems. It can be applied when evaluating the overall characteristics of a filter element per ISO 14085-1, or separately.Since the filtration efficiency of a filter element can change during its service life as it is clogging, this test method specifies its
32、continuous measurement by using on-line particle counters with continuous injection of test contaminant and recirculation of particles not retained by the test filter element until the differential pressure across the element reaches a given final or “terminal” value.This part of ISO 14085 allows th
33、e efficiency to be measured under both steady or cyclic flow conditions. It also is applied to measure the stabilized contamination levels that are produced by the filter element while testing with cyclic flow.This part of ISO 14085 is not intended to qualify a filter element under replicate conditi
34、ons 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.The tests data resulting from application of this part of ISO 14085 can be used to compare the performance of aerospace hy
35、draulic filter elements.2 Normative referencesThe following documents, in 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 docume
36、nt (including any amendments) applies.ISO 1219-1, Fluid power systems and 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 determi
37、nation of the first bubble pointISO 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 4405, Hydraulic fluid power Fluid
38、 contamination Determination of particulate contamination by the gravimetric methodISO 5598, Fluid power systems and components VocabularyISO 11171, Hydraulic fluid power Calibration of automatic particle counters for liquidsISO 11943, Hydraulic fluid power On-line automatic particle-counting system
39、s for liquids Methods of calibration and validationINTERNATIONAL STANDARD ISO 14085-3:2015(E) ISO 2015 All rights reserved 1BS ISO 14085-3:2015ISO 14085-3:2015(E)ISO 12103-1:1997, Road vehicles Test dust for filter evaluation Part 1: Arizona test dust3 Terms and definitionsFor the purposes of this d
40、ocument, the terms and definitions given in ISO 5598 and the following apply.3.1contaminant mass injectedmass of specific particulate contaminant injected into the test circuit to obtain the terminal differential pressure3.2cyclic flowchange of flow from the specified rated flow rate to 25 % of rate
41、d flow rate at a specified frequency and waveform3.3differential pressure p difference between the inlet and outlet pressures of the component under test, as measured under specified conditionsNote 1 to entry: See Figure 1 and Figure 2 for graphical depiction of differential pressure (3.3) terms.3.3
42、.1clean assembly differential pressuredifference between the tested component inlet and outlet pressure as measured with a clean filter housing containing a clean filter element3.3.2clean element differential pressuredifferential pressure (3.3) of the clean element calculated as the difference betwe
43、en the clean assembly differential pressure (3.3.1) and the housing differential pressure (3.3.4)3.3.3final assembly differential pressureassembly differential pressure at end of test equal to sum of housing plus terminal element differential pressures (3.3.5)3.3.4housing differential pressurediffer
44、ential pressure of the filter housing without an element3.3.5terminal element differential pressuremaximum differential pressure across the filter element as designated by the manufacturer or specification to limit useful performance3.4filtration ratioratio of the number of particles larger than a s
45、pecified size per unit volume in the influent fluid to the number of particles larger than the same size per unit volume in the effluent fluidNote 1 to entry: For steady flow testing, the filtration ratios (3.4) are designated with the Greek letter beta, .Note 2 to entry: For cyclic flow (3.2) testi
46、ng, the filtration ratios (3.4) are designated with the Greek letter sigma, .3.5free-flow dummy elementduplicate test filter element with its media layers removed to replicate the flow pattern in the housing generated by the test filter element2 ISO 2015 All rights reservedBS ISO 14085-3:2015ISO 140
47、85-3:2015(E)3.6rest conductivityelectrical conductivity at the initial instant of current measurement after a dc voltage is impressed between electrodesNote 1 to entry: It is the reciprocal of the resistance of uncharged fluid in the absence of ionic depletion or polarization.3.7retention capacityma
48、ss of specific particulate contaminant effectively retained by the filter element when terminal element differential pressure is reachedKeyx test time or mass injected 3 clean element differential pressurey differential pressure 4 housing differential pressure1 final assembly (end of test) different
49、ial pressure 5 clean assembly differential pressure2 terminal element differential pressureFigure 1 Differential pressure conventions for multi-pass test with steady flow ISO 2015 All rights reserved 3BS ISO 14085-3:2015ISO 14085-3:2015(E)Keyx test time or mass injected3 clean element differential pressure at test flow rate (qf)Y differential pressure 4 housing differential pressure at test flow rate (qf)1 final assembly (end of test) differential pressure 5 clean assembly differential pre
