1、BSI Standards PublicationBS ISO 14085-5:2015Aerospace series Hydraulicfilter elements Test methodsPart 5: Resistance to flow fatigueBS ISO 14085-5:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14085-5:2015.The UK participation in its preparation was entr
2、usted to TechnicalCommittee 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
3、 correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 80581 3ICS 49.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strate
4、gy Committee on 31 March 2015.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 14085-5:2015 ISO 2015Aerospace series Hydraulic filter elements Test methods Part 5: Resistance to flow fatigueSrie arospatiale Elments filtrants hydrauliques Mthode dessais Partie 5: Rsistance aux va
5、riations cycliques de dbitINTERNATIONAL STANDARDISO14085-5First edition2015-03-01Reference numberISO 14085-5:2015(E)BS ISO 14085-5:2015ISO 14085-5:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwise specified, no part of this publication m
6、ay 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 below or ISOs member body in the country of th
7、e 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 14085-5:2015ISO 14085-5:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Gra
8、phic symbols and circuit diagrams 25 Test equipment and supplies. 26 Accuracy of measurements and test conditions 47 Test procedure 48 Acceptance criteria 69 Data presentation 610 Identification statement . 6Annex A (informative) Flow fatigue test data report form 7 ISO 2015 All rights reserved iiiC
9、ontents PageBS ISO 14085-5:2015ISO 14085-5:2015(E)ForewordISO (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. Each
10、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 International
11、 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, Part 1. In particular the different approval criteria needed for the different ty
12、pes 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 the elements of this document may be the subject of patent rights. ISO shall not be
13、 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 received (see www.iso.org/patents).Any trade name used in this document is informa
14、tion 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 adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the
15、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 the following parts, under the general title Aerospace series Hydraulic Filter el
16、ements 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: Cleanliness Leveliv ISO 2015 All rights reservedBS ISO 14085-5:2015ISO 14085-5:2015(
17、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 contaminant particles in the liquid interferes with the ability of the hydraulic fluid to
18、 lubricate and causes wear and malfunction of the components. The extent of contamination in the fluid has a direct bearing in 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 ar
19、e 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 performs the actual process of filtration. The complete assembly is designated as a filter.The
20、effectiveness of the filter element in controlling contaminants is dependent on its design and its sensitivity to any dynamic operating conditions that may stress the filter element and cause damage to it, especially as it becomes clogged and the differential pressure rises.This part of ISO 14085 pr
21、ovides a procedure to determine the ability of a filter element, under increasing differential pressures, to withstand dynamic operating conditions by evaluating its remaining integrity and performance after being subjected to cyclic flow variations. ISO 2015 All rights reserved vBS ISO 14085-5:2015
22、BS ISO 14085-5:2015Aerospace series Hydraulic filter elements Test methods Part 5: Resistance to flow fatigue1 ScopeThis part of ISO 14085 specifies a method for determining the resistance of a filter element to flow fatigue caused by varying flow through the filter in various stages of the filter c
23、ontaminant loading process. The filter is subjected to a uniform varying flow rate for a specified number of cycles, at a number of predetermined differential pressures.Although the number of cycles and differential pressure conditions used in this part of ISO 14085 is meant to simulate possible ser
24、vice conditions, 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, contamination, and exact cyclic
25、 flow conditions.This part of ISO 14085 establishes a method for verifying the ability of a filter element to withstand the stress caused by cyclic differential pressures induced by a variable flow rate.The test data resulting from application of this part of ISO 14085 can be used to compare the per
26、formance of aerospace hydraulic 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
27、of the referenced document (including any amendments) appliesISO 1219-1,Fluid power systems and components Graphic symbols and circuit diagrams Part 1: Graphic symbols for conventional use and data-processing applicationsISO 2942, Hydraulic fluid power Filter elements Verification of fabrication int
28、egrity and determination of the first bubble pointISO 2943, Hydraulic fluid power Filter elements Verification of material compatibility with fluidsISO 5598, Fluid power systems and components VocabularyISO 12103-1, Road vehicles Test dust for filter evaluation Part 1: Arizona test dustISO 14085-3,
29、Aerospace series Hydraulic filter elements - Test methods Part 3: Filtration efficiency and retention capacity3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.INTERNATIONAL STANDARD ISO 14085-5:2015(E) ISO 2015 All rights r
30、eserved 1BS ISO 14085-5:2015ISO 14085-5:2015(E)3.1clean assembly differential pressuredifference between the tested component inlet and outlet pressure as measured with a clean filter housing containing a clean filter element3.2clean element differential pressuredifferential pressure of the clean el
31、ement at rated flow, calculated as the difference between the clean assembly differential pressure (3.1) and the housing differential pressure3.3differential pressure pdifference between the inlet and outlet pressures of the component under test, as measured under specified conditions3.4filter eleme
32、nt resistance to flow fatigueability of a filter element to resist structural failure or performance degradation due to flexing caused by cyclic system flow rate conditions3.5housing differential pressuredifferential pressure (3.3) of the filter housing without an element3.6rated flow ratemaximum de
33、sign flow rate for the filter element as specified by the manufacturer3.7terminal element differential pressuremaximum differential pressure (3.3) across the filter element as designated by the manufacturer to limit useful performance4 Graphic symbols and circuit diagramsGraphic symbols are used in
34、accordance with ISO 1219-1.5 Test equipment and supplies5.1 Pressure-sensing and recording instruments, shall have a frequency response sufficient to measure the full pressure-versus-time curve (see Figure 1).5.2 Flow fatigue cycle test stand, shall be capable of varying the test flow rate between 0
35、 l/min up to the rated or maximum test flow rate, within the requirements of Figure 1. Use a test stand similar to that depicted in Figure 2.5.3 Test filter housing, shall be used as recommended by the filter manufacturer and modified as needed to ensure that fluid cannot by-pass the filter element.
36、5.4 Test fluid, shall be compatible with the filter element materials of construction. If necessary, the compatibility of the fluid and filter element materials of construction can be verified in accordance with ISO 2943.NOTE A fluid viscosity between 14 mm2/s and 32 mm2/s at the test temperature is
37、 recommended; unless otherwise agreed between the parties involved.2 ISO 2015 All rights reservedBS ISO 14085-5:2015ISO 14085-5:2015(E)5.5 Cycle counting device, capable of recording the number of flow fatigue cycles.5.6 Test contaminant: Use ISO Fine Test Dust (ISO FTD), grade A2 in accordance with
38、 ISO 12103-1.Key1 actual test pressure (kPa)2 one cycle test time (s): TX time (s)Y pressure (kPa)pLlower test pressure: pL 10 % pupuupper test pressure: tolerance on puis 0 %/+10 %TRrise time: TR= (15 % 5 %)TT1time at pressure: T1= (35 % 5 %)TTFfall time: TF= (15 % 5 %)TT2time at lowest test pressu
39、re: T2= (35 % 5 %)TFigure 1 Flow fatigue cycle waveform ISO 2015 All rights reserved 3BS ISO 14085-5:2015ISO 14085-5:2015(E)Key1 contaminant injection in reservoir2 alternate point for contaminant injection3 test filterFigure 2 Typical filter element flow fatigue cycle test stand circuitNOTE The cir
40、cuit in this figure is simplified and includes only the basic components for conducting the test specified in this part of ISO 14085. Other components or additional circuitry (e.g. a clean-up filter loop) might be necessary. In all cases, connection lines to test filter should be as short as possibl
41、e, and piping should be rigid to limit initial pressure peak and prevent pressure overshoot6 Accuracy of measurements and test conditionsInstruments used to measure test parameters shall provide the reading accuracy specified in Table 1. Test conditions shall be maintained within the tolerances spec
42、ified in Table 1.Table 1 Instrument accuracy and test condition variationTest parameter UnitMeasurement accuracyAllowable test condition variationsFlow rate l/min 2 % 10 %Differential pressure kPa 2 % 0 %/+10 %Temperature C 1 C 3 CCycle rate Hz 10 %7 Test procedure7.1 Subject the filter element unde
43、r test to a fabrication integrity test in accordance with ISO 2942.7.2 Disqualify from further testing any element that fails to pass the criteria specified in ISO 2942.7.3 Install the test filter housing in the flow fatigue cycle test stand (see 5.2 and Figure 2).7.4 Plot the housing differential p
44、ressure versus flow rate. Determine the test filter housing differential pressure from at least 25 % up to 100 % of the maximum test flow rate at the test temperature selected. Record the results into column 3 of Table 3.4 ISO 2015 All rights reservedBS ISO 14085-5:2015ISO 14085-5:2015(E)7.5 Install
45、 the filter element in the test filter housing.7.6 Calculate and plot the final assembly differential pressure curve corresponding to the predetermined terminal element differential pressure plus the housing differential pressure at the same flow rates as used in 7.4. Record the results on the repor
46、t sheet into Column 4 of Table 3.7.7 Calculate the clean element differential pressure at maximum flow, then determine the element differential pressures and number of cycles required for testing. Use the conditions given in Table 2, unless otherwise specified. Enter the values into columns 2 and 5
47、of Table 3.Table 2 Specified flow fatigue duty cycleTest conditionElement differential pressureNumber of flow fatigue cycles1 2 clean element p at max flow 90 0002 4 clean element p at max flow 8 0003 Terminal element p 2 0004 System pressure (for non-by-pass type filters) or maximum full-flow by-pa
48、ss p (for by-pass type filters)5007.8 Complete columns 2, 3, and 5 in Table 3 using the information from 7.4, 7.6, and 7.7. Calculate the assembly differential pressures required for the flow cycling by completing column 4 in Table 3.Table 3 Test flow fatigue duty cycleTest conditionElement p calcul
49、ated from Table 2, column 2Housing p at maximum test flowAssembly p for fatigue testing (column 2 plus column 3)Number of flow fatigue cycles from Table 2, column 31 2 3 4 7.9 Set the system flow rate to the maximum test flow rate, then add test contaminant until the assembly differential pressure for test condition 1 (from Table 3) is reached.NOTE If it is advantageous to start flow cycling while loading the filter element to the designated assembly
