1、Hydraulic fluid power Filters Evaluation of differential pressure versus flowBS ISO 3968:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Hydraulic fluid power Filters Evaluation of differential pressure versus flowTransmissions hydrauliques Filtres valua
2、tion de la perte de charge en fonction du dbitINTERNATIONALSTANDARDISO3968Third edition2017-07Reference numberISO 3968:2017(E)National forewordThis British Standard is the UK implementation of ISO 3968:2017. It supersedes BS ISO 3968:2001 which is withdrawn.The UK participation in its preparation wa
3、s entrusted to Technical Committee MCE/18/-/6, Contamination control.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 are responsible for its correct applic
4、ation. The British Standards Institution 2017Published by BSI Standards Limited 2017ISBN 978 0 580 89001 7ICS 23.100.60Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committ
5、ee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 3968:2017 ISO 2017Hydraulic fluid power Filters Evaluation of differential pressure versus flowTransmissions hydrauliques Filtres valuation de la perte de charge en fonction du dbitINTERNAT
6、IONAL STANDARDISO3968Third edition2017-07Reference numberISO 3968:2017(E)BS ISO 3968:2017ISO 3968:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or uti
7、lized 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 the requester.ISO copyrig
8、ht officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 3968:2017ISO 3968:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwi
9、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
10、ow or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgISO 3968:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definit
11、ions . 14 Symbols 24.1 Letter symbols . 24.2 Graphical symbols 25 Operational characteristics to be tested 26 Filter to be tested . 36.1 Filter type 36.2 Filter element . 37 Test equipment. 37.1 General indications 37.2 Pump 37.3 Reservoir 37.4 Temperature control 47.5 Clean-up filter 47.6 Sampling
12、valve . 47.7 Mounting of filter 57.8 Test fluid . 68 Measurements . 68.1 Pressure measurement 68.2 Temperature measurement . 88.3 Kinematic viscosity measurement . 88.4 Flow rate measurement 98.5 Fluid cleanliness measurement 98.6 Accuracy of measuring instruments and test conditions . 99 Procedure.
13、 99.1 Pipework correction. 99.2 Cleanliness of test circuit . 99.3 Characteristics of the filter housing (filter type 6.1.3) 109.4 Characteristics of the filter assembly (filter type 6.1.3) .109.5 Characteristics of the filter element only (filter type 6.1.3)109.6 Characteristics of the head and spi
14、n-on (filter type 6.1.2) 109.7 Characteristics of the spin-on (filter type 6.1.1) .119.8 Characteristics of the bypass valve . 119.8.1 Preliminary installation 119.8.2 Determination of full flow rate characteristics .119.8.3 Determination of opening pressure . 119.8.4 Determination of closing pressu
15、re 129.8.5 Measurement of leakage rate . 1210 Presentation of results 1211 Identification statement (reference to this document) 14Annex A (informative) Introduction to the power loss equation and method to calculate 15Bibliography .17 ISO 2017 All rights reserved iiiContents PageBS ISO 3968:2017ISO
16、 3968:2017(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 member body interested in a subject f
17、or 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 Electrotechnical Commission (IEC) on
18、 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 types of ISO documents should be noted.
19、 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 held responsible for identifying
20、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 information given for the convenience
21、of users and does not constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical B
22、arriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 6, Contamination control.This third edition cancels and replaces the second edition (ISO 3968:2001), which has been tech
23、nically revised. It also incorporates the Technical Corrigendum ISO 3968:2001/Cor1: 2002.iv ISO 2017 All rights reservedBS ISO 3968:2017ISO 3968:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The wor
24、k 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-governme
25、ntal, 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 for its further maintenance are described in the
26、 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 .org/ directives).Attention is drawn to the pos
27、sibility 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 in the Introduction and/or on the ISO list
28、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 voluntary nature of standards, the meaning of ISO specific terms and expressions relate
29、d to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 131, Fluid power system
30、s, Subcommittee SC 6, Contamination control.This third edition cancels and replaces the second edition (ISO 3968:2001), which has been technically revised. It also incorporates the Technical Corrigendum ISO 3968:2001/Cor1: 2002.iv ISO 2017 All rights reserved ISO 3968:2017(E)IntroductionIn hydraulic
31、 fluid power systems, power is transmitted and controlled through a fluid under pressure circulating within a closed circuit. Filters maintain the cleanliness of the fluid by retaining the insoluble contaminants.Hydraulic filters normally include a housing that serves as the pressure-containing vess
32、el to direct the flow of fluid through a filter element that separates contaminants from the test fluid.This document foresees the possibility to test spin-on filters in which the replaceable unit does or does not include a filter head.In operation, fluid flowing through a filter meets resistance du
33、e to kinetic and viscous effects. The pressure required to overcome this resistance and to maintain flow is known as the differential pressure. The differential pressure is the total pressure difference observed between the filter inlet port and outlet port and represents the sum of the losses recor
34、ded in the housing and filter element.Factors which affect clean filter differential pressure are fluid viscosity, fluid specific gravity, flow rate, filter element media type and construction, as well as housing design. ISO 2017 All rights reserved vBS ISO 3968:2017Hydraulic fluid power Filters Eva
35、luation of differential pressure versus flow1 ScopeThis document specifies a procedure for evaluating differential pressure versus flow characteristics of hydraulic filters and constitutes a basis for agreement between the filter manufacturer and user.It also specifies a method for measurement of th
36、e differential pressure generated at different flow rates and viscosities by the relevant parts of a filter assembly, spin-on and any valves contained within the filter which are in the flow stream. The typical types of filter to be tested are as follows:Type 1: which are spin-on filters in which th
37、e replaceable unit does not include a filter head (it might or might not include the element by-pass valve);Type 2: which are spin-on filters in which the replaceable element is tested together with a filter head (it might or might not include the element by-pass valve);Type 3: which are filter asse
38、mbly, usually of the replacement element type, that is the housing (head and bowl) and element.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition c
39、ited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2909, Petroleum products Calculation of viscosity index from kinematic viscosityISO 3448, Industrial liquid lubricants ISO viscosity classificationISO 3675, Crude petroleum and
40、liquid petroleum products Laboratory determination of density Hydrometer methodISO 4021, Hydraulic fluid power Particulate contamination analysis Extraction of fluid samples from lines of an operating systemISO 4406, Hydraulic fluid power Fluids Method for coding the level of contamination by solid
41、particlesISO 5598, Fluid power systems and components VocabularyISO 6415, Internal combustion engines Spin-on filters for lubricating oil Dimensions3 Terms and definitionsFor the purposes of this document, the definitions given in ISO 5598 and the following apply:ISO and IEC maintain terminological
42、databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp3.1filter rated flow rateflow rate recommended by the filter manufacturer for a specified kinemat
43、ic viscosityINTERNATIONAL STANDARD ISO 3968:2017(E) ISO 2017 All rights reserved 1BS ISO 3968:2017Hydraulic fluid power Filters Evaluation of differential pressure versus flow1 ScopeThis document specifies a procedure for evaluating differential pressure versus flow characteristics of hydraulic filt
44、ers and constitutes a basis for agreement between the filter manufacturer and user.It also specifies a method for measurement of the differential pressure generated at different flow rates and viscosities by the relevant parts of a filter assembly, spin-on and any valves contained within the filter
45、which are in the flow stream. The typical types of filter to be tested are as follows:Type 1: which are spin-on filters in which the replaceable unit does not include a filter head (it might or might not include the element by-pass valve);Type 2: which are spin-on filters in which the replaceable el
46、ement is tested together with a filter head (it might or might not include the element by-pass valve);Type 3: which are filter assembly, usually of the replacement element type, that is the housing (head and bowl) and element.2 Normative referencesThe following documents are referred to in the text
47、in such a way that some or all of their content constitutes requirements 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 2909, Petroleum products Calculation of viscos
48、ity index from kinematic viscosityISO 3448, Industrial liquid lubricants ISO viscosity classificationISO 3675, Crude petroleum and liquid petroleum products Laboratory determination of density Hydrometer methodISO 4021, Hydraulic fluid power Particulate contamination analysis Extraction of fluid sam
49、ples from lines of an operating systemISO 4406, Hydraulic fluid power Fluids Method for coding the level of contamination by solid particlesISO 5598, Fluid power systems and components VocabularyISO 6415, Internal combustion engines Spin-on filters for lubricating oil Dimensions3 Terms and definitionsFor the purposes of this document, the definitions given in ISO 5598 and the following apply:ISO and IEC maintain terminological databases for use in standardization at the fo
