1、BSI Standards PublicationBS ISO 19973-2:2015Pneumatic fluid power Assessment of componentreliability by testingPart 2: Directional control valvesBS ISO 19973-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 19973-2:2015. It supersedes BS ISO 19973-2:2007
2、which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee MCE/18, Fluid power systems and components.A list of organizations represented on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
3、provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 85278 7 ICS 23.100.01 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was p
4、ublished under the authority of the Standards Policy and Strategy Committee on 30 September 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 19973-2:2015 ISO 2015Pneumatic fluid power Assessment of component reliability by testing Part 2: Directional control valv
5、esTransmissions pneumatiques valuation par essais de la fiabilit des composants Partie 2: DistributeursINTERNATIONAL STANDARDISO19973-2Second edition2015-09-01Reference numberISO 19973-2:2015(E)BS ISO 19973-2:2015ISO 19973-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015
6、, Published in SwitzerlandAll rights reserved. Unless otherwise 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. P
7、ermission can be requested from either ISO at the address below 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.orgBS ISO 19973-2:2015ISO 19973-2:201
8、5(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Symbols and units . 25 Test equipment. 25.1 Basic test equipment 25.2 Connecting piping and volume 45.3 Simultaneous operation of multiple pneumatically operated valves 46 Test conditions . 46.1 General test
9、 conditions 46.2 Initial condition 46.3 Cycling frequencies . 47 Test procedures . 67.1 Timing of checks and measurements 67.2 Type and scope of checks and measurement . 67.2.1 Functional check 67.2.2 Measurement of leakage . 67.2.3 Measurement of shifting pressures . 68 Failure criteria and thresho
10、ld levels . 88.1 General . 88.2 Functional failure 88.3 Failure due to leakage . 88.4 Failure due to shifting pressures . 98.5 Customised agreements 99 Data analysis . 910 Test report . 911 Identification statement (reference to this part of ISO 19973) 10Annex A (informative) Test data sheet 11Bibli
11、ography .14 ISO 2015 All rights reserved iiiContents PageBS ISO 19973-2:2015ISO 19973-2:2015(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 carrie
12、d 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 ISO, also take part in the work. IS
13、O 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, Part 1. In particular the different
14、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 the elements of this document may be t
15、he 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 received (see www.iso.org/patents).An
16、y 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 adherence to the WTO principles in t
17、he Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 131, Fluid power systems.This second edition cancels and replaces the first edition (ISO 19973-2:2007), which has been technically revised.ISO 19973 c
18、onsists of the following parts, under the general title Pneumatic fluid power Assessment of component reliability by testing: Part 1: General procedures Part 2: Directional control valves Part 3: Cylinders with piston rod Part 4: Pressure regulators Part 5: Non-return valves, shuttle valves, dual pr
19、essure valves (AND function), one-way adjustable flow control valves, quick-exhaust valves.iv ISO 2015 All rights reservedBS ISO 19973-2:2015ISO 19973-2:2015(E)IntroductionIn pneumatic fluid power systems, power is transmitted and controlled through a gas under pressure within a circuit. Pneumatic f
20、luid power systems are composed of components and are an integral part of various types of machines and equipment. Efficient and economical production requires highly reliable machines and equipment. This part of ISO 19973 is intended to provide requirements and test conditions that permit the asses
21、sment of the inherent reliability of pneumatic and electro-pneumatic directional control valves.It is necessary that machine producers know the reliability of the components that make up their machines pneumatic fluid power system. Knowing the reliability characteristic of the component, the produce
22、rs can model the system and make decisions on service intervals, spare parts inventory and areas for future improvements.There are three primary levels in the determination of component reliability:a) preliminary design analysis: finite element analysis (FEA), failure mode and effect analysis (FMEA)
23、;b) laboratory testing and reliability modelling: physics of failure, reliability prediction, pre-produc-tion evaluation;c) collection of field data: maintenance reports, warranty analysis.Each level has its application during the life of a component. A preliminary design analysis is useful to ident
24、ify possible failure modes and eliminate them or reduce their effect on reliability. When prototypes are available, in-house laboratory reliability tests are run and initial reliability can be determined. Reliability testing is often continued into the initial production run and throughout the produ
25、ction lifetime as a continuing evaluation of the component. Collection of field data are possible when products are operating and data on their failures are available. ISO 2015 All rights reserved vBS ISO 19973-2:2015BS ISO 19973-2:2015Pneumatic fluid power Assessment of component reliability by tes
26、ting Part 2: Directional control valves1 ScopeThis part of ISO 19973 provides test procedures for assessing the reliability of pneumatic directional control valves by testing and the methods of reporting the results of testing. General test conditions and the calculation method are provided in ISO 1
27、9973-1. The methods specified in ISO 19973-1 apply to the first failure, as obtained with the three-points moving average (3PMA) method, without repairs, but excluding outliers.The lifetime of pneumatic and electro-pneumatic directional control valves is usually given as a number of cycles. Therefor
28、e, whenever the term “time” is used in this part of ISO 19973, this variable is to be understood as cycles.This part of ISO 19973 also specifies test equipment and threshold levels for tests to assess the reliability of pneumatic directional control valves.2 Normative referencesThe following documen
29、ts, 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 document (including any amendments) applies.ISO 1219-1, Fluid power syste
30、ms and components Graphical symbols and circuit diagrams Part 1: Graphical symbols for conventional use and data-processing applicationsISO 5598, Fluid power systems and components VocabularyISO 8778, Pneumatic fluid power Standard reference atmosphereISO 19973-1, Pneumatic fluid power Assessment of
31、 component reliability by testing Part 1: General proceduresISO 80000-1, Quantities and units Part 1: GeneralIEC 60050-191, International Electrotechnical Vocabulary, chapter 191: Dependability and quality of service3 Terms and definitionsFor the purposes of this document, the terms and definitions
32、given in ISO 5598, ISO 19973-1 and IEC 60050-191 apply.NOTE Where a conflict of definitions exists for a term in any of these three documents, the following priority order applies: first, ISO 19973-1; second, ISO 5598; and third, IEC 60050-191.INTERNATIONAL STANDARD ISO 19973-2:2015(E) ISO 2015 All
33、rights reserved 1BS ISO 19973-2:2015ISO 19973-2:2015(E)4 Symbols and unitsUnits of measurement shall be in accordance with ISO 80000-1.NOTE Graphical symbols used in this part of ISO 19973 conform to the requirements given in ISO 1219-1.5 Test equipment5.1 Basic test equipmentBasic test equipment sh
34、all conform to the requirements given in Figure 1. Any silencers fitted to exhaust ports shall not restrict the valves flow rate.The basic circuits in Figure 1 do not incorporate all the safety devices necessary to protect against damage in the event of component failure. It is important that those
35、responsible for carrying out the test give due consideration to safeguarding both personnel and equipment.a) Two-position bi-stable valves2 ISO 2015 All rights reservedBS ISO 19973-2:2015ISO 19973-2:2015(E)b) Two-position mono-stable valves with spring or air returnc) Three-position valvesKey1 to 5
36、ports 9 volume6 control signal: electrical, pneumatic, or pilot operated 10 supply pressure to port 17 spring or air-spring return V valve being tested8 spring return to centre positionNOTE The pilot supply can be either internal or external as long as it has the capability described in 7.2.Figure 1
37、 Basic test equipment requirements ISO 2015 All rights reserved 3BS ISO 19973-2:2015ISO 19973-2:2015(E)5.2 Connecting piping and volume5.2.1 Connect the volume to the outlet ports of the test units either directly or by means of sections of tubes, in a manner that does not restrict flow.NOTE Volume
38、sizes are given in ISO 19973-1.5.2.2 Tubes in the connecting lines shall be kept as short as possible so that the volumes can be charged and vented within the times provided by the control signal.5.3 Simultaneous operation of multiple pneumatically operated valvesWhen testing pneumatically operated
39、valves, several test units may be operated simultaneously from one control valve. In doing so, the control pressure described in 6.3.1 shall be applied to all test units.6 Test conditions6.1 General test conditionsThe general test conditions shall be in accordance with ISO 19973-1.6.2 Initial condit
40、ionAll new test units shall pass a functional check (see 7.2) and the initial test data shall not exceed the threshold levels defined in this part of ISO 19973.6.3 Cycling frequencies6.3.1 Actuate the test valves in a manner to ensure that the pressure in the outlet port volumes drops below 10 %, an
41、d rises above 90 %, of the supply pressure during the cycle.6.3.2 The ratio between the actuation-impulse on/off times shall be 1:1.6.3.3 For mono-stable two-position valves, the control signal shall be applied in accordance with Figure 2.4 ISO 2015 All rights reservedBS ISO 19973-2:2015ISO 19973-2:
42、2015(E)KeyV valve control signal 0 control valve signal OFFt time nTcycle time1 control valve signal ON p2,p4pressure in the outlet port volumesFigure 2 Control signal for mono-stable two-position valves6.3.4 For bi-stable and three-position valves, the control signal shall be applied in accordance
43、with Figure 3.KeyV12, V14 valve control signals 0 control valve signal OFFt time nTcycle time1 control valve signal ON p2,p4pressure in the outlet port volumesNOTE Outlet pressure is shown as an example for a bi-stable two-position valve.Figure 3 Control signal for bi-stable and three-position valve
44、s ISO 2015 All rights reserved 5BS ISO 19973-2:2015ISO 19973-2:2015(E)7 Test procedures7.1 Timing of checks and measurements7.1.1 The following checks and measurements shall be made before, during, and after the endurance test: functional check in accordance with 7.2.1; measurement of leakage in acc
45、ordance with 7.2.2; measurement of shifting pressure in accordance with 7.2.3.7.1.2 Measuring intervals shall be determined in accordance with ISO 19973-1.7.2 Type and scope of checks and measurement7.2.1 Functional checkTest units shall be checked acoustically, optically, and tactilely under test c
46、onditions to determine whether the test units and the valves controlling them are operating correctly. The functional check is to see whether switching failures, incomplete charging of an output, or detectable or audible leakage is occurring. Remarkable characteristics shall be documented.7.2.2 Meas
47、urement of leakage7.2.2.1 The functional leakage (sum of the internal and external leakage) shall be recorded in each valve position (including the centre position of three-position valves), with test pressure applied to the inlet port.7.2.2.2 In addition, the following types of leakage may be measu
48、red for the valve type indicated: for pneumatically controlled valves: leakage rate in all internal pneumatic pilot lines and control chambers without test pressure applied to the inlet port, but with pilot pressure applied; for valves with auxiliary pilot air: leakage rate in all internal pneumatic
49、 pilot lines in all valve positions without test pressure applied to the inlet port, but with pilot pressure applied; for three-position valves with closed centre position: leakage rate in the closed centre position at the open outlet ports with inlet pressure applied to the inlet port; then leakage at the exhaust ports after applying test pressure to the outlet ports; for three-position valves with other types of centre positions: leakage rate at the exhaust ports with the valve in the centre position and w
