1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Determination of resistance to flow fatigue using particulate contaminantICS 23.100.60Hydraulic flu
2、id power Filter elements BRITISH STANDARDBS ISO 3724:2007BS ISO 3724:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 September 2007 BSI 2007ISBN 978 0 580 53336 5Amendments issued since publicationAmd. No. Date CommentsThis publication
3、 does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of ISO 3724:2007. It supersedes
4、BS ISO 3724:1976 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee MCE/18, Fluid power systems and components, to Panel MCE/18/-/6, Contamination control.A list of organizations represented on this committee can be obtained on request to its secretary.R
5、eference numberISO 3724:2007(E)INTERNATIONAL STANDARD ISO3724Second edition2007-08-15Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using particulate contaminant Transmissions hydrauliques lments filtrants Dtermination de la rsistance la fatigue due au dbit en util
6、isant un contaminant particulaire BS ISO 3724:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Graphic symbols and circuit diagrams 2 5 Test apparatus 2 6 Accuracy of measurements and test conditions. 4 7 Test procedure 5 8 Criter
7、ia for acceptance. 6 9 Data presentation 6 10 Identification statement (reference to this International Standard) 6 Annex A (informative) Data from round robin tests performed to verify the ISO 3724 procedure 8 Bibliography . 12 BS ISO 3724:2007iv Foreword ISO (the International Organization for Sta
8、ndardization) 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 for which a technical committee has been established has the righ
9、t 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 all matters of electrotechnical standardization. International
10、Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an
11、 International Standard requires approval by at least 75 % of the member bodies casting a vote. 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. ISO 3
12、724 was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 6, Contamination control. This second edition cancels and replaces the first edition (ISO 3724:1976), which has been technically revised. BS ISO 3724:2007vIntroduction In hydraulic fluid power systems, power is
13、transmitted and controlled through a liquid under pressure within an enclosed circuit. The fluid is both a lubricant and a power-transmitting medium. Filters maintain fluid cleanliness by removing insoluble contaminants. The filter element is a porous device that performs the actual process of filtr
14、ation. The effectiveness of the filter element in controlling contaminants is dependent upon its design and its sensitivity to any unsteady operating conditions that can stress and cause damage to the filter element. BS ISO 3724:2007blank1Hydraulic fluid power Filter elements Determination of resist
15、ance to flow fatigue using particulate contaminant 1 Scope This International Standard specifies a method for determining the resistance of a hydraulic filter element to flow fatigue after it has been loaded with particulate contaminant and subjected to a uniform varying flow rate and predetermined
16、maximum element differential pressure. It establishes a uniform method for verifying the ability of a filter element to withstand the flexing caused by cyclic differential pressures induced by a variable flow rate. NOTE Annex A summarizes data from a round robin test performed to verify the procedur
17、e specified in this International Standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any ame
18、ndments) applies. ISO 1219-1, Fluid power systems and components Graphic symbols and circuit diagrams Part 1: Graphic symbols for conventional use and data-processing applications ISO 1219-2, Fluid power systems and components Graphic symbols and circuit diagrams Part 2: Circuit diagrams ISO 29411),
19、 Hydraulic fluid power Filter elements Verification of collapse/burst pressure rating ISO 2942, Hydraulic fluid power Filter elements Verification of fabrication integrity and determination of the first bubble point ISO 2943, Hydraulic fluid power Filter elements Verification of material compatibili
20、ty with fluids ISO 55982), Fluid power systems and components Vocabulary 1) To be published. (Revision of ISO 2941:1974) 2) To be published. (Revision of ISO 5598:1985) BS ISO 3724:20072 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5598 and the fo
21、llowing apply. 3.1 filter element resistance to flow fatigue ability of a filter element to resist structural failure due to flexing caused by cyclic system flow rate conditions 3.2 maximum assembly differential pressure pAsum of the housing differential pressure and the maximum element differential
22、 pressure 3.3 housing differential pressure pHdifferential pressure of the filter housing without an element 3.4 maximum element differential pressure pEmaximum differential pressure across the filter element designated by the manufacturer as the limit of useful performance 4 Graphic symbols and cir
23、cuit diagrams Graphic symbols used in this International Standard are in accordance with ISO 1219-1 and circuit diagrams in accordance with ISO 1219-2. 5 Test apparatus 5.1 Pressure-sensing and recording instruments, with a frequency response capable of measuring the full pressure-versus-time curve
24、(see Figure 1). 5.2 Flow fatigue cycle test stand, capable of varying the test flow rate from 0 l/min up to the rated flow rate (see Figures 1 and 2). 5.3 Test filter housing, capable of ensuring that the fluid cannot bypass the filter element. The filter shall be capable of being modified to suit t
25、his purpose. 5.4 Test fluid, with a viscosity between 14 mm2/s and 32 mm2/s at the test temperature. The compatibility of the fluid and filter element material shall be verified in accordance with ISO 2943. Any fluid that is compatible with the filter element material may be used. 5.5 Cycle counting
26、 device, capable of recording the number of flow fatigue cycles. 5.6 Inert particulate contaminant, not able to add strength to the filter element, used to load the filter element being evaluated. NOTE Test dust according to ISO 12103-1 is suitable. BS ISO 3724:20073Key X time (s) Y pressure (kPa) 1
27、 actual test pressure (kPa) 2 one test cycle, T pLlower test pressure; pLu 10 % pUpUupper test pressure; tolerance on pUis 10 % TRrise time; TR= (15 5) %T T1time at pressure; T1= (35 5) %T TFfall time; TF= (15 5) %T T2time without pressure; T2= (35 5) %T Figure 1 Flow fatigue cycle test waveform BS
28、ISO 3724:20074 Key 1 contaminant injection 2 system pump 3 alternative point of contaminant injection 4 cycling valve 5 temperature sensor 6 filter under test 7 differential pressure transducer 8 relief valve 9 flow meter 10 heat exchanger NOTE The circuit in this figure is simplified and includes o
29、nly the basic components needed for conducting the test specified in this International Standard. Other components or additional circuitry (e.g. clean-up filter loop) can be used. Figure 2 Typical filter element in flow fatigue cycle test stand circuit 6 Accuracy of measurements and test conditions
30、Instruments used to measure test parameters shall provide a reading accuracy in accordance with Table 1. Test conditions shall be maintained within the tolerances specified in Table 1. Table 1 Instrument accuracy and allowed test condition variation Test condition SI unit Instrument accuracy Toleran
31、ce on reading Allowed test condition variationFlow rate l/min 2 % 10 % Differential pressure kPa 2 % 10 % Temperature C 1 C 3 C Cycle rate Hz 10 % BS ISO 3724:200757 Test procedure 7.1 Subject the filter element under test to a fabrication integrity test in accordance with ISO 2942. 7.2 Disqualify f
32、rom 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 curve of housing differential pressure (pH) versus flow rate (q). Determine the test filter housing dif
33、ferential pressure from at least 25 % up to 100 % of the rated flow rate at the test temperature selected. Record the results in the test report (see Table 2). 7.5 Install the filter element in the test filter housing. 7.6 Calculate and plot the maximum assembly differential pressure (pA) curve, cor
34、responding to the predetermined maximum element differential pressure (pE) plus the housing differential pressure (pH), at the same flow rates as those given in 7.4. Record the results in the test report (see Table 2). 7.7 Add the test contaminant until the maximum assembly differential pressure (pA
35、) is reached. NOTE 1 The filter element will need more contaminant in order for the maximum element differential pressure to be reached at 25 % of the rated flow rate. However, because the filter element can experience particle desorption due to the variation in flow rate, it is suggested that initi
36、al contaminant be injected at the minimum or intermediate flow rate (that is 25 % or other percentage of rated flow rate) until the maximum assembly differential pressure is reached. This approach can minimize the total amount of contaminant used throughout the test, as the differential pressure can
37、 be maintained by increasing the flow rate instead of adding more contaminant. If it is advantageous to start flow fatigue cycling while loading the filter element to the maximum assembly differential pressure, ensure that the cycle counting device is reset to zero before proceeding to 7.8. Initiall
38、y, contaminant should be added in a uniform manner. For incremental injections, a mass of 5 % of the estimated filter element contaminant capacity per injection is recommended. Adjustments to the quantities of contaminant added and time intervals between injections may be required. NOTE 2 The test c
39、an be interrupted and restarted as necessary. If the test is interrupted, additions of contaminant will most likely be required to regain the maximum assembly differential pressure. 7.8 Begin the flow fatigue cycle test. Each flow fatigue cycle shall consist of varying the flow rate through the filt
40、er element from 0 l/min to a flow rate between 25 % and 100 % of the rated flow rate and then back to 0 l/min, while maintaining the differential pressure-versus-time trace specified in Figure 1. The frequency of the test cycle rate shall be selected from the range 0,2 Hz to 1 Hz (inclusive) and sha
41、ll remain constant within the tolerances given in Table 1 throughout the test. A relief valve may be used (see Figure 2) and adjusted as necessary to limit peak pressure to the maximum assembly differential pressure within a tolerance of 10 %, as specified in the waveform shown in Figure 1. Contamin
42、ant may also be added periodically during the test to maintain differential pressure. 7.9 Monitor and control the assembly differential pressure by reducing or increasing the flow rate, as needed, between 25 % and 100 % of the rated flow rate. 7.10 Subject the filter element to the required number o
43、f flow fatigue cycles. 7.11 Obtain and present a typical differential pressure-versus-time trace for at least one cycle (see Figure 1). 7.12 Subject the filter element to a collapse/burst test in accordance with ISO 2941, with the exception that the bubble point test before the collapse/burst test i
44、s not required. BS ISO 3724:20076 8 Criteria for acceptance The filter element shall be accepted if it passes the collapse/burst test in accordance with ISO 2941, after the completion of the required number of flow fatigue cycles and with the exception given in 7.12. 9 Data presentation As a minimum
45、, present all of the test data and calculation results mentioned in Clause 7. The format of the test report should be that of the example given in Table 2. 10 Identification statement (reference to this International Standard) Use the following statement in test reports, catalogues and sales literat
46、ure when electing to comply with this International Standard: “Method of determining filter element resistance to flow fatigue using particulate contaminant conforms to ISO 3724:2007, Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using particulate contaminant.” BS
47、 ISO 3724:20077Table 2 Data and calculation results from determination of resistance of filter element to flow fatigue particulate contaminant Example format Test laboratory: _ Test date: _ Operator: _ Filter and element identification Element identification number: _ Filter housing identification n
48、umber: _ Spin-on canister: Yes _ No _ Minimum element bubble point: _ Pa Operating conditions Test fluid Type: _ Ref.: _ Batch no.: _ Viscosity at the test temperature: _ mm2/s Test temperature: _ C Test contaminant Type: _ Batch no.: _ Test system Maximum flow rate, q: _ l/min Maximum element differential pressure: _ kPa Test results Element integrity Bubble point according to ISO 2942: _ Pa Pass Fail Wetting fluid: _ Differential pressure (p) at test flow rate(s) include filter housing and calcu
