1、BRITISH STANDARDBS ISO 23181:2007Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using high viscosity fluidICS 23.100.60g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55
2、g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 23181:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 September 2007 BSI 2007ISBN 978 0 580 53503 1National forewordThis British Standard is the UK implementation of ISO 2318
3、1:2007.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.This publication does not purpo
4、rt 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. Amendments issued since publicationAmd. No. Date CommentsReference numberISO 23181:2007(E)INTERNATIONAL STANDA
5、RD ISO23181First edition2007-08-15Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using high viscosity fluid Transmissions hydrauliques lments filtrants Dtermination de la rsistance la fatigue due au dbit en utilisant un fluide haute viscosit BS ISO 23181:2007ii iii
6、Foreword ISO (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 for which a t
7、echnical 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 all matters
8、 of electrotechnical standardization. International 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 circulate
9、d to the member bodies for voting. Publication as an 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
10、for identifying any or all such patent rights. ISO 23181 was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 6, Contamination control. BS ISO 23181:2007iv Introduction In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressu
11、re 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 filtration. The effectiveness of the filter element in contro
12、lling contaminants is dependent upon its design and its sensitivity to any unsteady operating conditions that can stress and cause damage to the filter element. The flow fatigue test procedure using high viscosity fluid specified in this International Standard can be used when the same element needs
13、 to be subjected to further testing, for example a multi-pass test, after the flow fatigue test has been applied in order to meet a purchasers acceptance criteria. In addition, this International Standard can be used to simulate start-up conditions of mobile hydraulic equipment by using a high visco
14、sity fluid to generate the required differential pressure. The attention of users of this International Standard is drawn to the fact that round robin testing has shown that flow fatigue resistance characteristics determined in accordance with this International Standard differ from characteristics
15、determined in accordance with ISO 3724. BS ISO 23181:20071Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using high viscosity fluid 1 Scope This International Standard specifies a method for determining the resistance of a hydraulic filter element to flow fatigue w
16、hen subjected to high viscosity fluid, using a uniformly varying flow rate up to a predetermined maximum differential pressure and a controlled waveform. It establishes a method for verifying the ability of a filter element to withstand the flexing caused by cyclic differential pressures induced by
17、a variable flow rate. NOTE See the Introduction of this International Standard for information about its applicability. 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
18、references, the latest edition of the referenced document (including any amendments) 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 componen
19、ts Graphic symbols and circuit diagrams Part 2: Circuit diagrams ISO 29411), 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
20、, Hydraulic fluid power Filter elements Verification of material compatibility with fluids ISO 3448, Industrial liquid lubricants ISO viscosity classification ISO 4406, Hydraulic fluid power Fluids Method for coding the level of contamination by solid particles ISO 55982), Fluid power systems and co
21、mponents Vocabulary 1) To be published. (Revision of ISO 2941:1974) 2) To be published. (Revision of ISO 5598:1985) BS ISO 23181:20072 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply. 3.1 filter element resistance to flow
22、 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 pressure 3.3 housing differential pressure pHdiffer
23、ential 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 3.5 high viscosity fluid fluid that is classified by its manufacturer as havi
24、ng a viscosity greater than or equal to 198 mm2/s at 40 C NOTE This viscosity level is classified as ISO VG 220 in accordance with ISO 3448. 4 Graphic symbols and circuit diagrams Graphic symbols used in this International Standard are in accordance with ISO 1219-1 and circuit diagrams in accordance
25、 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 (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 F
26、igures 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 this purpose. 5.4 Test fluid, with a viscosity equal to or greater than 198 mm2/s at 40 C (ISO VG 220, in accordance with ISO 3448). Th
27、e viscosity of the test fluid shall provide the desired maximum element differential pressure at the test temperature and flow rate selected. Care shall be taken to ensure that the fluid chosen does not create adverse suction conditions in the main pump, otherwise cavitation could occur. The fluid i
28、n the system should be cleaned to a solid contamination level of 18/16/13 or cleaner in accordance with ISO 4406 prior to installing the filter element under test in the circuit. The compatibility of the fluid and filter element material shall be verified in accordance with ISO 2943. Any fluid that
29、is compatible with the filter element material may be used. 5.5 Cycle counting device, capable of recording the number of flow fatigue cycles. BS ISO 23181:20073Key X time (s) Y pressure (kPa) 1 actual test pressure (kPa) 2 one test cycle, T pLlower test pressure; pLu 10 % pUpUupper test pressure; t
30、olerance 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 ISO 23181:20074 Key 1 system pump 2 cycling valve 3 temperature sensor 4 filter under test 5 differential
31、pressure transducer 6 relief valve 7 flow meter 8 heat exchanger NOTE The circuit in this figure is simplified and includes only 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 u
32、sed. Figure 2 Typical filter element in flow fatigue cycle test stand circuit 6 Accuracy of measurements and test conditions 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
33、 Table 1. Table 1 Instrument accuracy and allowed test condition variation Test condition SI unit Instrument accuracy Tolerance 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 23181:200757 Test pro
34、cedure 7.1 Subject the filter element under 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 F
35、igure 2). 7.4 Determine the test filter housing differential 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). Plot the curve of housing differential pressure (pH) versus flow rate (q) for the test fi
36、lter housing (Curve 1). 7.5 Install the filter element in the test filter housing. Determine the assembly differential pressure (pA) at the same flow rate as that used in 7.4. Record the results in the test report (see Table 2). Plot the curve of assembly differential pressure (pA) versus flow rate
37、(q) (Curve 2). 7.6 Calculate and plot the differential pressure curve of the filter element by subtracting the values used to produce Curve 1 (see 7.4) from those used to produce Curve 2 (see 7.5). Determine from the resulting curve the flow rate required to reach the predetermined maximum element d
38、ifferential pressure (pE), and record the results in the test report (see Table 2). Determine from Curve 2 the maximum assembly differential pressure (pA), and record the results in the test report (see Table 2). 7.7 Set the flow rate at the value determined in 7.6, and check that the maximum assemb
39、ly differential pressure (pA) has been reached. If this cannot be achieved, repeat steps 7.4 to 7.6, either at a lower test temperature or with a fluid that has a higher viscosity. 7.8 Begin the flow fatigue cycle test. Each flow fatigue cycle shall consist of varying the flow rate through the filte
40、r element from 0 l/min to a flow rate not exceeding 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 shall remain co
41、nstant within the tolerances given in Table 1 throughout the test. 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 throughout the entire duration of the test. A relief valve may be used (see Fi
42、gure 2) and adjusted as necessary to limit peak pressure to the maximum assembly differential pressure (pA), within a tolerance of 10 %, as specified in the waveform shown in Figure 1. 7.10 Subject the filter element to the required number of flow fatigue cycles. 7.11 Obtain and present a typical di
43、fferential-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 is not required. 8 Criteria for acceptance The filter elemen
44、t 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, present all of the test data and calculation results mentioned in Clause 7.
45、 The format of the test report should be that of the example given in Table 2. BS ISO 23181:20076 10 Identification statement (reference to this International Standard) Use the following statement in test reports, catalogues and sales literature when electing to comply with this International Standa
46、rd: “Method of determining filter element resistance to flow fatigue using high viscosity fluid conforms to ISO 23181:2007, Hydraulic fluid power Filter elements Determination of resistance to flow fatigue using high viscosity fluid.” Table 2 Data and calculation results from determination of resist
47、ance of filter element to flow fatigue using high viscosity fluid Example format Test laboratory: _ Test date: _ Operator: _ Filter and element identification Element identification number: _ Filter housing identification number: _ Spin-on canister: Yes _ No _ Minimum element bubble point: _ Pa Oper
48、ating conditions Test fluid Type: _ Ref.: _ Viscosity at the test temperature: _ mm2/s Test temperature: _ C Test system Maximum flow rate, q: _ l/min 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 calculated final assembly curves in accordance with ISO 23181:2007, 7.4 to 7.6: Flow rate, q: _ l/min Filter housing differential pressure, pH: _ kPa Maximum element differential pressure, pE: _ kPa Max
