1、Designation: D 6546 00 (Reapproved 2005)An American National StandardStandard Test Methods forand Suggested Limits for Determining Compatibility ofElastomer Seals for Industrial Hydraulic Fluid Applications1This standard is issued under the fixed designation D 6546; the number immediately following
2、the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods co
3、ver the procedure for measuringphysical properties of elastomer seals in the form of O-ringsafter exposure to industrial hydraulic fluids and thermal aging.The measured properties are then compared to the physicalproperties of elastomer seals that have not been exposed to theindustrial hydraulic flu
4、ids and thermal aging. The changes inthese properties form a basis for assessing compatibility whenthese changes are compared against the suggested limits inTable 1.1.2 While these test methods involve the use of O-rings,they can also be used to evaluate the compatibility of theelastomeric compounds
5、 of specialty seals with industrial hy-draulic fluids and their resistance to thermal aging. Thecompounds can be molded into O-rings for evaluation pur-poses.1.3 These test methods provide procedures for exposingO-ring test specimens to industrial hydraulic fluids underdefinite conditions of tempera
6、ture and time. The resultingdeterioration of the O-ring material is determined by compar-ing the changes in work function, hardness, physical proper-ties, compression set, and seal volume after immersion in thetest fluid to the pre-immersion values.1.4 The values stated in SI units are to be regarde
7、d as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine
8、 the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 395 Test Methods for Rubber PropertyCompressionSetD 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD 471 Test Method for Rubber PropertyEffect of LiquidsD 1414 Test Met
9、hods for Rubber O-RingsD 2000 Classification System for Rubber Products in Auto-motive ApplicationsD 2240 Test Method for Rubber PropertyDurometerHardnessD 3677 Test Methods for RubberIdentification by Infra-red SpectrophotometryD 3767 Practice for RubberMeasurement of DimensionsD 5028 Test Method f
10、or Curing Properties of PultrusionResins by Thermal AnalysisE 1131 Test Method for Compositional Analysis by Ther-mogravimetry2.2 SAE Standard:3AS568A O-ring Sizes3. Terminology3.1 Definitions:3.1.1 batchall the O-rings molded from the same lot ofmaterial and presented for inspection at one time.3.1
11、.2 compounda fully formulated elastomer materialcontaining all fillers and cross-linking agents.3.1.3 fluid saturation effectthe absorption of fluid by theelastomer until an equilibrium swell value is reached at aparticular temperature.3.1.4 O-ringa rubber seal of homogeneous compositionmolded in on
12、e piece to the configuration of a torus with circularcross section.3.1.4.1 DiscussionO-rings are used as both dynamic andstatic seals. The size of the O-ring is normally designated by adash number corresponding to the size tables listed inAS568A.The dimensions for the O-rings used in these test meth
13、ods arelisted in Annex A2.3.1.5 ultimate elongationthe amount of stretch that theO-ring is exposed to before breaking.1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.N0 on Hydraulic Fluids.Cu
14、rrent edition approved May 1, 2005. Published June 2005. Originallyapproved in 2000. Last previous edition approved in 2000 as D 654600.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
15、formation, refer to the standards Document Summary page onthe ASTM website.3Available from Society of Automotive Engineers, 400 Commonwealth Drive,Warrendale, PA 15096.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.6 work functi
16、onwork done on a test specimen to cause20 % deformation.4. Significance and Use4.1 When more than one elastomer seal material is tested,the test methods yield comparative data on which to basejudgements as to expected service quality. Suggested in-serviceproperty change limits are provided. Property
17、 changes beyondthese limits will indicate limited service life of the elastomerseal.4.2 These test methods attempt to simulate service condi-tions through controlled aging and evaluation of propertychanges but may not give any direct correlations with actualpart performance since actual service cond
18、itions vary widely.These test methods yield comparative data and indications ofproperty changes of the elastomeric seal material under idealservice conditions. These test methods can be used for qualitycontrol purposes, for engineering assessments, for serviceevaluation, and for manufacturing contro
19、l. The informationfrom these test methods can be used to anticipate expectedservice quality.5. General Test Methods5.1 Except as otherwise specified, the test methods forrubber O-rings referred to in 5.1.1-5.1.6, which are applicablein general to vulcanized rubber, shall be complied with asrequired
20、and are hereby made a part of these test methods.5.1.1 Tension TestTest Methods D 412 and D 1414.5.1.2 Compression SetTest Methods D 395 and D 1414.5.1.3 Fluid AgingTest Method D 471 and Test MethodsD 1414.5.1.4 HardnessTest Method D 2240.5.1.5 Compositional AnalysisTest Methods D 3677 andTest Metho
21、d E 1131.5.1.6 Degree of CureTest Method D 5028.5.2 In case of conflict between the provisions of the ASTMtest methods referenced in 5.1.1-5.1.6 and the detailed provi-sions of the test methods in Test Methods D 6546, the lattershall take precedence.6. Test Conditions6.1 TemperatureThe test temperat
22、ure shall be the maxi-mum sustained temperature anticipated in service.6.2 Immersion PeriodsThe following immersion periodsare recommended: 24 h, 72 h, 100 h, 250 h, 500 h, and 1000 h.The final immersion period will depend upon the results of theprevious immersion period. If the changes in the physi
23、calproperties have deteriorated beyond the suggested limits, thenfurther testing is not required. The tolerance for any immersionperiod shall be 61 % of the immersion period.7. Test Fluids7.1 For reliable compatibility assessments, it is desirable touse the fluid with which the elastomer will come i
24、n contact inactual service. For comparative tests, samples of fluid from thesame drum or shipment shall be used.8. Test Specimen8.1 The test specimens shall be O-rings molded from thesame compound batch from which the actual seals will bemolded. The test samples should approximate the cross sectiono
25、f the actual seal to be used so that the fluid saturation effect isproperly considered. The test samples should be either -021,-120, -214, or -320 O-rings, in accordance with AS568A.These have an approximate inside diameter of 25.4 mm (1 in.)and represent the most popular cross sections of seals use
26、d inindustrial systems. The actual dimensions of each O-ring sizeare listed in Annex A2.8.2 Test specimens shall be wiped clean of external con-taminants prior to testing by using a clean dry wipe.9. Suggested Compatibility Test Limits9.1 For a critical seal application, property change limits, asde
27、scribed in Table 1, should be observed.9.2 All values are in reference to soak time in the opera-tional fluid at the operating temperature of the application.Values reflect changes from the determined pre-immersionoriginal physical property values of the test specimens.9.3 If the changes are within
28、these limits, the elastomershould be considered compatible. Once a seal material is foundto be compatible, all seals for that system should be ordered byspecific compound or specification and not by ClassificationD 2000 call out number or generic polymer designation.10. Procedure for Change in Volum
29、e10.1 Apparatus:10.1.1 Test Container, a Mason jar (quart size) fitted with alid to prevent liquid and vapor from escaping. The lid shall notcontaminate the test liquid. Cover the lid with aluminum foil.10.1.2 Heating Device, a forced air oven, aluminum blockheater, or oil bath heater. Maintain the
30、temperature within61C (1.8F).10.1.3 Test SpecimenThe test specimen shall consist of anentire O-ring. The same specimen may be used for all tests withTABLE 1 Property Change LimitsTime, h MaximumVolumeSwell,%MaximumVolumeShrinkage,%HardnessChange,Shore APointsMaximumTensileStrengthChange,%MaximumElon
31、gationChange,%MaximumWorkFunctionChange,%MaximumCompressionSet, %24 15 3 67 20 20 612 .70 15 3 67 20 20 612 20100 15 3 68 20 20 612 20250 15 4 68 20 20 612 25500 20 4 610 25 25 617 301000 20 5 610 30 30 620 35D 6546 00 (2005)2hardness and volume determinations made prior to stress-straintests. Place
32、 the test specimen in the test liquid so that it is notdistorted or in contact with the sides of the test container orwith the other test specimens. Test a minimum of three testspecimens at one time. It is also important that only O-rings ofone size and one material compound be placed in the testcon
33、tainer.10.1.4 Analytical Balance, an analytical balance capable ofallowing a test specimen to be weighed whether in air or whilesubmerged in water.10.2 Volume ChangeTest three specimens.10.2.1 Weigh each test specimen in air, M1, to the nearest 1mg, and then weigh each specimen immersed in water, M2
34、,atroom temperature. It is important that all air bubbles clingingto the test specimen be removed before reading the weight inwater. Blot the specimen dry.10.2.2 Suspend the specimens in the glass jar by the use ofcorrosion-resistant wire. Separate the specimens by bendingsmall loops in the wire or
35、by locating them in differentlocations so that they do not contact each other.10.2.3 Suspend the specimen vertically so that 25.4 mm (1in.) of test fluid is between the lower extremity of the specimenand the bottom of the apparatus. Add enough test fluid to coverthe specimen to a depth of 25.4 mm (1
36、 in.) over the upperextremity of the specimen.10.2.4 Place the test apparatus in the heating device adjustedto maintain the sample at the test temperature for the requiredlength of time. At the end of the required immersion period,remove the specimen from the apparatus. Cool the specimen toroom temp
37、erature by immersing it in a cool, fresh amount ofthe test fluid for 45 min.10.2.5 At the end of the cooling period, remove the speci-men from the fluid, wipe with a cloth dipped in acetone, andblot dry. Weigh each test specimen in air, M3, and then weigheach specimen immersed in water, M4.10.2.6 So
38、me oils can be very viscous and may be difficult toremove with an acetone wipe. Since these oils do not readilyvolatize, specimens exposed to these oils can be cooled bysuspending them for 45 min in air at room temperature shieldedfrom draft. This will allow the majority of the oil to drip off thesu
39、rface of the specimen. Then proceed with the acetone wipeand weighing process described in 10.2.5. Report when thisalternate method of specimen cooling is used.10.2.7 The change in volume is calculated as follows:DV,%5M32 M4! 2 M12 M2!M12 M2!3 100 (1)where:M1= initial mass of specimen in air, g,M2=
40、initial mass of specimen in water, g,M3= mass of specimen in air after immersion, g, andM4= mass of specimen in water after immersion, g.10.3 Volume Shrinkage-Simulated Dry Out (Optional TestMethod)Test three specimens.10.3.1 In some situations when long downtimes are ex-pected, the O-ring should no
41、t shrink beyond 5 % of its previousvolume change value since this can affect its ability to be aneffective seal when the system is restarted. In those cases inwhich a positive volume change was obtained in 10.2 and longsystem down times are anticipated, it is recommended thatvolume shrinkage be dete
42、rmined. To perform this optional testmethod, additional O-rings will have to be tested in accordancewith 10.2 and then tested in accordance with 10.3 since thenormal test for volume change is immediately followed by thedestructive tensile test.10.3.2 The test specimen shall consist on an entire O-ri
43、ng.The specimen must first be submitted for the volume swell test.This specimen is only to be used for this test sequence and notfor any other testing.10.3.3 Place the test specimen from the volume swell test ina forced-air oven that allows air circulation around the testspecimen, and maintain the o
44、ven at a test temperature of 23 61C (73.4 6 1.8F) for 22 6 0.25 h. At the end of the requiredperiod, remove the specimen from the oven and allow it to aircool.10.3.4 Weigh each test specimen in air, M5, and then weigheach specimen immersed in water, M6.10.3.5 The change in volume or shrinkage is cal
45、culated asfollows:DV,%5M52 M6! 2 M32 M4!M32 M4!3 100 (2)where:M3= initial mass of volume swell specimen in air afterimmersion, g,M4= initial mass of volume swell specimen in water afterimmersion, g,M5= mass of volume swell specimen in air after dry out, g,andM6= mass of volume swell specimen in wate
46、r after dryout, g.11. Changes in Tensile Strength, Work Function,Elongation, and Hardness11.1 Original PropertiesThe original tensile strength,work function, ultimate elongation, and hardness shall bedetermined using a duplicate set of specimens of O-rings of thesame cross section as those that are
47、to be immersed in the testfluid. The O-rings shall be from the same batch as those that areto be immersed in the test fluid.11.2 Properties After Exposure to the Test Fluid, for deter-mining the tensile strength, work function, ultimate elongation,and hardness of specimens after immersion in the tes
48、t fluid atthe test temperature.At the end of the required immersion time,remove the specimens, and if necessary, cool them to roomtemperature in a fresh sample of the same fluid for 45 min. Atthe end of the cooling period, remove the specimen from thefluid, wipe it with a cloth dipped in acetone, an
49、d blot dry.Immediately determine the hardness, tensile strength, workfunction, and ultimate elongation in accordance with thefollowing test methods, using the original cross-sectional areaof the untreated specimens.11.2.1 Three specimens shall be tested. The test specimenshall consist of the entire O-ring. These specimens must first besubmitted to the volume swell test and cannot be used for anyother testing since physical property tests are destructive.D 6546 00 (2005)311.3 Hardness ChangeMeasure the hardness in accor-dance with
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