1、Designation: D892 10Designation: 146/2000British Standard 5092Standard Test Method forFoaming Characteristics of Lubricating Oils1This standard is issued under the fixed designation D892; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method co
3、vers the determination of the foam-ing characteristics of lubricating oils at 24C and 93.5C.Means of empirically rating the foaming tendency and thestability of the foam are described.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informa
4、tiononly.1.3 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 the applica-bility of regulatory limitations prior to use. For s
5、pecificwarning statements, see Sections 7, 8, and 9.1.1.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D6082 Test Method for High Temperature Foaming Char-acteristics of Lubricating OilsE1 Sp
6、ecification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Per-meability of Rigid Porous Filters for Laboratory UseE1272 Specification for Laboratory Glass Graduated Cylin-ders3. Terminology3.1 Definitions:3.1.1 diffuser, nfor gas, a device for dispersing gas int
7、o afluid.3.1.1.1 DiscussionIn this test method the diffuser may bemade of either metallic or non-metallic materials.3.1.2 entrained air (or gas), nin liquids, a two-phasemixture of air (or gas) dispersed in a liquid in which the liquidis the major component on a volumetric basis.3.1.2.1 DiscussionEn
8、trained air (or gas) may form microsize bubbles in liquids that are not uniformly dispersed and thatmay coalesce to form larger bubbles below or at the surfacewhich break or form foam.3.1.3 foam, nin liquids, a collection of bubbles formed inor on the surface of a liquid in which the air or gas is t
9、he majorcomponent on a volumetric basis.3.1.4 lubricant, nany material interposed between twosurfaces that reduces friction or wear between them. D60823.1.4.1 DiscussionIn this test method, the lubricant is anoil which may or may not contain additives such as foaminhibitors.3.1.5 maximum pore diamet
10、er, nin gas diffusion, thediameter of a circular cross-section of a capillary is equivalentto the largest pore of the diffuser under consideration.3.1.5.1 DiscussionThe pore dimension is expressed inmicrometres (m).3.1.6 permeability, nin gas diffusion, the rate of a sub-stance that passes through a
11、 material (diffuser) under givenconditions.3.2 Definitions of Terms Specific to This Standard:3.2.1 dynamic bubble, nthe first bubble to pass throughand escape from the diffuser followed by a continuous succes-sion of bubbles when testing for the maximum pore diameter inAnnex A1.1This test method is
12、 under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.06 on Analysis of Lubricants.Current edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 1946. Last previous edition approved in 2006 as D89
13、2061.In the IP, this test method is under the jurisdiction of the StandardizationCommittee. This test method has been approved by the sponsoring committees andaccepted by the cooperating societies in accordance with established procedures.DOI: 10.1520/D0892-10.2For referenced ASTM standards, visit t
14、he ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100
15、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1.1 DiscussionWhen a diffuser is immersed in aliquid, air can be trapped in the pores. It can escape eventuallyor as soon as a pressure is applied to the diffuser. When testingfor maximum pore diameter (Annex A1) th
16、e escape of suchbubble shall be ignored.3.2.2 foam stability, nin foam testing, the amount of foamremaining at the specified time following the disconnecting ofthe air supply.3.2.2.1 DiscussionIn this test method, foam stability isdetermined from measurements made 10 min 6 10 s afterdisconnecting th
17、e air supply. In cases after the air supply hasbeen disconnected, where the foam collapses to 0 mL beforethe 10 min settling time has elapsed, the test may be terminatedand the foam stability result recorded as 0 mL.3.2.3 foaming tendency, nin foam testing, the amount offoam determined from measurem
18、ents made immediately afterthe cessation of air flow.4. Summary of Test Method4.1 Sequence IA portion of sample, maintained at a bathtemperature of 24 6 0.5C is blown with air at a constant rate(94 6 5 mL/min ) for 5 min, then allowed to settle for 10 min(unless the case described in 3.2.2.1 applies
19、, in which case, thetime duration can be shortened). The volume of foam ismeasured at the end of both periods.4.2 Sequence IIAsecond portion of sample, maintained ata bath temperature of 93.5 60.5C, is analyzed using the sameair flow rate and blowing and settling time duration asindicated in 4.1.4.3
20、 Sequence IIIThe sample portion used in conductingSequence II is used for Sequence III, where any remainingfoam is collapsed and the sample portion temperature cooledbelow 43.5C by allowing the test cylinder to stand in air atroom temperature, before placing the cylinder in the bathmaintained at 24
21、6 0.5C. The same air flow rate and blowingand settling time duration as indicated in 4.1 is followed.5. Significance and Use5.1 The tendency of oils to foam can be a serious problemin systems such as high-speed gearing, high-volume pumping,and splash lubrication. Inadequate lubrication, cavitation,
22、andoverflow loss of lubricant can lead to mechanical failure. Thistest method is used in the evaluation of oils for such operatingconditions.6. Apparatus6.1 Foaming Test Apparatus, an example of a suitableset-up is shown in Fig. 1, consisting of a 1000-mL graduatedcylinder or cylinders (meeting Spec
23、ification E1272 class Btolerance requirement of 66 mL and at least graduations of 10mL) held in position when placed in the baths, such as fittedwith a heavy ring or clamp assembly to overcome the buoy-ancy, and an air-inlet tube, to the bottom of which is fasteneda gas diffuser. The gas diffuser ca
24、n be either a 25.4-mm (1-in.)diameter spherical gas diffuser stone made of fused crystallinealumina grain, or a cylindrical metal diffuser made of sinteredfive micron porous stainless steel (Note 1). The cylinder shallhave a diameter such that the distance from the inside bottomto the 1000-mL gradua
25、tion mark is 360 6 25 mm. It shall becircular at the top (Note 2) and shall be fitted with a stopper,such as those made of rubber, having one hole at the center forthe air-inlet tube and a second hole off-center for an air-outlettube. The air-inlet tube shall be adjusted so that, when thestopper is
26、fitted tightly into the cylinder, the gas diffuser (Note3) just touches the bottom of the cylinder and is approximatelyat the center of the circular cross section. Gas diffusers shallmeet the following specification when tested in accordancewith the method given in Annex A1:Maximum pore diameter, m
27、Not greater than 80Permeability at pressure of 2.45 kPa (250 mm) water,mL of air/min3000 to 6000NOTE 1Gas diffuser permeability and porosity can change during use;therefore, it is recommended that diffusers be tested when new andperiodically thereafter preferably after each use.NOTE 2Graduated cylin
28、ders with circular tops can be prepared fromFIG. 1 Foaming Test ApparatusD892 102cylinders with pouring spouts by cutting them off below the spouts. Thecut surface is to be smoothed before use by fire polishing or grinding.NOTE 3Gas diffusers may be attached to air-inlet tubes by anysuitable means.
29、A convenient arrangement is shown in Fig. 2.NOTE 4It may be necessary to confirm the volume of the cylinder.6.2 Test Baths, large enough to permit the immersion of thecylinder at least to the 900-mL mark and capable of beingmaintained at temperatures constant to 0.5C (1F) at 24C(75F) and 93.5C (200F
30、), respectively. Both bath (Note 6)and bath liquid shall be clear enough to permit observation ofthe graduations on the cylinder.NOTE 5Air baths may also be utilized for heating purposes. Limiteddata has shown that both liquid and air baths give equivalent results.However, the precision estimates gi
31、ven in Section 13 are based on usingonly liquid baths.3NOTE 6Heat-resistant cylindrical glass jars approximately 300 mm(12 in.) in diameter and 450 mm (18 in.) in height make satisfactory baths.6.3 Air Supply, from a source capable of maintaining an airflow rate of 94 6 5 mL/min through the gas diff
32、user. The airshall be passed through a drying tower 300 mm in heightpacked as follows: just above the constriction place a 20-mmlayer of cotton, then a 180-mm layer of indicating desiccant,and a 20-mm layer of cotton. The cotton serves to hold thedesiccant in place. Refill the tower when the indicat
33、ingdesiccant begins to show presence of moisture. A flowmetersensitive to the required tolerances can be used to measure theair flow (Note 7).NOTE 7A manometer type flowmeter, in which the capillary betweenthe two arms of the U-tube is approximately 0.4 mm in diameter and 16mm in length, and in whic
34、h n-butylphthalate is the manometric liquid, issuitable.6.3.1 The total volume of air leaving the foaming testapparatus shall be measured by a volume measuring device(Note 9) capable of accurately measuring gas volumes of about470 mL. The air shall be passed through at least one loop ofcopper tubing
35、 placed around the inside circumference of thecold bath so that the volume measurement is made at approxi-mately 24C (75F). Precautions are to be taken to avoid leaksat any point in the system.NOTE 8Alternatively,a1Lcylinder (with 10 mL graduation marks)full of water is inverted in a tall, large bea
36、ker also filled with water. Thereshould be no air bubbles inside. Air leaving the copper loop in the bath isconnected below the cylinder. When the test is started, air will flow intothe cylinder, displacing the water. At the end of the test, the volume of airin the cylinder is measured by equalizing
37、 the water levels inside andoutside the cylinder.Alternatively, the total volume of air passed would bethe difference between the final and the initial volumes of water in thecylinder.NOTE 9Awet test meter calibrated in hundredths of a litre is suitable.6.4 Timer, graduated and accurate to1sorbetter
38、.6.5 Temperature Sensing Device, capable of covering thetemperature range from at least 20 to 100C, with an accuracyof 60.5C.Athermometer having a range as shown below andconforming to the requirements as prescribed in SpecificationE1 or specifications for IP thermometers has been foundsuitable to u
39、se:TemperatureRangeThermometerASTM No. IP20 to 102C 12C 64C7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all cases. Unless indicated otherwise, it is intended thatall reagents conform to the specifications of the committee onAnalytical Reagents of the America
40、n Chemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.3Supporting data have been filed at ASTM International Headquarters
41、 and maybe obtained by requesting Research Report RR:D02-1516.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, B
42、DH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Dimensions in millimetres (inches)FIG. 2 Attachment of Gas Diffusers to Air-Inlet TubesD892 1037.2 Acetone(WarningExtremely flammable, vaporscan cause a fl
43、ash fire).7.3 Compressed Air, hydrocarbon free and dry to a dewpoint of 60C or lower.NOTE 10If the source of compressed air is ensured to the statedspecifications, the drying tower in 6.3 may not be necessary.7.4 Heptane(WarningFlammable, vapor harmful).7.5 Propan-2-ol(Solvents with equivalent clean
44、ing andsolvency characteristics may be substituted for propan-2-ol.)7.6 Toluene (Methylbenzene)(Solvents with equivalentcleaning and solvency characteristics may be substituted fortoluene.)8. Hazards8.1 (WarningUsers of this test method shall be trainedand familiar with all normal laboratory practic
45、es, or under theimmediate supervision of such a person. It is the responsibilityof the operator to ensure that all local legislative and statutoryrequirements are met.)8.2 (WarningCleaning solvents have flash points lowerthan ambient temperatures. Avoid the possibility of fire orexplosion.)8.3 (Warn
46、ingThe fumes from the test oil and the bathshall be vented in a manner compatible with local governmentregulations.)8.4 (WarningSome apparatus assemblies can have asmuch as 20 L of heat transfer oil at 93.5C. Therefore, in theevent of breakage of the containing vessel, provisions forsuitable contain
47、ment of the spill is advisable.)9. Preparation of Apparatus9.1 Thorough cleansing of the test cylinder and air-inlettube is essential after each use to remove any additiveremaining from previous tests which can seriously interferewith results of subsequent tests.9.1.1 CylinderRinse the cylinder with
48、 heptane.(WarningFlammable, vapor harmful.) Wash the cylinderwith a suitable detergent. Rinse the cylinder, in turn, withdistilled water, then acetone (WarningExtremely flam-mable, vapors can cause a flash fire) and dry in a current of thecompressed air or in a drying oven. Interior walls that drain
49、 thewater cleanly, that is without drops forming, are adequatelycleaned.NOTE 11Certain detergents are notorious for adhering to glass;therefore, it is important to realize that such a circumstance can affect thetest result. Several rinsings with water and acetone may be required.9.1.2 Gas Diffuser and Air TubeClean the gas diffuserwith toluene (solvents with equivalent cleaning and solvencycharacteristics may be substituted for toluene.) and heptane.Immerse the gas diffuser in about 300 mL of toluene. Flush aportion
