ASTM_D_5621_-_20.pdf

Designation:D562120Standard Test Method forSonic Shear Stability of Hydraulic Fluids1This standard is issued under the fixed designation D5621;the number immediately following 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()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the evaluation of the shearstability of hydraulic fluids in terms of the final viscosity thatresults from irradiating a sample of the hydraulic fluid in asonic oscillator.1.2 Evidence has been presented that a good correlationexists between the shear degradation that results from sonicoscillation and that obtained in a vane pump test procedure.21.3 This test method uses millimetres squared per second(mm2/s),an SI unit,as the unit of viscosity.For information,the equivalent unit,cSt,is shown in parentheses.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D2603 Test Method for Sonic Shear Stability of Polymer-Containing OilsD6022 Practice for Calculation of Permanent Shear StabilityIndexD7042 Test Method for Dynamic Viscosity and Density ofLiquids by Stabinger Viscometer(and the Calculation ofKinematic Viscosity)3.Summary of Test Method3.1 Aconvenient volume of hydraulic fluid is irradiated in asonic oscillator for a period of time and the viscosities beforeand after irradiation are determined by Test Method D445 andD7042.A standard reference fluid containing a readily shearedpolymer is run frequently to ensure that the equipment impartsa controlled amount of sonic energy to the sample.3.2 The conditions to obtain the data for the precisionstatement were:30 mL sample,12.5 min calibration,and40 min sample irradiation at 0 C jacket temperature.4.Significance and Use4.1 This test method was developed using Test MethodD260391.4.2 This test method permits the evaluation of shear stabilitywith minimum interference from thermal and oxidative factorsthat may be present in some applications.It has been foundapplicable to fluids containing both readily sheared and shear-resistant polymers.Correlation with performance in the case ofhydraulic applications has been established.5.Apparatus5.1 Sonic Shear Unit,fixed frequency oscillator and sonichorn.5.2 AuxiliaryEquipmentTofacilitateuniformperformance,the following auxiliary equipment is recom-mended:5.2.1 Cooling Bath or Ice Bath,to maintain a jackettemperature of 0 C.5.2.2 Griffn 50 mL Beaker,borosilicate glass.5.2.3 Sonic-Insulated Box,to enclose the sonic horn toreduce the ambient noise level produced by the sonic shearunit.5.3 ViscometerAny viscometer and bath meeting the re-quirements for determining kinematic viscosity:Test MethodD445 or D7042.Whichever method is chosen,that same1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved May 1,2020.Published May 2020.Originallyapproved in 1994.Last previous edition approved in 2019 as D5621 19.DOI:10.1520/D5621-20.2Stambaugh,R.L.,Kopko,R.J.,and Roland,T.F.,“Hydraulic PumpPerformanceA Basis for Fluid Viscosity Classification,”SAE Paper No.901633.Available from Society of Automotive Engineers,400 Commonwealth Dr.,Warrendale,PA 15096.3For referenced ASTM standards,visit the 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.method must be used for the before and after samples as wellas calibration samples.6.Reference Fluids6.1 The reference fluid is ASTM Reference Fluid B,4apetrole