ASTM_D_7342_-_07.pdf

Designation:D734207Standard Test Method forShear Stability of Lubricating Grease in Presence of Water(Water Stability Test)1This standard is issued under the fixed designation D7342;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.Scope1.1 This test method covers two procedures for determiningthe shear stability of lubricating grease in the presence of water(wet shear stability)by a full scale grease worker or a rollstability test apparatus.Both procedures can be used todetermine the relative wet shear stability of greases,but theresults between procedures are not directly comparable.Thistest method is also known as the water stability test.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.2.Referenced Documents2.1 ASTM Standards:2D217 Test Methods for Cone Penetration of LubricatingGreaseD1403 Test Methods for Cone Penetration of LubricatingGrease Using One-Quarter and One-Half Scale ConeEquipmentD1831 Test Method for Roll Stability of Lubricating GreaseD1193 Specification for Reagent Water3.Terminology3.1 Definitions:3.1.1 consistency,nof lubricating grease,degree of resis-tance to movement under stress.3.1.1.1 DiscussionThe term consistency is used somewhatsynonymously with penetration.Generally,consistency refersto the worked penetration of a grease.D2173.1.2 lubricating grease,nsemi-fluid to solid product of adispersion of a thickener in a liquid lubricant.3.1.2.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces.Other ingredients arecommonly included to impart special properties.D2173.1.3 penetration,nof lubricating grease,depth that thestandard cone,when released to fall under its own weight for5 s,enters the sample.D2173.1.4 thickener,nin lubricating grease,substance com-posed of finely divided particles dispersed in a liquid lubricantto form the products structure.3.1.4.1 DiscussionThe thickener can be fibers(such asvarious metallic soaps)or plates or spheres(such as certainnon-soap thickener)which are insoluble or,at most,only veryslightly soluble in liquid lubricant.The general requirementsare that the solid particles to be relatively stable,gel-likestructure with the liquid lubricant.D2173.1.5 wet shear stability,nof lubricating grease,change inconsistency of a mixture of sample and small amount of waterafter a specified amount of working in a grease worker or a rollstability test apparatus.3.1.6 worked penetration,nof lubricating grease,thepenetration at 25C,without delay,of a sample after 60 doublestrokes in a standard grease worker.D2173.1.7 working,nof lubricating grease,subjection of asample to the shearing action of the standard grease worker.D2174.Summary of Test Method4.1 A grease sample mixed with a small amount of water issubjected to low shear at 20 to 35C for a specified time orstrokes in a standard grease worker(Procedure A)or a rollstability apparatus(Procedure B).The difference between thecone penetration before working and the cone penetration afteris used as a measure of the wet shear stability of the grease.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.G0.07 on Research Techniques.Current edition approved May 1,2007.Published May 2007.DOI:10.1520/D7342-07.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 It is known that contamination by water can affect theshear stability of some greases in service.Both test proceduresspecified in this method are widely used to determine the wetshear stability of greases in service.Many grease specificationsrequire these procedures as a wet shear stability test.Noaccurate correlation is established between the test results andwet shear stability of grease in actual service.6.Apparatus6.1 Motorized Grease Worker,as specified in Test MethodsD217.6.2 Roll Stability Test Apparatus,as specified in TestMethod D1831.6.3 Penetrometer,as specified in Test Methods D217.6.4 One-Quarter or One-Half Scale Cone and Shaft withWorker,as described in Test