ASTM_D_7669_-_20.pdf

Designation:D766920Standard Guide forPractical Lubricant Condition Data Trend Analysis1This standard is issued under the fixed designation D7669;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.INTRODUCTIONThis standard provides specific guidelines for trend analysis,as they are applied to conditionmonitoring of machinery.The main purpose of trend analysis is to learn how rapidly the machine andfluid are deteriorating.A significant change in trend is indicative of a developing failure.Interventionin the early stages of deterioration is much more cost effective than failure of the machine.Maximum reliability of in-service machine components and fluids requires a program of conditionmonitoring to provide timely indications of performance and remaining usable life.To achieve thesegoals,a condition monitoring program should monitor the rate of progression of the failure byincluding sufficient tests to determine the rate of degradation,increase of contaminants,and quantityand identity of metal debris from corrosion or wear.The condition monitoring process determines the presence of oil-related failure modes,allowingremedial maintenance to take place before failure and subsequently expensive equipment damageoccurs.In order to diagnose and predict machinery and fluid condition,the rate of change of machinecondition must be trended.Equipment maintainers expect conditionmonitoring information to clearlyand consistently indicate machinery condition,that is,the rate-of-change of component damage overtime and the risk of failure.Trending utilizes a comparison of a condition parameter with time.For example,plots of acondition-related parameter as a function of time is used to determine when the parameter is likely toexceed a given limit.Forecasting the expected breakdown of a machine well in advance enables theoperator to minimize the machines downtime1.Scope*1.1 This guide covers practical techniques for condition datatrend analysis.1.2 The techniques may be utilized for all instrumentationthat provides numerical test results.This guide is writtenspecifically for data obtained from lubricant samples.Otherdata obtained and associated with the machine may also beused in determining the machine condition.1.3 This guide provides a methodology for assessingchanges in lubricant during service.For limits on a specificlubricant parameter used in different system types,users shouldrefer to Practice D4378,Practice D6224,or other establishedindustry criteria,such as from the OEM.Guide D7720 may beused to determine limits if unavailable through the otherreferences given.1.4 This guide does not address upper or lower controllimits.These limits are provided by product manufacturers,defined in ASTM specifications,or both.The range betweenupper and lower control limits should be greater than the rangewithin each test methods repeatability coefficient.See Prac-tices D3244,D6299,and D6792 for more information aboutensuring that process control limits do not violate statisticalfundamentals.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the1This guide is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.96.04 on Guidelines for In-Services Lubricants Analysis.Current edition approved Oct.1,2020.Published October 2020.Originallyapproved in 2011.Last previous edition approved in 2015 as D7669 15.DOI:10.1520/D7669-20.*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.Development of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D3244 Practice for Utilization of Test Data to DetermineConformance with SpecificationsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum Products,LiquidFuels,and