ASTM_D_7669_-_15.pdf

Designation:D766915Standard 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 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:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD7720 Guide for Statistically Evaluating Measurand AlarmLimits when Using Oil Analysis to Monitor Equipmentand Oil for Fitness and ContaminationD7874 Guide for Applying Failure Mode and Effect Analy-sis(FMEA)to In-Service Lubricant TestingE2587 Practice for Use of Control Charts in StatisticalProcess Control3.Terminology3.1 Definitions of Terms Specific to This Standard:1This 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 April 1,2015.Published May 2015.Originallyapproved in 2011.Last previous edition approved in 2011 as D7669 11.DOI:10.1520/D7669-15.2For 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.*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 States1 3.1.1 alarm,na means of alerting the operator that aparticular condition exists.3.1.2 alarm limit,nset-point threshold used to determinethe status of the magnitude or trend of parametric conditiondata.3.1.2.1 DiscussionIn OEM provided alarm limits indi-vidual measurements are interpreted singly.Most fluid andmachine failure modes do not give rise to symptoms identifi-able by a single measurement parameter.Early positive iden-tification of a fault generally requires the combination ofmultiple condition measurements into a unique fault signature.See Guide D7874.3.1.2.2 DiscussionEstablishing proper alarm limits can bea valuable asset for interpretation of test results to reflect theequipments operation.The level and trend alarms can assistthe equipment maintainer with reliability control and improve-ment.With the trending approach established,the machineoperators next objective is to establish