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Foreword

ThiscodeisdevelopedbySinopecEngineeringIncorporationincooperationwithotherinvolvedorganizationsbasedontherequirementsofDocumentJIANBIAO〔2008〕No.105issuedbytheMinistryofHousingandUrban-RuralDevelopment-"NoticeontheDevelopmentandRevisionPlanofNationalEngineeringConstructionStandards(2”Group)in2008".

Inpreparingthiscode,theworkingteamdevelopedthecodebasedonwideandextensiveinvestigationsandstudiesmade,practicessummarized,commentsrequestedaswellasreferencestointernationalcodesandstandards.

Thiscodecomprises15chapters,andmainlyincludesGeneralprovisions,Terminologiesandabbreviations,Safetylifecycle,Safetyintegritylevel,GeneralRequirementsforDesign,Sensors,Finalelements,Logicsolvers,Communicationinterfaces,Humanmachineinterfaces,Applicationsoftware,Engineeringdesign,Configuration,integrationandcommissioning,acceptancetesting,Operationandmaintenance,Managementofchanges,Documentationmanagementetc.

TheMinistryofHousingandUrban-Rura?DevelopmentofthePeople'sRepublicofChinaisinchargeofadministrationofthiscode,ChinaPetrochemicalCorporation(SinopecGroup)isresponsibleforitsroutinemanagement,andSinopecEngineeringIncorporationistaskedforexplanationofspecifictechnicalcontents.Ifanycommentsandrecommendationsareproposedinimplementation,pleasesendyourcomments/recommendationstoSinopecEngineeringIncorporation(Address:21Anyuan,AnhuiBeiLi,ChaoyangDistrict,Beijing,Postcode:100101)aslareferenceforrevisingthiscodeinthefuture.

Chiefdevelopmentorganization,co-developmentorganization,participatingdevelopment

organization,chiefdrafterandchiefreviewerofthecode:

ChiefDevelopmentOrganization:

SinopecEngineeringIncorporation

Co-DevelopmentOrganization:

ChinaHuanqiuContractingandEngineeringCorp.

SinopecNingboEngineeringCo.,Ltd

BeijingConsenAutomationControlCo.,Ltd

Sinopec-Honeywell(Tianjin)Co.Ltd

ParticipatingDevelopmentOrganization:

SinopecLuoyangPetrochemicalEngineeringCorporation

SinopecShanghaiEngineeringCo.,Ltd

CNPCEastChinaDesignInstitute

CNPCDaqingPetrochemicalEngineeringCo.,Ltd

SinopecYangziPetrochemicalCo.,Ltd

HIMA(Shanghai)SafetySystemCo.,Ltd

TimingWinner(Beijing)AutomationEquipmentCo.,Ltd

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ChiefDrafter:

HuangBuyuYeXiangdongFanZonghaiMaLeiHuChenZhangJianguoGaoShengjunLiLeiLinRongHuTongyinZhuXiangxuanZhangYuekun

WangFabingZhangTongkeChiefReviewer:

ZhaoYongdengDingLanrongWangLifengWangChenglinWangShengliLiuJunLiYumingSongZhiyuanYangJinchengLinHongjun

ZhouJiaxiangZhaoZhuGuZhengGeChunyuPeiBingan

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Contents

1GeneralProvisions (1)

2TermsandAbbreviations (2)

2.1Terms (2)

2.2Abbreviations (4)

3SafetyLifeCycle (5)

3.1GeneralRequirements (5)

3.2EngineeringDesign (5)

3.3Integration,CommissioningandAcceptanceTesting (6)

3.4OperationandMaintenance (6)

4SafetyIntegrityLevel (7)

4.1GeneralRequirements (7)

4.2SafetyIntegrityLevelAssessment (7)

5GeneralRequirementsforDesign (9)

6Sensors (10)

6.1GeneralRequirements (10)

6.2SeparationRequirementsforSensors (10)

6.3RedundancyRequirementsforSensors (10)

6.4RedundancyMethodsofSensors (10)

6.5DiscreteSensors (10)

7FinalElements (11)

7.1GeneralRequirements (11)

7.2SeparationRequirementsforControlValves (11)

7.3RedundancyRequirementsforControlValves (11)

7.4ControlValveAccessories (11)

8LogicSolvers (12)

8.1GeneralRequirements (12)

8.2SeparationRequirementsforLogicSolvers (12)

8.3RedundancyRequirementsforLogicSolvers (12)

8.4ConfigurationRequirementsforLogicSolvers (12)

8.5ConfigurationRequirementsforLogicSolverInterfaces (13)

9CommunicationInterfaces (14)

9.1GeneralRequirements (14)

9.2ConfigurationRequirementsforCommunicationInterfaces (14)

10HumanMachineInterfaces (15)

10.1OperatorStations (15)

10.2AuxiliaryConsoles (15)

10.3MaintenanceOverrideSwitches (15)

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10.4OperationOverrideSwitches (16)

10.5ResetPushButtons (16)

10.6EmergencyShutdownPushButtons (16)

10.7EngineeringWorkstationsandSequenceEventRecorders (16)

11ApplicationSoftware (17)

11.1ConfigurationandProgramming (17)

11.2SecurityofApplicationSoftware (17)

11.3DesignandConfigurationofApplicationSoftware (17)

12EngineeringDesign (18)

12.1BasicEngineeringDesign(BED) (18)

12.2DetailedEngineeringDesign(DED) (18)

13Configuration,IntegrationandCommissioning,AcceptanceTesting (20)

13.1Configuration,IntegrationandCommissioning (20)

13.2AcceptanceTesting (20)

14OperationandMaintenance,ManagementofChanges (22)

15DocumentationManagement (23)

ExplanationofWordinginThisCode (24)

ListofReferenceCodes/Standards (25)

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1GeneralProvisions

1.0.1Thiscodeisdevelopedtopreventandmitigatetheprocessrisks,securethestaffandpropertysafetyandprotecttheenvironmentinpetrochemicalplants.

1.0.2Thiscodeisapplicabletotheengineeringdesignofsafetyinstrumentedsystemforgrassroots,revampandexpansionprojectsinpetrochemicalplants.

1.0.3Inadditiontothiscode,theengineeringdesignofsafetyinstrumentedsystemshallalsocomplywiththecurrentnationalcodesandstandards.

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2TermsandAbbreviations

2.1Terms

2.1.1Safetyinstrumentedsystem

Aninstrumentedsystemthatisusedtoimplementoneormoresafetyinstrumentedfunctions.

2.1.2Risk

Thespecifichazardouseventsandconsequencesthatarepredicted.

2.1.3Processrisk

Theriskthatisgeneratedfromvariationsofprocessconditionsduetoabnormalevents.

2.1.4Safetylifecycle

Awholetimedurationfromthestartoftheconceptdesigntoallsafetyinstrumentedfunctionsarenolongeravailableforuse.

2.1.5Hazard

Thepossibilityresultingindangerouseventssuchasinjurytopersonnel,illhealth,propertylossanddamagetoenvironment.

2.1.6Riskassessment

Awholeprocesstoassesstherisksizeandtodeterminetheriskrating.

2.1.7Protectionlayer

Anyindependentmechanismthatisusedforriskreductionbyusingcontrolling,preventingandmitigatingmeasures.

2.1.8Safetyfunction

Afunctiontobeimplementedbysafetyinstrumentedsystem,othersafetyrelatedsystemsorexternalriskreductionfacilitiesforthepurposeofachievingormaintainingtheprocessinsafestate.

2.1.9Safetyinstrumentedfunction

Asafetyprotectionfunctionorsafetycontrolfunctionimplementedbysensors,logicsolvers,finalelementsandrelatedsoftwareforthepurposeofpreventingandmitigatingconsequencesofdangerouseventsorkeepingtheprocessinsafestate.

2.1.10Fault

Anabnormalconditionthatmaypossiblyresultinthereductionorlossofimplementingcapabilityofthefunctionalunits.

2.1.11Safetyintegrity

Theaverageprobabilityofsafetyinstrumentedfunctionsthatareachievedbysafetyinstrumentedsystemunderthespecifiedconditionsandwithinthespecifiedtime.

2.1.12Safetyintegritylevel

ThelevelofsafetyfunctionthatisrangedfromSIL1toSIL4inanorderfromlowleveltohighlevel.

2.1.13Failure

Aterminationofonecertainfunctionorimplementingcapabilityofonefunctionalunit.

2.1.14Dangerousfailure

Afailurethatmaypossiblyresultinpotentialdangerousconditionorfunctionlossofsafety

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instrumentedsystem.

2.1.15Safefailure

Afailurethatmaynotresultinpotentialdangerousconditionorfunctionlossofsafetyinstrumentedsystem.

2.1.16Sensor

Acomponentofsafetyinstrumentedsystem,whichisusedtomeasuretheprocessvariables.

2.1.17Logicsolver

Acomponentofsafetyinstrumentedsystem,whichisusedforperforminglogicfunctions.

2.1.18Finalelement

Acomponentofsafetyinstrumentedsystem,whichisusedtoexecutethecommandsorspecifiedactionsoflogicsolverstokeeptheprocessinsafestate.

2.1.19Basicprocesscontrolsystem

Asystemthatrespondstotheinputsignalsfromprocessmeasurementsandotherrelateddevices,otherinstruments,controlsystemsoroperatorsandgeneratesoutputsignalsbasedonprocesscontrolrules,algorithmsanddesiredmannertoperformprocesscontrolandoperationofrelatedequipments.

2.1.20Fail-safe

Afunctionthatenablesthecontrolledprocessintoapre-specifiedsafestateincaseoffailureofsafetyinstrumentedsystem.

2.1.21Redundancy

Twoormorecomponentsorsystemsthatareusedtoindependentlyperformonesamefunctionforachievingmutualbackupandswitch-over.

2.1.22Faulttolerant

Acapabilitythatthefunctionalunitiscapableofcontinuouslyexecutingthespecifiedfunctionsincaseoffaultorerror.

2.1.23On-offvariable

Avariablethathasonly0or1digitandusedtoindicatethestateofanobjectoranevent.Itisalsocalleddiscretevariable.

2.1.24Switch

Adevicethathastwostablepositions,includingsoftwareswitchandhardwareswitch.

2.1.25Pushbutton

Adevicethathasonlyonestableposition,includingsoftwarepushbuttonandhardwarepushbutton.

2.1.26Mechanicalcontact

Amechanicalelectricaldevicethatcompriseselectricallyconductivemetalcomponents,whichmaychangetheenergizingorde-energizingstateundertheactionofexternalfactors.

2.1.27Contact

Anelectricaldevicethatenablesthechangeofenergizingorde-energizingstateundertheactionofexternalfactors,includingmechanicalcontactandelectroniccontact.Softwarecontactisalsoincludedinarithmeticcomponentsofprogrammablelogicsolver.

2.1.28Normallyclosedcontact

Acontactthatisclosedundernormalconditionswithouteffectofexternalfactors.

2.1.29Normallyopencontact

Acontactthatisopenundernormalconditionswithouteffectofexternalfactors.

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2.1.30Programmableelectronicsystem

Asystemthatisusedforcontrolling,protectingormonitoringpurposesbasedontheelectronicdevicesthatmaybefunction-orientedprogrammedorchangetheoperationprocedures.

2.2Abbreviations

BPCS(BasicProcessControlSystem)

CPU(CentralProcessUnit)

EMC(ElectroMagneticCompatibility)

FAT(FactoryAcceptanceTesting)

FLD(FunctionalLogicDiagram)

FBD(FunctionalBlockDiagram)

FDS(FunctionalDesignSpecification)

HAZOP(HazardandOperabilityStudy)

HMI(HumanMachineInterface)

HSE(Health,SafetyandEnvironment)

MOS(MaintenanceOverrideSwitch)

OOS(OperationalOverrideSwitch)

PES(ProgrammableElectronicSystem)

PHA(PreliminaryHazardAnalysis)

PFDavg(ProbabilityofFailureonDemandAverage)

PLC(ProgrammableLogicController)

SAT(SiteAcceptanceTesting)

SER(SequenceofEventsRecorder)

SIF(SafetyInstrumentedFunction)

SIL(SafetyIntegrityLevel)

SIS(SafetyInstrumentedSystem)

UPS(UninterruptablePowerSupply)

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3SafetyLifeCycle

3.1GeneralRequirements

3.1.1Inengineeringdesignofpetrochemicalplants,managementactivitiesshallbedeterminedforSISateachstageduringSISsafetylifecycle.

3.1.2ThesafetylifecycleofSISshouldincludeengineeringdesignstage,integration,commissioningandacceptanceteststage,operationandmaintenancestage.

3.1.3Safetylifecycleactivities(Figure3.1.3)shouldincludeSISconceptdesign,processhazardanalysisandriskassessment,allocationofsafetyfunctionsfor/differentprotectionlayers,SILassessmentandreview,technicalrequirementsforSIS,basicengineeringdesignforSIS,detailedengineeringdesignforSIS,SISintegration,commissioningandacceptancetesting,SISoperation,maintenanceandmanagementofchanges,SISfunctiontestingandSISdecommissioningetc.

Integration,

commissioning

andacceptance

Operationandtesting

maintenanceEngineeringdesign

1.Projectconceptdesign

2.Processhazardanalysisandriskassessment

3.Allocationofsafetyfunctionsforprotectionlayers

4.SILassessmentandreview

5.TechnicalrequirementsforSIS

Otherriskreductionmethodsdesign_

6.BasicengineeringdesignforSIS

7.DetailedengineeringdesignforSIS

8.SISintegration,commissioningandacceptancetesting

9.SISoperation,maintenanceandmanagementofchanges

10.SISfunctiontesting

11.SISdecommissioning

Figure3.1.3Workflowforsafetylifecycle

3.2EngineeringDesign

3.2.1Conceptdesignshouldincludepreliminaryprocesshazardanalysis,mainsafetycontrolstrategiesandmeasures,andcorrespondingdescriptions.

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3.2.2Processhazardanalysisandriskassessmentshouldincludeidentificationofthedangerouseventsandtheircausesoftheprocessandrelatedequipment,thesequence,possibilityandconsequencesofthedangerousevents,determinationofrequirementsandmeasuresforriskreduction,anddeterminationofSIFs.ProcesshazardanalysisandriskassessmentshouldemployHAZOPmethodorPHAmethod,andmayusesafetychecklistmethod,failuremodeandconsequenceanalysismethod,causeandeffectanalysismethodetc.

3.2.3Allocationofsafetyfunctionsfortheprotectionlayersmayincludeassigningthesafetyfunctionsofprotectionlayersforpreventing,controllingormitigatingprocessrisksandassigningtheriskreductiontargetsoftheSIFs.ThesafetyfunctionsofprotectionlayersshallbeassignedinaccordancewiththecurrentnationalstandardFunctionalSafetyofElectrical/ElectronieProgrammableElectronicSafety-relatedSystemsGB/T20438andFunctionalSafety-safetyInstrumentedSystemsforProcessIndustrySectorGB/T21109.

3.2.4SILsmaybeassessedanddeterminedbasedontheresultsofprocesshazardanalysisandallocationofsafetyfunctionsfortheprotectionlayers.

3.2.5TechnicalrequirementsforSISmayincludesafetyinstrumentedfunctionsandsafetyintegritylevels,processsafetystates,operationmodes,andtestintervals

3.2.6BasicengineeringdesignforSISshouldincludeSISdesigndescription,SISspecification,causeandeffectdiagramorfunctionnarratives.

3.2.7DetailedengineeringdesignforSISshouldincludeSISdesigndescription,SISspecification,functionallogicdiagram,andconfigurationprogramming.

3.3Integration,CommissioningandAcceptanceTesting

3.3.1SISintegration,commissioningandacceptancetestingshallcomplywiththetechnicalrequirementsspecifiedinSISspecificationsandthefunctionallogicdiagrams.

3.3.2SIScommissioningshallcomplywithtechnicalrequirementsforSIS.

3.3.3AcceptancetestingforSISshallincludeFATandSAT.Hardware,systemsoftwareandapplicationsoftwareforSISshallcomplywithtechnicalrequirementsforSIS.

3.4OperationandMaintenance

3.4.1Operationandmaintenanceshallfollowtheoperationandmaintenanceprocedures,andenableoperationandmaintenanceprocesstocomplywiththefunctionalsafetyrequirementsasspecifiedinthetechnicalspecificationforSIS.

3.4.2ModificationsorchangesmadetothehardwareandapplicationsoftwareofSISshallfollowthemanagementofchanges(MOC)procedure,theyshallbeauthorizedandapprovedinaccordancewithMOCapprovalprocedure,thedesignedSILshallnotbechanged,andMOCrecordsshallberetained.

3.4.3Trainingshallbeprovidedfortheoperationandmaintenancestaffsonaregularbasis,andtrainingcoursesshouldincludeSISfunctions,preventableprocesshazards,sensorsandfinalelements,SISlogicactions,alarmsetpointsofSISandprocessvariables,andresponseafterSISisactivated.

3.4.4FunctionaltestintervalsshallbedeterminedbasedonSIStechnicalrequirements,andfunctionaltestsshallbemadeinaccordancewithSIStestprocedures.

3.4.5SISdecommissioningshallbereviewedandapproved.SISupdateproceduresshallbedevelopedasrequired,andtheupdatedSISshallachievethespecifiedSIFs.

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4SafetyIntegrityLevel

4.1GeneralRequirements

4.1.1Safetyintegrityshouldbecomprisedofhardwaresafetyintegrityandsystemsafetyintegrity.

4.1.2SafetyintegritylevelsmayincludeSIL1,SIL2,SIL3andSIL4.

4.1.3Inlowdemandmode,thesafetyintegritylevelofsafetyinstrumentedfunctionsshallbemeasured

bytheprobabilityoffailureondemandaverage,andshouldbedeterminedinaccordancewithTable4.1.3.

Table4.1.3Safetyintegritylevelofsafetyinstrumentedfunction(lowdemandmode)

Safetyintegritylevel(SIL)

Probabilityoffailure(lowdemandmode)ondemandaverage(PFDavg)

4

≥10=5且<10-4≥10-5to<10-?

3

≥10-?且<10-3≥10-4to<10-3

2

≥10-3且<10-2

≥10-3to<10-

1

≥10-2且≤10-1≥10-2to<10-1

4.1.4Inhighdemandmode,thesafetyintegritylevelofsafetyinstrumentedunctionsshallbemeasuredbytheprobabilityoffailureondemandaverage,andshouldbedeterminedinaccordancewith

Table4.1.4.

Table4.1.4Safetyintegritylevelofsafetyinstrumentedfunction(highdemandmode)

Safetyintegritylevel(SIL)

Frequencyofdangerousfailure(highdemandmode)(perhour)

4

≥10-?且<10-8

≥10-?to<10-8

3

≥10-8且<10-7

≥10-8to<10-7

2

≥10-7且<10-6

≥10-7to<10-6

1

≥10-6且<10-5

≥10-6to<10-5

4.2SafetyIntegrityLevelAssessment

4.2.1SILassessmentshouldincludethefollowingcontents:

1TodeterminetheSILforeachsafetyinstrumentedfunction.

2Todeterminethediagnosis,maintenanceandtestingrequirements.

4.2.2ThemethodsusedtoassesstheSILshallbedeterminedbasedontheprocesscomplexity,the

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currentnationalstandards,riskcharacteristics,riskreductionmethodsandstaffexperiences.Mainassessmentmethodsshallbelayerofprotectionanalysismethod,riskmatrixmethod,calibratedriskgraphmethod,empiricalmethodorotherpropermethods.

4.2.3ReviewmeetingshouldbeusedforassessingtheSIL.MaindocumentsforreviewshouldincludeP&IDs,processdescription,plantandequipmentlayouts,hazardousareaclassificationdrawings,safetyinterlockcause-and-effectdiagramsandotherrelateddocuments.AndthemainstaffsinvolvedinSILassessmentshouldbesourcedfromprocess,processcontrol(instrument),HSE,equipment,processoperationandmanagementdisciplines.

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5GeneralRequirementsforDesign

5.0.1EngineeringdesignofSISshallsatisfythesafetyinstrumentedfunctionsandSILrequirementsofpetrochemicalplants.

5.0.2EngineeringdesignofSISshallconsiderreliability,availability,maintainability,traceabilityandeconomics,andavoidunder-designorover-design.

5.0.3SISshallcompriseofsensors,logicsolversandfinalelements.

5.0.4ThefunctionsofSISshallbedeterminedbasedonHAZOPanalysis,safetyprotectionforstaffs,process,equipmentandenvironment,andtherequiredSILs.

5.0.5TheSILforpetrochemicalplantsshallnotbehigherthanSIL3.

5.0.6SISshallcomplywithSILrequirements.SILmaybedeterminedbycalculatingtheprobabilityoffailureonSIS.

5.0.7SISmayachieveoneormoreSIFs,andseveralSIFsmayshareonecommonSIS.WhenseveralSIFsareimplementedinoneSIS,thecommonpartswithinSISshallcomplywiththehighestSILrequiredbyeachSIF.

5.0.8SISshallbeindependenttothebasicprocesscontrolsystem,andshallindependentlyperformSIFs.

5.0.9SISshallnotinterveneorsubstitutethefunctionsofbasicprocesscontrolsystem.

5.0.10BasicprocesscontrolsystemshallnotinterveneSISoperationorlogicexecution.

5.0.11SISshallbefail-safedesigned.WheninternalfailureoccursinSIS,SISshallbringtheprocessintoasafestatefollowingdesiredmanner.

5.0.12LogicsolversforSISshallbedesignedwithhardwareandsoftwareself-diagnosisfunctions.

5.0.13IntermediatingpartsshallbeminimizedforSIS.

5.0.14Thecentralprocessingunit,input/outputunits,communicationunitandpowersupplyunitoflogicsolvershallemployredundanttechnology.

5.0.15LightningsurgeprotectionshallbeimplementedforSISinaccordancewithcurrentrelevantlightningprotectionstandardsofthenation.

5.0.16DualUPSsystemsshouldbeappliedtosupplyA.CpowerforSIS.

5.0.17EquipotentialbondingshallbeappliedforSISgrounding.

5.0.18SIShardware,operationsystemandprogrammingsoftwareversionsshallbeofficiallyissuedversions.

5.0.19SISsoftware,programming,upgradingormodificationdocumentsshallbebackedup.

5.0.20UniqueclockshouldbeprovidedforalltheequipmentinSIS.

5.0.21IfseveralSISsaredesignedforalarge-scalepetrochemicalproject,eachSISshallbecapableofworkingindependently.

5.0.22IfpossibleexternalinterferenceexistsinSISinputandoutputsignalloops,isolationmeasuresshallbetaken,suchasuseofisolatorsandinterposingrelays.

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6Sensors

6.1GeneralRequirements

6.1.1Sensorsincludeanalogueanddiscretesensors,andanaloguesensorsshouldbeusedforSIS.

6.1.2SmarttransmitterswithHARTprotocolsignalssuperimposedto4mA-20mADCsignalsshouldbeusedforsensors.

6.1.3Inexplosionhazardousarea,sensorsshallbeExdorExitype.WhenExisystemisused,isolatedtypesafetybarriersshallbeused.

6.1.4IngressprotectionoffieldinstalledsensorsshallnotbelowerthanIP65.

6.1.5SensorsshallnotadoptfieldbusorothercommunicationmethodsastheinputsignalsforSIS.

6.1.6Thesensorsandtheirtapsshouldbeindependentlyprovided.

6.1.7SensorperformanceandconfigurationshallcomplywithSILrequirements.

6.2SeparationRequirementsforSensors

6.2.1ForSIL1safetyinstrumentedfunction,sensorsmaybesharedwiththebasicprocesscontrolsystem.

6.2.2ForSIL2safetyinstrumentedfunction,sensorsshouldbeindependentfromthebasicprocesscontrolsystem.

6.2.3ForSIL3safetyinstrumentedfunction,sensorsshallbeindependentfromthebasicprocesscontrolsystem.

6.3RedundancyRequirementsforSensors

6.3.1ForSIL1safetyinstrumentedfunction,singlesensormaybeused.

6.3.2ForSIL2safetyinstrumentedfunction,redundantsensorsshouldbeused.

6.3.3ForSIL3safetyinstrumentedfunction,redundantsensorsshallbeused.

6.4RedundancyMethodsofSensors

6.4.1Whenhighsafetyisrequired,"OR"logicarchitectureshallbeused.

6.4.2Whenhighavailabilityisrequired,"AND"logicarchitectureshallbeused.

6.4.3Whenbothhighsafetyandhighavailabilityarerequired,2003logicarchitectureshouldbeused.

6.5DiscreteSensors

6.5.1Discretesensorsmayincludeprocessvariableswitches,manualswitches,pushbuttonsandrelaycontacts.

6.5.2Forthediscretesensorsusedforemergencyshutdown,theircontactsshallbeinclosedstateundernormalcondition,andthecontactsshallbeinopenstateunderabnormalcondition.

6.5.3Thecriticalinputloopsshouldbeprovidedwithopencircuitandshortcircuitfailuredetectionfunctions.OpencircuitandshortcircuitfailuresofinputloopsshouldgeneratealarmsandberecordedinSIS.

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7FinalElements

7.1GeneralRequirements

7.1.1Finalelementsshallincludecontrolvalves(regulatingtype,on-offtype),solenoidvalvesandmotors.

7.1.2Finalelementsshouldusepneumaticcontrolvalvesratherthanmotoroperatedcontrolvalves.

7.1.3FinalelementsshallsatisfySILrequirements.

7.2SeparationRequirementsforControlValves

7.2.1ForSIL1safetyinstrumentedfunction,controlvalvesmaybesharedwiththebasicprocesscontrolsystem,buttheyshallensureSISactionsatfirstpriority.

7.2.2ForSIL2safetyinstrumentedfunction,controlvalvesshouldbeindependentfromthebasicprocesscontrolsystem.

7.2.3ForSIL3safetyinstrumentedfunction,controlvalvesshallbeindependentfromthebasicprocesscontrolsystem.

7.3RedundancyRequirementsforControlValves

7.3.1ForSIL1safetyinstrumentedfunction,singlecontrolvalvemaybeused.

7.3.2ForSIL2safetyinstrumentedfunction,redundantcontrolvalvesshouldbeused.

7.3.3ForSIL3safetyinstrumentedfunction,redundantcontrolvalvesshallbeused.

7.3.4Controlvalveredundancymethodsmayincludeacombinationofaregulatingtypecontrolvalveandaon-offtypecontrolvalve,oracombinationoftwoon-offtypecontrolvalves.

7.4ControlValveAccessories

7.4.1Solenoidvalveassembledwiththeregulatingtypecontrolvalveshallbeinstalledbetweenthevalvepositionerandactuatorpneumaticconnection.Solenoidvalveassembledwiththeon-offtypecontrolvalveshallbeinstalledontheactuator.

7.4.2Inexplosionhazardousarea,solenoidvalvesandvalvepositionswitchesshallbeExdorExitype.WhenExiisselected,isolatedsafetybarriersshallbeused.

7.4.3DegreesofprotectionofsolenoidvalvesandvalvepositionswitchesinstalledinthefieldshallnotbelowerthanIP65.

7.4.4Solenoidvalvesshouldbe24VDCnormallyenergizedtype,andpowerforsolenoidvalvesshallbefedbySIS.

7.4.5Whenhighsafetyisrequired,theredundantsolenoidvalvesshouldadopt"OR"logicarchitecture,andwhenhighavailabilityisrequired,theredundantsolenoidvalvesshouldadopt"AND"logicarchitecture.

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8LogicSolvers

8.1GeneralRequirements

8.1.1Logicsolversshouldemployprogrammableelectronicsystem.ForthecasewhereI/Ocountsareveryfewandthelogicfunctionsaresimple,thelogicsolversmayuserelaysystem.'Andlogicsolversmaybeacombinationofprogrammableelectronicsystemandrelaysystem.

8.1.2Thefunctionalsafetyofprogrammableelectronicsystemusedforlogicsolversshallbecertifiedbythenat