PT100尺寸说明.docx

PT100尺寸说明.docx

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PT100尺寸说明

GLOBALEngineeringGUIDELINE

GuidelineforSelectingandSpecifying

TemperatureElements

3PS15001

Revision3

22February2007

Page1of32

RESPONSIBLEGROUP:

ProcessControls

CURRENTCONTACT:

DavidC.Arner

DenotesRevision

TableofContents

DOUBLECLICKONGREENNUMBERTOGOTOTHATSECTION

Section

Title

Page

Purpose

2

Scope

2

RelatedDocuments

2

Definitions

3

TemperatureElements

4

RelativeMeritsofRTDsandThermocouples

5

ThermocoupleTypes

6

ThermocoupleAccuracy

8

ThermocoupleCables

9

RecommendedDefaultUDimensionsforWeldedandThreadedApplicationsOutsideColdBoxes

26

RTDWiringOptions

11

TypicalTerminalArrangement

15

ThermowellStyles（ThreadedWell）

16

ThreadedWellandThreadolet

18

ThreadedWellandThreadedElbowlet

18

DN20SocketWeldInstallation

19

DN20SocketWeldElbowInstallation

20

FlangedThermowellInstallation

21

ThreadoletInstallationDimensions

23

WeldoletInstallationDimensions

23

ElbowInstallationNominalDimensions

24

FlangedThermowellInstallation

25

ThermowellExtensions

27

FastResponseThermocouplesforReciprocatingO2Compressors

31

DOUBLE-CLICKGREEN"TOC"TORETURNTOTABLEOFCONTENTS

1.PURPOSE

1.1Thisglobalengineeringguidelineprovidesbackgroundinformationandrecommendationsfortheselectionandspecificationoftemperatureelements.

1.2Thisguidelineisintendedtoencourageconsistentanduniformgoodpracticewhilemeetingperformanceandreliabilityrequirements.

2.scope

2.1ThisguidelineappliestotemperatureelementsforbothAir Products-ownedand-operatedplantsandforplantssuppliedtothirdparties.

2.2ThisguidelineconsidersbothRTDandthermocoupletypesoftemperatureelements.Othertemperaturemeasurementmethods（e.g.,thermisters,optical）areexcluded.

2.2.1Thisguidelinespecificallydoesnotincludedetailsofverylowtemperatureapplications（liquidhydrogenandliquidheliumapplications）forwhichsilicondiodetypetemperatureelementshavetypicallybeenspecified.

2.3Thisguidelinehasbeenpreparedspecificallyconsideringtherequirementsof:

∙AirSeparationPlants

∙HyCOPlants

∙Chemicals

Thegeneralprinciplesdescribedwithinthisguidelinemaybeappliedtootherplanttypeswithcaution.Additionalconsiderationsmayapplytoothertypesofplants（e.g.,ultrahighpurityplants）.

2.3.1Thisguidelineisnotintendedforlaboratoryscaleorotherspecialapplications.

2.3.2Interestedpartiesareinvitedtomakeproposalstobroadenthescopeofthisdocumenttocoverotherprocessesatafutureissue.

2.4ThisguidelinemakesreferencetoexistingTier4Specifications,andprovidessomesupportingbackgroundinformationforthesespecifications.

3.relateddocuments

3.1AirProductsEngineeringDocuments

3MA27036MechanicalRequirementsforDistillationbyTemperatureControlforPackedandTrayedColumns.

3PS00007SelectionandInstallationofTransmitters

3PS00016MaterialSelectionforControlValvesandInstrumentationinOxygenService

3PS15002UseofThermowellsinPressurizedSystems

3PS45004OxygenCompressorTemperatureProtectionSystem

4WPS-TEMP01TemperatureSensorsandThermowellsforColdBoxService

4WPS-TEMP02ResistanceTypeTemperatureDetectors（RTDs）forCryogenicandGeneralService

4WPS-TEMP03TemperatureSensorsandThermowellsforOxygenCompressors-FastResponseType

4WPS-TEMP04TemperatureSensorsforTray-TypeColumns

4WPS-TEMP05TemperatureSensorsforSurfaceTypeMeasurements

4WPS-TEMP06TemperatureSensorsandThermowellsforGeneralService

4ECE-M25ColdBox/CanTemperatureElementInstallation

APGAirProductsPEDCommitteeGuidelines（Intranet）

Providedforbackgroundinformationonly（notreferencedinthetext）

Tobepublishedatadatesubsequenttothisissuedate

3.2AmericanSocietyforTestingandMaterials（ASTM）

E230StandardSpecificationandTemperature-ElectromotiveForce（EMF）TablesforStandardizedThermocouples

E608/E608MStandardSpecificationforMineral-Insulated,Metal-SheathedBase-MetalThermocouples

E1137StandardSpecificationforIndustrialPlatinumResistanceThermometers

3.3Instrumentation,Systems,andAutomationSociety（ISA）

MC96.1TemperatureMeasurementThermocouples

3.3InternationalElectrotechnicalCommission（IEC）

IEC60584-1Thermocouples.Part1:

ReferenceTables

IEC60584-2Thermocouples.Part2:

Tolerances

IEC60751IndustrialPlatinumResistanceThermometerSensors

3.4BritishStandards（BS）

BSEN60584-1Thermocouples.Part1:

ReferenceTables

BSEN60584-2Thermocouples.Part2:

Tolerances

BSEN60751IndustrialPlatinumResistanceThermometerSensors

3.5GermanStandards（DIN）

DINEN60584-1Thermocouples.Part1:

ReferenceTables

DINEN60584-2Thermocouples.Part2:

Tolerances

3.6NationalInstituteofStandardsandTechnology（NIST）

ITS-90InternationalTemperatureScaleof1990

4.Definitions

4.1RTDmeansResistanceTemperatureDetector（i.e.,theactualsensingelementinaPRT）.OperationisbasedontheprincipleofResistanceThermometry,i.e.,whenametal’selectricalresistanceincreaseswithincreasingtemperature.MetalsthathaveshownarelativelinearityandrangabilityforuseintemperaturemeasurementarePlatinumandNickel.

4.2PRTmeansPlatinumResistanceThermometer（thewholeassembly）,i.e.,aPRTusesaRTD.

4.3ThermocoupleOperationisbasedontheSeebeckEffectwherebyavoltageiscreatedalongametalwireinthepresenceofatemperaturegradient.AthermocoupleusesapairofdissimilarmetalwiresjoinedattwopointssuchthatanetEMFisgeneratedwhenthejunctionsareatdifferenttemperatures.Standardcombinationsofdissimilarmetalssuitableforarangeofapplicationsaregiventhermocoupletypedesignators.SeeTable2forthermocoupletypescurrentlyusedbyAirProducts.

4.4ElectromotiveForce（EMF）–ThetermEMFisusedthroughoutthisdocumenttodescribethevoltagesthataregeneratedduetotemperaturegradientsinthermocoupleinstallation.

4.5ColdJunctionCompensation–ThenetEMFgeneratedbyathermocoupleinstallationdependsonthetemperaturesbothatthemeasuringthermocouplejunction（hotjunction）,andatthereferencejunction（coldjunction）[i.e.,thejunctionbetweenthethermocouplecable（orcompensatingcable）andthecoppercablesorterminals]oftheassociatedtransmitter/controlsystem.Coldjunctioncompensationistheprocessofcompensatingforerrorsthatwouldotherwisebeintroducedbychangesintemperatureatthereferencejunction.Historically,theseerrorswereeliminatedbyimmersingthereferencejunctioninanisothermalenvironment（e.g.,meltingice）.Incontemporaryindustrialsystems,thethermocouplecable（orcompensatingcable）

isconnecteddirectlytotheassociatedtransmitter/controlsystem.Thetransmitter/controlsystemcompensateselectronicallyfortheactualtemperatureatthereferencejunction（i.e.,atthetransmitter/controlsystem’sterminals）.

4.6Thefollowingdimensionaldefinitionsareusedinthisdocument:

IDdimensionisthepipeinternaldiameter（whichdependsonpipenominalboresizeandwallthicknessorschedule）.Forexample,seeFigure9A.

LLaggingextensionlength.SeeFigure12andparagraph5.6.21.1.

NNippleExtensionlength.SeeFigure12andparagraph5.6.21.1.

ODdimensionisthepipeexternaldiameter（whichdependsonpipenominalboresizeonly）.Forexample,seeFigure9A.

sdimensionisthesetbackfromthepipewallODtothebottomofthefittingengagement.SeeFigure14foranexample.

TThermowellExtensionlength.SeeFigure12andparagraph5.6.21.1.

thdimensionisthepipewallthickness.

Udimensionistheinsertionlengthofthethermowellwellmeasuredfromthetipofthewelltothe:

∙Bottomofthethreadforthreadedwells

∙Bottomoftheweldsectionforweldedwells

∙Bottomoftheflangeforflangedwells

CAUTION:

ThereissomevariabilityinthelettercodesusedfordimensionsbothinotherAir Productsstandardsandinindustry.Careshouldbetakentoclarifyterminologywhenreferringtodimensionsby"letter."

5.TemperatureElements

5.1StandardsforTemperatureElements

5.1.1Section3,above,illustratesthattherearemanynationalandinternationalstandardsfortemperatureelements.

5.1.2AirProducts’viewisnottofavoronestandardoveranother（e.g.,ASTMoverIEC）.Consequently,temperatureelementsmaybespecifiedinaccordancewithanyinternationallyrecognizedstandard.

5.1.3TheEuropeanandIECstandardsaretypicallyidenticaltooneanother.However,therearesomesignificantdifferencesbetweenIECandAmericanStandards（e.g.,claimedaccuraciesandthermocouplecablecolors）.

5.1.4Consequently,itisnecessarytospecifythermocouplesandcompensatingcabletoaparticularstandardtoachieveconsistentcolorcoding.Particularstandardsarelikelytobepreferredforcertainprojectstosuit:

∙Localconventions

∙Clientrequirements

5.2ElementType

5.2.1Becauseofthemanytypesoftemperatureelementsavailable,theremaybeseveralpotentialsolutionsforanyparticularapplication.

5.2.2ForAirProductstoachievebenefitsfromstandardization,thisguidelinerecommendsstandardelementtypesformostapplications.

5.2.3Thesestandardelementtypesshouldbespecifiedwheneveritispracticaltodoso.However,othertechnicallyacceptablealternativesmaybespecifiedwhenthereisanoverridingreasontodoso,suchas:

∙Modificationstoanexistingplantwhenadifferentelementtypeisusedasstandard.

∙Whenanexistingproduct-basedplantdesignisbeingrepeatedwithoutre-