Heliumleakdetectoroperation,Calibrationandmaintenanceprocedures

FermilabTechnicalDivision

ES-298031RevA

HeliumLeakDetectorOperation,CalibrationandMaintenanceProcedures

Initiatedby Frank Juravic Jr.Date10/29/01

ApprovedbyTed BealeDate10/29/01

HeliumLeakDetector

Operation,CalibrationandMaintenanceProcedures

Purpose

Thepurposeofthisprocedureistoprovidetheheliumleakdetectoroperatorwithanoverviewofoperationrequirements,calibration,andmaintenanceofleakdetectorsfortheTechnicalDivision.It,alsoincludes,Fermilab’sengineering specificationspertainingtotheheliumleakcheckrequirements,weldingprocedures, etc...Thisisintendedforanoperator'sreferencenottraining.

Preface

ITheleakdetectorsystemthatisusedatFermilabevolvedfromthe needtopumponvarioussizedvolumeswithanassortmentoffixturing,toprotectthesuperconductingmagnetsfromoilbackstreamingfromtheroughingpumpandtoreducethepermeationofhelium.

ITheleakdetectorsystemconsistsofaMassSpectrometerLeak

Detector(MSLD),RoughingSystem,inletmanifoldwithgaugingandaheliumstandardleak.

ITheleakdetector'smanualisthereferenceforalloperation,

maintenanceandtroubleshootingfortheleakdetector.

I Theproceduresforstartupandshutdownpresentedinthismanual

havebeendevelopedtoutilizetheAutoProtectioncircuitontheMSLDandtheRoughingSystem.

LeakDetectorSystem

RoughingSystem

1.RoughingValve

2.RoughingColdTrap

3.VentValve

4.StandardLeak

5.MicronGauge

6.RoughingPump

7.InletManifold

LeakDetector

8.DiffusionPumpValve

9.DiatronValve

10.OutputMeter

11.Pressure

12.ElectronicStripChart

Index

IStartUpProcedures

IDailyOperationILeakChecking

Procedures

IShutDownProcedure

IAVS2.1Calibration I Maintenance

PreventativeMaintenance

MaintenanceProcedures Troubleshooting

***EngineeringSpecificationsandAVS2.1are foundinLeakDetectorfolder.***

FlowDiagramofOperation,

CalibrationandMaintenance

StartupProcedure

DailyStartupforLeakDetectorStation*

RoughingPumpSystem

1.CloseVentValve

2.Closesystemvalveorblankoffinlet.

3.OpenRoughingValve.

4.CheckPressureonMicronGauge:<30microns

5.FillRoughingColdTrap.(PPErequired)

LeakDetector

1.SwitchAuto-protectionOFF,listenfor fore pumptogurgle.

2.Checkdiffusionpumpstatus(SwitchONtwentyminutewait).

3.OpenDiffusionPumpIsolationValve.

4.OpenDiatronIsolationValve.

LeakDetector(Cont..)

5.SwitchGaugeON;CheckPressureon Leak Detector.

A.Mid-scaleorless,fillcoldtrap.(PPErequired).

B.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

6.SwitchFilamentON.

A.IonizingCurrent(Mid-scale).

B.Accelerator(60-80volts)}.

7.SwitchAuto-protectionON.

Allgaugereadingsarefornormaloperation.Ifareadingdeviatesfromnormal,checkMaintenanceTroubleshooting

*DailyStart-upProceduresarefollowedondaysthattheDailyShut-downProcedureswereperformedpreviously.

DailyStartupforLeakDetectorStation*

RoughingPumpSystem

1.CloseVentValve

2.CloseSystemValveorblankoffinlet.

3.OpenRoughingValve.

4.CheckPressureonMicronGauge:<30microns

5.FillRoughingColdTrap.(PPErequired)

LeakDetector

1.SwitchAuto-protectionOFF,listenforfore pumptogurgle.

2.CheckValvestatus.

3.OpenDiatronIsolationValve.

4.SwitchGaugeON;CheckPressureonLeakDetector.

A.Mid-scaleorless,fillcoldtrap.(PPErequired).

B.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

6.SwitchFilamentON.

A.IonizingCurrent(Mid-scale).

B.Accelerator (60-SOvolts)}.

7.SwitchAuto-protectionON.

WeekendStartupforLeakDetectorStation*

LeakDetector

1.SwitchAuto-protectionOFF,listenforfore pumptogurgle.

2.SwitchDiffusionPumpON.(Allow20minutesforwarmup)

RoughingPumpSystem

1.OpenRoughingValve.

2.CheckPressureonMicronGauge:20microns

3.FillRoughingColdTrap(PPErequired)

LeakDetector

1.OpenThrottle Valve;CheckMicronGauge,20Microns,OpenDiatronIsolationValve;CheckMicrongauge20Microns

2.OpenDiffusionPumpIsolationValve.(Allow20minutesforwarmup)

3.CloseThrottleValve

4.SwitchGaugeON;CheckPressureonLeakDetector.

A.Mid-scaleorless,fillcoldtrap.(PPErequired)

B.Ifscaleisgreaterthan midscaleswitchgaugeofffor aminuteandtryagain.

5.SwitchFilamentON.

A.IonizingCurrent(Mid-scale).

B.Accelerator(60-80volts).

6.SwitchAuto-protectionON.

Allgaugereadingsarefornormaloperation.Ifareadingdeviatesfromnormal,checkMaintenanceTroubleshooting

WeekendStart-upProceduresarefollowedondaysthattheWeekendShut-downProcedureswereperformedpreviously.

TotalStartupforLeak-DetectorStation*

LeakDetector

1.AssureRoughingValve,ThrottleValve,DiatronIsolationValve,DiffusionPumpIsolationValveareclosed.

2.Switch PowerONlistenforfore pumptogurgle.

3.SwitchAuto-protectionOFF.

4.SwitchDiffusionPumpON.(Allow20minutesforwarmup)·

RoughingPumpSystem

1.SwitchRoughingPumpON

2.OpenRoughingValve.

3.CheckPressureonMicronGauge:30microns

4.FillRoughingColdTrap.(PPE required)

LeakDetector

1.OpenThrottleValve;CheckMicronGauge,30Microns,OpenDiatronIsolationValve;CheckMicrongauge30Microns

2.OpenDiffusionPumpIsolationValve.(Allow20minutesforwarmup)

3.CloseThrottleValve

4.SwitchGaugeON;CheckPressureon LeakDetector.

A.Mid-scaleorless, fillcoldtrap.(PPErequired)

B.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

5.SwitchFilamentON.

A.IonizingCurrent(Mid-scale).

B.Accelerator(60-80volts).

6.Switch Auto-protectionON.

Allgaugereadingsarefornormaloperation.Ifareadingdeviatesfromnormal,checkMaintenanceTroubleshooting

TotalStart-up ProceduresarefollowedondaysthattheTotalShut-downProcedureswereperformedpreviously.

DailyOperation

I Calibration

LeakDetection

Maintenance

IPayAttention

IEmergencyShutDown

T e c h n i c a lD i v i s i o nES-298031RevAF r a n k1 u r a v icJ r.

Daily Operation*

I Calibration12OSADuPont/CEC

Openleakdetectortostandard(STD)leak.

*PeakHeby adjustingAcceleratorVoltageformaximumoutputmeterdeflection.

CalculateaMDL.

DailyOperation*

Calibration112OSAAmetek

•Open leak detector to STD leak.

•*CalibrateforHe(Ifnecessary,peakHewithHeliumadjust).

•CloseSTDleak;Adjusttozeroonmostsensitivescale.

•OpenSTDleak;Keepmeteronscale;adjustCalibratetomatchSTDvalue.

DailyOperation

I LeakDetection

I Visuallyinspectwelds

Checktheprintforthetypeofweld

IfnotasspecifiedwriteQCRorDR

IConnectleakdetectortopartorsystemandleakcheckperspecification.

IfleakcheckisOK,fillinappropriatelabeloridentifier

IfleakcheckfailswriteQCRor DR

Doastripchartofleakcheckasrequired.

DailyOperation

ILeakDetection

Allleakcheckingshouldbewithappropriatefixturing.

Useo-ringswithlowpermeabilitytoHe.
Metalhose.
Useputtyonlyinextremeemergencies.
Supportbellowsfromcollapsingwhennecessary.

DailyOperation

ILeakDetection

Typesofleakchecking

Vacuuminside,Bagandspray.
Vacuumoutside,Heliumpressurenottoexceed30psig.
Snifferprobe,Heliumpressurenottoexceed30psig.

DailyOperation

Maintenance

ColdTrapcleaning.

Fixtures

Checkforcleanliness

Checkforscratchesinsealingsurface

O-rings;checkforcuts.

DailyOperation

I PayAttention

Astheoperatorofamassspectrometerleakdetectoronehastobeonconstantvigilance.

Poorornosensitivity

Highbackground

Slowcleanuptohelium

Irregularoutputmeteroperation

Roughingsystemcontamination(high backgroundwithroughvalveopen)

DailyOperation

I OccasionallytheColdTraphastoberemoved duringthedayandtheoperatorhastobeabletocontinueleakchecking.

ReturntonormaloperationbyfollowingColdTrap

Removal(SpecialCases)MaintenanceProcedure

DailyOperation

I IfyoufallowedtheemergencyshutdownprocedureinDailyOperationsandwanttoresume leakchecking.

ColdTrapWarm:FollowTotalStartupProcedure

ColdTrapCold:FollowEmergencyStartupProcedure

•DailyOperation

I Emergency ShutDown

I CloseDiatronIsolationValve;DiffusionPump

IsolationValve;ThrottleValve.

I SwitchFilament,Gauge,DiffusionPumpOFF

I CloseRoughingValve;Switch Roughing

PumpOFF.

I Makesuretherearenoscrewsholdingthecoldtraptight.

I ThistakeslessthanThirtySecondstoperform.

LeakTestProcedure

I Leaktestsetup

Visuallyinspectallweldsperprintspecifications.

Visuallyinspectsealingsurfacesforscratches.

InspectforcleanlinessperES-107220,ifnecessary.

IIfanyoftheabovefailwriteQCRIDRandwaitfordisposition.

..•

LeakTestProcedure

LeakTestSetup

Considerationswhenselectingproperfixturing.

Fixturingmayrequiresomeimagination.

Selectfixturingandgasketsthatdonothinderjointverification.

Caution:Bellowsaresubjecttoforcesthatcan damagethepart.Useexpansionfixturesdesignedforthatbellows.

KeeptheuseofApiezonvacuumputtytoaminimum(assurenottocoverwelds).

LeakTestProcedure

IRoughingSystem

Connectpartorsystemtoleakdetectorsystem.

Assureastandardleakispartofsystemandpreferablyattheoppositeendofsystemfromthepump. Duringpumpdownkeepstandardleakopen

Open RoughingValve.

CAUTION:Theforcescreatedwhenpumpingaresufficient todamagethetestitem.Ifsomethinghappenstothetestitemduringpumpdown,thefirstactionistoopentheventvalve.

Monitormicrongauge,at20micronsclosestandardleak.

NOTE:Smallcomponentpartstakeashorttimetoreach20microns.

Onlargepartsormagnetsthetimetopumpdownto100microns,withjusttheroughingpump,isthefollowingformula.

t=12ps

IMSLD

LeakTestProcedure

SwitchmultipurposemetertoPressure.

OpenThrottleValve.

CAUTION:Thisprocedurerequirestheinspectortouseextremecaretopreventtheleakdetector'sinternalvacuumtoreachalevelthatcancausedamagetothefilament(abovemid-scale).

NOTE1:Iftheauto-protectionactivates,closeThrottleValveandretry.

NOTE2:Onapumpdownthatexceedstheestimatepumpdowntimeandif500microns,slowlyopentheThrottleValvekeepingthePressureneedlemidscale.Sprayhelium,checkingforlargeleaks.If noleaksarefoundcheckforcleanlinessproblemsortheroughingpumpneedsanoilchange.

IMSLD

LeakTestProcedure

WhenThrottleValveiscompletelyopenandPressureis

<midscale,closeRoughingValveslowlymonitoringthePressurenottoriseovermidscale.

CheckOutputMeterfor<85%mostsensitivescale.

NOTE:IfoncleanpartsyouhavetowaitforOutputMetertoread

<85%,sprayheliumlookingforleaks.Ifnoleaksarefoundchangeo-ringsand/orgasketsfortheymayhavepermeabilityproblems.

WhenOutputMeteris<85%onmostsensitivescaleandthe

RoughingValveisclosed,thepartisreadyfortesting.

LeakTestProcedure

I LeakTest/LeakTestLabel

NOTE:VacuumLeaktestperES-107240.ThefollowingitemsexpandonderivingnecessarydataforLeakTestLabel(LTL).

SCALEUNITSBEFOREHELIUMPROBE

FollowES-107240testprocedure#3 FollowES-107240testreport#1

Ifcauseforrejection,endtest.WriteQCRIDR. RecordonLTLOutputMeterposition

SCALEUNITSWHILEENCLOSUREFLOODING

FollowES-107240testprocedure#3

FollowES-107240testreport#1

Ifcauseforrejection,endtest.WriteQCRIDR.

RecordonLTLOutputMeterposition

LeakTestProcedure

ILeakTest/LeakTestLabel

DETERMINATION OFMINIMUMDETECTABLELEAK

MDS

Page 1 of 80

UsethedeterminationfromMSLDstripchartforAVS2.1

RecordonLTL.

RESONSE

OpenStandardLeak(keepOutputMeteronscale).

RecordonLTLOutputMeterposition.

Page 1 of 80

......

Page 1 of 80

CloseStandardLeak(keepOutputMeteronscale).

RecordonLTLOutputMeterposition.

LEAKVALUE

ValueofStandardLeak fortestatmcc/sec(helium)

Page 1 of 80

RecordonLTL.

Page 1 of 80

MDL

CalculateMDL

RecordonLTL.

Page 1 of 80

LeakTestProcedure

IPostLeakTest

Testsetupremoval.

CloseThrottleValve.

OpenVentValve.

Removetestitemfixturing. Closeventvalve.

Cleanandstoretestitem.

Cleanandstoretestfixturing/gaskets.

Documentationoftestitem.

LTLperES-107240 testresult#4

Completetestpaperworkandsignoff.

Page 1 of 80

ShutDownProcedure

Page 1 of 80

DailyShutDown

LeakDetector

1.SwitchFilamentandGaugeOff

2.CloseDiatronIsolationValve

3.Maintenance;ColdTrapCleaningProcedure

4.CloseThrottle

Page 1 of 80

WeekendShutDown

LeakDetector

1.SwitchFilamentandGaugeOff

2.CloseDiatronIsolationValve

3.Maintenance;ColdTrapCleaningProcedure

4.CloseThrottle

RoughingPump

1.OpenVent

2.ShutoffRoughingPump

3.OpenRoughingValve

4.Remove,cleanandreinstallRoughingColdTrap(safetyequipmentrequired).

5.CloseVentValve,RoughingValve

Page 1 of 80

TotalShutDown

LeakDetector

1.SwitchFilamentandGaugeOff

2.CloseDiatronIsolationValve

3.Maintenance;ColdTrapCleaningProcedure

4.CloseThrottle

5.SwitchPower OFF

1.OpenVent

RoughingPump

2.ShutOffRoughingPump

3.OpenRoughingValve

4.Remove,cleanandreinstallRoughingColdTrap(safetyequipmentrequired).

5.CloseVentValve,RoughingValve

T e c h n i c a lD i v i s i o nES-29803lRevAF r a n kJ u r a v icJ r.

T e c h n i c a lD i v i s i o nES-29803JRevAF r a n kJ u r a v icJ r.

AVS2.1Calibration

I Equipment Start-up

Allow MSLD to warm up for 30 minutes.

Allow chart recorder to warm for 30 minutes.

Peak helium response on MSLD.

Close Throttle Valve.

Open Standard Leak and Roughing Valve.

T e c h n i c a lD i v i s i o nES-298031RevAF r a n kJ u r a v i cJ r.

AVS2.1Calibration

I Equipment Start-up

Allow MSLD to warm up for 30 minutes.

Allow chart recorder to warm for 30 minutes.

Peak helium response on MSLD.

Close Throttle Valve.

Open Standard Leak and Roughing Valve.

T e c h n i c a lD i v i s i o nES-298031RevAF r a n kJ u r a v i cJ r.

AVS2.1Calibration

I Record MSLD Output Meter on Strip Chart

Name file per section requirements.

Enter MSLD property number.

Enter Standard Leak's value.

Run for twenty minutes.

I

T e c h n i c a lD i v i s i o nES-298031RevAF r a n kJ u r a v i cJ r.

I

AVS2.1Calibration

I Record helium response on Strip Chart

Open Throttle Valve; Close Standard Leak; Roughing Valve

Zero on most sensitive scale.

Open Standard Leak; Calibrate on White 1o-8

Scale

Run for five minutes. Close Throttle Valve.

Stop Chart Recorder

T e c h n i c a lD i v i s i o nES-298031RevAFr n n kJ u r a v i cJ r.

AVS2.1Calibration

I Evaluate Strip Chart

Determine straight line approximations of the chart for each 1 - minute interval (1 - min).

Drift

Drift equals the sum of total change in chart's slope for each 1- min in output, divided by 20

Drift

Total Change

------

T e c h n i c a lD i v ii o nES-298031RevAF r a n kJ u r a v icJ r.

AVS2.1Calibration

I Evaluate Strip Chart

Determine straight line approximations of the chart for each 1 - minute interval (1 - min).

Noise

Noise equals the average of the maximum peaks in 1- min, multiplied by two, divided by 20

Noise =

NOTE: Neglect any large peak within any 5 - min

AVS2.1Calibration

I StoreStripChart

Storefileindepartment’s StripChartlocationonserver

Maintenance

Preventative Maintenance

Maintenance

PreventativeMaintenance

I Keepingleakdetectorsandroughingsystemsreliablerequiresapreventativemaintenanceprogram.

NOTE:Metalhoses,fixtures,o-ringsandgasketsshouldalsohavearegimethat assurescleanliness.

Maintenance

PreventativeMaintenance

Leakdetectorscanhavealongintervalbetweencleaningsifnotabused.

TheDiffusionPumpoilhastobereplacedwhenunusually goodsensitivityisdetected.

Onlyreplacefilamentsasneeded.

Maintenance

PreventativeMaintenance

Leakdetector'sforepumpoilshouldbereplacedBi-annually.

TheVBeltshouldbeinspectedbi-annually.

AnydoubtinconditionofVBelt,replace

Maintenance

PreventativeMaintenance

Roughing pumpsshouldhavetheoilchangedeverythreemonthsifused continuously.Heavydutyworkmayrequireoilchangemonthly.

TheVBeltshouldbeinspectedbi-annually.

AnydoubtinconditionofVBelt,replace.

Maintenance

PreventativeMaintenance

Metal bellowsshouldbecleanedwithanultra-sonicbathBi-annuallyorasnecessary.

Fixturingshouldbecleanedandinspectedfordamageasused.

Maintenance

PreventativeMaintenance

I Gasketando-ringsbecometroublesomewith permeability ofhelium.Replaceasnecessary.

Maintenance

Procedures

I
I / ShutDown;ColdTrapSpecialCases;ColdTrap / I
I
ChangeRoughingPumpOil
ChangeLeakDetector
ForePumpOil
I / ChangeFilament / I

Maintenance

Procedures

I ColdTrapRemovalforShutDowns

CloseRoughingValve;CloseSystem Valve(Blankoffinletmanifold);

OpenVentValve

SwitchFilamentOFF;GaugeOFF;AutoProtectionOFF

CloseDiatronIsolationValve;CloseDiffusionPumpIsolationValve;

SwitchDiffusionPumpOFF(DailycanbeleftON)

OpenThrottleValve

Cautiouslyremoveanddumpcoldtrap(PPErequired)

Clean ColdTrapWell andinspecto-ring

InstallcleanedColdTrap

CloseVent Valve;OpenRoughingValve

CheckMicronGauge<20Microns

CloseThrottleValve

Maintenance

Procedures

I ColdTrapRemoval(SpecialCases)

CloseRoughingValve;CloseSystemValve(Blankoffinletmanifold);

OpenVentValve

SwitchFilamentOFF;GaugeOFF;Auto ProtectionOFF

CloseDiatronIsolationValve;CloseDiffusionPumpIsolationValve

OpenThrottleValve

Cautiouslyremoveanddumpcoldtrap(PPErequired)

CleanCold TrapWellandinspectoring

InstallcleanedColdTrap

CloseVentValve;OpenRoughing Valve

CheckMicronGauge <20Microns

OpenDiatron(checkMicronGauge20Microns)

Page1

Maintenance

Procedures

I ColdTrapRemoval(SpecialCases)

Close ThrottleValve

OpenDiffusionPumpValve

SwitchGaugeON;CheckPressureonLeakDetector.

A.Mid-scaleorless,fillcoldtrap.(PPErequired)

B.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

:SwitchFilamentON.

A.IonizingCurrent(Mid-scale).

B.Accelerator(60-80volts).

SwitchAuto-protectionON.

Resumeoperation.

Page2

Maintenance

Procedures

Start-upafterEmergencyShutDownFrostoncoldtrap

1.OpenRoughingValve;OpenVentValve;CloseSystemValve(Blankoffinletmanifold).

2.Carefully removeColdTrap;Empty LN2toasafeplace(PPErequired).

3.Warmcoldtrapandcoldtrapwellthencleanandreinstall.

4.CloseRoughingValve;SwitchRoughingPumpON;AutoProtectionOFF(Listenforforepumptogurgle).

5.OpenThrottleValve:Carefully removeColdTrap;Empty LN2toasafeplace(PPErequired).

5.Warmcoldtrapandcoldtrapwellthencleanandreinstall.

6.OpenRoughingValve;SwitchDiffusionPumpON(20minutewarmup).

a.CheckMicrongauge20microns

b.OpenDiatronValve(checkMicronGauge20Microns)

Page3

Maintenance

Procedures

Start-upafterEmergencyShutDown

7.CloseThrottleValve;OpenDiffusionPumpValve(20minutewarmup).

8.SwitchGaugeON;CheckPressureonLeakDetector.

a.Mid-scaleorless,fillcoldtrap.(PPErequired)

b.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

9.SwitchFilamentON.

a.IonizingCurrent(Mid-scale).

b.Accelerator (60-80volts).

10.SwitchAuto-protectionON.

11.Resumeoperation.

Page4

Maintenance

Procedures

Start-upafterEmergencyShutDown

1.SwitchRoughingpumpON;SwitchAutoProtectionOFF;SwitchDiffusionPumpON(20minutewarmup)

2.OpenRoughingValve

a.CheckMicrongauge20microns

b.OpenDiatronValve(checkMicronGauge20Microns)

3CloseThrottleValve;OpenDiffusionPumpValve(20minutewarm up).

4.SwitchGaugeON;CheckPressureonLeakDetector.

a.Mid-scaleorless,fillcoldtrap.(PPErequired)

b.Ifscaleisgreaterthanmidscaleswitchgaugeoffforaminuteandtryagain.

5.SwitchFilamentON.

a.IonizingCurrent(Mid-scale).

b.Accelerator (60-80volts).

6.SwitchAuto-protectionON.

7.Resumeoperation.

Maintenance

Procedures

IRoughingpumpoilchange.

If theroughingcoldtrapisfull emptyperdirectionsintheColdTrapCleaningProcedure.

OpenVentValve;OpenRoughingValve

SwitchRoughingPumpOFF

Openoildrain

Whenflowisveryslow,jogpumptoremoveoiltrappedinthevaneregionofpump.

Alsolookatusedoilforsludge.Ifsludgeisexcessive,removeoilcoverandclean.Removalofoilcoverrequiresaspecialgasket.

Closeoildrainandfillwith HE-200oilandquantityoilrecommendedbymanufacture.(Normallymiddleofsightglass.)

Resumenormaloperation.

Maintenance

Procedures

IMSLDForePumpoilchange.

UseTotal ShutDownProcedure.

OpenLid;RemovebackofMSLD

RemoveV-beltcover;InspectVbelt(Anydoubtreplace);ReplaceV-beltcover.

Openoildrain

Whenflowisveryslow,jogpumptoremoveoiltrappedinthevane regionofpump.

CloseoildrainandfillwithHE-200oilwithquantityofoilrecommendedbymanufacture.(Normallymiddleofsightglass.)

ReplacebackofMSLD;Closelid

IChangeFilament

Maintenance

Procedures

Note:IfFilamentisblownduetohigh pressureandleakdetection willberesumed.

IDailyShutDownProcedure

ILoosenMagnetholderandremovemagnet

IRemoveFuse;Disconnectpre-amp

IRemoveDiatronEnvelopewithDiatron.

IRemoveDiatron.(Replacefilamentpermanualinstructions)CleanDiatronEnvelope

IReplaceDiatron (checkingforalignment);replaceDiatronEnvelope;Magnet

IDailyStartUp

IAlignmagnetperleakdetectormanualinstructions

Maintenance

Troubleshooting

Maintenance

Start-upTISProcedures

I20microns

Cleanroughingsystemcoldtrap(PPErequired)

Changeoilinroughingpump(HE-200)

Leakcheckroughingsystem

I100microns

Leakcheckroughingsystem

Changeoil(HE-200)

Overhaul roughingpump

Maintenance

Start-upT/SProcedures

Autoprotection-nogurgle

ReplaceForePumpVbelt

SomeproblemswithstartuparecoveredinDailyOperatingT/S

Maintenance

DailyOperationsT/SProcedures

INOTE:Ifnotthesolutiontoproblemrefertoleakdetectormanualfor furthertroubleshootingsuggestions.

1NoSensitivity:

IfthefilamentlightisglowingverybrightandthereisnoIonizingCurrent,replacethefilament.

2Poor Sensitivity:

CleanColdTrap(PPErequired).

3ExcessiveSensitivity:

Changediffusionpumpoil.

4Excessivenoise:

Checkforloosescrewsonpre-amplifier.

Page1

Maintenance

DailyOperationsT/SProcedures

I NOTE:Ifnotthesolutiontoproblemrefertoleakdetectormanualfor furthertroubleshootingsuggestions.

IPoorpressure‘pressuregauge’reading:

Leaktestleakdetector.

IUnusuallyslowcleanup:

Cleancoldtrap(PPErequired).

IOutputmeterdeflectsfullscale(positive/negative):

Checkforloosescrewsonpre-am

Page2

EngineeringSpecification

Mostengineeringspecificationastheyrefertovacuum,welding, cleaningetc.areinbackofbook.

TheprocedureAVS2.1isalsoinaPDFfile.

Conclusion

Thismanualshouldhelpyouthroughmanysituations

Whenindoubtrefertomanualsprovidedwiththeequipment

rcalling3014

DuPont Super Leak Detector Start-Up Procedure

Gloves and face shield are recommended when using liquid nitrogen

James 03/03/10

1)Open the standard leak

2)Remove the cold trap bucket

3)If the bucket is trapped the machine was shut down incorrectly. Break the vacuum at the KF16 connection to the fore pump.

4)Close the diffusion pump valve.

5)Switch on the main power.

6)Let the fore pump run a minimum of two minutes.

7)Switch on the diffusion pump.

8)The diffusion pump will take a minimum of twenty minutes to warm up.

9)Close the roughing pump valve and start the roughing pump.

10)Let the rougher warm up a minimum of two minutes.

11)Close the manifold vent valve.

12)Close the throttle valve.

13)Turn off the auto protection (red button) auto protection is off when the LED is lit.

14)Open the roughing pump valve.

15)The fore pump will take at least a minute to pump out the back side of the throttle valve

16)Let the Hastings gauge bury.

17)Check the O ring on the cold trap.

18)Wipe down the cold trap bucket with alcohol.

19)Insert the cold trap bucket.

20)Open the throttle valve.

21)Add nitrogen at 50 microns or less.

22)Let the Hastings gauge bury.

23)Check the boil, it should be calm.

24)Slowly open the analyzer cell valve

25)Let the Hastings gauge bury.

26)Close the throttle valve.

27)Open the diffusion pump valve.

28)Let the analyzer cell pump for at least five minutes.

29)Check the boil, it should be calm.

30)Press / hold the (green button) until the relay picks up (~ three seconds) and release.

31)Let the analyzer cell warm up a minimum of twenty minutes.

32)The background initially should be around 4.5E-9 and dropping

33)Pirani gauge should show one bar only.

34)Turn on the auto protection (red button) protection is on when the LED is not lit.

35)After warm up the background should go down to 2.5E-10 +/- .5 nominal. Also known as 0 This may require more time. It is important to remember that until the background is at some base line, calibrating should not be performed.

36)After background nominal or base line is reached check calibration.

37)Check the Hastings, it should be buried.

38)Slowly open the throttle valve.

39)Check the Hastings, it should be buried.

40)Slowly open the throttle valve.

41)Close the roughing pump valve.

42)Compare the standard leak value with the read out.

43)Let the standard leak pump down to a base line.

44)Divide the standard leak value by the signal output

45)The sensitivity specification is 1.0 to 2.5

46)If tuning is necessary follow these steps.

Press the Spectro button.
Triode pressure should be no higher than one
Press next three times.
Accelerator voltage is the only adjustment.
Accelerator voltage nominal is 211-213
To adjust voltage press F2.
Press +/- to calibrate.
Press F2
Close the calibrated leak to see manifold background. (Background should be in the E-10 range)
Press the next button to leave the Triode Pressure displayed

Some important things to remember:

Regardless of what any gauge reads the cold trap never lies. If the boil is not calm there is pressure in the system.

Don’t let the cold trap run dry as it will release contaminates into the system.

If a nominal value cannot be reached there is a reason. Some of the most common causes are as follows:

High pressure
Internal or external leak
Diffusion pump oil is contaminated
Fore pump oil is contaminated

Analyzer cell is contaminated
Cold trap is or was dry
Insufficient time has been given to reach the value
Standard leak valve in the closed position is bleeding through
Standard leak O ring shaft seal is bleeding through
Manifold vent valve in the closed position is bleeding through

Protect the analyzer cell. It should not be out of a state of vacuum at any time.

Protect the diffusion pump. It cannot run out of a state of vacuum.

In both these cases damage always occurs, it’s just a question of how much.

DuPont Super Leak Detector Shut-Down Procedure

James 03/12/10

1)Close the throttle valve

2)Turn off the analyzer cell (round black button)

3)Close the analyzer cell valve

4)Close the diffusion pump valve

5)Turn off the auto protection (red button) auto protection is off when the LED is lit

6)Wait approximately 15 second for the back side of the throttle valve to pump out

7)Turn off the diffusion pump

8)Close the roughing pump valve or turn off the roughing pump

9)Vent the manifold (leave open)

10)Slowly open the throttle valve

11)This will free the cold trap bucket

12)Remove the cold trap bucket

13)Recycle the nitrogen into a hand dewar

14)Let the diffusion pump cool down a minimum of twenty minutes

15)After cool down turn off the main power

16)Open the diffusion pump valve to vent the fore pump

If the cold trap bucket is reinserted and seated prior to venting the fore pump it will become trapped under vacuum and this will necessitate breaking vacuum at the KF16 connection to the fore pump to release it.

DuPont Super Leak Detector Cold Trap Bucket Exchange

James 03/12/10

During leak detector operation often a fresh clean cold trap bucket is advantageous and sometimes necessary. It never hurts to exchange the bucket.

Here are some typical conditions for which this is true.

1)Extended pumping will not reduce pressure

2)Extended pumping will not reduce background

3)Pumping on a dirty part

4)Pumping on water

5)Chemical contamination ( WILL DISTROY THE ANALIZER CELL )

There are cases in which a bucket may have to be exchanged several times. A water load is a classic example. If the bucket is removed and found to have ice / snow on the walls, exchanges must be done until the majority of the water is removed. As this is being done the pressure should be reduced with each exchange. Pumping time for each exchange will vary with the condition of the source.

Don’t waste time warming up the bucket, Have a fresh clean bucket ready.

During the exchange pressure is rising in the analyzer cell.

So methodically change it quickly.

Procedure:

1)Turn on the roughing pump (valve closed)

2)Close the throttle valve

3)Turn off the auto protection (red button) auto protection is off when the LED is lit

4)Wait approximately 15 second for the back side of the throttle valve to pump out

5)Turn off the analyzer cell (round black button)

6)Close the analyzer cell valve

7)Close the diffusion pump valve

8)Vent the manifold ( leave open )

9)Slowly open the throttle valve to release the cold trap bucket ( leave it open )

10)Remove the bucket

11)Check the O ring

12)Insert the fresh bucket

13)Close the manifold vent valve

14)Open the roughing pump valve

15)Check the Hastings gauge

16)Add nitrogen at 50 microns or less

17)Let the gauge bury

18)Check the boil, it should be calm

19)Close the throttle valve

20)Open the diffusion pump valve

21)Check the boil, it should be calm

22)Wait a minimum of a minute

23)Open the analyzer cell valve

24)Wait a minimum of two to three minutes for stabilization

25)Turn the analyzer cell back on

26)Turn on the auto protection (red button) protection is on when the LED is not lit