lhc hardware commissioning review 11-13 may 2005 cryogenic vacuum system paul cruikshank for at/vac

LHC HARDWARE COMMISSIONING REVIEWLHC HARDWARE COMMISSIONING REVIEW11-13 May 200511-13 May 2005

CRYOGENIC VACUUM CRYOGENIC VACUUM SYSTEM SYSTEM

Paul CruikshankPaul Cruikshank

for AT/VACfor AT/VAC

P. Cruikshank Hardware Commissioning Review, 11-13th May 2005

OutlineOutline

Cryogenic vacuum system Cryogenic vacuum system layoutlayout

Leak testing sequenceLeak testing sequence Failures Failures SummarySummary


Cryogenic Vacuum Cryogenic Vacuum SystemSystem

COLD BEAM VACUUM = 6 SUBSECTORSCOLD BEAM VACUUM = 6 SUBSECTORSCRYOMAGNET INSULATION VACUUM = 14 + 5 SUBSECTORSCRYOMAGNET INSULATION VACUUM = 14 + 5 SUBSECTORS

Insulation Vacuum sectorization:

Magnet vacuum barriers Jumper vacuum barriers Cryogenic line vacuum barriersQRL vacuum jacket

Magnet vacuum vessel

Q7R Q9R Q11R Q13R Q15R Q17R Q19R Q21R Q23R Q25R Q27R Q29R Q31R Q33R Q33L Q31L Q29L Q27L Q25L Q23L Q21L Q19L Q17L Q15L Q13L Q11L Q9L Q7L

sector 7-8L8 R7


Cryogenic Vacuum Cryogenic Vacuum System - AT/VAC tunnel System - AT/VAC tunnel

activitiesactivities Individual System Tests (during LHC installation)Individual System Tests (during LHC installation)

Leak testing of beam vacuum and cryostat vessel Installation & commissioning of vacuum instrumentation &

controls

HC testsHC tests Leak & pressure test of cryomagnet helium circuits

Collaboration AT, AB, TS Departments

DocumentationDocumentation Leak test procedures exist but details are missing The pressure test ‘owner’ needs to defined

ManpowerManpower Baseline activities – 1 technical engineer per Sector (VAC staff)

2 teams of 2 persons per Sector (S105) Intervention teams – depends on failure rates (S105 or VAC

staff). A ‘piquet’ service is not foreseen


Cryogenic vacuum Cryogenic vacuum system-leak testingsystem-leak testing

What needs to be leak tested ?What needs to be leak tested ?LT1) Welds between insulation vacuum & beam vacuum LT2) Elastomer joints between air & insulation vacuumLT3) Welds between helium lines & insulation vacuum

A) Low pressure leak testB) Final leak test combined with pressure test

LT4) Elastomer joints between air & insulation vacuum (W bellows only)

In theory, only the new joints created in the tunnel need to be leak tested, but LT3 globally tests ins. and beam vacuum systems.

HELIUM

HELIUM

INS. VAC

AIR

BEAM VAC

BEAM VAC. INSTR(MQ ONLY).

COLD BORE(S) &BEAM SCREEN(S)

HEAT EXCHANGER

CRYOSTAT VESSEL

MAGNET INSTR.

VACUUMBARRIER(MQ ARC ONLY).

MAGNET COLD MASS BUSBAR LINE(S).

SHIELD LINE(S).


LEAK TESTING DURING INSTALLATION & HCLEAK TESTING DURING INSTALLATION & HC eg IR8L INNER TRIPLET eg IR8L INNER TRIPLET


Cryogenic vacuum Cryogenic vacuum systemsystem

- leak testing sequenceleak testing sequence

Planned for Planned for success….success….

leak test beam vac & cryostat

leak test he lines (low pressure)leak test he lines (pressure test)

open W bellowsinstall MLI, close W bellows & pump

214 m

sector


Cryogenic vacuum Cryogenic vacuum systemsystem

- failure impact- failure impact

214 m

sector

As planned Failure without impact Failure with impact


Cryogenic vacuum Cryogenic vacuum system - failuressystem - failures

An ES (to be published) summaries vacuum failures An ES (to be published) summaries vacuum failures scenarios and their consequences.scenarios and their consequences.

To recover from a failure, time needs to be To recover from a failure, time needs to be allocated to – localise the fault, intervene, repair, allocated to – localise the fault, intervene, repair, return to test conditions, retest.return to test conditions, retest.

Examples:Examples:Replace a BPM button = 1,1,4,4,1 = 11 hrsReplace a BPM button = 1,1,4,4,1 = 11 hrsRepair an interconnect he leak = 4,1,8,8,4 = 27 hrsRepair an interconnect he leak = 4,1,8,8,4 = 27 hrsRepair a cold mass leak before cooldown = 4,1,Repair a cold mass leak before cooldown = 4,1,??,8,4,8,4Repair a cold mass leak after cooldown = 4,1,Repair a cold mass leak after cooldown = 4,1,??,8,4 + ,8,4 +

WU + CDWU + CD

Unforeseen interventions on the cryogenic vacuum Unforeseen interventions on the cryogenic vacuum system may be required due to other system system may be required due to other system failures eg busbar repairfailures eg busbar repair


Sector 8-1 leak testing –Sector 8-1 leak testing –the goalposts are the goalposts are

moving !moving !

The sector 8-1 will be installed with The sector 8-1 will be installed with discrete magnet strings. 6 out of discrete magnet strings. 6 out of every 8 magnet interconnects will be every 8 magnet interconnects will be performed.performed.

MB+MB+MB+SSS+MB+MB+MB

All leak testing could be left until the All leak testing could be left until the arrival and interconnection of the arrival and interconnection of the missing SSS (Dec 05). The missing SSS (Dec 05). The alternatives need to be discussed….. alternatives need to be discussed….. could these discrete strings be leak could these discrete strings be leak and pressure tested independently and pressure tested independently from the QRL (early startup, quality from the QRL (early startup, quality feedback, etc) ?feedback, etc) ?


SummarySummary

Leak testing of the cryogenic vacuum system Leak testing of the cryogenic vacuum system straddles the end of installation and the start of straddles the end of installation and the start of HC.HC.

Leak testing resources are foreseen via S105 – but Leak testing resources are foreseen via S105 – but based on planning v1.7based on planning v1.7

Documentation is not yet completeDocumentation is not yet complete Failures due to leaks, instrumentation and utilities Failures due to leaks, instrumentation and utilities

are possible during the HC.are possible during the HC. Leak failures which require magnet replacement Leak failures which require magnet replacement

and/or warming of cold magnets will have the and/or warming of cold magnets will have the biggest time impactbiggest time impact

There is no contingency in the baseline planning There is no contingency in the baseline planning for leak failuresfor leak failures

A vacuum piquet service is not (yet) foreseen A vacuum piquet service is not (yet) foreseen during HCduring HC

The Sector 8-1 leak testing sequence should be The Sector 8-1 leak testing sequence should be reviewedreviewed

lhc hardware commissioning review 11-13 may 2005 cryogenic vacuum system paul cruikshank for at/vac

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