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LEAK TESTING in SMACC

LEAK TESTING in SMACC. Cold vacuum system recall Phase 1, 2 & 3 VSC activities Resources, Infrastructure Still to do......... Paul Cruikshank on behalf of TE-VSC. LHC arc cold vacuum systems - recall. LHC arc cold vacuum systems - recall. LHC arc cold vacuum systems - recall. QRL

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LEAK TESTING in SMACC

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  1. LEAK TESTING in SMACC • Cold vacuum system recall • Phase 1, 2 & 3 VSC activities • Resources, Infrastructure • Still to do......... • Paul Cruikshank on behalf of TE-VSC Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  2. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  3. LHC arc cold vacuum systems - recall Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  4. LHC arc cold vacuum systems - recall Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  5. LHC arc cold vacuum systems - recall QRL cryostat Vacuum barriers Jumpers LHC magnet cryostat Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  6. LHC arc cold vacuum systems - recall Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  7. LHC arc cold vacuum systems - recall LHC cryostats were designed with DN100 ISO-K ‘pumping’ ports at vacuum subsector extremities. 300l/s turbos can be installed (and removed) without breaking vacuum Tunnel equipment: 63 m3/hr mobile primaries – 20 units 300 l/s mobile primaries – 40 units MS Leak detectors – 20 units Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  8. LS1 leak test support & consolidation - cold vacuum - typical activities in an arc time window before train Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  9. LS1 leak test support & consolidation - cold vacuum - typical activities in an arc time window before train 50 % 10% 10% 20% 10% IS Workload Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  10. Phase 1 leak testing • Cryostat still closed & under vacuum • Tightness status of arc IV and BV • Under vacuum, > 80 K, • He pressure constant, • 3 days/arc • Longitudinally localise known helium leaks (see later) • Insulation Vacuum degradation to assist warm-up • Insulation vacuum venting to tunnel air • RF ball test (see C.Garion presentation) Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  11. Phase 1 - activities 22 internal He leaks to solve 2 leaks > 10-4mbarl/s , 12 leaks > 10-6mbarl/s @ RT Highest priorities are: 3-4, A27L4, coldmass circuit – very large leak should be localised quickly 4-5 QRL SubS B, line C – will need dedicated intervention scenario with CRG Note: - the LHC operates with these leaks; - the 2 biggest leaks weren’t present at RT after welding and PTest; - for many of known leaks, search in 2006 & 2007 was not successful, but they have not evolved. - previously eliminated leaks a) at welds - incomplete, inclusions, porosity, LME, etc b) others - shocks, inclusions, false arcs, ultrasonic vibrations, etc Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  12. Longitudinal leak localisation - which IC to open? An under vacuum leak test in molecular flow conditions, using turbomolecular pump, mass spectrometer leak detector and helium as tracer gas. Assume linear conductance of cryostat, so C  1/L (with & without MLI) For S >> C1 or C2: q1/q2 C1/C2 L2/L1 For LHC cryostats, S ~ C so apply correction for effective pumping speed Experience shows method is not perfect to one interconnect! Additional adjacent interconnects were often opened to localise the leak. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  13. Phase 1 - Leak testing • Known internal leaks: • Re-measure the known internal helium leaks before venting: • Cryostat under vac, temp > 80 K, He pressure constant, • Two 8 hour days per known leak with above conditions. • Need CRG support to pump and pressurise circuits. • Leaks in the same arc can be treated in parallel • After venting @ RT, MSC to open 5 priority interconnects/leak (1 day). • VSC will need pressure ~ 6 bar in cold mass &c’k circuit for 2 days. • Co-activity with ‘special intervention team’ needs to be co-ordinated. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  14. Clamshells – recall • ~20 diameters and diameter combinations for LSS standalones • NBR, polyurethane, silicone rubber, metal+mastic Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  15. Clamshells • Support rings for asymmetricalmodels • Sealing on non-perfect tube surfaces: • alcohol for smalldefects to allow a E-8 mbar.l/s residual signal to reduce to E-10 range • mastic for bridging gaps • vacuum grease for intermediatedefects (e.g. surface scratches) • Samespace as orbital welding machine Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  16. Phase 2 - Leak testing in train • Leak test all new welds before W closure: • Validate beam vacuum – new PIMs • Validate 100% M welds with clamshell – 60 IC/week • Validate 100% other new welds with clamshell (new magnets, etc. ) • Treat non-conformities with MSC special intervention team (& MME) Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  17. Phase 2 - Clamshells on M • Technical challenges: • ~ 10’000 M welds to clamshell • Want to develop & validate a ‘long clamshell’ to test both M welds • How to supply He into 214 m cold mass volume (also pump out of air)? • Baseline - via one unwelded M sleeve • Special interface tool to develop – modified clamshell, • Local pumping system and backfill (~ 6 m3) from He bottle, • Option 1 - via M2N hose – must be cut & rewelded – 13 positions/arc • Option 2 - via QRL – when available (R2E, cryo maintenance) • Any ‘holes’ in 214 m cold mass envelope will block clamshell test (& train) • eg M lines, N connection box at SSS, jumper, diode, DFBA • Second pass required after final M sleeve is welded • Expect between 10 to 50 leaks on M welds (installation statistics). Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  18. Phase 2 - LT Support - SIT & DFBA • Special intervention team • Cryomagnet exchange (MB & SSS) = V, X, E, N, C’, K lines • Y repairs = X, CCryostat, diodes, Q6 He level gauge, Q1 braids, • Clamshells and special tools exist • Dedicated VSC team • DFBA • Main splices, lyras, flexible hoses - 1.9 K volume of DS • Pigtails – 4.5 K bath – independent closed He volume • DFBAK HCM removal – above plus jumper & LCM interconnect, • Clamshell geometries to develop, beam vacuum equipment to remove. • Dedicated VSC team(s) IV & BV • Other challenges: • Closed volumes can be pumped and backfilled (& pressurised) with He • Open volumes must be injected with He just prior to welding then clamshelled on-line. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  19. Phase 3 - Leak testing after W closure • Evacuate & global leak test all insulation vacuum subsectors after W closure: • Evacuate with mobile groups • Validate cryostat envelope – W, DN200, new magnets, reclamping, etc • Validate internal helium circuits at 1 bar – M, N, new magnets, Y, etc. • Need helium via QRL, all headers of sectors closed • A closure rate of 60 IC/week gives ~ 12 vacuum subsectors in parallel • Validate internal circuits after P.Test at 50% of design pressure • Treat any non-conformities with MSC special intervention team & CRG • Duration of 2-3 weeks/vacuum subsector – expect 0 - 3 internal leaks/arc. Leak imported from phase 2: Clamshell not possible, Clamshell poor sensitivity, Interconnection damage Leak opened by outgassing or Leak opened by P.Test Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  20. Documentation • Procedures: • Existing procedures for arc & LSS leak testing • Existing maintenance procedures for pumping groups • Existing procedures for vacuum degradation • Existing procedure for relief spring installation • Need to produce generic procedure for clamshell tests • Data storage: • Use of WISH tool to define status of leak test tasks • Create NCR in edms in case of leak and attach to WISH step • Maintain test/activity details in VSC Excel files – who, what, when, • Team leaders in the tunnel send daily reports • Maintain overview table of subsector status, • List of known He leaks – NCR in edms Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  21. Resources summary • VSC Staff • 2 Engineers, 1 Fellow, 5 technicians • Vacuum support contract S133 • 14 industrial support staff required for ins vacuum system (& B.Vac) arc activities in 2013, then reduction will depend on agreed planning. • FSU support (FSU-TE-09,S145) • 0.5 additional workshop mechanic for PIM activity (+0.5 for expts) • Polish collaboration • 6 eng/technical staff for cold beam vacuum interconnect QA • inspection at opening/closing, beam vac temporary protection, • endoscopy at PIM cutting positions • install protection shells •  All will require safety training, access training, safety equipment.......... Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  22. Infrastructure needs • Bungalows/office space: • Office space at even points only (shared with VSC-LBV) • CERN wireless intranet & telephone • QA, doc, tech meeting, storage of sensitive equipment • Polish Collaboration – all equipment provided by VSC • cars, bikes, trailers, safety equip, PC, cameras • PEFRA; • 3 dedicated VSC Pefra at each even point from tunnel access date. • for mobile pumping groups, detectors, tooling – shared with LBV. • Dedicated VSC/EIV logistics zone on surface: • At each even point, 5m2 storage & 14 bicycles & 5 trailers. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  23. Still to do in 2012 • Optimise phase 1, 2 & 3activities with SMACC & LS1 coordination • Complete inventory of SIT & DFBA tasks • Continue procurement of additional clamshells • Develop tooling for helium injection at unwelded M sleeve. • Expand, integrate, equip & train IS, FSU, & PL teams • Create ECRs • Complete QA procedures • Complete PPSPS, Safety Folder, DIMR, • Other? Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  24. Thanks for your attention. Paul Cruikshank TE/VSC Leak Testing in SMACC 3rd LHC Splice Review, 12-14 Nov ‘12

  25. VSC Consolidation – Insulation Vacuum Minor task Paul Cruikshank LS1 Preparation - Insulation Vacuum 20th June 2012

  26. VSC Support – Insulation Vacuum • These projects will require extensive VSC leak testing/technical support • Are they already in ‘PLAN’ ? Paul Cruikshank LS1 Preparation - Insulation Vacuum 20th June 2012

  27. VSC Consolidation – Cold Beam Vacuum Due to synergies, some VSC resources are shared between insulation & beam vacuum arc activities Low priority Paul Cruikshank LS1 Preparation - Insulation Vacuum 20th June 2012

  28. VSC Consolidation – Insulation Vacuum (not in tunnel) Activities outside tunnel are also added to ‘PLAN’ to have overview of all resource needs.......... Paul Cruikshank LS1 Preparation - Insulation Vacuum 20th June 2012

  29. Clamshells on M lines (1) • Why weren’t M line clamshells adopted during LHC installation ? • Many ‘holes’ in 214 m cold mass chain (late magnets, NCR, ELQA, etc) – late clamshell tests would stop series W closure. • Masked time was available to treat leak non-conformities after W closure. • Was less leak testing parallelism per arc and per sector. • Why adopt M line clamshells for splice consolidation? • Early feedback on weld quality in advance of W closure • Little masked time available to treat leak non-conformities in global test • Whole arc is closed in 4 weeks – twice rate of LHC installation peak • (Most) leak identification & repair is removed from critical path • In proposed LS1 planning, clamshells can be performed in masked time. • If no M clamshell test – foresee several additional NC weeks in global test Paul Cruikshank LS1 Preparation - Insulation Vacuum 20th June 2012

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