August 16 th , 2013 LS1 Committee (LSC) L. Tavian on behalf of A. - PowerPoint PPT Presentation

August 16 th , 2013 LS1 Committee (LSC) L. Tavian on behalf of A. Perin & K. Brodzinski, TE-CRG L. Tavian, TE/CRG, LSC 16.08.2013 Page 2

Content Introduction: • the faulty equipment (QRL & DFBA) • The failure mode of compensators based on multi- • ply bellows. Status and repair plan of QRL compensators • Status and repair plan of DFBA gimbal bellows • Conclusions • L. Tavian, TE/CRG, LSC 16.08.2013 Page 3 Page 3

The faulty equipment (QRL Line C) Internal ply damage (S45, 14R4) External ply damage (S78, 10R7) Witzenmann DN100 multi-ply bellows compensators (4 plies of 0.3 mm) L. Tavian, TE/CRG, LSC 16.08.2013 Page 4

The faulty equipment (DFBA) Calorstat DN120 multi-ply gimbal bellows (2 plies of 0.2 mm) DFBAK shuffling module: Internal ply collapsing L. Tavian, TE/CRG, LSC 16.08.2013 Page 5

The failure mode (QRL as typical) He (P, T) crack Metallographic observations (EN-MME) A “virtual” leak (not seen during global leak test) Filling of the inter-ply space with time (3-4 years of operation) Pressure increase of the inter-ply space during warm-up  compensator collapsing ! Maxi pressure with conservative assumption: isochoric transformation and space initially at line conditions (P, T) Difficult to survive !! - CM: 1500 bar - Line C: 1200 bar Could be saved by - Line E & F: 120 bar non-isochoric - Line D: 20 bar process ! - Line B: 1 bar L. Tavian, TE/CRG, LSC 16.08.2013 Page 6

What are the operation indicators ? 1 Case 1: Ply scratches on the vacuum side: Sector 81 Sub-sector D 0.8 - Transitory vacuum break QRL vacuum [mbar] - Followed by permanent He leak (the 0.6 virtual leak is becoming a real one) 0.4 The “easiest” case: - 6 clear cases identified on the QRL 0.2 - 1 case on the QRL with only the He leak (no transitory vacuum break). 0 11/4/13 12:00 12/4/13 0:00 Case 2: Only plastic deformations or ply scratches on the He side: - No operation indicator ! - But the mechanical integrity of the concerned compensators is not acceptable  high risk of damage during the next pressure test or cool-down - Possible identification via: - Visual inspection (direct or endoscopic) - 1 case identified on the DFBA (at present) - Or systematic X-Ray campaigns - 1 case identified on the QRL (at present) L. Tavian, TE/CRG, LSC 16.08.2013 Page 7 Page 7

Content Introduction: • the faulty equipment (QRL & DFBA) • The failure mode of compensators based on multi- • ply bellows. Status and repair plan of QRL compensators • Status and repair plan of DFBA gimbal bellows • Conclusions • L. Tavian, TE/CRG, LSC 16.08.2013 Page 8 Page 8

QRL Line C compensator status QRL sub-sector A B C D E F G H I LT S12 X-ray LT S23 X-ray LT E S34 X-ray LT E S45 X-ray LT E S56 X-ray LT E S67 X-ray LT E E S78 X-ray E LT S81 X-ray Case 1: Damage compensateur identified by LT and confirmed by X-rays : Total (final) 7/560 (1.25 %) Case 2: Damage compensateur (still tight) identified by X-rays only: Total (provisional) 1/115 (~1 %) Leak-tested sub-sector (VSC) E: Extracted from the QRL X-rayed sub-sector compensators on Line C (CRG, MME) (Nominal rate: 1 per week) X-rayed sub-sector compensators on Line B, D, F (CRG, MME) X-ray still to be done (according to LSC #14 action) L. Tavian, TE/CRG, LSC 16.08.2013 Page 9 Page 9

QRL spare status At CERN • 4 DN100 spare compensators (nominal for line C) • 8 DN80 spare compensators (could be used in sub-sector E, F, G, H and I where • the flow is reduced) The 12 spares are under validation: leak tests to identify possible virtual leaks • (“booming” test) after 10 mechanical cycles. Additional spares. • Meeting with Witzenmann on 6 Aug’13 ( optional contact with BOA and Skodock) • 5 new spares (DN100): delivery scheduled on CW44 or 45 • New welding procedure more reliable with systematic “booming” test (at CERN) • Flange Flange 4 plies 4 plies 4 plies 2 rings 2 rings Present procedure New procedure L. Tavian, TE/CRG, LSC 16.08.2013 Page 10 Page 10

Repair plan for QRL compensators 2013 2014 Aug Sep Oct Nov Dec Jan CW 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 1 2 3 4 5 X-Ray S45 & S56 (CRG & MME) X-Ray of remaining QRL (~5.5 sectors) TBC (CRG & MME) CERN spare validation (12 units) (CRG & VSC) Delivery of new spares (5-10 units) New spare validation (5 units) (CRG & VSC) Compensator 1 T1 T2 T1 T2 T3 Compensator 2 T1 T2 T1 T2 T3 Compensator 3 T1 T2 T1 T2 T3 Compensator 4 T1 T2 T1 T2 T3 Compensator 5 T1 T2 T1 T2 T3 Compensator 6 T1 T2 T1 T2 T3 Compensator 7 T1 T2 T1 T2 T3 Compensator 8 T1 T2 T1 T2 T3 T1 Mechanical preparation (CRG) Final order and slot allocation T2 Compensateur integration/welding and leak test (CRG & VSC) to be refined and validated in T1 Screen and MLI interconnect integration (CRG) collaboration with the central coordination (EN-MEF) T2 External envelop closure/welding (CRG) T3 Individual and global leak test (VSC) T1 (Team 1): 2 persons (2 technicians) T2 (Team 2): 2 persons (1 welder + 1 mechnanics) (TE-VSC support to be added) T3 (Team 3): VSC support L. Tavian, TE/CRG, LSC 16.08.2013 Page 11 Page 11

Content Introduction: • the faulty equipment (QRL & DFBA) • The failure mode of compensators based on multi- • ply bellows. Status and repair plan of QRL compensators • Status and repair plan of DFBA gimbal bellows • Conclusions • L. Tavian, TE/CRG, LSC 16.08.2013 Page 12 Page 12

DFBA gimbal bellows status Endoscopic inspection through line M interconnects Dates Bellows status Dates Bellows status Secteur DFBA IP DFBA IP Découpe M Inspection Découpe M Inspection Lower Upper Lower upper DFBAB 1R 07-Aug 08-Aug ok ok 1-2 DFBAC 2L 19-Aug DFBAD 2R 13-Aug 14-Aug ok ok 2-3 DFBAE 3L 19-Aug DFBAF 3R 21-Aug 3-4 DFBAG 4L 26-Aug DFBAH 4R 28-Aug 4-5 DFBAI 5L 31-Aug DFBAJ 5R 20-Apr 18-Jul ok ok 5-6 DFBAK 6L 18-Jul ok damaged DFBAL 6R 25-Apr 18-Jul ok ok 6-7 DFBAM 7L - 26-Jul ok ok DFBAN 7R 15-Jun 02-Aug ok ok 7-8 DFBAO 8L - 02-Aug ok ok DFBAP 8R - 25-Jul ok ok 8-1 DFBAA 1L 07-Aug 08-Aug ok ok Thanks to MSC Present statistics (total 32 bellows): 1/20 (5 %) for early opening Spare status: 2 spare bellows at CERN (still under search) of M sleeves ! Meeting with Calorstat foreseen end of Aug’13 L. Tavian, TE/CRG, LSC 16.08.2013 Page 13 Page 13

Repair plan for the DFBA gimbal Repair work could be eased if bellows can be replaced by rigid assembly • (bus-bars could remain in place)  thermo-mechanical analysis under progress (conclusion by end Aug’13) Scenario 1: In-situ repair • Very tricky access issue • Very risky operation • No repair time defined yet • upper bellows Lower bellows Scenario 2: Workshop repair • Mechanical and electrical (112 splices from 13 kA to 600 A) disconnection of the • shuffling module  ~2-3 weeks (MSC, MME, CRG, HE) Transport to surface (HE) • Repair  ~3 weeks (rigid assembly) to ~6 weeks (new gimbal bellows) (MME) • Transport to tunnel (HE) • Reconnection of the shuffling module  4 weeks (MSC, MME, CRG, MPE, VSC, • ABP-SU) Total : 9 to 13 weeks (2 to 3 months)  Resource availability to be confirmed ! • L. Tavian, TE/CRG, LSC 16.08.2013 Page 14 Page 14

Conclusion QRL compensators: • 8 damaged compensators identified at present on line C including 1 deformed and • tight (identified only via X-ray). Line C X-ray on the remaining sub-sectors (+150 kCHF) is highly recommended to • identify all the cases 2  impact if a leak appears at 80 K during next cool-down: 200 kCHF of LN2 + 3 months of delay for the concerned sector. The known case repair could be completed by end 2013  to be validated by the • central coordination. Additional mechanical analysis is underway to evaluate the failure risk of Line B, D, • E and F compensators (C. Garion). DFBA gimbal bellows: • 1 damaged gimbal bellows identified at present by endoscopic inspection. Inspection • completion by end of Aug’13 No solution yet for in-situ repair. • Workshop repair: first rough estimation of 2 to 3 months per shuffling module • depending on repair type (rigid or not)  resource and schedule still to be consolidated. Quid of all the other multi-ply bellows operated under cryogenic conditions • (especially under LHe I, LHe II, SHe @ 4.5 K)? Under investigation for the DSLs • L. Tavian, TE/CRG, LSC 16.08.2013 Page 15 Page 15

Acknowledgments Many thanks to all the Groups which have collaborated to the treatment of this new issue: (By appearance order) • EN-MME (X-Ray; metallographic analysis, DFBA repair investigation) • TE-VSC (global and individual leak tests; mechanical calculation on bellows) • EN-MEF (central coordination and schedule) • TE-MSC (opening of line M sleeves) L. Tavian, TE/CRG, LSC 16.08.2013 Page 16 Page 16