Cutting and welding First internal LHC Dipole Diode Insulation Consolidation - PowerPoint Presentation

Slide1

Cutting and welding

First internal LHC Dipole Diode Insulation Consolidation

Review

10 Oct 2017

G. Favre

/

A.

Amorim

Carvalho

Project overview

1232 diodes to be consolidated

2464 covers to be opened and re-welded

30 weeks (W9 to W39 2019) for cutting operations

30 weeks (W22 to W52 2019) for welding operationsIntervention team Covers cutting (and covers machining when required): 6 mechanics (EN/MME)Covers tacking and re-welding: 6 welders (EN/MME)Welding quality control : 2 technicians for welding inspection (notified Body)Traceability: 1 technician BE/OP (2 technicians/50% each) 1 administrative student (as LS1) new requestProject management : 1 engineer (EN/MME) as of now

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Project overview

Work organisation

Single train

Work on 4 fronts in parallel (4 interconnects)

6 efficient working hours per day10 diode containers opened and closed per dayDrawingsWelding map: LHCMB__S0268Covers: LHCMB__S0130 & LHCMB__S0130 131Diode container: LHCMB__S0129Tee : LHCMB__S012810 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Info/lessons learned from the series prod.

Welding process used by the 3 manufacturers

(Alstom,

A

nsaldo, Noell)TIG manual weldingwithout filler metalWelding qualifications: complete for Alstom (WPQR, WQ), info. not found for Ansaldo&NoellWeld throat depending of the manufacturer: a=2 for Ansaldo&Noell, a=1 for AlstomQ: What was the throat thickness really obtain for the series production ?Controls : Visual inspection, pressure and leak tests

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MMEWPQR Alstom

Info/lessons learned from the previous

consolidations

(dipoles & quadrupoles

)

Covers cuttingOrbital cutting machines Axial machining better than radial machining (less lips consumption) 10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

RadialAxial

One set available TE/MSC

Info/lessons learned from the previous consolidations

(dipoles & quadrupoles)

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MMENominal position

1st cut: -2.5 mm255 dipoles already opened 1 time2nd cut: -5 mm3rd cut: -7.5 mmUnchanged internal volume

Info/lessons learned from the previous consolidations

(dipoles &

quadruoples

)

After few cuts (3 ? TBC), the groove in the covers has to be re-machine. In some cases covers may have to be changed.10 Oct 2017First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Info/lessons learned from the previous consolidations

(dipoles & quadrupoles)

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

In case of new cover installation, the internal volume of the diode container will be affected. The compatibility with the insulation has to be checked (enough room?)

w

ith new covers

Info/lessons learned from the previous consolidations

(dipoles & quadrupoles)

Covers welding

Manual welding

Necessity to distribute the gap before welding (ovalization facing the Tee necking, gap up to 1 mm locally)Depending of the case necessity to use filler metal Diode container dimensions w.r.t nominalVariation of the internal diameter (gap up to 1 mm)Variation of the thickness along the diameter (i.e. from 1.6 mm to 2.2 mm, nominal 2 mm)

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME1 mm

Open

points

(1/2)

Define the weld size (throat)

2 mm difficult to reach (even with the use of filler metal)FEM to be done to define the minimum throat acceptable (see next slides)Chose the appropriate welding method Option 1: Manual welding with or without filler metal (solution used to date)PRO: Less demanding with respect to the joint preparation (possibility to accommodate significant gaps, and defects)CONS: Reproducibility of the result depend of the welderOption 2: Orbital welding without filler metalPRO: ReproducibilityCONS: Demanding regarding the joint preparation (limited gap allowed)CONS: use of filler metal would be (very) difficult

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Open points

(2/2)

Check the effect of the weld on the new

electrical insulation

Max. temperature reach during weldingDiminution of the internal volume in case of new cover installation10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Numerical assessment

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

A. Amorim Carvalho1mm ?Norm EN 13445: 3 Unfired Pressure Vessels Weld case (joined lips) is not compliant.Proposal (with acceptance from HSE):Annex C: Design by analysis – Method based on stress categoriesAnnex T: Design by experimental methods of the weld in an equivalent structure10.5

1st cut3

rd cut5th cutStudy objectives:Minimum cover thickness?Minimum size of the throat a?

Pressure vessel + cryogenic applicationComprehensive approach needed.

Numerical assessment

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

A. Amorim Carvalho1mm ?

Local stress concentrationLinearization of different paths: analysis of the worst case scenarioAssessment to be performed for the configurations:1st cut (- 2.5mm) & 5th cut (- 12.5mm)Considering different weld sizes: 0.5mm, 1.0mm, 1.5mm and 2mm

Numerical assessment

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

A. Amorim CarvalhoImpact of the gap between the cover and tube will also be assessedGap can go up to 1mm

Workflow including QC steps & traceability

Covers cutting

Engraving of covers

to keep the traceability w.r.t. the diode container

Dimensional control of the diode containers: ovalization, wall thickness, number of cuts already done in the past, etc.Covers machining (when required) : level of activation? marching in RP workshop bldg. 109? HSE input requiredDiode consolidation with dedicated tests & controls and traceability (electrical, cleanliness, pictures of the inside, etc.) Green light for covers re-weldingCovers installation: gap distribution and tack-welding Covers welding: welding parameters will be registeredQuality control of the welds: visual inspection (video registering)Production of witness samples: control of the weld size and compactness (micrographs)Local leak test using clamp shell tooling

10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Next steps

Welding and cutting tests on representative samples

Validation of the weld throat thickness with HSE

Select the appropriate welding method (automatic or manual)

Qualifications: cutting & weldingDefine the acceptance criteria for the welds acceptation (visual inspection)10 Oct 2017

First internal LHC Dipole Diode Insulation Consolidation Review

G. Favre EN-MME

Procurement of the equipment for the series prod.Procurement of covers spares…

Thanks for your attention

Questions?