2. Preparation of the activities for the LHC Long Shutdown 2
Section Operation

3. LS2
Maintenance
Maintenance plan must be done (3.3kV motors, Compressors, instrumentation, Charcoal, ORS, electrical cabinets, Vacuum…); All plants LHC/Atlas/Cms
quid of Dryers
cleaning of ORS and HP pipes (LHCA_Linde)
Dedicated Maintenance for Cold Compressor cartridges, Mapag and associated instrumentation.
QRL X-ray after warming up and repair if necessary
Leak check of all QRL valves Line C to B/D and repair if necessary
QUI/RM valve leak check and repair if necessary
P4 helium guard leak & P18 VLP to be solved
Helium guard: Leak test of the circuits and individual leak research on all the components (O-ring for valve shaft, O-ring for valve or instrument flanges)
TE-CRG-OP_GF

4. LS2 Consolidation/improvement Mechanical hardware
16 Valves plugs to be exchanged on QRL_CV920
QUI U tube valves to be motorized
RM R1, QUI-P2… must be made operational
Switchable cooling water filter for cold boxes
Electrical/instrumentation hardware
Cold compressors Electrical cabinet upgrade to avoid P2 communication problems
Upgrade of AMB/VFD to end cold compressors refurbishing
Instrumentation to upgrade (TT cold comp, LHE level sensors TT turbines…)
Controls
Atlas: Migration to CPC6
Improvement of control system to increase availability (Majority voting, Alternative sensor, Safety chain upgrade…)
PVSS upgrade
PLC update to M580 to be ended
TE-CRG-OP_GF

5. LS2 Consolidation not yet approved
Outlet turbines TU2 & TU4 on Linde LHCA cold boxes: add sectorization valve
QUI: sectorizations valves
P2 and/or P8, LHCA AL: major compressor station upgrade
LHCA (AL/Linde): electrical cabinet refurbishing
Possible co-activities and associated issues P4
Upgrade of LHCa/b to fit with new RF cavities scheme P6
Commissioning of the re-liquefier
Atlas/CMS
Civil engineering to prepare HL-LHC
LHC
Pressure tests
TE-CRG-OP_GF