ID week 27 th of April 15 C3F8 cooling- Compressors & C3F8 status O. Crespo-Lopez EN/CV

Current status Run conditions: – Leak rate: 1.72 kg/day – All loops open – Pressure stability in the racks: ok no drop since the start – Air compressed: 46 compressor start-up in 24h (leak to be checked)

Compressors compressorhoursstatus Next maintenance Maintenance type remark Not runningIn h2.500 h Not runningIn h2.500 h RunningIn h5.000 hTo be done in June RunningIn h5.000 hTo be done in July Not runningIn h5.000 h RunningIn 800 h2.500 hTo be done in June 79140Running (master) In h hTo be done in June with Haug (3 days of work) Compressors maintenance: h (≈3 months of run): replacement of the outlet filter h: replacement of the 2 nd stage O-rings + outlet filter h: big maintenance with replacement of all the mechanical parts

Cooling plant in general Action list for the next technical stop without stop of the plant: Preventive Maintenance – Maintenance on the compressors & 7, these ones will be stopped one by one for (WARNING: during the swap of the compressor 7 master there is a risk to stop the plant) – Filling of the plant – Replacement of the liquid filters – Leak search in the racks in UX15 (side compressed air and C3F8) Specific corrective maintenance – Replacement of the electrovalves to drain the water on the air compressors Fluid – C 3 F 8 CERN: kg – New order on going CERN on June) – New 5 years contract for September 2015

specific point Liquid condenser – During the re-commissioning of the plant it has been observed that the condenser was not able to fully condense and to sub-cool the C 3 F 8. – New problem on the condenser? Clogging? Apparently during the last LHC run in 2012 the system was already running in these conditions. – Currently to be able to condensate and maintain the 15 bars we need some mixed water flow inside the subcooler of the tank. – This situation is clearly not a problem for the operation of the plant but we are looking for a new condenser in view to have the good material Proposal – We are waiting several offers from suppliers – As soon as we will find the good material we will circulate an Engineering Change Request for acceptance – Once the new CERN we will prepare this one to be ready for replacement ASAP – The best way will be to replace this one during Christmas shutdown to be able to fully test the new behavior.