Figure 1. Figure 1. QXL pipe element lifting and alignment. Credits: Michele Sisti (right and top left), Antonio Perin (bottom left) / CERN

By Michele Sisti (CERN)

The first phase of the installation of the new HiLumi LHC Cryogenic Distribution Line (QXL) in the underground galleries at Point 1 was completed at the beginning of February.

This first phase of the installation, called 1A-1, concerns approximately 150 m of straight line located in the HiLumi LHC underground gallery UR15 at LHC Point 1.

Sixteen multi-header straight modules, called ‘pipe elements’ and designed and manufactured in Poland by the contractor KrioSystem, were first lowered to the new underground galleries, lifted to the vault of the gallery and attached to pre-installed supports. The pipe elements were then carefully aligned by the contractor, and their position was validated in collaboration with the CERN survey team (BE-GM).

All process lines were then welded at the interconnection points, with 150 welds completed and thoroughly inspected in collaboration with the CERN welding inspection team (EN-MME) over a period of 12 weeks. Each weld was individually leak-tested and, after installation of the multilayer insulation and thermal screens, the vacuum envelope of the interconnections was closed with a final weld.

The successful completion of this phase has allowed the validation of the installation methods and procedures, paving the way to the subsequent phases of installation, which have already started at LHC Point 5.

Figure 2. Welding at QXL interconnection points. Credit: Michele Sisti / CERN

Figure 3. Delivery of QXL pipe elements at CERN Point 5. Credit: CERN