QRL closes the circle

Installation began on the last sector of the cryogenic distribution line (QRL) about three weeks ahead of the revised schedule. Besides the recent start on sector 1-2, two other sectors are still being installed. QRL installation is expected to be complete by October.

Installation of a single sector involves placing 325 elements and making almost 2000 internal welds. The average time now needed for installing each sector is about four and a half months, compared to the 11 months it took to install the first sector. 'Now people are very well trained and they know they can go fast with a good quality,' said QRL project engineer Germana Riddone. As proof of that quality, QRL technicians can look at the results of the latest pressure test on sector 5-6. There were no internal leaks in the sector and out of 1000 external interconnections there were only three leaks. The QRL project was hampered early on by technical problems in sector 7-8, the first piece to be installed. The installed elements were cut, repaired and reinstalled by CERN and now everything is back on track.