PU Jack Taskforce Kick-off Meeting
Minutes
PU Jack Taskforce Kick-off Meeting
PU Jack Taskforce Kick-off Meeting (15 June 2023) · Indico (cern.ch)
Present: Stefano Sgobba, Philip Schwarz, Jeremie Bauche, Michael Lazzaroni, Michel Noir, Mateusz Sosin, Patrick Bestmann
Intoduction & Motivation
Patrick presented the Introduction, including the history of the PU pads since 2003. The different failure modes have been shown as well as the measures taken during LS2. Apart from the development of a mechanical alternative which is way too expensive, no other development was undertaken since the LS2.
With the failing PU inserts in the LHC Triplet jacks the problem gets another urgent character and BE-GM proposes to coordinate and bundle the efforts while the responsibilities remain unchanged.
In particular:
- Coordinating Tests & Research with EMPA and A+P
- Centralizing purchase and tests at CERN
- Coordinating a tracing strategy
- Coordinating the installation of monitoring jacks as pre-warning
So far, a contact with the EMPA institute was established, targeting a more detailed analysis and understanding of the problem and -if possible- the development of a more suitable version of PU pads. They are also proposing the characterization of the used pads today and a FEM analysis to better evaluate the situation and develop a precise hardware specification. Today the specs are limited to dimensions, hardness and casting process.
The supplier A+P would be a very important strategic partner in the development as we need an industrial supplier. They agreed for a first meeting next week to define a strategy, knowing that the volume of our PU pad orders is tiny for their scale. We need to keep them interested and at the same time drill down to the manufacturers expertise.
Next actions
Patrick showed a list of proposed actions:
- Production & installation of monitoring jacks
- Purchase of PU pastilles for NA
- Developing reinforced specifications with EMPA and A&P
- Defining full test procedure and acceptance criteria @ CERN
- Study solutions for HL-LHC motorized jacks
- Clearing storage & enhance tracing
- Investigate status of TI2 and TI8 (possible action for LS3)
- Establishing long-term maintenance intervals
Discussion
Patrick pointed out that the TI2 and TI8 transfer lines should be closely looked at as the lifetime based on the SPS experience is coming to the end. Jeremie pointed out that during the discussions for the LS2, at least in the SPS it was clear that one needs to count with a systematic exchange every two Long Shutdowns (10–12 years).
Patrick asked for the next purchase as the North area will need 300 pads for the YETS23-24. BE-GM needs also pads for testing and the spares from MSC are already all installed in consolidated jacks. For the LS3 a much bigger quantity is needed, but one might wait two more years before the purchase to see if the research is leading to a better product.
ACTION: BE-EA, TE-MSC, BE-GM to confirm needs for a rapid purchase delivered before YETS23-24
Patrick raised the question of reinforced tracing of the PU-Pad batch inside the jacks and the position of the jacks. Philip reminds that here the ownership is important to get a coherent process. Patrick proposed to give serial numbers to the jacks and to trace their position in INFOR. Jeremie reminds that the jack is technically not attached to the magnet but the slot and so the layout would be more adapted.
ACTION: TE-MSC and BE-GM to propose a tracing strategy for all PU jacks
The need of around 70 jacks bodies in addition to the pads raised the question of a digital model and drawings for a fabrication. We will need anyway the model for the FEM analysis, and Michael proposed to take care of the models and fabrication drawings.
ACTION: BE-EA to create model and fabrication drawings based on the existing scanned drawings
For the monitoring jacks we propose to install 5 units in different conditions inside different machines. Stefano suggested installing a bigger quantity in order to be able to make intermediate mechanical tests which will be destructive.
ACTION: BE-EA to build 10 monitoring stands for the jacks