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HL-LHC BPM Project. Technical Meeting CERN-BINP #2
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Europe/Zurich
1. Teleworking Situation in BINP
Only 70 % of workshop personnel work on-site
The scientific staff works mostly remotely
The communication with technologists and designers is therefore limited.
2. Design details discussion
a. Question about the bodies LHCBPMQST_B0009 and LHCBPMQST_A0008
The suggestion is to produce BPMs' bodies with additional welding joint as shown (red) in the picture below:
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the left side where the walls are thin to avoid possible leaks
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additional forging of the small part will be done.
Gerhard's comment: material comes already 3D forged: possible until L/D factor 3. Extra welding will complicate manufacturing.
Alexander: electroerosion of this length is not possible in BINP but can be subcontracted. In case the proposal of the additional weld is accepted, electroerosion can be done in-house.
b. For the ConFlat machining, BINP has experience with different machining methods providing good results. Instead of a nose-ball mill of small diameter, they use the boring head with automatic (or CNC controlled) transversal feed (I found YouTube videos explaining similar tools: here and here). BINP can provide CERN a sample for inspection.
c. Assembly LHCBPMQBC_A0010: Alexander asks if D2 cooling nozzles can be replaced by the subassembly of a thin wall tube and a small sheet metal flange? Then this subassembly is welded to the body. BINP will provide a detailed sketch for discussion.
d. Part LHCBPMQBC_A0001: Is it possible to increase diam. 12? Is it also possible to increase the diameter of the cooling channel? This would simplify the drilling.
--> BI needs to check it with the design office.
3. Quality Assurance:
a. BINP workshop is certified by ISO 9001:2015
b. Welders have the necessary qualifications, and certificates can be provided.
c. BINP welding drawings contain WPS in the form of tables (example attached).
d. CERN requests that welding parameters be defined on test pieces, which shall be sent to CERN before the pre-series' welding starts.
e. Dmitry will provide a WPQR example to Alexander.
4. Quality control
a. CMM in the BINP workshop is ok to measure all the parameters.
b. Alexander: Leak test level is not possible with rubber connections (10^-10)
Gerhard: commented that if the rubber joints don't see the He, it should be ok. It's a question of the procedure. For DN16 flanges, we will use copper seals, LHC type (soft copper seals are not acceptable; CERN will provide the seals).
Alexander asked to specify seal type and He injection duration for the leak test (for how long is the He is applied).
Agreed that the procedures for how exactly the measurement and other operations will be discussed and made --> action all.
5. AOB
15 warm BPMs can be added to the scope. The addendum should be prepared as schedule and scope will change.
Next meeting: 26.11 --> 10AM.
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