commercial

1. Experiences at MKS 3 with different sealing types machined Leaks @ commercial Rf connector CF 16

2. Diamond shape gasket Specialty Large gap for rinsing and degreasing ; large “leak seeking” grooves for flushing Guiding “nose”

3. P Michelato INFN Milano Part of CARE Wp investigations

4. Problems we found Part 1 Problems observed CF CF system - Tolerances - Supplier of commercial systems have different tolerances from supplier to supplier - „Hand made“ beam pipe to Cf 35 vary in tolerances - Tolerances in Cu gasket (up to 30 % leak rate on some „batches“ observed - Hardness of Cu Al system - Tolerances in height not relevant for Tightness - Actually hardness loose tolerances HB>60  distance flange to flange varies Diameter - Angle of knife edge compression distance flange to flange varies

5. Forces on gasket Soft Seals

6. Problems we found part 2 CU Conflat - „0 to 0“ distance leaking - Large gap flange to flange ( Groove not deep enough) leak under non axial forces - Gasket to thin leaking - Gasket OD to small needs to be re tightened down to 0 to 0 distance - CU too soft needs retightening (CF soft CU  floating under compression) - Big stainless flange fast T variation leaking • ALMg SI 05 • - Distance 0-0 leaking • Large gap ok • Material too hard No floating no spring loading • (compression forces always at the limit plastic to elastic deformation spring loading effect) • - Gasket OD too small limited leak tightness during T variation • -Material too soft • no defined distance • limited leak tightness due to larger surface( reduced forces on sealing surface) • Harder material • high forces no spring loading effect  leaking during cool down