AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40
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Message ID: 418     Entry time: Thu Jul 13 08:46:44 2023
Author: TD 
Subject: Replacing wire seal 
09.30 CARME chamber status

      Edwards scroll pump ON
      Edwards Speedivac valves #1 & #2 OPEN
      VAT gate valves OPEN

      Re-connect Leybold Pirani gauge to local display/control
      CARME chamber pressure 2.4mbar

      Scroll pump should be able to achieve < 0.1mbar - indicates significant leak

      Davide will first check bolt torques for all flanges opened during most recent vacuum cycle

12.05 Additional torque did not resolve problems
      ML test COF600 seal with isopropanol and observed increased chamber pressure

      Will open COF600 seal after lunch

13.55 COF600 seal removed - one section marked by Kapton tape shows some distortion and a burr on the inner diameter - see attachments 1 & 2. 


      ML speculated that perhaps the seal was lightly too long and a section of circumference was forced outwards?
      Vacuum surfaces cleaned with isopropanol and tissues - red/brown discoloration probably indicating copper observed

14.30 New COF600 seal installed, flanges closed, bolts finger tight, bolts then systematically torqued in small increments 

      COF600 torques finger tight, 10, 20, 30, 40, 60, 80, 100, 120, 140, 160Nm x2
      DN100 flanges doenstream finger tight, 8, 16, 24Nm

16.40 Start scroll pump and slowly rough chamber

18.00 Roughing CARME chamber pressure flatlines c. 30mbar indicating a large leak.
      ML ran some isopropanol around COF600 flange and observed response in roughing pressure of c. 0.2-0.3mbar at c. 30mbar which appears to confirm COF600 is leaking.


      
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