Pumpdown / Venting if IP is separated from DPS

  • Don't do this without asking for permission first

  • Make sure that the DPS is separated from the IP (upstream valve "VVPG:LI20:3172" and downstream valve "VVPG:LI20:3250" should be closed; the window in a valve "VVPG:LI20:3208" should be open). A left click on the red encircled valves shows their status.

  • Pump down to mechanical vacuum: open valve "VVPG:LI20:3189"; monitor pressure, e.g., using "VGXX:LI20:3259:DS1:COMBO_P"
  • Vent: close valve "VVPG:LI20:3189" and gently open the nitrogen flow in the tunnel (1-a few Torr per second is an acceptable speed)
  • Monitor: VGXX:LI20:3259:DS1:COMBO_P and VGCM:LI20:M3201:P
  • Sample vent profile (top is reference):


  • No labels