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  1. Switch the LIquefier to Manual + Liquefy mode (Manual + Idle mode is also the same because Liquefy/Idle option has no effect when it is in the 'Manual' mode)
  2.  Ensure the dewar pressure alarm threshold is around 0.2 psi (navigate to the Liquefier 'Settings' to check that).
  3.  Set the inlet flow to 60slm: enter 60slm on FC501(A/B)Q (then press enter)
  4.  Set the outlet flow for the maximum flow by opening SVV(A/B) and the manual hand valve bypassing the SVN(A/B)
     Note: Currently, this bypass valve exists only for LQ-B (will install one for LQ-A soon)
  5.  Open the magic valve NV501A/B completely (~9 turns).
  6.  Turn ON the cold-head-heaters manually on the "Helium Compressors" screen.
  7.  It will take about ~8hrs to warm up the cold heads to the room temperature
  8.  Once the cold head temperatures reach > 272 K, then wait for + 1 hr, and turn OFF the cold head heaters manually on the "Helium Compressors" screen.
  9.  Let the warm gHe circulate through the cold heads + Dewar with 60slm in and out for another couple of hours.
     You can skip this step 9 if there is a time constraint.
  10.  To avoid going the LQ to "Alarm" mode, change the Dewar alarm pressure to 0.2 psi or below (box on the top right corner of the following screenshot).
  11.  Pressurize the Dewar A/B to 8 psi by opening SV501(A/B) and then setting the flow to 40 slm on FC501BQMC (i.e. enter 40 on the panel popping up on the lower right and press enter).

         
  12.  To Vent:
         Option 1: Open VPC,  Open VJV(A/B) to reduce the Dewar pressure through the transfer line.
         Option 2: Open SVVB + the SVNB bypass valve
         Option 3: Open SVNB and set FCA/BQMC to 60slm
         
  13. Repeat steps (11) and (12) several times until the cold-head temperatures are at room temp. and also the Dewar pressure holding at 8 psi once pressurized.

  14. Close the two needle valves close to the Dewar level gauge.
         


  15.  Set the Dewar Alarm pressure to -30 psi on the Dewar settings page (this is to avoid the LQ(A/B) going to the alarm mode) on QT HMI (change top right box to -30 psi).
         


  16. Connect a dry-pump with a KF flex hose to the relevant port shown on the following figure (LQ-B top section, LQ-A bottom section: check the labels on the manifold components.
           

  17. Start the pump.

  18. Open the relevant hand-valve (shown in the above image) to pump down the relevant Dewar.

  19. Then purge/pressuzire using step (11)

  20. Repeat steps (18) and (19) a few times by having 15 mins gap between each purge and pump-down.

  21. Set the Dewar Alarm pressure 0.5 psi on the Dewar settings page.

  22. Open the two needle valves close to the Dewar level gauge.

  23. Consider one by one of each tube (at a time) connecting to the level meter (2 copper and 2 plastic) and disconnect each to relieve the gas for a few seconds while the Dewar pressure is at 8psi.

  24. Make sure that all 4 tubes are reconnected properly, and also make sure that two needle valves close to the Dewar neck are fully opened.

  25. Follow the steps on QT System Starting Procedure to get the Liqeufier back to Run+Auto+Liquefy mode.


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