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Empty the Pre-Cool Circuit

To empty the pre-cool circuit:
  1. Ensure that manual valves V11, V12 and V14 are all open.
  2. On the computer control panel, select refrigerator.
  3. Select empty the pre-cool circuit.
  4. A pop up will appear which reads:

    This will start pumping on the cold part of the pre-cool circuit.

  5. Press Continue.

It will pump on the pre-cool circuit for $ \sim 2$ hours in order to boil off any helium which has condensed in the pre-cool lines. If this does not boil off, it will act as a heat load later, and may prevent a full cool down.

Once this is complete, you are ready to [sec:cooldown.condense]begin condensing.

Figure 4: Running a Full Pre-Cool.
[Begin an automated pre-cool.] \includegraphics[width=.31\textwidth]{figures/start_precool.eps} [Empty the pre-cool circuit.] \includegraphics[width=.31\textwidth]{figures/empty_precool.eps}

Jonathan Ouellet 2014-08-26