Iceman - I would close the liquid line service valve and the hot gas service valve to prevent any refrigerant to enter the vessle.
While pumping down the liquid is very chaotic, and there is nothing entering the vessle.
What do you mean about the relation of the float switch and the liquid level? the float swich is aprox 10" above the float level control.
While pumping down the pressure would stay around 5psi.
Process temp setpoint is -40deg.
Process fluid is a citris based antifreeze, delimonene

Do you do long distance service calls iceman?

Clay