Last week (Sept. 30th) I set CP4 in manual mode and doubled the LLCV to double nominal value (up to 66% open). Fill from 92% to 100% full took about 17 min. and another hour to see LN2 spew out the exhaust. Then I set LLCV back to nominal 32% open (actually slightly less than nominal probably given the level of the Dewar) to see how long it would take to boil back to 92% full. Answer is ~ 26 hrs. Today I remembered to set the CP4 PI lower limit setting back to 20% (important when Dewar gets filled).