...

• The incoming helium to the fridge is controlled by the fridge valves, namely the run valve and the bypass valve.  Operational procedures are explained on this page [Fridge Valve Control System at NM4]. 
• The outgoing helium from the fridge is controlled by the gate valve and the gate-valve bypass.  Operational procedures are explained on this page [How to control the Fridge Return flow (GV and GV Bypass)].

Important Facts

1. How long does the fridge would last if the starting liquid level is 100%? ~ 8 hrs from (100% to 10%) with maintaining cernox 7 temperature below 50 K
   Note: Set Separator flow to 10slm.
   https://e906-gat1.fnal.gov/data-summary/e1039/target-all.php?sel_mode=date_time&Y0=2024&M0=06&D0=16&h0=20&m0=00&s0=00&Y1=2024&M1=06&D1=17&h1=11&m1=10&s1=00&Cryo+Temperature_Cernox+7&Cryo+Level_Nose+LHe+Level
   Image Added
   
   

2. How long does the fridge would last if the starting liquid level is Heat Ex. Bottom?  ~16 hrs

Procedures

1. Fridge Fill Procedure
2. Fridge Emptying Procedure