John, Chandra

Overfilled CP4 today while monitoring exhaust pressure and flow (from control room).

-Manually set LLCV to 66% open (double nominal value)
-Took 17 min. to fill to 100% (started at 90%)
-Took another 60 min. to see a drastic change in flow and pressure beyond 100% full (i.e. cooling exhaust line) *constant 66% open
-When exhaust pressure spiked to ~6 psi (flow meter spiked to ~480 slpm) we terminated the experiment and lowered LLCV to 20%, then 10%
-Kyle reported the new plastic flex line froze and all exhaust pipe was cold to the touch. Flow meter read -5decC.
-John and I measured uninsulated exhaust line temp afterward:  -8degF where pipe exits building (lots of frost build up) and ~26degF several feet downstream

We will repeat experiment tomorrow morning after exhaust line warms up but this time run until LN2 flows out end of exhaust line. We will install one or a few thermocouples along exhaust line.