1215 hrs. local -> Kyle on site to check on 80K pumps

Local temperature are dipping into the "single digits" which means now is an opportune time to investigate if our old problem of over-filling or under-filling of 80K pumps will result from frozen LLCV valve stems is going to be a problem.  Recall that in the past this had occurred but could not be confidently attributed to water freezing in the old pneumatic actuators or from water freezing in the valve stem from having got past too loose packing nuts. Or, both for that matter.  Chandra R. and John W. had replaced the pneumatic actuators with electric (water tight) ones last spring so now is the first real world test.  Initially, I'm on site to verify that the recently elevated exhaust pressures on CP3 and CP4 weren't the result of continuous overfilling -> Inspection of the Y-mid's CP3 and CP4 showed neither was overfilling and both are fine for now (remnant standing LN2 in lines from yesterday's overfill?).  

By dumb luck, I found that CP6 was indicating a frozen valve stem while I was on site - "Go figure!" -> As found, the local actuator pointer was showing ~30% open and the actuator motor was making noise.  The PID output was "railed" at its programmed minimum of 20% open.  I had John W. (he and Bubba also on site for separate instrument air issue) switch CP6's level control to manual 50% open -> the motor then went quiet and it stroked open to 50% as per the pointer.  Next, I had him change the value to 0% open and the stem stroked closed smoothly until stopping at about the 30% open value (as indicated by the local pointer).  I then tested the valve stem packing nut and found that it was completely loose, i.e. no thread engagement.  So, even though the local heat tape is wrapped around most of the exposed valve stem, was energized and working, water which made it past the ineffective packing washer was able to freeze nonetheless.  This is because this area is about 2" away from the closest heat tape wrap ->  I heated up the frozen area with a heat gun and lightly engaged the packing nut.  I then had John W. alternate between 100% open and 0% open to demonstrate that the valve could stroke through its whole range smoothly etc..  I setup and am leaving a heat lamp to prevent this unit from refreezing (which it would do, now that water is past the packing washer) and had John W. reduce the Beckhoff PID minimum to 15% open down from its as found value of 20%.  

 1535 hrs. local -> Kyle leaving site