Kyle, Chris (Apollo)-Installed BSC9 east door at X-end

Kyle, X-end - IP12 controller died last night as room was too warm with QDP80 and all (5) of the purge air compressors running (BSC9 door off soft cover on - typically purge flow is set to max when door and soft cover are both off then reduced when soft cover is installed)  Also, purge air drying tower had switching failure this morning and dewpoint measured -13C -> Investigation showed that "purge air valve" which dictates air pressure on tower which is regenerating dessicant was set at ~95psi -> corrected by setting value to 65psi - this alone will cause ultimate "dryness" to be poor.  Additionally, deduced that 1of4 gravity-style check valves was stuck open - this would be the source of the switching failure -> whacked check valve body with knuckles during portion of cycle when air flows "against the arrow".  This freed the stuck flapper and now ok -> Purge air system Ok now measure <-54C comming from supply but ~-17C when blowing back out of VE -> Don't have good means to dry-out VE other than filling with (now) dry air then decoupling purge connection and letting VE blow out into the room, reconnect purge and refilling VE to 1psi with dry air, decoupling etc... which I did several times throughout the day.  

Note: purge air was measured to be <-54C at time X-end was vented.  95psi setting at drying tower causes inefficiency but doesn't cause noticeable problem until demand becomes high for an extended period of time.  


Kyle, Y-end - Finally have good vapor pressure at Y-end LN2 dewar (new value is 6 turns ccw from fully closed economizer valve adjuster screw) -> no more "low N2 flow" alarm on QDP80 -> Resumed pumping Y-end.