(Travis S., Jordan V., Gerardo M.)
Today we were only able to vent the YBM (manifold on the Y-Arm), to do so, we hard closed GV1, GV2, GV5 and GV7.  GV5 and GV7 are pneumatic valves, they closed with pressure of 25 psi both, very good pressure.  Then we measured the purge air dew point, -42.1 ^oC.  One issue that we encountered was that it took a while to vent to atmosphere, the wide range gauge at PT180 is way off indicating 998 torr for a vented to atmosphere volume, should be more like 762 Torr today, we will check on how to reset that value.
Vacuum envelope for the YBM is vented and ready for the viewport work tomorrow.  However, the manifold for the X-Arm still under vacuum, no work should take place there until fully vented.