Kyle, Gerardo

It would be desirable to remove all of GV11 and GV12's external AIP plumbing to aid in the installation of a bake-out enclosure scheduled to be installed as part of the CP4 decommissioning exercise.  Today we connected a Tee having a port with a conductance-limited needle valve attached and a small turbo pump (backed by pump cart) to GV11's annulus pump port.  Bottled UHP N2 was then plumbed to the needle valve which allowed us to administer a controlled amount of dry nitrogen into the inlet of the turbo pump.  With the turbo inlet pressure at around 1 torr or so, we de-energized GV11's AIP controller and valved-in our test setup.  The net effect is that we were slowly venting the annulus volume with dry nitrogen while monitoring PT210 and PT245 to see if any of GV11's inner O-rings were then leaking this administered N2.  As can be seen in the attached graphs, we confirmed that there was leakage into PT210 side.  We allowed the annulus volume to increase into the "tens of torr" before abandoning the experiment, shutting off the N2 and letting the turbo evacuate the administered gas.