(Travis S., Jordan V., Gerardo M.)
Today we replaced the ion pump for HAM2, but since the annulus system is shared with HAM1, both annulus ion pumps were powered off (HAM1 and HAM2), and the entire annulus system was vented with nitrogen gas. The AIP for HAM2 was removed, along with an elbow, the elbow was replaced with an isolation valve, we used a second hand O-ring valve because the new valve turned out to be short by 1".  After torquing all bolts on the ion pump and on the "new valve", the system was pumped down by a can turbo at the isolation valve and backed by an aux-cart, no issues pumping the annulus system down, since the aux-cart gauge already reports a vacuum pressure of 4.5X10^-05 Torr.  BTW, the can turbo at the top, flex hose and aux-cart will remain pumping on the annulus system until good vacuum pressure is achieved, and they will be a noise source.
Note for future work here: The pipes that make up this annulus system does not allow for an easy installation, during installation a person has to lift up on the pipes, while a second person pulls outward on the pipe to give space at the conflats to insert the copper gasket.  The tension on the pipes is something that we noted during the removal of the old ion pump, when the conflats were being unbolted, the gap between both increased on its own, showing us how much the pipes were flexed upward.