The clean air purge on BSC 4 needed to be relocated to allow HAM 10's iLIGO crossbeams to be removed. The valve needed to be moved from the flange on HAM 10 to the flange on HAM 9. The blank and the valve swapped places. Unfortunately the clean air purge on BSC 4 needed to be rotated to accommodate this. The conflat was replaced with a new one, and the flange has been flagged with a note that it needs a leak check. 

BSC 4 purge air valve needs a leak check!

Scott and Ed meanwhile worked on removing the old stacks and jacking the support tubes. So the new HEPI piers will be able to be set tomorrow while the leveling of HAM 9 finishes.