Finished venting IP4 with bottled UHP N2 (started Friday afternoon then halted).  Also vented (with bottled UHP N2) non-VE side of closed 12.8" gate valve (new VAT valve) mounted on OMC tube and having 16.5"-2.75" CFF zero-length reducer flange with 1 1/2" pump port valve.  New valve doesn't leak!  

Chandra will be in early tomorrow to remove connected equipment and supervise installation of IP4 onto the OMC.