We hymned and hawed and decided that we prefer to have two metal sealed valves in series as a redundancy so I vented CP1's 55 L/s ion pump and swapped a second 1.5" valve in place of the 1.5" elbow that connects the ion pump assembly to the 1.5" pump port valve which is part of CP1.  I then pumped the ion pump to down and leak tested the new joints.  

This completes WP #7205