--obsolete-- 8Pi Vent Valve for E1171 implantations (may4/2009)

By Chris Ruiz
To restrict venting speed of 8Pi chamber, ILE1A:VV9 has had a manual needle valve installed on the external side. This means that when roughing and VV9 is therefore closed, a small volume of air is locked between VV9 and the needle valve. This is enough to cause a 2Torr airburst into the 8Pi when initially opening VV9 to vent. This is causing the 20ug/cm^2 DLC foils to BREAK!.
Solution:
   We request interlock be removed on VV9  so we can rough with it open(temporarily) and then close when we go to a high vacuum with turbo on.
What we ACTUALLY did was bypass the interlock on the roughing valve(ILE1A:RV9) so that we can rough with the vent valve open.