Yesterday, Grant entered the Ante Room with David Wang to visually inspect the two sets of failed c-seals from the Heat Shield circuit, to remove the second set from the Heat Shield water blocks, and to leak check the heat shield circuit with o-rings and a water-block-to-leak-detector fitting.
Some photos of the inspected seals are in the attached design review presentation. Some unusual marks were observed on both sets of failed seals.
The heat shield lines and water block assembly leak checked successfully to the bottom of the leak rate range ("UNDER" ~1x10-9 atm cc / sec on the Varian 979) with a great flood of helium on all joints with no response anywhere. |