The leak check of the cold box diff pump fittings. Found a leak at the
base of the diff pump on the tee that is apparently used to fill the pump
with oil. The fitting was removed and a plug was removed that resembled a
dip stick (approx 1" long). Tbe dip stick was charred black as if it had
been hot. The seal between the dip stick and the tee was not an O-ring.
It looked like a high temperature glue? For leak checking purposes, an O-
ring was fitted to the dip stick and reinserted in situ. Only the top
portion of the tee was removed. The lower cap was slathered in vacuum
grease. Pumping back down was slow. After two hours the vacuum was down
to 2 torr. At 6:30 pm, the vacuum was 200 mtorr, so I turned on the
filament and tried again to leak check. I was able to get the throttle
valve open a little wider than previously, but we still had a big leak. I
checked at the tee and got a strong response, but I also checked at the
diff pump connections and also got a response, albeit much less. We may
have to blank off the entire diff pump to isolate the cold box so that we
can leak check the system. Dimo said he will be able to help tomorrow.
For now, I will leave the roughing pump on the cold box and isolte the
leak detector. See you tomorrow.
P.S. I left a voice mail re: welding at TITAN 8:30 am/blankets/work
permits/extractor. cb |