Ulvac CRYO-U Series Instruction Manual page 58

Regeneration
for five minutes, the roughing process has been
completed. If it increased 6.5Pa or more in five
minutes, repeat the rough pumping procedures to
40Pa and the pressure buildup check.
Ⅳ．Cool down
Open the roughing valve (RV1) after the pressure
buildup check has completed.
Then rough pump the cryopump to 40Pa. Close
the roughing valve (RV1) and start the cryopump.
When the cryopump is cooled down to the
prescribed temperature, the regeneration process
is completed.
・When the main valve is not a reverse pressure compatible valve, start regeneration of the
cryopump after returning the vacuum chamber to atmospheric pressure so that the main
valve may not open during regeneration.
・A pump case might dew during warming up depending on the installation environment.
In order to prevent a short circuit, please do not place an electric device under the
cryopump.
6-6
CAUTION
ULVAC CRYOGENICS INCORPORATED
Ⅲ
Close roughing valve (RV1),
Power off Heater (option)
Press. buildup check
completed
Ⅳ
Open roughing valve (RV1)
Pressure ≨ 40Pa
Close roughing valve (RV1)
Start up cryopump
Cool-down completed
Yes
Regeneration completed
No
Yes
No
Yes
No