Cleaning The Cryopump - Ulvac CRYO-U Series Instruction Manual

Maintenance
8.3.

Cleaning the Cryopump

When it seems that the cryopump has been used to evacuate toxic or dangerous materials,
you must contact the safety supervisor beforehand, and confirm a safe recovery method.
The majority of the cause deteriorating the
on the 80K shield and the 80K baffle. It's re
parts once a week with the main valve closed, in order to observe the degree of
contamination. When removing the cryopump from the vacuum chamber for maintenance of
the refrigerator etc, inspect the 80K shield, 80K baffle and 15K cryopanel at the same time.
Cleaning of Inner kit
◆
Especially the 80K baffle tends to get contaminated most. Perform the 80K baffle cleaning
as follows:
１．Remove the cryopump from the vacuum chamber and put the cryopump on the floor
with the mounting flange up. At this time, be sure to support the cryopump not to fall
down.
２．Wipe out the 80K baffle with clean cloth dipped in alcohol.
When 15K cryopanel is seriously corroded or contaminated, replace with the new one
Do not wipe the blackened surface of the 80K shield with alcohol. Otherwise the blackened
surface may be peeled off with a solvent.
Maintenance of the pressure relief valve
◆
If the pressure relief valve is kept capped for a long time, it may fail to open at required
pressure.
8-4
WARNING
performance of
commended to
CAUTION
WARNING
ULVAC CRYOGENICS
the cryopump is contamination
check the temperature of these
INCORPORAT ED