Ulvac CRYO-U Series, Instruction Manual

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Regeneration
6-2 ULVAC CRYOGENICS INCORPORATED
6.2 Regeneration Time
Regeneration is required when any of the following events occurs after the cryopump has
been cooled down. In order to maintain the stable refrigeration performance, it is
recommended to perform regeneration before these events occur. Especially when handling
dangerous gases, perform regeneration regularly before these events occur.
①
Temperature of 15K cryopanel
：
20K or more
②
Temperature of 80K shield
：
130K or more
③
Ultimate pressure of the cryopump five minutes after closing the main valve
:1.3
×
10
-4
Pa or more
④
When the amount of pumped gases reaches the pumping capacity as shown in Table 1-1.
⑤
When the cryopump can not maintain the original performance
Note: For
①
and
②
above, temperature indicator(s) is(are) required.
6.3 Warm-up Method
There are three methods for warm-up.
◇
Unassisted warm-up
Switch off the cryopump and wait for the 80K shield, 80K baffle, and 15K cryopanel to
warm up to room temperature naturally. If quantity of the gas captured in the
cryopump is less than the volume of the cryopump and safety of the gas is proved,
perform this process, “Unassisted warm-up”.
If flammable gas, explosive gas, or combustion enhancing gas is pumped in the cryopump,
be sure to treat the gas safely by diluting it with inert gas (nitrogen gas that its dew point
temperature is
－
40
℃
or below or argon).
Refer to Paragraph 6.Regeneration after pumping flammable, explosive, or combustion
enhancing gas in the Safety section.
CAUTION