Ulvac CRYOPUMP CRYO-U Series Instruction Manual page 59

CRYO-U Cryopump Instruction Manual
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†For Your Information†
・The warm-up time required for the 15K cryopanel to reach room temperature depends on
the kind and quantity of the gas captured in the cryopump, or the warm-up method.
・If a large amount of the gas is amassed by the cryopump, the inner pressure of the
cryopump may become higher than atmospheric pressure during warm-up process in the
regeneration because most captured gas evaporates for a short time.
In this case, the pressure relief valve will open according to the following condition to
release the gas. The pressure at which the pressure relief valve begins to open is 10
kPaG, and full open is 20 kPaG.
ULVAC CRYOGENICS INCORPORATED 6-7