Ulvac CRYOPUMP CRYO-U Series Instruction Manual page 23

Ensure that the bolts are securely tightened. Loosened bolts or bolts tighten
under the regulation torque may cause severe injury or equipment damage.
R type Refrigerator
RM type Refrigerator
9. Do not charge the system with excessive helium gas
The refrigeration system in our cryopump systems circulates high-pressure helium gas to
generate refrigeration cycle. Charging the system with helium gas more than appropriate
value does not enhance the performance of refrigerator. Conversely, if helium gas pressure
exceeds the specified level, the pressure relief valve may work, resulting in leakage caused
by particles stuck in the vacuum seal in the valve. In addition, some compressor units
activate pressure sensor which may lead to disabling cryopump operation.
Do not charge the system with helium gas exceeding the appropriate volume.
10. Power source of cryopump system
Refer to the instruction manual of the compressor unit to be utilized with the cryopump, and
confirm the power source required for the system.
(1) Make sure to connect the earth wire to a ground terminal.
Earth : D-class grounding with the ground resistance of 100 Ω or less.
(2) Install ground-fault interrupter on the electric supply line for the compressor unit.
(3) Do not connect any devices except a cryopump system on the outlet of the ground-fault
interrupter.
1
Self-sealing coupling
Self-sealing coupling
1
1
1
1
1
Self-sealing coupling
Self-sealing coupling
1
1 1
Presser relief valve
Figure 3 Bolt Locations
ULVAC CRYOGENICS INCORPORATED
1
Cylinder bolt
1
2
1
Presser relief valve
2
1
Cylinder bolt
2
1
2
2
①：Bolts ②：Plugs
①：Bolts ②：Plugs
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