Ulvac UTM1600 Series, Instruction Manual, Page: 61 / 108

6.4 Shutting Down
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6.4
Shutting Down
CAUTION
After having operated the turbo molecular pump for evacuation of corrosive gas, keep the
pump internal as vacuumed even after shutdown. Inflow of water content in the air to the pump
internal would cause rapid corrosion trouble of the pump internals. The pump corrosion may
result in damaging the vacuum vessel interior and other units, causing pressure fluctuation by
stopping the pump and dispersal of parts.
CAUTION
When reducing internal pressure of the turbo molecular pump up to around the atmospheric
pressure by use of inert gas, etc., adjust the pressure reducing valve so that the internal pressure
of the same pump does not exceed 20 kPa GAUGE.
CAUTION
Electrical energy isolation (Lockout / Tagout) should be achieved by opening the main
disconnect device or circuit breaker of host equipment, thereby removing power from this
product. The main disconnect device or circuit breaker of host equipment should be suitably
located and easily reached, and it should be marked as the disconnecting device for the
equipment.
For shut-down of the turbo molecular pump, follow the sequence below.
6.4.1 Preparations Prior to Shutting Down Operation
(1) Check that process gas inflow is in complete stop. When main valve is provided between
the turbo molecular pump and vacuum chamber, close the valve, too.
(2) When purge gas is being fed into the turbo molecular pump, stop the gas feed, too.
(3) When forevacuum valve is provided between the turbo molecular pump and backing
vacuum pump, close the valve, too.