22
Operation
Flush pump with
flushing gas
Close shut-off valve in the intake line and separate the pump from the process.
Open flushing gas feed at the intake flange.
Pump is operated for an additional 20 to 40 minutes while flushing gas is suctioned in.
Close sealing gas valve.
Switch off the pump.
Venting should be performed via the suction side, do not ventilate vacuum chambers
through the pump.
Stop flushing gas feed.
Switching back on
After switching off the pump it can be switched back on again within 5 minutes. If you wait
any longer then leave the pump to cool to ambient temperature before switching back on
again.
WARNING
Exposed, rotating rotors!
Danger of crushing! The rotors will continue to run under vacuum after the motor has
been switched off.
Never disconnect any pipe connections at the vacuum flange or fore-vacuum flange
or any sealing gas lines while the pump is running.
NOTICE
High pressure in the sealing gas line when the pump is switched off!
Risk of damage to the pump seals.
Lower sealing gas pressure to < 1200 hPa or stop sealing gas feed immediately.
NOTICE
Roots pump damage due to the rotors starting up!
Differences in the rate of cooling of the pump housing and rotors can cause damage to
the pump.
If the pump / pumping station is switched off and at a standstill for > 5 minutes, then
only switch it on again after ventilation and a waiting period of at least 120 minutes to
allow a balanced temperature of rotors and housing.