6. Allow the condensate to discharge continuously for 30 minutes.
7. Close the shut-off valve on the vacuum line.
8. Close the gas ballast valve.
6.4 Flushing the screw pump with fluid
Flushing the screw pump with fluid is optional. Flush the inside of the screw pump with fluid after appli-
cations with process media that could adhesively bond inside the screw pump.
Prerequisites
● Shut-off valve in the vacuum line closed
● Screw pump disconnected from process
Required consumables
● Demineralized water (<5° dGH) water
Procedure
1. Reduce the pump rotation speed to n < 10 Hz.
2. Open the flushing fluid supply.
3. Operate the screw pump for 10 to 15 minutes at n < 10 Hz depending on the process.
– Determine the ideal flushing duration as a function of the process in question.
4. Shut off the flushing fluid supply.
5. Operate the screw pump for a further 20 minutes with the vacuum line closed after flushing.
6. Switch the screw pump off.
7. Vent the screw pump.
8. Allow the screw pump to cool down.
9. Shut off the cooling water flow.
6.5 Flushing the screw pump with gas
Equipping the screw pump with a gas flushing device is optional. Perform flushing with flushing gas af-
ter fluid flushing or to protect the compression chamber against corrosion.
Prerequisites
● Shut-off valve in the vacuum line closed
● Screw pump disconnected from process
Required consumables
● Flushing gas
Procedure
1. Open the flushing gas supply.
2. Operate the screw pump for 3 to 5 minutes depending on the process while the screw pump takes
in the flushing gas.
– Determine the ideal flushing duration as a function of the process in question.
3. Shut off the flushing gas supply.
4. Switch the screw pump off.
5. Vent the screw pump.
6. Allow the screw pump to cool down.
7. Shut off the cooling water flow.
6.6 Switching off the vacuum pump
Procedure
1. Close the shut-off valve in the vacuum line and isolate the screw pump from the process.
2. Switch off the screw pump in each pressure range between atmospheric pressure and final pres-
sure as required.
3. Shut off the cooling water flow.
4. Vent the screw pump to atmospheric pressure via the vacuum side.
5. Ensure that you do not vent the vacuum chamber through the screw pump.
6. Switch off the process- and pump-specific media supply (e.g. the sealing gas supply).
Operation
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