Closing the gas ballast valve
+
3
1
2
-
Fig. 20:
Gas ballast valve with flushing gas connection
1
Gas ballast valve
3
Dosing screw
2
Flushing gas connection (hose nozzle)
1. Connect the hose (DN 5 mm) to the flushing gas connection.
2. Select the type and quantity of the flushing gas used according to the process.
3. Consult Pfeiffer Vacuum if necessary.
4. Set the flushing gas pressure to max.
1,500 hPa (absolute)
.
5. Set the desired gas quantity using the dosing screw:
Max. 1,700/1,875 l/h
(Duo 35/65).
6. Close the dosing screw by rotating to the right up to the stop.
7. Open the dosing screw by rotating to the left up to the stop.
6.3.3 Gas ballast valve with solenoid valve (option)
NOTICE
Risk of damage from unacceptably high flushing gas pressure
Increased flushing gas pressure compromises the operational reliability of the pump, and causes in-
creases in power input and operating temperature.
► Observe the maximum permissible flushing gas pressure of
1,500 hPa (absolute)
.
► Dose the flushing gas quantity with the dosing screw in the gas ballast valve or on site.
Using an electromagnetic valve to externally control the flushing gas flow facilitates handling of the gas
ballast, and allows the process-driven intake of clean air or other gases.
1
2
Fig. 21:
Gas ballast inlet with solenoid valve
1
Flushing gas connection
2
Solenoid valve
Operation
33/66
