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6. Start-up
Note:
Do not start the pump until it has been filled with liquid and vented.
6.1 Priming
The suction pipe and the pump must be filled with liquid and vented before the pump is started.
If the liquid level is below the pump inlet or there are airlocks in the suction pipe, proceed as follows:
1. Close the discharge isolating valve and open the isolating valve in the suction pipe.
2. Loosen the air vent screw (pos. 17).
3. Remove the plug (pos. 20) from one of the pump flanges, depending on the pump location.
4. Pour liquid through the priming hole.
5. Make sure the suction pipe and the pump are completely filled with liquid.
6. Fit the plug and tighten securely.
7. Tighten the air vent screw (pos. 17).
The suction pipe can to some extent be filled with liquid and vented before it is connected to the pump. A priming device can
also be installed before the pump.
6.2 Checking the direction of rotation
Note:
The pump must be filled with liquid when checking the direction of rotation.
The correct direction of rotation is indicated by the arrow on the pump housing. When seen from the motor fan, the pump should
rotate clockwise. Start the motor only for a short moment.
6.3 Start-up
1. Completely open the suction isolating valve and leave the discharge isolating valve almost closed.
2. Start the pump.
Note:
Sudden, large pressure changes in the discharge pipe may damage the pump.
3. Vent the pump during starting by loosening the air vent screw (pos. 17) in the pump head until a steady stream of liquid runs
out of the vent hole.
4. When the piping system has been filled with liquid, slowly open the discharge isolating valve until it is completely open.
5. In case of overload, throttle the valve on the discharge side until the motor is not overloaded.
6. If the pump does not build up pressure at once, stop it and repeat the starting procedure.
6.4 Restarting
Do not restart the pump until the pump shaft stands still.
6.5 Stopping
Backflow is stopped by means of the non-return valve or counter pressure in the pipeline.
Switch off the motor and check that it slows down smoothly.
Fit the coupling guard before starting the pump.
In hot-water installations, special attention should be paid to the risk of personal injury caused by scalding hot water.
The motor should not be removed when checking the direction of rotation, as this may damage the shaft seal.
Pay attention to the orientation of the vent hole to ensure that the escaping water does not cause personal injury or
damage to the motor or other components.
In hot-water installations, special attention should be paid to the risk of personal injury caused by scalding hot water.
The pump must never be operated for long periods if the isolating valve on the discharge side is closed.
Backflow of the pumped liquid must not result in a change in the direction of rotation of the pump.
