KRAL DL3 Series, Operating Instructions Manual, Page: 45 / 60

14 Troubleshooting
14.2 Troubleshooting
Fault identification Cause Remedy
– – 3 – – – – Pump subject to mechanical stress
1. Support the weight of the pipe system.
2. Connect the pump station correctly to the pipe system
Ä
Connection, Page 18.
– – 3 – – – – Vibrations/pulsations in the system
Bear the pump station elastically.
-or-
Make the connections with hoses.
– – 3 – – – – Flow speed in the pressure line or suction line too high
Set the flow speed in the pressure line so that it does not exceed 3 m/s.
-or-
Set the flow speed in the suction line so that it does not exceed 1 m/s.
-or-
Contact the manufacturer.
– – 3 4 – – 7 Ball bearing damaged
Replace the ball bearing, see corresponding operating instructions of the pump.
– 2 3 4 – – 7 Superficial damage to pump parts coming into contact with the liquid
Contact the manufacturer.
– – – – – – 7 Shaft seal damaged through dry running
Replace the shaft seal, see corresponding operating instructions of the pump.
– – – – – – 7 Inlet pressure too high
1. Reduce the inlet pressure at the system side.
2. Replace the shaft seal, see corresponding operating instructions of the pump.
– – – – – – 7 Inlet pressure too low
Install a non-return valve at the pressure side.
– – – – – – 7 Shaft seal is overloaded through thermal/chemical influences
1. Check the maximum operating temperature.
2. Check the suitability and resistance of the elastomers with regard to the pumped liquid.
-or-
Contact the manufacturer.
– – – – – – 7 Overload of the shaft seal by pressure build-up during the heating process
Open the pressure-side/suction-side shut-off device in order to avoid a pressure build-up
through heat expansion of the pumped liquid.
1 2 3 4 5 – – Cold start when delivering high-viscosity liquids
Install the heating system.
– – – – – – 7 Differential pressure is too high and has overloaded the idle screws
Contact the manufacturer.
– – – – – – 7 Viscosity is too low and has overloaded the idle screws
Contact the manufacturer.
1 2 3 4 – – 7 Pump damaged through dry running
Contact the manufacturer.
1 – – – – – – Pump does not vent
Vent the pressure line at the highest point.
1 2 3 – – – – Reversing valve lever in the incorrect position
Switch the lever of the reversing valve to the correct position Ä During opera-
tion, Page 22.
– 2 – – 5 – – Pressure maintaining valve set incorrectly
Set the pressure maintaining valve
Ä
During operation, Page 22.
Tab. 15: Fault table
Operating instructions OID 06en-GB Edition 2019-11 45