The pump does not supply the nominal flow rate/
excessive noise:
-
Insufficient supply (see various causes as above).
-
Pump speed is below the rated speed;
-
Excessive internal leakage of pressure control
valve.
-
Worn valves.
-
Excessive leakage from the pressure seals.
-
Cavitation due to:
1) Improper sizing of suction ducts/undersized
diameters.
2) Insufficient flow rate.
3) High water temperature.
The pressure supplied by the pump is insufficient:
-
The user flow (nozzle) is or has become greater
than the pump capacity.
-
Insufficient revolutions per minute.
-
Excessive leakage from the pressure seals.
-
Imperfect functioning of the pressure control
valve.
-
Worn valves.
Pump overheats:
-
The pump is working in overpressure conditions
or pump rpm is higher than the nominal value.
-
Oil in the pump casing is not at level or not the
recommended type as detailed in chapter 7
(see par. 7.6).
-
Excess belt tension or joint or pulley alignment is
incorrect.
-
Excessive pump tilt during operation.
Vibrations or hammering on pipes:
-
Air suction.
-
Faulty operation of pressure control valve.
-
Valves malfunction.
-
Non-uniformity of transmission motion.
32