General Pump MW Owners Manual - Manual (Page 20)

GENERAL PUMP
A member of the Interpump Group
MW/S SERIES
15. TROUBLESHOOTING
The pump does not produce any noise at start-up:
• The pump is not primed and is running dry
• There is no water in the inlet line
• The valves are blocked
• The delivery line is closed and does not allow the air in the pump to be discharged
The pump pulses irregularly (knocking):
• Air suction
• Insufficient feeding
• Bends, elbows, fittings along the suction line obstruct the fluid’s passage
• The inlet filter is dirty or too small
• The booster pump, where provided, supplies insufficient pressure or flow rate
• The pump is not primed due to insufficient head or the delivery line is closed during priming
• The pump is not primed due to valve seizing
• Worn valves
• Worn pressure packings
• Incorrect operation of the pressure adjustment valve
• Transmission problems
The pump does not deliver the rated flow / is noisy:
• Insufficient feeding (see the causes listed above)
• RPM are less than the rated flow
• Excessive amount of water by-passed by the pressure adjustment valve
• Worn valves
• Leakage from the pressure packings
• Cavitation due to:
1) Wrong sizing of the suction hose/
undersized diameters
2) Insufficient flow rate
3) High water temperature
Insufficient pump pressure:
• The nozzle (or has become)too large
• Insufficient RPM
• Leakage from the pressure packings
• Incorrect operation of the pressure adjustment valve
• Worn valves
Overheated pump:
• The pump is overloaded (pressure or RPM exceed the rated values)
• Oil level is too low, or the oil is not of a suitable type, indicated in Chapter 7 (see paragraph 7.4)
• Incorrect alignment of the joint or pulleys
• Excessive inclination of the pump during operation
Pump vibrations or knocking:
• Air suction
• Incorrect operation of the pressure adjustment valve
• Valve malfunction
• Irregular drive transmission motion
Page 20
Ref 300790 Rev.D
11-12