SP-LR Self-Priming Liquid Ring Pump Troubleshooting

A malfunction in a pump system may be caused by various reasons and is not necessarily the pump itself. Issues with the pipework or other fluid accessories within the system can be contributing factors. Furthermore, if the operating conditions differ too greatly from the provided specification for which the pump was selected for can also be a major contributing factor.

Consequently, it is always recommended to check the following first:

• Has the pump been installed correctly?

• Are the operating conditions still according to the initial specification?

• Are the other fluid accessories within the pipework functioning correctly?

In general, the following malfunctions can be identified:

1. Pump provides little or no flow
2. Pump does not reach duty point
3. Pump provides irregular flow
4. Pump leaks
5. Pump vibrates excessively
6. Pump makes too much noise
7. Motor overheats
8. Motor cuts out on thermal overload
9. Pump has seized

Below is a table of the possible causes and solutions of these malfunctions.

Malfunction									Cause	Action
1	2	3	4	5	6	7	8	9
	X				X	X			electrical connection defective	Have qualified electrician check the electric connections
	X								wrong rotation direction	Have qualified electrician reverse the sense of rotation of the electric motor
X	X	X			X				insufficient pre-pressure	Increase the pre-pressure or place the pump on a lower position
	X						X		pump operating at the wrong speed	Check the motor speed
								X	contaminations or objects in the pump	Clean the pump, if necessary disassemble
X	X	X							air in the piping	Inspect the piping
	X								valve in suction pipe is not completely open	Entirely open the valve in the suction pipe
	X								pump selected with too small delivery head	Install another pump
X	X	X						X	suction pipe or filter blocked	Clean the suction pipe or the filter
			X						shaft seal defective	Disassemble the pump and replace the shaft seal
			X						O-ring seal defective	Disassemble the pump and replace the O-ring seal
							X		liquid temperature is too high	Decrease the liquid temperature
X							X	X	impeller is jammed	Disassemble the pump and replace the impeller
				X	X		X	X	impeller is damaged	Disassemble the pump and replace the impeller
				X	X	X	X	X	motor shaft is bent	Replace the motor
				X	X	X	X	X	extension shaft is loose	Disassemble the pump, inspect the extension shaft, reassemble it and readjust.
				X	X	X	X	X	bearings are damaged or worn	Replace the motor. For IG(F): replace the bearings
							X	X	motor is overloaded	Check the viscosity of the liquid.
										Switch off the motor and check if the pump does not drag. If so, disassemble the pump and repair it

Inspection & Maintenance Schedule

Routine inspection and maintenance can avoid unnecessary and expensive downtime as well as operating costs. It is recommended to check the following on a daily basis:

• That the valve in the suction pipe is completely open
• That the inlet pressure is not too low in order to avoid the occurrence of cavitation
• The delivery pressure is in line with system requirements
• That the shaft seals are not leaking.
• Pressure and Flow of the flushing system, if present
• The temperature of the heating/cooling system, if present

For IG & IGH Variants periodically check the bearing oil levels. The oil must be changed annually or after every 5000 operating hours.