PLP Sanitary Lobe Pump Troubleshooting

Malfunction in Sanitary Lobe Pumps 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. 1. Pump provides no flow
   2. Pump provides irregular flow
   3. Capacity is too low
   4. Pump overheats
   5. Motor overheats

1. Excessive Screw / Rotor wear
2. Excessive wear of shaft sealing
3. Pump vibrates excessively or makes too much noise
4. Pump has seized
5. Pump stops upon startup

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

Inspection & Maintenance Schedule

Routine inspection and maintenance can avoid unnecessary and expensive downtime as well as operating costs. It is recommended to regularly check:

• If the pump functions properly – excessive noise levels may indicate wear problems to bearings and gears, dragging of rotors/lobes on the pump casing or cavitation.
• Pressure and Flow of the flushing system, if present
• The temperature of the heating/cooling system, if present
• Oil level in the gearbox – If the oil level has reduced, check the pump for oil leakages
• Monitor regularly the pump suction and discharge pressure conditions to ensure they are in line with typical system levels.

Oil Changes

• 300 operating hours after the initial commissioning
• Every 3000 operating hours or at least every 3 months
• If not being used regularly, every 2000 operating hours, or at least every 3 months