The pumping equipment works 365 days under mild or harsh external conditions. It can place a lot of stress on the pump. The centrifugal pump has to operate at BEP or Best Efficiency Point. When the centrifugal pump’s hydrodynamic unbalance load is minimum, then this is the actual best efficiency point. If the pump operates little away from this BEP, then the hydrodynamic unbalanced load increases. This change affects the efficiency, reliability, and performance of the pump.
A regular maintenance program is necessary to prevent major setbacks and extend the life of the centrifugal pump. The main parts that do all the hard work are the AC induction motor and the pump itself. Mechanical energy gets transformed into hydraulic energy by the pump, whereas electrical energy gets converted into mechanical energy by the AC motor. Scenarios that can dampen the centrifugal pump’s efficiency are –
- Friction between the wear rings to maintain impeller clearances
- Double volute design
- Heat generated because of packing
- Over lubricated bearings
- Obstruction within piping passage due to dirt or foreign particles
Operators who comply with preventative sanitary pumps maintenance program certainly benefit from no-downtime and costly-repairs. Even for parts replacement, they consider suppliers like Flowtrend for consistency and high-quality springs, valves, vacuum breakers, and other components.
Routine preventative maintenance practice includes monitoring of the –
- Bearing temperature, lubricant condition [no frothing] and vibration level
- Shaft seals for visible leakage
- Pump vibration in excess can increase bearing temperature and changes in the pump alignment
- A decrease in the pump discharge pressure indicates the widening of impeller clearance
- Check pump’s foundation integrity and tighten the hold-down bolts
- Check shaft alignment
- Change oil of new pumps after the initial 200 hours and then post 2000 operating hours or three months, whichever is first. If the pumps used grease as lubricants, then grease the bearings post-2000 operating hours or three months, whichever is first.
[Only use non-foaming or non-detergent lubricant oils. Excess oil can increase heat and cause frothing. If you notice frothing, then change the oil immediately because frothing indicates the oil has excessive water content. In case of re-grease able bearings ensure to avoid combining greases with differing consistencies. Even avoid over greasing, which can increase temperature and create layered solids near the bearing races.]
- Bearing frame & foot for rust, scale, cracks or roughness and dirt.
- Shaft and sleeves for pitting or grooves.
- Casings for wear and tear.
- Impeller for corrosion damage.
- Frame adapter for warpage or cracks.
- Replace worn out housing of the bearings.
- Seal chambers
If the operating conditions are severe then shorten the monitoring or maintenance intervals.