Various reasons can cause centrifugal pumps to become stuck, and it is important to know them for proper maintenance and operation. Some of the factors that contribute to pump seizure are described below:
Mechanical Failure：
- Bearing Issues: One of the major causes of centrifugal pump seizures is bearing problems. The bearings that are not lubricated enough can overheat and seize up, thus stopping their operations.
- Impeller and Casing: Sometimes, the impeller may get into contact with the casing either due to wearing out or misalignment. This friction may cause seizure.
- Mechanical Seal: A bad mechanical seal could lead to leakage and overheating which may result in eventual pump seizure.
Lubrication Issues:
- Inadequate Lubrication: Lack of adequate lubrication makes moving parts within a pump produce too much friction which leads to overheating then finally seizing up.
- Contaminated Lubricant: Dirty, grit or otherwise impure lubricating oil may also make bearings fail resulting in the pump becoming seized.
Installation Issues:
- Over-tightening: While installing bolts and fasteners might create excessive mechanical strain on pump components hence increasing chances of seizure if they are tightened more than necessary.
- Misalignment: Bearings will be subjected to increased stress leading to prematurely collapse if there is incorrect alignment between motor shafts and a pump
Operational Issues:
- Cavitation: Cavitation arises when vapor bubbles form and collapse in case a fluid handled by a centrifugal pump gets heated beyond its boiling point at a certain pressure. As an outcome, this can damage impellers or take seizure eventually.
- Flow Rate: The pumping speed being below minimum speeds destroys pumps through excessive heat generation leading failure while high flow rates brings about vibration risks as well as cavitations
Electrical issues:
- Phase Imbalance: Motor overheating occurs as a result of electrical imbalances in power supply thus leading to potential seizure tendencies on its part.
- Voltage Fluctuations: Motor may not be provided with steady power, which in turn can result in seizures taking place.
Maintenance:
- Lack of Maintenance: A pump needs periodic maintenance to work properly. Overlooking warning signals such as strange sounds or sudden temperature rise may lead to an immediate failure of a pump and its seizure.
Environmental Factors:
- Corrosion: Pump parts can corrode due to chemicals present either in the fluid being pumped or where it is working leading to weakened structures and thus increasing chances of seizure.
- Temperature: The high ambient temperature also leads to the pump failure by quickening breakdown of lubricants hence causing inadequate lubrication that takes seizure with time.
To minimize the risk of a centrifugal pump seizing, it is important to identify these causes and implement routine maintenance inspections as well as proper operating practices.
