Centrifugal and Vane Pump Questions

During disassembly, you notice that the impeller is stuck on the shaft. What is the safest method to remove it?

• Hit it forcefully with a hammer

• Use an impeller puller and apply gradual pressure

• Heat the impeller with a torch to expand it

• Use a wrench to twist it off

A newly assembled centrifugal pump is experiencing reduced flow even though the motor is running at full speed. What could be the cause?

• The impeller is installed backwards

• The discharge valve is fully open

• The bearings were replaced with oversized ones

• The pump casing bolts are too tight

After reassembling the pump, you find excessive leakage around the pump casing. What should you check first?

• The alignment of the pump to the motor

• The torque specification of the casing bolts

• The size of the suction pipe

• The impeller clearance

While running a test after reassembly, you notice the pump is producing cavitation sounds. What could be the reason?

• The suction line is partially blocked

• The impeller is oversized for the pump casing

• The pump speed is too low

• The discharge valve is fully closed

A centrifugal pump is making excessive noise after reassembly. What could be the issue?

• The shaft is over-lubricated

• The impeller is misaligned or damaged

• The suction line is too short

• The discharge valve is stuck open

A vane pump you reassembled is failing to prime. What should you check first?

• The drive shaft lubrication

• The end plates for leaks

• The suction line for air leaks

• The vanes for correct positioning

During disassembly, you find that the vanes are unevenly worn. What does this indicate?

• The rotor is spinning too slowly

• The cam ring is worn or damaged

• The pump was running without lubrication

• The bearings are over-tightened

After reassembling a vane pump, the system pressure is unstable. What is the most likely issue?

• The vanes are installed in the wrong direction

• The rotor is spinning too fast

• The seals were not cleaned properly

• The impeller was damaged

While testing a newly assembled vane pump, you hear a high-pitched noise. What could be the cause?

• The pump is running dry due to a suction issue

• The rotor is moving too slowly

• The vanes are too loose

• The cam ring is misaligned

If a vane pump has excessive leakage at the end plates, what is the most likely cause?

• The vanes are over-lubricated

• The seals or gaskets are worn

• The pump casing is misaligned

• The rotor is spinning too fast