Aux 1 Unit 5 Q7

1 / 10

What is cavitation in the context of pump operation?

D) The overheating of the pump motor

C) The mixing of air with the pumped fluid

A) The formation and subsequent collapse of vapor bubbles in a liquid

B) The process of fluid flow becoming more laminar

2 / 10

What visual signs might indicate that cavitation damage has occurred in a pump?

C) Discoloration of the pumped fluid

B) Pitting or cratering on the impeller and pump casing

D) Decreased noise during operation

A) Smooth surfaces on the impeller

3 / 10

What happens when vapor bubbles formed by cavitation collapse inside a pump?

B) The collapsing bubbles generate shock waves that can cause pitting and damage to the impeller and pump casing

A) The pump operates more efficiently

C) The fluid temperature decreases significantly

D) The pump flow rate increases

4 / 10

Where in a pump does cavitation typically start?

A) In the discharge line

D) In the pump casing

B) At the suction side or near the impeller

C) In the motor housing

5 / 10

Which of the following is a common operational cause of increased cavitation in a pump?

B) High fluid temperature, which reduces the liquid’s vapor pressure and makes cavitation more likely

D) Properly sized suction piping

A) Operating the pump at a flow rate lower than the design point

C) High discharge pressure

6 / 10

How does cavitation affect the overall efficiency of a pump?

C) It has no impact on pump efficiency

B) It decreases the pump’s efficiency by causing flow disruption and component damage

A) It improves the pump’s efficiency by reducing pressure losses

D) It increases the pump’s flow rate

7 / 10

How can inadequate Net Positive Suction Head (NPSH) available lead to cavitation in a pump?

C) It means that the available pressure at the pump suction is too low to keep the fluid from vaporizing, leading to cavitation

D) It increases the fluid’s boiling point, preventing cavitation

B) It provides enough pressure to prevent cavitation

A) It ensures that cavitation cannot occur

8 / 10

Why might operating a pump at a flow rate higher than its design capacity lead to increased cavitation?

D) Higher flow rates always prevent cavitation

C) The pump is designed to handle any flow rate

B) The increased flow rate can cause a drop in suction pressure, leading to cavitation

A) The pump is more efficient at higher flow rates

9 / 10

How does operating a pump with a clogged or restricted suction line increase the risk of cavitation?

D) It has no effect on cavitation risk

B) It increases the pressure at the pump inlet, preventing cavitation

A) It decreases the fluid velocity, preventing cavitation

C) It decreases the pressure at the pump inlet, increasing the likelihood of vapor bubble formation

10 / 10

Why is cavitation particularly damaging to pump components?

D) It slows down the rotational speed of the impeller

A) It causes the fluid to become corrosive

B) It leads to thermal expansion of the pump parts

C) The rapid pressure changes and collapse of bubbles result in high-velocity impacts on pump surfaces

Your score is