Centrifugal Pump Online Quiz – Part 2

Centrifugal Pumps are the heart of the chemical, petrochemical, and refinery industrial. Pumps are extremely diverse, varying in type, size, and materials of construction. This online test on Centrifugal Pump part 2 is used to test/refresh your knowledge on the centrifugal pump.

Welcome to your Centrifugal Pump Online Quiz Part 2

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1. For Cryogenic or hot liquid application which type of impeller is most preferable _______

Closed Impeller

Open Impeller

Semi-open Impeller

All the above

2. Shaft deflection(slenderness ratio) is very important design parameter for which of the following pump

Between Bearing pumps

Vertical Pumps

Overhung pumps

All the above

3. Which type of impeller is not most efficient _______

Closed Impeller

Open Impeller

Semi-open Impeller

All the above

4. If a pump is developed high head than the specific speed number of the impeller is _____

Higher

Lower

No change in Specific Speed

Not able to predict it

5. As per American National Institution standard B73.1 for ___________

Vertical Centrifugal pumps

Between Bearing Pumps

Positive displacement Pumps

Horizontal Centrifugal Pumps

6. If a pumping liquid temperature is more than 200°F (100°C) _________ type of volute design is more preferable.

Centerline

Offset design

7. What will happen if a vent valve of the centrifugal pump is opened during running condition?

Pump vibration will be increased

Pump impact in pump running condition

Motor will be overloaded

Pump lost is priming

8. For Overhung(OH) pump design shaft stiffness factor L³/D⁴ is shall be limited as _____

<40

<50

<60

<70

9. To maintain laminar flow at pump suction, _________straight pipe length is required at pump suction pipeline

Minimum 4 Pipe diameter

Minimum 5 Pipe diameter

Minimum 6 Pipe diameter

Minimum 7 Pipe diameter

10. If the viscosity of the pumping liquid is increased then which of the following statement is/are correct?

Pump brake horse power will decrease

Pump NPSHr will increase

Pump flow rate will decrease

All the above

11. As per API 610, the required head raise by changing the rated impeller to Maximum impeller will be_____

5%

10%

15%

20%

12. Which of the following statement is/are correct with reference to Oil mist lubrication when compare with Flooded type lubrication?

Oil mist can provide a positive pressure inside the bearing to keep out contaminants

Oil mist lubrication increase the bearing life to 90%

Oil mist lubrication decreases premature failure of bearing to 30%

All the above

13. To prevent the Vane Pass Syndrome it is best practice to maintain _____% of clearance between the minimum impeller tip to cut-water for smaller impeller sizes (less than 14' or 355 mm).

2

3

4

5

14. Which of the following statement about radial impeller is not correct

Radial impellers are suitable for high head and low flow conditions

Radial impeller have high specific speed number

Radial impellers exhibit a flat head/capacity curve from shut off to about 75% of their best efficiency

Radial flow impellers are normally started with a discharge valve shut

15. The stuffing box pressure of double suction impellers is equal to ____________

Discharge Pressure

Differential Pressure

Suction Pressure

10% of differential pressure

16. As per API 610 pump casing hydro test pressure shall be of ___________

1.25 x MAWP

1.5 x MAWP

1.75 x MAWP

2 x MAWP

17. Which of the following statement about Axial flow impeller is/are correct

Axial flow pump impeller have high specific speed number

Efficiency of the these type of impeller is higher when they run at the highest efficiency

They have the lowest NPSH requirement

All the above

18. As per API 610, Allowable operation range of a pump is _________

Minimum Continuous stable flow(MCSF) to 105% of BEP

Minimum Continuous stable flow(MCSF) to 110% of BEP

Minimum Continuous stable flow(MCSF) to 115% of BEP

Minimum Continuous stable flow(MCSF) to 120% of BEP

19. Due to uneven pressure (Radial thrust) act on the impeller, which of the following is not correct?

Excess load act on bearings

Excess shaft deflection on mechanical seal

Uneven wear of wear rings

Excess wear of volute casing

20. Foot mounted centrifugal pump model is acceptable  in _________ code

API 610

ASME B73.1

ASME B73.2

21. As per Affinity law, which of the following equation is correct?

Q1/Q2 = N2/N1

Q1/Q2 = N1/N2

Q1/Q2 = (N2/N1)^2

Q1/Q2 = (N1/N2)^2

22. Which of the following type of impeller will be more efficient?

Forward curved impeller

Radial impeller

Backward curved impeller

23. Consider a situation where the NPSH available at the pump inlet is 0.4m. Then which of the following pump type is the best selection?

Horizontal End Suction pump (OH2)

Multi stage Between bearing pump (BB3)

Inline pump (OH6)

Vertical Canned type pump (VS6)

24. For the Radial impeller, the diameter D2/D1 will be _____

>2

<2

1

0.5

25. Which of the following method is not used to reduce the thrust force act on the multi-stage pump?

Back to back arrangement of impellers

Balancing drum and balancing piston arrangement

By pass line installed from pump discharge to suction side

Balanced impeller

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