Turbine flow meter – 20 Most Common Interview Questions with Answers

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✅ Basic Conceptual Questions

1. What is a turbine flow meter and how does it work?
   A turbine flow meter measures volumetric flow rate using the mechanical motion of a rotor placed in the flow stream. The fluid flow turns the rotor; the rotational speed is proportional to flow rate.

2. What is the principle behind turbine flow meters?
   It works on mechanical rotation—the rotor blades spin at a speed directly proportional to the velocity of the fluid.

3. What types of fluids can be measured using turbine flow meters?
   Turbine meters are ideal for clean, low-viscosity liquids and gases, such as water, hydrocarbons, solvents, and natural gas.

4. What are the key components of a turbine flow meter?

   • Rotor and blades

   • Flow straighteners

   • Bearings

   • Pick-up coil (sensor)

   • Housing and shaft

5. What is the output signal of a turbine flow meter?
   Typically, it provides a pulsed output, where each pulse corresponds to a fixed volume of fluid.

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✅ Performance and Design Questions

6. How is the flow rate calculated from the turbine meter signal?
   Flow rate = (Number of pulses per unit time) / (K-factor), where K-factor = Pulses per unit volume.

7. What is the typical accuracy of a turbine flow meter?
   Accuracy ranges from ±0.25% to ±1.0% of reading, depending on the design and calibration.

8. What is the typical turndown ratio for a turbine flow meter?
   A typical turndown ratio is 10:1 to 20:1, but high-performance models may exceed this.

9. What are flow straighteners and why are they used?
   They reduce flow turbulence and ensure laminar flow, improving measurement accuracy.

10. How do temperature and viscosity affect turbine flow meter performance?

• High viscosity can reduce rotor spin, affecting accuracy.

• Temperature changes can affect density and K-factor.

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✅ Installation & Application Questions

11. What are the installation requirements for turbine flow meters?

• Straight pipe runs (typically 10D upstream, 5D downstream)

• Proper alignment

• Avoid air pockets and vibration

• Flow direction must match arrow on the body

12. Can turbine flow meters be used for bidirectional flow?
    Special bi-directional turbine meters exist, but most standard models are unidirectional.

13. What are common applications of turbine flow meters?

• Custody transfer of hydrocarbons

• Water treatment

• Chemical processing

• Aerospace fuel flow monitoring

14. Why are turbine meters not recommended for dirty fluids?
    Suspended solids or debris can damage rotor blades and bearings, leading to failure.

15. How do you calibrate a turbine flow meter?

• Use master meters or gravimetric methods

• Calibration involves determining the K-factor

• Can be done in a flow lab or in-situ

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✅ Troubleshooting & Comparison Questions

16. What are common problems with turbine flow meters?

• Bearing wear

• Rotor blockage

• Signal noise

• Flow profile disturbances

17. How do turbine flow meters compare to magnetic flow meters?

• Turbine meters: Good for clean, low-viscosity fluids

• Magnetic meters: Better for dirty or conductive fluids, no moving parts

18. Can turbine flow meters measure gas flow?
    Yes, specially designed gas turbine meters are used in natural gas and industrial gas applications.

19. What are the maintenance requirements for turbine flow meters?

• Periodic inspection and cleaning

• Bearing replacement

• K-factor re-calibration

20. What factors influence the selection of a turbine flow meter?

• Fluid type and viscosity

• Flow rate range

• Pressure and temperature limits

• Required accuracy

• Installation constraints