Francis Turbine: Definition, Parts, Working, Advantages and Disadvantages and Much More

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Francis turbines are one of the most used turbines in the world and further fulfill half of the electricity demands around the globe.

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Today I am going to discuss- Francis Turbine with its definition, parts, working, advantages and disadvantages, and much more down the road with a free PDF to download at the end.

So, Without further delay, Let’s dive into mainstream…

What is Francis Turbine?

Francis turbine is a reaction type of water turbine with an inward flow and with mixed flow in radial and further axial directions.

This turbine was invented by an American engineer James Francis, that’s why it is named the Francis turbine.

francis turbine

Main Components of Francis Turbine-

The major Francis turbine components are as follows-

  1. Casing
  2. Penstrock
  3. Guide Vanes
  4. Runner
  5. Draught Tube


It is an airtight chamber with a spiral shape to maintain the constant speed and pressure of incoming water. All the internal appliances of this turbine are situated in this casing.


It is way from where the water enters the turbine radially.

Guide Vanes-

Guide vanes are used to guide the water toward the runner without losing the momentum and pressure of the water while sending it to the runner.

These guide vanes are fixed at an angle in the periphery and this arrangement of vanes is also known as a guide mechanism.


it is a circular wheel mounted on a shaft to further rotate the generator connected to the turbine shaft.

Runner uses water’s kinetic and pressure energy to rotate itself and further creates mechanical energy to rotate the shaft of the generator.

This runner consists of radial curved vanes which further help to strike the water efficiently from all directions.

Draught Tube-

This draft tube is used to discharge the water axially after striking the runner and this further helps to prevent the turbine from cavitation.

Francis turbine

Working of Francis Turbine-

The pressurized water comes from the penstock and enters into the spiral casing radially which further helps to maintain the pressure and speed of the water.

Now, the guide mechanism helps water to flow into the runner area by diverting the water into the runner’s blade without losing the pressure and motion of the water, all thanks to the guide vane design.

Now, Diverting water strikes the runner’s blade and causes it to start rotating the runner blades with the help of pressure and kinetic energy.

The connected generator shaft to the runner also starts to rotate and further the generator produces electricity and supplies it to power substations.

Used water exists from the draught tube axially maintaining the pressure of the water which further helps the turbine to prevent cavitation.

Characteristics of Francis Turbine-

  1. Head– Medium Head (60-200m)
  2. Discharge– Medium
  3. Range of Flow– Medium
  4. Specific Speed– Medium(200-400 rpm)


The major benefits of this turbine are as follows-

  • One of the most efficient turbine
  • Operating and controlling the turbine is much easy than others
  • economical Turbine
  • Compact and easy to install due to its small size
  • Controlling of the head is quite easy in this turbine


The major drawbacks of this turbine are as follows-

  • Shortage of equipment is one of the major drawbacks of this turbine including the runner. This can be solved by improving the after-sale services from manufacturers before listing Francis turbine for sale.
  • chances of cavitation
  • Complex in design
  • Maintenance and replacement of parts can be high in cost.


The major uses of this turbine are as follows-

  • Obviously, To generate electricity
  • Can be used as a pump by adding a motor to the runner


Wrapping Up-

This is all I have for the Francis turbine. I hope I discussed all the aspects of this turbine, If something is missed, Mention it in the comment section.

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Here are two related articles, you must consider before leaving-

Constant Volume & Constant Pressure Gas Turbine

Difference Between Impulse and Reaction Turbine

How Thermal Power Plant Works?



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