Differences between Francis and Kaplan Turbine

The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts.

The Kaplan turbine is a propeller-type water turbine that has adjustable blades. It combines automatically adjusted propeller blades with automatically adjusted wicket gates to achieve efficiency over a wide range of flow and water levels.

The tabular form gives a comparison between Francis and Kaplan turbines below.

S.no	Francis Turbine	Kaplan Turbine
1	Francis turbine is a mixed flow turbine.	The Kaplan turbine is a purely axial flow turbine.
2	Francis turbine has a large number of blades in the runner and it varies from 16 to 24.	Kaplan turbine has a small number of blades in the runner and it varies from 3 to 8.
3	The runner blades are not adjustable.	The runner blades are adjustable.
4	The disposition of the shaft may be horizontal or vertical.	The disposition of the shaft is always vertical.
5	Francis turbine is a medium head turbine and the head varies between 60 m to 250 m.	Kaplan turbine is a low head turbine capable of working under the head less than 60 m.
6	Francis turbine works under medium discharge.	Kaplan turbine works under high discharge.
7	Francis turbine specific speed varies from 50 to 255.	Kaplan turbine specific speed varies from 255 to 860.
8	Resistance is significant due to many vanes and the greater area of contact with water.	Resistance to overcome is less due to fewer vanes and less contact area.
9	The ordinary governor is used for his governing.	The heavy-duty governor is used for its governing.
10	For the same power, it is less compact.	For the same power, it is more compact.