Main parts of a Francis Turbine

Francis Turbine consists more complex parts than Pelton Turbine.It's operation is also complicated.

Francis type Turbine units cover a wide head range, from 20 meters to 700 meters, and their output power varies from just a few kilowatts up to 1 GW. Francis turbines may be designed for a wide range of heads and flows.

Spiral Case: provides encased water path to contain the water pressure

Stay Ring: Supports total weights of superposed parts, such as generator turbine rotating parts and superposed concrete.

Runner: absorbs the energy from the water and converts it to rotational motion of the main shaft.

Head cover: Supports the weights of guide vanes and confine the vibrations and unnecessary movements of the wicket gates

Bottom Ring: provide drainage space

Shaft Seal: Prevent water leakage between main shaft and head cover.