The function of surge tank

The main functions of a surge tank are:

It reduces the amplitude of pressure fluctuations by reflecting the incoming pressure waves

It improves the regulation characteristic of a hydraulic turbine.

The surge tank dimensions and location are based on the following considerations

The surge tank should be located as close to the power or pumping plant as possible;

The surge tank should be of sufficient height to prevent overflow for all conditions of operation;

The bottom of surge tank should be low enough that during its operation the tank is drained out and admit air into the turbine penstock or pumping discharge line; and

The surge tank must have sufficient cross sectional area to ensure stability.