A
surge tank is a standpipe or storage reservoir at the downstream end of a closed
aqueduct or feeder pipe. A surge tank is used to absorb sudden rises of pressure
and to supply water quickly if there is a drop in pressure. A surge tank, also
known as a surge drum, is an open tank to which the top of a surge pipe is
fitted, to avoid the loss of water during a pressure surge. A surge tank is an
additional reservoir or storage space, placed in between the main storage
reservoir and the powerhouse, and as near to the powerhouse as possible. Surge
tanks are generally used in high or medium head plants, where there is
considerable distance between the power unit and the water source.