Why Dump Tubes are used in Thermal Power Plants

A Dump Tube is a fixed orifice, which reduces the bypass steam pressure to the condenser pressure. The steam entering the water cooled condenser from the bypass valve can be directed to avoid damage to the condenser. The dump tube is welded to the steam pipe downstream of the bypass valve. Applications of the dump tube:
Water-cooled condenser: dump tube mounted in the condenser.
Air-cooled condensers: dump tube is mounted on the bypass line, which is connected to a header going from the turbine outlet to the condenser.