An insert inlet tube assembly for a flash tank including a sidewall and an insert inlet port has been conceived, the insert inlet tube assembly may comprise: a tubular section configured to be inserted into the inlet port and fixed to the inlet port, and an insert outlet of the tubular section, and inserted into an inlet port of the chamber, wherein the insert inlet tube extends inward of the sidewall and the insert outlet has an elongated cross-sectional shape oriented substantially parallel to a center vertical axis of the flash tank and substantially perpendicular to a radial line of the flash tank, such that the insert outlet is substantially tangential to the sidewall.