The Apparatus is designed to study the pressure drop in two-phase flow under different patterns. The set-up consists of a test section, made of Borosilicate Glass to visualize the different patterns. A Centrifugal Pump, with flow control valve and by-pass valve, is provided to supply water to the pipe line. At outlet, a Separator is provided to separate the air from water. Two Rotameters one each for Air and Water are provided to measure the flow rates.