Cavitation refers to the formation of vapour bubbles in flowing fluids due to strong low pressure. The unit mounted on the hydraulic bench is used to demonstrate the process of cavitation. It consists of a venturi tube made from clear acrylic to allow an easy visualization inside the section. When water flow rate increases, pressure at the throat is reduced complying with the Bernoulli equation until the vapour pressure of the liquid is reached and small bubbles of vapour form and then they collapse violently as the pressure rises again downstream; this phenomenon is called cavitation. Bourdon gauges indicate the pressure upstream of the contraction, inside the throat and downstream of the contraction. Flow control valves before and after the test section enable to adjust flow and pressure so that the phenomenon of cavitation can be demonstrated.