The orifice in a waterjet cutting system is responsible for converting pressure into speed. As the water is forced through the extremely small hole of the orifice, the velocity of the jet stream increases considerably. This increase in velocity is responsible for creating a Venturi effect, or vacuum, which pulls abrasive into the cutting stream.
The extreme conditions that the orifice is placed under will eventually cause the component to fail. In order to maintain the desired performance of the waterjet cutting system, the orifice must be periodically replaced according to the manufacturer's specifications. The video below details the complete process of replacing the orifice on an abrasive cutting head.
NOTE: Always place a tray under the cutting head to catch any parts that may drop into the tank.