This catalogue deals with topics relating to water and airflows. The Fundamentals of Fluid Mechanics and Flow in Pipes sections cover a wide range of areas. As well as hydrostatics and the structure of pipe networks, it also analyses pipe friction loss and illustrates streamlines. The modular HM 150 series facilitates experiments on laminar and turbulent flow, pressure and flow measurement, discharge from orifices and vortex formation. In addition, it includes modules with small turbomachines and a small flow channel. Fans, pumps and turbines are dealt with extensively in the Turbomachine Demonstrators and Turbomachines sections. The Components in Piping Systems primarily consist of sectional models, e.g. valves or pumps. The Hydrology and Hydraulic Engineering section contains different sizes of flow channels with a wide range of accessories. Sediment transport and seepage processes in the ground can also be analysed. In addition, the topics of surge tanks and water hammer in pipelines are also dealt with. Many topics relating to airflow can be found under Principles Fundamentals of Aerodynamics and Airflow. Experiments on the drag forces of bodies, boundary layers, Pitot and Pitot-static tubes, flow in pipe, visualisation of streamlines, aerodynamics, Bernoulli's theorem and flow in nozzles are possible. There are also two wind channels (subsonic and supersonic).