This standard is included in DIN Handbook 384/2. Deals with terms, letter symbols and units relating to the flow of liquids through rotodynamic and positive displacement liquid pumps and positive displacement liquid pumps and associated installations. Provides a means of clarifying communications between the installation designer, operator, manufacturer and plant constructor. Identifies the units in common usage but all further legal units may be used. A definition of a liquid pump is included. Does not cover terms, letter symbols and units that refer to the component parts of rotodynamic and positive displacement pumps and installations.