ABSTRACT
Pumping involves the movement of liquid, or, occasionally, a liquid-gas mixture, from a suction source to a discharge point. The hydraulic gradient is that the pump is the only device adding energy. And it has to add all the energy required; not only that to overcome the difference between pressures at the suction source and discharge point, but also the losses in the connecting conduits. Pump size is determined by the required flow rate. For new plants or well-documented existing plants, flow rates are obtained from process data. Careful establishment of system characteristics is crucial. Failure to do so can lead to the wrong pump being selected, resulting in problems with the process or equipment or both. In most respects, system characteristics are essentially independent of the pump type. System friction covers losses from piping entrance and exit, fittings, valves, reducers, strainers, flow meters, and the piping run itself.
