Contractors and end users involved in desalination business are already asking for high efficiency pumps. In Sulzer we think that it is important for them to know how they can ask for the most efficient pump by means of learning about main basic principles (specific speed, suction specific speed and NPSH) of a centrifugal pump. These parameters have strong influence on the right pump selection, not only in order to increase pump efficiency, but also to be able to keep efficiencies values through pump life cycle, and decreasing maintenance periods. Additionally, comparison between two different plants concept: Separated feed lines or common pressure centre will be shown with different examples depending on plant size, indicating in every case the achievable efficiency. Askhelon SWRO Plant in Israel is the best example of the direct application of the above mentioned concepts in a real SWRO Plant, where high pressure RO feed pump efficiency of 88.5% has been reached on site.