Fully automatic, non self-priming, frequency-controlled simplex pressure boosting system made from stainless steel (1.4301) for particle-free water. Due to frequency adjustment, the system keeps the selected operating pressure extremely constant even with changing flow requirements. Pressure surges in the system are avoided by the intelligent control system, thus continuous partial load operation is provided in wide flow ranges. The system operates much more energy-efficiently and quietly than unregulated systems. The set pressure can be adjusted with the optionally available programming device (communication adapter for Android and iOS devices).