Pressure unit with pump and membrane pressure tank. Suitable for water supply in homes that do not have a city network or where the city network does not have satisfactory pressure. For irrigation, garden watering, small industrial installations, and wherever else water pressure boosting is required. The operation of the pump is determined by the pressure switch settings. The pump starts when the pressure drops to the lower limit of the pressure switch and stops when the pressure rises again to the upper limit. The number of pump starts depends on the differential pressure setting of the pressure switch (usually 1.5-2 bar) and the size of the pressure tank. Therefore, the size of the pressure tank must be appropriate for the respective pump.