Fully assembled automatic pressure assembly with pump and diaphragm pressure vessel. Suitable for water supply in houses that do not have a city network or where the city network does not have sufficient pressure. For irrigation, garden watering, for small industrial installations and elsewhere where reinforcement of water pressure is required. The operation of the pump is determined by the adjustment limits of the pressure switch. 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 starts of the pump depends on the setting of the differential pressure of the pressure switch (usually 1.5-2bar) and the size of the pressure vessel. The size of the pressure vessel must therefore be suitable for the respective pump.