The pressure tanks of Varem LS line are a basic element for long lasting and efficiency of a potable water distribution system. The pressure tank stores the pressurized water of the booster systems working as hydrodynamic flywheel during drawing. This application reduces the ON/OFF switching frequency of the booster system. A pressure switch adjusts the internal pressure and activates the pump only if the water pressure in the tank is lower than the minimum required. Switching on, the pump loads the storage tank again.