The differential by-pass valve is used in systems working with variable flow rates, for example in those making widespread use of thermostatic
valves or 2-way motorised valves. It ensures a flow recirculation proportional to the number of valves being closed, while limiting the maximum
differential pressure value generated by the pump. In chilled water systems with high head pumps, installation of the version with a setting range
between 100 and 400 kPa is advisable.