Reducing regulator is a simple control device in which all the energy to operate it is derive from the control system. It is designed for industrial furnaces and heating application. It can be used to control flow, lever or pressure. It maintains a desired reduced outlet pressure while providing the required fluid flow to satisfy a variable downstream demand. The value at with the reduced pressure is maintained is the outlet pressure setting of the regulator. These regulators can maintain a constant outlet pressure over a wide range of flow even if the inlet pressure varies.