Device for the regulation of flow applied to flow valves working under pressure differential

摘要

A device for regulating flow comprises a main valve operating under differential pressure wherein the main valve has a main flow inlet and a main flow outlet. The main flow inlet is equipped with a valve seat over which a main shutter is adjusted in a perpendicular direction to its shuttering plane. The main shutter has a hole on its locking face communicating with a pressure chamber disposed above the main shutter. A secondary control valve regulates small flows through the hole so as to create greater or less pressure within the pressure chamber to close or open the main shutter.