A Pneumatic Pressure Regulator with Flow Feedback

The offset of secondary pressure is a recurring problem in pressure regulators. In conventional pressure regulators, reduction of the offset requires increase of loop gain, which deteriorates pressure control stability. This paper proposes a new pressure regulator that reduces the offset without loss of stability. The pressure regulator is composed of a pilot valve, a Venturi tube for flow rate detection and a main valve. The pressure at the throat of Venturi is fed back to the pilot valve, which reduces the offset of the regulating pressure. Simulation was carried out for the proposed system, and design parameters were determined thereby. A prototype of the designed pilot valve was manufactured and experimented upon. The experimental results revealed the effectiveness of the proposed design.