Dedrooped bypass valve

Abstract

A differential pressure regulator connected in a fluid system including a bypass line and including a valve body with a high pressure inlet and a compensation inlet connected to the high pressure side of the system, a low pressure inlet, and a bypass outlet. A valve member is reciprocable within the valve housing and includes an intermediate passage between the compensation inlet and the bypass outlet, a metering port between the intermediate passage and the bypass outlet, and a compensating port between the compensating inlet and the intermediate passage. The position of this valve member controls the degree of opening of the ports. Also included is spring biasing the valve toward the closed position of the ports. The high and low pressure inlets are coupled to high and low pressure faces on the valve member, and the resulting forces act with the spring force to adjust bypass flow to achieve the substantially constant pressure drop. A compensating chamber including an inlet connected to the intermediate passage and a third pressure face is disposed such that pressure applied to the third pressure face results in a compensating force which moves the valve member toward the closed position of the ports. The pressure applied to the third pressure face is dependent on a compensating pressure drop across the compensating port. The compensating port is sized and positioned to cause a pressure drop varying as a function of valve position to compensate for increased forces tending to close the bypass port at high bypass flows.