Control valve for keeping the rate of flow at a fixed value

摘要

A constant-flow fluid regulating valve includes a valve casing having inlet and outlet ports at opposed ends thereof. A spring is mounted coaxially within the casing between the inlet and outlet ports and interiorly of a slide member that is slidable axially within the valve casing. The spring is adapted to bias the slide member towards the inlet port. An orifice plate having a plurality of apertures is carried by the slide member for movement therewith within the valve casing. A guide member is fixedly and coaxially mounted within the valve casing downstream of the slide member. Circumferential surfaces on the guide member and slide member define together an intermediate flow passage through which the fluid passing through the valve must travel before exiting by means of the outlet port. The spring force tends to offset fluid pressure differentials acting on the opposed surfaces of the orifice plate to thereby maintain the cross-sectional area of the intermediate flow passage substantially constant and consequently also the flow rate of the fluid through the valve.