| 摘要 |
An improved control valve to control very low rates of flow having a valve body housing a throttle mechanism. The throttle mechanism comprising a bore and throttle plunger, having a helical exterior groove, sized with an annular passage therebetween. The size of the cylindrical passage is selected and held within limits so that media of a chosen viscosity maintains fully developed laminar conditions as it enters and exits the valve, by keeping the Reynolds Number under 4000. The flow rate is controlled by varying the distance that the throttle plunger extends into the bore. Because the valve operates under constant laminar conditions this varying distance yields linear results between the length of engagement of the throttle plunger in the bore and the flow rate resulting in an increased accuracy control valve.
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