Needle Valve

(1) Valve by which fluid flow rate is controlled by the degree of insertion of a tapered needle into a fixed diameter orifice. This type of valve can provide a fine gradation of flow. (2) Valve in which a blunt, conically ended needle seats on a fixed diameter orifice. With this type of valve there is little or no gradation of flow, control being limited to full, with needle lifted, or none, with needle seated.

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