One type of body design for a needle valve is the bar stock body. Bar stock bodies are common, and, in globe types, a ball swiveling in the stem provides the necessary rotation for seating without damage. The bar stock body is illustrated in Figure below.

Needle valves are frequently used as metering valves. Metering valves are used for extremely fine flow control. The thin disk or orifice allows for linear flow characteristics. Therefore, the number of handwheel turns can be directly correlated to the amount of flow. A typical metering valve has a stem with 40 threads per inch.

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