We provide needle valves, which are used to precisely regulate the flow rates of pure gases or liquids. Smooth flow control is made possible by gradations in the stem and plunger adjustments. The typical characteristics of these valves include modest flow rates and a sizable pressure drop between the inlet and the output. Needles valve standard port diameters range from 1/8" to 2". (2 to 12 mm). The most typical use of a needle valve is to regulate the flow of gases, like propane in a tank.