A needle valve is used to accurately control flow rates of clean gases or liquids. Gradual adjustments of the stem and plunger enable smooth flow control. These valves generally have low flow rates and a relatively significant pressure drop from the inlet to the outlet. The most common application of a needle valve is to control gas flow, such as propane in a tank.
Needle valves are available with a wide range of port and orifice sizes. The connection ports can have male or female ends. Common thread standards used are NPT (National American Pipe Thread), BSP (British Standard Pipe), or metric (ISO standards). The most commonly used needle valves range from 2 to 12 mm or 1/8” to 2”. Ensuring the correct port size and orifice size ensures efficient flow and system operation with fewer chances of wear and/or leakage