Needle valves can be used as a leakproof on-off valve or to accurately regulate the flow rate. They are manually operated and generally used for relatively low flow rates. These valves are only suitable for clean media and can be used in one flow direction. The pressure drop of is quite large compared to other valves such as ball valves. Because turning the control knob causes a relatively small change in the position of the needle, settings are smooth and gradual. This also reduces the chance of water hammer. Needle valves are available in a wide range of port sizes and materials such as brass or stainless steel. More information can be found in our Technical Information Center.