Needle valves are available in stainless steel, bronze, cast iron etc depending on the kind of application and are designed with a metallic needle in materials including brass, bronze, stainless steel, along with seat generally made form PVC, CPVC, PTFE etc. Needle valves are normally manually operated, but can be modified to act as a variable restrictor. These valves are available in different types of end connections including double ferrule type, NPT, BSPT and many other standard connections and in various packing materials for different applications depending on requirements, temperature and medium to be moved.