Manual throttle valve is the simplest and most basic throttle valve, which is no different from the globe valve with conical channel structure. there are two kinds of structures: right-angle type and straight-through type, and there are three connection modes with pipeline: pipe joint, welding and flange connection. Manual throttle valves for halogenated hydrocarbon refrigerants are generally made of copper and the nominal diameter of the channel is 2~8mm. Ammonia manual throttle valves are generally made of cast iron and steel, and a few are made of stainless steel. At present, manual throttle valves are all stereotyped products.