1. By function: ball valve, gate valve, balance valve, stop valve, safety valve, pressure reducing valve, check valve 2. By material: iron, zinc and gold, magnesium alloy, copper, nickel plating, zinc plating, cadmium plating, copper electroplating 3. By brand: imported brand (jacket, Minnie, Isaacson, Danfoss, Jeffrey, Metz, boma, etc.) domestic brand (manrhett, Sanye, wanyang, etc.), According to the control mode, it can be divided into automatic temperature control valve and manual temperature control valve. 5. Control mode classification: thimble control and mechanical knob control。