According to the structure, it can be divided into four types: tight-type plug valve, self-sealing plug valve, plug valve and oil-filled plug valve. According to the channel form, it can be divided into three types: straight-type plug valve, three-way plug valve and four-way plug valve. There is also a ferrule type plug valve.
Plug valves are classified by purpose including: soft-sealed plug valves, oil-lubricated hard-sealed plug valves, lifted plug valves, three-way and four-way plug valves.
