Plug valve is closed into a plunger-shaped rotary valve, by rotating 90. So that the passage on the valve plug on the valve body and the mouth of the mouth connected or disconnected, to achieve a valve on or off. The shape of the plug may be cylindrical; or conical. In cylindrical valve plugs, the channels are generally rectangular; in tapered plugs, the channels are trapezoidal. These shapes make the plug valve structure lightweight, but it also produces a certain pressure loss. Plug valves are best suited for use as shut-off and switch-on media as well as shunting, but are sometimes used for throttling depending on the nature of the application and the erosion resistance of the sealing surfaces. Due to the wiping effect of the movement between the sealing surfaces of the stopcock and full contact with the flowing medium when fully open, it can also generally be used for media with suspended particles. Another important feature of the plug valve is its ease of adaptation to multichannel structures, so that one valve can take two, three, or even four different flow paths. This simplifies the design of the piping system, reducing the amount of valves and some of the connections needed in the equipment. Plug valves are widely used in oilfield mining, transportation and refining equipment, but also widely used in petrochemical, chemical, gas, natural gas, liquefied petroleum gas, HVAC industry and general industry.