This series of fan-shaped blind plate valve is also called goggle valve, flap valve, fan valve, and is a device that can cut off the gas medium required by GB6222–86 “Industrial Gas Safety Regulations”. It is used in gas medium pipeline system of industrial and mining enterprises, municipal administration, environmental protection and other industries, especially suitable for absolute cut off of toxic, harmful and flammable gases. It is also suitable to be used as a blind plate at the end of the pipeline to shorten the maintenance time or to connect a new pipeline system. Compared with other valve devices that make absolute cut-off in the pipeline, this series of fan-shaped blind plate valve has the characteristics of novel structure, light weight, small size, convenient operation, speed of action, and absolutely reliable cut-off gas performance.