The blind plate is mainly used to completely isolate the production medium to prevent the shut-off valve from closing tightly, affecting production, and even causing accidents. Blind plates should be set at the parts that require isolation, such as the equipment nozzle, the front and back of the shut-off valve, or between two flanges. It is often recommended to use 8-shaped blind plates; for single-use parts such as pressing and blowing, plug Board (round blind board).