The “8” blind board is a kind of pipe fittings, mainly for convenience of maintenance. You can paint the upper half of the “8” in black. It’s half a blind board and half an iron ring. Usually used for pipeline flange which needs to change the process. The material mainly includes carbon steel, stainless steel and alloy. It can be selected according to pipeline pressure grade and pipeline medium. Usually used in large diameter pipelines, usually use flange end occupied spacing to keep the pipeline unblocked, when needed, the other end of the same thickness of blind plate to cut off the pipeline.