Difference between standard blind plate and non-standard blind plate

What is the difference between non-standard flange blind plate and figure-eight blind plate? The function is different. Blind plate is a flange with no hole in the middle, which is used to block the nozzle. The figure-8 blind plate is a kind of pipe fittings, mainly for the convenience of maintenance. The specific shape can be painted black on the upper part of the figure-8. This is half blind and half hoop. The function of non-standard flange blind plate is different. The function of non-standard flange blind plate is the same as that of head and pipe cap, but the non-standard flange blind plate seal is a detachable sealing device, and the seal of head is not ready to be opened again. There are many types of sealing surfaces, including plane, convex surface, concave-convex surface, tenon-groove surface and ring connection surface. Materials are carbon steel, stainless steel, alloy steel, copper, aluminum, PVC and PPR. 8-shaped blind flange is often used for pipeline non-standard flange that needs to change the process. The main materials are carbon steel, stainless steel and alloy, which can be selected according to the pipeline pressure grade and pipeline medium.