The puddle flange , invarious flange standards, there are requirements for the surface roughness of the sealing surface, but because of the wide variety of gaskets and different roughness requirements, the standards cannot specify one by one. When using metal flat gaskets, metal tooth-shaped gaskets, metal wave gaskets and metal cladding gaskets, the surface roughness of the flange sealing surface needs to be Ra3.2～1.6μm, which presents certain difficulties for the processing of large-diameter flange surfaces. The use of a flexible graphite plate or tape on the surface can compensate for the disadvantages caused by the large surface roughness.
