Spiral wound metallic gaskets used on standard ANSI pipe flanges are color coded on the OD edge to identify their winding & filler materials. The most common is a yellow painted edge with a pink stripe. This signifies a 304 stainless steel winding and Mica-Graphite filler.
Another common winding is 316 stainless steel with a flexible graphite filler. Its color code is a green painted edge with a gray stripe. There are many others spiral wound gasket color codes. Please contact us for a color code chart that identifies the various combinations.