Gaskets

ASME standards describe several designs, but the most common are the raised face and the flat face. The difference between them is that the raised face flange has a raised region surrounding the pipe bore. The bolt holes are outside of this. The flat face flange has no such step. For either raised face or flat face flanges there are two available types of gaskets. Ring Gaskets are a continuous ring and full-face gaskets include bolt holes.