Description Raised Face Flange In this type of flange, the surface of the flange that is placed in front of the other flange and on which the washer or gasket is placed is made more prominent than the general surface of the flange. According to the standard in Raised Face Flange, the amount of protrusion in all sizes for classes 150 and 300 is 1.6 mm and for higher grades is 6.4 mm. In the protrusion section, the surface may be completely polished with a smooth finish or have a serrated finish groove. Mm and its distance from each other is 0.8 mm. For more information, call 09339765265 Call 09123261608.