Lap Joint Flanges does not have a raised face, they used in conjunction with a “Lap Joint Stub End”. These flanges are nearly identical to a Slip On flange with the exception of a radius at the intersection of the flange face and the bore to accommodate the flanged portion of the Stub End. These flanges slip over the pipe and are not welded or otherwise fastened to it. Bolting pressure is transmitted to the gasket by the pressure of the flange against the back of the pipe lap (Stub End).
