lap joint Flanges

The type of flanges on the series 740 are Lap Joint flanges. The lap thickness (raised face) is between 3/16" (4.75mm) and 3/8" (9.52mm), depending on the valve size. Unless otherwise specified, the finish on the face will be serrated, concentric as defined in ASME B16.5(
A flat (smooth) finish is also available.

Flange thicknesses, bolt sizes, bolt circles for different classes conform to ASME B16.5

These images show the serrated finish of the flange face.

Lap Joint 3D view                  Lap Joint cross section view            Serration detail view