Author Description

The technical background behind the new ASME B&PV Code Section VIII Division 2 rules, for the design of conical transitions with and without a knuckle or flare are presented in this publication. The conical transition rules without knuckles or flares were developed using thin shell theory and are an extension of the rules in ASME B&PN Code Case 2150. The discontinuity stresses developed at the cylindrical-to-conical shell junction are computed using parametric equations developed in close form for both the large end and small end junctions. The stresses at conical transitions with knuckles or flares are formulated based on a rational approach by applying the pressure-area method. For both of the design methods the applicable loading includes pressure and externally applied net section axial foces and bending moments. The resulting stresses calculated from either method are compared to an allowable stress to qualify the design. If an overstress condition exists, the thickness of the shells in the vicinity of the junction is required to be increased.