Question:

Why are stiffening rings not taken into account at the Cone-Shell junctions under internal pressure?

Answer:

According to CODAP design standards, stiffeners are not used to reinforce conical junctions under internal pressure. Instead, the small end shell thickness must be increased to ensure structural integrity.

If a user wishes to apply additional reinforcement using stiffening rings, this approach is not supported by AutoPIPE Vessel (APV). The software does not handle reinforcement through stiffeners at these junctions.
Therefore, the recommended solution is to increase the shell thicknesses rather than relying on stiffening rings.