COMPRESS does not provide option for extending nozzles with piping, elbows, tees, etc.
Nozzles can only have an attached flange with bolted cover, or a welded head or cover.
You can design components that extend beyond the nozzle by modeling in a second COMPRESS vessel design file: model the nozzle neck as the main cylindrical shell, then add the additional components.
For your case with a nozzle (boot) neck constructed of a forged nozzle with a rolled plate extension, I suggest the approach of modeling in a second file. If the materials were the same you "could" model as a Type 9 nozzle, which is intended for integral "self-reinforced" nozzle forgings for which the special rules of Figure UG-40 sketch (e) must be considered.
Tom Barsh
Codeware Technical Support