(1) COMPRESS provides option for transitions under the component menu. However, both ends of the transition are assumed to be "open"; ie: it will not have a closed end as for a cone type head. However, you should be able to enter a small value for the small end diameter and be done with it.
(2) COMPRESS does not provide for piping or other components to be attached to the end of a nozzle other than flanges, bolted covers, and heads.
However, you can design the nozzle neck as a 6" cylinder in a second COMPRESS file. Then attach a transition to the end of the cylinder. This will get you calculations for the cone and the cone-cylinder junctions. COMPRESS provides option for eccentric cones only for horizontal vessels, not vertical.
Tom Barsh
Codeware Technical Support