In AutoCAD Plant3D we use end connection rule to connect the parts. You can change the rule in the project settup -> End connections.
e.g. Pipe + fittings+ valves looking for same ND to connect the parts.
To fix your problem, Go to Catalog editor and change the ND size to 110 and update the same part in your spec and use it.
Thanks & Regards,
S. R. Rajasekaran
Plant Solutions - AEC