Autodesk CIVIL3D - CIVILDESIGNCOMP 2007 SLM CD Tutorials Manual page 707

9 Right-click Modifiers
select the top two barrel segments, and the upper two horizontal pipe
segments, and then press Enter.
10 Right-click Modifiers
select the upper horizontal pipe segment, and the vertical pipe segment,
and then press Enter.
11 Switch the view to SE Isometric.
Exercise 3: Creating Profiles and Establishing Parameters | 695
Boolean Add. When prompted to select objects,
Boolean Add. When prompted to select objects,