- Create a pipe by applying thickness to a cylinder:
- Create another, smaller diameter pipe, and place it so that it pierces the wall of the first pipe:
- Select the first pipe, then the second pipe (order of selection is important), and click the 'Embed object' option from the Join tools dropdown toolbar button.
- Use some cross-section tool (Clipping plane, Arch Section Plane, Arch Cut Plane) to reveal internals. On the picture below, Arch Section Plane is used.