Do you really need to model it? I wouldn't.
I would just use a detail line and a notation to call it out on a plan view. Then I would cut a section view through a suitable bit and use detail elements to draw it as your picture shows.
If you do want it modeled and part of a system so you can schedule it and stuff, I would make a new pipe type and use it to model the system, and then in the section view I would still use detail items to make it look how you want it too look instead of like round pipe.
