Use the Pipe Placement tools to draw pipe in your model.
When the Pipe or Pipe Placeholder tool is selected, the Modify | Place Pipe tab provides the following options for placing piping:
Inherit Elevation: inherits the elevation of the element being snapped to.
Inherit Size: inherits the size of the element being snapped to.
Slope Off: draws pipe without slope.
Slope Up: draws pipe with slope up.
Slope Down: draws pipe with slope down.
Show Slope Tooltip: displays slope information while drawing sloped pipe.
Add Vertical:sloped pipe connects using the current slope value.
Change Slope: sloped pipe connects directly regardless of the slope value.