The Turn 2D and 3D Layers On command turns the 2D and 3D pipe layers on.
To turn the 2D and 3D pipe layers on, go to
Ribbon: DM Plumbing->3D-BIM-> 
Turn 2D and 3D Layers On
Pulldown Menu: DM Plumbing->Layer Management->Turn 2D and 3D Layers On
The 2D and 3D pipe layers will be turned on and visible on the drawing.
If this command is run while in a paper space viewport, the VP Freeze setting for the layers will be changed to Thawed.