To create piping with a new line number

On the ribbon, click Home tab Part Insertion panel Pipe Spec list.
In the list, click Route New Line.
In the Assign Tag dialog box, do the following:
- In the box labeled TargetObject.Number, enter the line number (for example: 101).
  To create an unassigned pipe line, leave this box blank.
- In the Spec list, click a spec (for example: CS300).
- In the Size list, click a size (for example: 6”).
- Click Assign.
In the drawing area, click to specify the location for the start point of the pipe.
Click to specify the next point of the pipe.
Press ENTER to finish routing pipe.