Data shortcut the pipe network into the other drawing. If you don't want the updates to the source file to reflect in the destination file, promote the data shortcut for the pipe network and then they will be in the drawing without linking to the original file.
Christopher
http://civil-3d.blogspot.com/
Civil Reminders
http://blog.civil3dreminders.com/
http://www.CivilReminders.com/
Alumni