There are a few options for 1 line piping in autocad mep. You can use the Single Line and Graphical 1 line based on size and using the plan / model displays or you can use the 1 line Displays which are similar to the single line display. The difference between the Single line and Graphical is the scale. Single line is always real scale and graphical is scaled to the plot scale based on the location of connector 1 of the object which may cause some issues. Also the size of the symbol drastically affects the display.
If you only want 1 line displays, you may want to space items out to appear correct in plan view. Like you would of done when drawing simple 2D plans.
The 1 line mvpart symbols scale to 95% of the laying length between connectors.
The rise drop trimming and scaling issues were fixed in 2009.
HTH
Gregg Stanley
AutoCAD MEP QA
Edited by: gregg.stanley@autodesk.com on Feb 20, 2009 7:54 PM
Gregg Stanley
QA Analyst
AEC
Autodesk, Inc.