Darwin Designer

Question

Hi, 
 I am practicing Darwin Designer, in Cost/ Properties Tab, I see two type new pipe that one's cost optional Pipes and onother is Cost new. I don't know meaning of the line that content zero value for both Diameter and Unit Cost. I also can't understand how to self-explain the some of results is zero as well. 
 
 Please explain for me.. 
 Thanks!

Jesse Dringoli · Accepted Answer

Dang, 
 
Including a zero diameter entry in the costs/properties table gives Designer the freedom to essentially remove a pipe as a possible option in the design. This is demonstrated in the Quick Start Lesson called "Darwin Designer to Optimize a Pipe Network", under Help > WaterGEMS Help > Contents > Quick Start Lessons. This is also mentioned in the Help topic called "Costs/Properties Tab"

Jesse Dringoli · Answer

Note that more information on this subject (using the zero diameter option in Darwin Designer) can now be found in the below Support Solution, which is also linked to the top of this forum thread. 
 
 communities.bentley.com/.../22014.using-the-zero-diameter-option-in-darwin-designer