So here is a simplified Dynamo file, CAD file and spreadsheet. I have narrowed down the issue to this (and it is included in the attached examples): Originally I had pipes P10001, P10002 and P10003. Then I interjected a new pipe into the network after pipe P10002; this new pipe became P10003 and the former became P10004. When I run the Dynamo (which as noted in the green instruction blocks is based on the user selecting a pipe from the network), it puts the latest pipe last in order, even though it should be further up the chain. Thus, the flowline changes to the pipe are incorrect (out of order). Is there a type of “sort” filter or something that should be run? If you look closely, everything stays in order (both the Keys and the Pipe Names) until the very end… 
pipes.dwg (955.7 KB) Pipes - by network2.dyn (106.8 KB) pipes.xlsx (658.6 KB)
This is just a small sample of what I am trying to accomplish, as it is not uncommon for me to interject new pipes, or to remove others, as a project goes along.
As always, any help is greatly appreciated!
(A note – be sure to link up not only the spreadsheet but also the correct sheet by name)…
Jacob, you’ve got some good content on Dynamo there on YouTube – thanks for posting that.