I just found an exploit/bug

When moving a pipe, it keeps its content level. If you have two pipes partially filled with a liquid and then use this mod's ability to move pipe pieces to separate them, you get two pipe pieces, each of them with the content of the entire system it was once attached to.

Example:
You have two pipe pieces filled with 5/100 crude oil. They are connected together, so the system's content is 10/200 crude oil (Because of 2.0 logic)

Separating the pipes with this mod caused both of them to have 10/100 in their respective pipes. Placing a third pipe to reconnect them finalizes the duplication into 20/300. This can be repeated indefinitely.

This can also be reversed to destroy fluids... but at that point just delete all pipes to delete the fluid.

Thank you for the report! This behavior is the bug reported here: https://forums.factorio.com/viewtopic.php?f=7&t=117768

Basically, you have a pipe that contains 50 of a 100 possible fluid connected to a larger system that contains "1000" in total. When moving, I call get_fluids(1) and I receive "1000" instead of the "50". get_fluid is defined as 'Gets fluid of the i-th fluid storage.' but it returns the contents of the fluid system. After moving, I apply the stored values back to the pipe and so it assigns "1000" back to the pipe. As the pipe can only hold "100", it now contains '100'.

I could work around this by actually looking at entity.fluidbox[1] and peel the values out but that seems to be diminishing returns. I actually hope that the bug(s) in the game are fixed. I'll give it a few days but if I see no movement on the bug reports, I might look more into fixing that.

For now, consider it "free fluid" ;-)

A- well... I never considered this as a side effect from a bug inside the base game. Not this mod's fault then :p

I wrote a summarization here: https://forums.factorio.com/viewtopic.php?f=7&t=118003

The behavior you see is a consequence of the workaround that I implemented to be able to move storage tanks around (otherwise you lose all of the tank contents).

I thought so that this might be due to 2.0 shenanigans, as I wrote in my initial bug release.
Interesting to read out how it works and glad that you made a bandage fix for this mod fork to allow us to retain fluids in moved pipes and tanks, even if that results in "free fluid" sometimes.

2.0.14 fixes this (and the 2.2.0 release removes the fluid workaround).

Ok, so once 2.0.14 comes out as stable, this is officially solved. Technically it's already solved then.