The length of the line is -0.03 to 0.04. The plot over the Z-axis (the same axis the line travels over) has also been set from -0.03 to 0.04 within the graph. The pipe itself is a bit smaller than that.

In which direction would you like a plane? I've created one now at the same location as the line down the middle of the fluid domain perpendicular to the fluid flow like so:
I can retrieve data from this area in the chart but it looks like this:
Over the x-axis (where it should create a line due to 0 thickness of the plane) I'm getting this:
But having selected the plane as data series and measuring along the x-axis I would assume the line created should remain at X [m] = 0, right?
Thank you for the help so far. The method with the plane as data series for a scattered line has given me data I could work with. The only question that remains now is why the plane shown over the x-axis isn't on exact 0.