How to model and animate a bifurcated path? I don't know how to model a bifurcated path.

I'd like to do something good instead of that is bad bifurcation at 2 seconds of this video (the pipe is not full: it doesn't follow the full path at the bifurcation)

https://drive.google.com/file/d/1W22dFRZ_5Bj46ntfcV-lu6O2fK7URCJE/view?usp=sharing

blender file of this video:
https://drive.google.com/file/d/1M-8bKI7HsQxkfTsXez3lHQMdFCpU40yR/view?usp=sharing

Update

Thank you for these links showing how to fork a path. But even with this fork created, the pipe does not follow it. A solution?

thanks
Curves cannot be forked to create branches. And if you create more than one segment within the same curve object you won't be able to adjust an animation of those segments independently. You need separate objects.

As an example:

Let's say you animate the bevel Factor of a curve by animating the End, setting a keyframe with value 0 at frame 0, and one with a value of 100 at frame 60.

To make keyframes just hover the cursor over the value and press I.



Then you create a new segment with a new curve object and align it to start where you want the fork to start. A single curve cannot be animated at different rates in different segments, that is why it has to be a separate new curve. In this example I'm using the snap to function (Shift+S) to place the new segments precisely over the older curve.



Animate the start and end of the bevel for the second curve so that it starts at the point you want.