Hi,

I have both Squeak Through and Flow Control installed, the pipes have the “Squeak Through” label, see https://i.imgur.com/R2G4yUT.png
Are those mods incompatible?

Thanks!

That label is just showing you that Squeak Through has modified those pipes. Flow Control doesn't actually change the base game's pipes, it adds new ones.
Even if Squeak Through modifies the Flow Control pipes, it should still be fine. As far as I am aware, Flow Control and Squeak Through are compatible.
If you get any errors (the game won't start, or it crashes and the error message/crash log mentions Flow Control), please let me know.

Ah yes indeed, I didn’t notices the new pipes, so I was trying to use the regular pipes. Sorry for the mistake :)
I confirm the compatibility between Squeak Through and Flow Control.