Flow rate sensor for a watercooled VFD - LinuxCNC

Anyone with a water cooled VFD and running LinuxCNC also using a flow rate sensor? And if so, Are you doing any interrupts if the rpms drop below a specified threshold? If so or found a resource that does that post there HAL file that does this?

I ask this so I don’t have to spend making such a system of someone is already doing the same thing.

Thanks in advance.