The yEd does not cover a significant sector: chemical engineering. Rather, the PFD (Process Flow Diagram) or P&ID (Pipe and Instrument Diagram) is universally needed to describe any plant.
Kindly provide a "PFD palette", with the PFD-specific nodes. (Note that a PFD cannot be replaced by a flowchart.)
Some rival products such as Lucidchart, Dia, Visio and Visual Paradigm already have them.