Free diagramming software for process control and P&ID - Alternatives to Visio

Hello

As the title says, do you know about some alternatives (fully free) to make process diagrams with symbol libraries like visio? My university used to give visio but not anymore and I don't want to acquire it the old faithful way (a well known bay).

Currently I'm using inkscape for svg graphics and i have to manually draw equipment, which is very time consuming.

Thank you for your help.