I found LucidChart from a resource I found about P&ID symbols from Assured Automation my automated valve supplier. It is very simple to use and there is a free trial available. I have not used it in a database driven project, and I don't know if that is a feature or not.
Can anyone recommend the best complete resource for Metal specifications, properties, standards, etc?
I am mainly interested in those used to make valves: Brass, Carbon Steel, Stainless Steel, Ductile Iron.