"PS, so which government body adopted "standard temperature and pressure" maybe I should move there. (grin)."

Some states here in the U.S.A. have adopted specific piping codes for some specific types of piping systems.

The same can be said for Boiler and Pressure vessels as well. In Europe coverages vary somewhat but in the EU itself the PED is adopted as law I believe.

So where you are is an important consideration.