i have a question regarding on PID standards ISO 14617. Below is the attached symbol graphic, i seem cannot find anywhere what actually this symbol refer to from standards that i have looked up; PIP, ISO, DIN and BS. I would appreciate if anyone could clarify this to me and also it would be great to have a website or anything on where i could refer for more information about standards.
Thank you
so here i attached the diagram, i did lookup to https://www.edrawsoft.com/pid/images/pid-legend.pdf



