AutoCAD P&ID has four different symbol standards templates JIS, ISA, PIP, ISO/DIN. Depending on your company’s standards, guidelines, templates and region, the one you use will vary. It’s important to start with the correct standard, as changing later will require remapping of your entire diagram. It is not good practice to use two different standards for a P&ID and it should be avoided.
AutoCAD P&ID JIS – Japanese Industrial Standards
AutoCAD P&ID ISA – International society of automation
AutoCAD P&ID PIP – Process Industry Practices
AutoCAD P&ID ISO – International Organization for Standardization
AutoCAD P&ID DIN – Deutsches Institut für Normung