Which of the following is not typically shown on a P&ID?

• A. Electrical power supply wiring
• B. Pipes and vessels
• C. Instrumentation tags
• D. Control loops

Answer: (A)

P&ID diagrams map how the process flows through piping and equipment and how instruments and controllers interact to control that flow. They show pipes and vessels to depict the physical layout, instrumentation tags to identify sensors and actuators, and the control loops that connect sensors, controllers, and final control elements. Electrical power supply wiring, on the other hand, is not typically included in a P&ID; the diagram focuses on process relationships, not the details of electrical power distribution. The actual power wiring, distribution, breakers, and cables belong to electrical diagrams or power distribution drawings. So the item not shown in a typical P&ID is electrical power supply wiring.