What is a P & ID drawing? Definition, Uses, Symbol Edgevarsity
What is a P & ID drawing? Definition, Uses, Symbol

What is a P & ID drawing? Definition, Uses, Symbol

Engineering drawing is a critical aspect in oil and gas courses for mechanical engineers. Different types of engineering drawing enhance the functionality of various equipment and structures in the oil and gas industry. Out of the different types of drawings used, we will discuss the Piping & Instrumentation Diagram or P&ID drawing. Many of you would want to know how to read P & ID drawings. But, here, we will get the basics clear in the first place.

P & ID drawing explained.

A piping and instrumentation diagram (P&ID) illustrates a process system that includes all necessary components such as piping, vessels, control valves, instrumentation, and other process equipment in the system. The P&ID is the principal schematic drawing used for laying out a process control system’s installation. You must know that the P&ID drawing is significant in all stages, from development and operation to completion within the processing system.

The P&ID drawing is usually used in the Process Industry and Engineering field. Piping and Instrumentation diagrams are vital elements in the design, modification, and maintenance phase of a systematic engineering process.

P & ID symbols

Comprehending a P & ID diagram needs expertise. Therefore, it is necessary and suggested to use symbols for ease of understanding the entire process ecosystem.

To create a clear and informative P & ID diagram, a combined need for an in-depth understanding of engineering design and the required symbols are needed.

If you are pursuing any oil and gas training courses online, P & ID drawings are an integral part of it.

The symbol used to draw a P&ID can vary from different industries to projects and clients. Typically, the core engineering team will define a symbol library to be used on the desired project. 

Key Points to remember about the P & ID drawing symbols:

  • P & ID drawings have a set of standard symbols used to represent the components in the diagrams.
  •  P & ID symbols are not subject to scale and aren’t dimensionally accurate. They are a mere representation of a specific type of component. 
  • For better identification and further specification of components, these P & ID symbols are sometimes labelled with words, letters, and numbers.
  •  The purpose of P & ID drawings is not to serve as a floor plan or map of the system but to illustrate the system’s process.

Uses of P & ID diagram

The P & ID diagram is majorly used in:

  • Planning and implementing the entire design and layout of the processing system
  • Specifying different components used in the processing system
  • Structuring the progress of various control system schemes
  • (HAZOP – hazard and operability study) for better safety and hazard management
  • Phases of the control system such as installation and development
  • As a critical reference document for practical training of the employees regarding process system operation
  • Enhanced maintenance and alteration to the process control system

Now that you are aware of the critical topics related to the P&ID drawings, you can go ahead with creating them based on standards and reading them appropriately.

P & ID drawings are an integral part of the online course for piping engineering; you can find m more details by checking the link.


by Debashree P

Debashree is an Aeronautical engineer by education and a curious researcher by passion. She is passionate about engineering and technology. She is an avid technology writer who has a knack for developing content for websites, newsletters, blogs, articles, advertising and marketing materials based on the requirements. Technologies of her interest include Aviation, Oil & Gas and AI.