It’s easier said than done but to develop a P&ID is the most important task you can learn as a graduate chemical engineer. Learn to read before you make one.
Now that you have read some P&ID’s, you would have understood the basic philosophy of making one behind it.
Most of the time symbols vary because it depends on the client since each company has their rules.
P&ID originator needs to confirm and decide the symbol with the client at first.
Make a LEGEND of all the symbols used, so it is easy for a reader to understand.
The underline principle is simple and straightforward:
1. The plant must run smoothly and safely.
2. The plant must be safe enough for startups and shut down.
3. The plant must be safe to carry out maintenance. And that means each equipment, instrument, valve, etc. can be safely taken under maintenance or replacement if necessary.
It should follow:
IMSO: Installation, Maintenance, Safety, Operation.
One should keep all these points in mind before you make P&ID.