How to

P&ID (Piping and instrument diagram) & PFD (Process flow diagram).

P&ID: Schematic illustration of instruments and their interconnection is called P&ID.

PFD:Process flow diagram.PFD gives an overview of the plant process.PFD is a simplified version of P&ID.
Symbols,circles and lines are used to represent instrument and their interconnection.For identifying instruments and pipe lines tag numbers are used.For reading P&ID(Piping & instrument diagarm) one must be familiar with standard instrument symbols and standard identification letter.


Instrument Location:The presence or absence of a line determines the location of the physical device.Some instruments are a part of a distributed control system where a specific controller or indicator can be selected from many others but shown in one location.


Piping and connection symbols:These symbols are used to identify how the instruments in the process connect to each other.And what type of singnal is being used.

Valve symbols.

Learn to read instrumentation drawings.

Tag: P&ID,Piping and instrument diagram,PFD,Process flow diagram,Valve symbol,Instrument symbols



Related posts

How to do Megger test/insulation resistance for transformer?


How to do the control valve maintenance?


What is Instrument location layout and Junction box location layout?

denizen robo


Enzar January 12, 2011 at 5:12 am

Would you sir elaborate on what is the difference between piping and pipe-ling?

Author June 1, 2011 at 8:36 am

Blog author send me a test mail to [email protected]

Its really urgent

profmaster June 3, 2011 at 7:33 am

Thanks Dear. Your Blog is also very nice & informative. I liked it & this is one of very few technical blogs which I like. Keep it up.

Sijo Joy February 22, 2012 at 11:07 am

Its a gud post regarding PID diagrams. You can find more on PIDs in the following link:

VILAS PATIL May 10, 2012 at 6:28 pm

Its Really more Informative and helpful for Beginner as well as for Experience person also. !!!!appreciated work!!!NICE JOB

Milind Vaidya February 13, 2013 at 9:19 am

I want symbols of local push button & PLC operated pump

Asis Dev March 26, 2013 at 1:20 pm

To read and understand P&ID one should have basic concept on standard symbol, notation, abbreviation etc. Many articles are available on internet focusing on P&ID. Here is a link:

This link provide sufficient reference on reading P&ID.

Asis Dev October 3, 2013 at 8:40 pm

Best reference for P&ID standard:

PiyushPanchal January 13, 2014 at 6:46 am

Thank you very much Sir, Its Really more Informative and helpful for Beginner,
appreciated work.

AcuteSoft December 9, 2014 at 3:34 pm

Piping and Instrument Diagram is a very important for a person sitting in the control room. Each and every part of the power plant can be easily operated and the placement of the devices can be easily recognized in case of any problem. And it can be solved easily.

Leave a Comment

Follow Us on LinkdIn