CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: Design Calculations for Beadmill Discs   Next in Forum: Sizing a Cooling Coil
Close
Close
Close
19 comments
Member

Join Date: Sep 2008
Posts: 5

Piping and Instrumentation Diagram (P&ID)

09/25/2008 1:52 AM

Hello to all

What is the role of P&ID unit?

Thank you

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
4
Power-User
Engineering Fields - Mechanical Engineering - New Member Technical Fields - Technical Writing - New Member

Join Date: May 2007
Location: Parallel 45
Posts: 227
Good Answers: 21
#1

Re: P&ID purpose

09/25/2008 1:55 AM

PIPING AND INSTRUMENTATION DIAGRAM (P&ID)

This drawing is commonly referred to as the "P&ID" Its objective is to indicate all process and service lines, instruments and controls, equipment and data necessary for the design groups. The process flow diagram is the primary source of information for developing the P&ID.The P&ID should define piping, equipment and instrumentation well enough to cost estimation and for subsequent design, construction, operation and modification of the process. Material balance data, flow rates, temperatures, pressures and piping fitting details are not shown and purely mechanical piping details such as elbows, joints and unions are inappropriate to P&IDs.

P&ID Layout

The layout of the P&ID should resemble, as far as practicable, that of the process flow diagram. The process relationship of equipment should correspond exactly. Often it is useful to draw equipment in proportion vertically, but to reduce horizontal dimensions to save space and allow room for flow lines between equipment. Crowding information is a common drafting fault - it is desirable to space generously, as more often than not, revisions add information. On an elevational P&ID, a base line indicating grade or first-floor level can be shown. Critical elevations are noted.For revision purposes, a P&ID is best made on a drawing sheet having a grid system - this is a sheet having letters along one border and numbers along the adjacent border. Thus, references such as "A6", "B5", etc., can be given to an area where a change has been made.

Flow Lines On P&IDs

All flow lines and interconnections should be shown on P&IDs. Every line should show direction of flow and be labeled to show the area of project, conveyed fluid, line size, piping materialor specification code number (company code)and number of the line.

Interconnecting P&ID

This drawing shows process and service lines between buildings and units, etc. and serves to link the P&IDs for the individual processes, units or buildings. Like any P&ID, the drawing is not to scale. It resembles the layout of the site plan, which enables line sizes and branching points from headers to be established and assists in planning pipe ways.

Hope this helps!

__________________
Look over to the next challenge
Register to Reply Good Answer (Score 4)
Anonymous Poster
#3
In reply to #1

Re: P&ID purpose

09/26/2008 3:03 AM

It helped me also. However i would like to know how to develop plot plans and equipment location (placing equipments) on the plot plan. And also how to rout pipes using autocad. plus where to download pipe fittings and components into the autocad design center so as to make drafting faster.

Looking forward to hear from you.

Samson

Register to Reply
Anonymous Poster
#6
In reply to #3

Re: P&ID purpose

09/26/2008 11:25 AM

The easiest way to develope a P&ID is to get samples of existing P&ID's and study the relationship of components with the actual layout. Much easier than trying to get it from a book. In other words, copy a sample and adapt it to your conditions.

Register to Reply
Guru
Hobbies - DIY Welding - pipewelder

Join Date: Apr 2007
Location: North Georgia, USA
Posts: 672
Good Answers: 33
#4
In reply to #1

Re: P&ID purpose

09/26/2008 9:18 AM

That was a very good answer IMO. I would like to add that I would not go too far with a cost estimate from a P&ID drawing especially if the materials of the piping is stainless or another of the more expensive materials. It is usually true that the more costly materials such as instruments and control valves are identified enough on the P&ID that one can get feel for a good chunk of the cost. Pipe footage, Supports, details and the amount of turns in a system cannot be determined from a P&ID and I would consider this important in figuring a cost estimate.

pipewelder

__________________
pipewelder
Register to Reply
Guru
Engineering Fields - Piping Design Engineering - Retired Piper

Join Date: Feb 2007
Location: Bayonet Point, Florida
Posts: 635
Good Answers: 60
#7
In reply to #1

Re: P&ID purpose

09/26/2008 1:12 PM

AUREL MARES, You gave a very good yet very simple answer. If you don't mind I am going to copy your words and use them (with credit to you) the next time someone asks this question again.

__________________
Do it once and do it right
Register to Reply
Power-User
Engineering Fields - Mechanical Engineering - New Member Technical Fields - Technical Writing - New Member

Join Date: May 2007
Location: Parallel 45
Posts: 227
Good Answers: 21
#9
In reply to #7

Re: P&ID purpose

09/27/2008 1:29 AM

No problem PennPiper! Thank you!

__________________
Look over to the next challenge
Register to Reply
Power-User

Join Date: Jul 2008
Location: India
Posts: 457
#10
In reply to #1

Re: P&ID purpose

09/27/2008 1:42 PM

its good forum

i want to know more about the PID.

__________________
thoughts becomes things.
Register to Reply
Active Contributor

Join Date: Jan 2011
Posts: 23
#17
In reply to #1

Re: P&ID purpose

03/20/2011 2:20 AM

piping & instrument diagram is helppfull to understand about the plant.. from p&id engineer can understand the number of instrument used and what type of instrument used and how they are interconnected..

http://instrumentpedia.blogspot.com/2010/12/p-piping-and-instrument-diagram-pfd.html

Register to Reply
2
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1746
Good Answers: 243
#2

Re: Piping and Instrumentation Diagram (P&ID)

09/26/2008 1:52 AM
__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply Good Answer (Score 2)
Anonymous Poster
#14
In reply to #2

Re: Piping and Instrumentation Diagram (P&ID)

05/12/2009 10:28 AM

DO you have a copy of

P&ID / Engineering Drawings Interpretation

I cannot get it off the link neither internet archive, can you please email me at sean_bhola@yahoo.com

Register to Reply
Anonymous Poster
#5

Re: Piping and Instrumentation Diagram (P&ID)

09/26/2008 10:44 AM

hey all.

I thought P&ID or simply PID means Process and Instrumentation Diagram. This is one stop document to know the details of instrumentation and the control logic of the process setup.

Register to Reply
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1746
Good Answers: 243
#8
In reply to #5

Re: Piping and Instrumentation Diagram (P&ID)

09/26/2008 2:19 PM

P&ID means "Piping and Instrumentation Diagram", not "Process and Instrumentation Diagram".

__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply
Anonymous Poster
#11
In reply to #8

Re: Piping and Instrumentation Diagram (P&ID)

11/26/2008 2:33 AM

I think Process and Instrumentation Diagram is acceptable too.

Register to Reply
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1746
Good Answers: 243
#12
In reply to #11

Re: Piping and Instrumentation Diagram (P&ID)

11/27/2008 7:48 AM

Please, don't think

__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply
Anonymous Poster
#13
In reply to #12

Re: Piping and Instrumentation Diagram (P&ID)

01/14/2009 2:18 AM

Yes, sometimes you have to be blunt to drive the point home.

Very Good !

Chuck Cowlagi

Register to Reply
Anonymous Poster
#15
In reply to #11

Re: Piping and Instrumentation Diagram (P&ID)

09/08/2009 12:18 PM

I agree that Process and Instrumentation Diagram is acceptable. A P&ID is a graphical representation of the process and the instrumentation used to control. Process consists of the equipment, the piping, and the controls, and in some cases process design information such as pump design, tank volumes, etc. So the P&ID is much more than just piping and instrumentation. Another reason that Process is acceptable as opposed to Piping is that not all processes have piping. You may have several pieces of equipment, one after the other, on a drawing and yet there is no piping other than instrument air lines. This is very common in material handling systems.

Given everything I said, I was taught the proper terminology is Process and Instrumentation Diagram. I would surmise that it has evolved into Piping and Instrumentation Diagram, because not all "processes" are developed by "Process" Engineers, who historically have come from Chemical Engineering. And yes, I am a Chemical Engineer. Experience - over 30 years.

Register to Reply
Anonymous Poster
#16
In reply to #15

Re: Piping and Instrumentation Diagram (P&ID)

12/15/2009 4:10 AM

Assalam-o-Alikum please help me i have to do a project on gap analysis in P&ID diagram and it is totally a new topic for me how can i do that?? how can i relate this term to TQM

Register to Reply
Active Contributor

Join Date: Jan 2011
Posts: 23
#18

Re: Piping and Instrumentation Diagram (P&ID)

05/31/2011 7:39 AM

p&id- piping and instrument diagram. this drawing is for describing what are the instrument used in a plant and how they are connected.. with this engineer can understand what are the interlocks.. for controller programming also detailed study of p&id is required..

standard p&id symbols

Register to Reply
Participant

Join Date: Oct 2011
Posts: 4
#19

Re: Piping and Instrumentation Diagram (P&ID)

10/01/2011 6:04 AM

Since an example could be useful, FSvsPID.pdf is attached, to indicate a flow sheet & corresponding PID of a pump taking diesel from a tank and transferring it to a drum and then on. Note that flow sheet notes flows and specific conditions of the fluid, but does not show all pipes, valves and instruments of the installation as PID does. However the PID would usually note main data of Diesel tank, Diesel pumps, Diesel drum somewhere, which is not done here. Information on these two diagrams differs to some extend from company to company, but main concept is to give info of process with Process Flow sheet and leave pipes, valves, detailed controls, even spare diesel pump to the Instrument and Piping diagram. One flow sheet can produce numerous PIDs, the reverse has not been seen.
It is pointed out that a Licensor usually gives only flow sheets for a new Unit, but these are more detailed than the above, e.g. indicating PSVs, main instrumentation and controls with their "philosophy" (these may not be specified completely but show how to). Corresponding PIDs and Process data sheets are elaborated by the Engineer (another company) in the detailed engineering phase.
Please consider following apparent errors on presented PID, which I cannot correct (no scanner available):
1. Unit name is 80 (not 50)
2. Consequently line designation is 3"-De-801821 (not 3"-De-501821)
It is also noted that:
α) Line class AB (arbitrary) corresponds to pipe specification suitable for pressure, temperature and fluid handled, usually taken from a table agreed between Owner and Engineer before Project implementation.
β) Designation is indicative for one line. Each line shall have its designation written beside it. This is not standardized, differs widely from company to company.
γ) The PID would have finally more valves not indicated here, e.g. valve for drain on diesel tank, valve on suction before each 80-P-3A/B(operating, standby), valve and check valve on discharge of each 80-P-3A/B; also strainer on suction of each 80-P-3A/B.

http://www.ziddu.com/download/16605465/FSvsPID.pdf.html

for more reference read the ariticle..

how to interpret a p&id(p&id symbol) ?

Register to Reply
Register to Reply 19 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

Abdel Halim Galala (3); Anonymous Poster (8); AUREL MARES (2); denizen360 (2); PennPiper (1); pipewelder (1); sandeep lokhande (1); tojo.iesl (1)

Previous in Forum: Design Calculations for Beadmill Discs   Next in Forum: Sizing a Cooling Coil
You might be interested in: Piping Services, Piping Systems, Blank ID Cards

Advertisement