P&ID question that is driving me nuts

[StoneCold]

I am working on a batch chemical plant design. We are just starting the P&ID's and I find my self looking at three possible options for laying them out. The first would be by area, such as each reactor, or the tanker truck unloading area, or tank farm. The second method is to just show the piping and conections for each system. Say solvent delivery, or Nitrogen piping, vent header. Or the third option is to do each area with arrows that lead to the main nitrogen header or solvent delivery system.

I am sure this is obvious to you guys who lay this out all the time but I am having a hard time getting it started with some master plan.

Any good advice. I am just trying to get it going until I can get a contract engineering firm in to clean it up. But I don't want to do it all twice either.

Regard
StoneCold

 

[BenThayer]

i like things to be intuitive for the sake of the operators whenever i can.

i would likely prefer the area methods of the tank, unloading and tank farm. that way, if i go out to the tank farm with the drawing, i only need the one drawing and not a combination of three systems for one location.

i would say that this is just my $0.02 but you did not pay that much for the advice. good luck!

 

[JLSeagull]

Hybrid
Consider the area layout for the process flow to and from the reactor and processing equipment; and utility flow diagrams that resemble the plant layout for utilities, the tanker truck unloading area, tank farm etc.

 

[dcasto]

I perfer to have P&ID's in order of flow. From bringing in feed stocks, to process to storage to loading out. Its your unit based that you talked about.

Utilities like vents, flares, water and fuel are shown entering the page witout regaurd to origins. Then a Utility page that shows exact layout on how the utility enters/leaves the system.

 

[Khansahib]

The way I understand you are confused in three different drawings. Plot Plan, PFD and P&ID. I think you should start with Plot Plan
In a plot plan you show a general arrangement of how the equipment (truck/tanks/reactors) will be placed on the ground.
In the second step draw PFD, In this you show the flow rates, pressure, temperature stream number etc.

Lastly, draw P&ID, in which you give details of each instrument and equipment.

 

[katmar]

My preference (and it seems to be the usual way) is to follow JLSeagull's proposal and put each major equipment item on its own drawing with "railway lines" across the top for the utilities, and then to have separate utility P&ID's that show all the users of that utility on one drawing.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[zerosum]

I've seen it done quite a few ways but for long term usefulness, I agree with JL Seagull.

 

[StoneCold]

Thanks guys for all your input.

I believe that the only practical way to get it done is to follow JL Seagulls advice and do major equipment P&ID's and utility Drawings.
I like the idea of the utlity lines running across the top. I had forgotten about doing it that way from my time with the oil boys.

Best Regards

StoneCold

 

[davefitz]

I would recommend the P+ID be organized by system, and not simply by location. The general arrangement dwgs ,plot plans , equipment layout, etc give details based on location.

The P+ID dwg is used by the process designers, control enginers, and plant operators who are primarily focusing on an understanding of indivual processes, so it makes more sense to organize it based on systems. The millwrights and pipefitters that are asembling the equipment, and the operators that want to locate it, would refer to the GA or layougt dwgs for exact physical location of each nozzle, pipe, valve, pump, etc.

 

[dogtop]

What about reading the Process Industry Practice on how to develop P&IDs?

As someone else stated, $0.02 US Dollars!

 

[greg87]

Ideally each unit process should have its own P&ID. [however, occasionally more than one drawing may be needed so it is not too congested.] A key consideration is how you intend to organize the numbering for the equipment and instrumentation. A systematic numbering system is important, and how the systems are organized in the P&IDs will determine how easy that is.
The order of the P&IDs should follow the main process/product flow.
For utilities, the equipment for each utility would have its own P&Id. The distribution piping for each utility would have its own P&ID, with the branches going to each process p&id going off the page with a sheet reference flag. Each process p&id would have the utility branch[drop, connection] at the side with a sheet reference arrow. Having utility lines running thru process P&IDs results in clutter on the process drawing, makes it difficult for someone to follow the utility routing, and makes it even more difficult to change P&IDs in the event that a location of a drop is changed. The process system on the process P&ID most important, and utility and other info can be better shown on a utility P&ID and plot plan.
A component should never be shown on 2 p&ids. Deciding what the criteria will be for the breaks between drawings is important and its even more important be consistant in application of that criteria.

 

[FrancisL]

I agree with greg87 - the best examples I have seen are where there are P&ID's for each Unit and I mean Units as defined in the ISA S88.01 standard.
Also the numbering is important. If you have several units that are similar the tag numbers for each instrument should be the same with only the unit number part changed.