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 P&ID Take-off and mapping 
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Joined: Sun Jan 22, 2012 10:02 pm
Posts: 283
Software for the take-off and mapping from a P&ID is essential fo the success of ISO 15926.

I have done it manually for a P&ID snippet showing the anti-surge controls of a centrifugal compressor, just for my education. As Victor assured me, that shouldn't be done manually. So the software folks are invited to chip in.

The results of my hard labo(u)r can be found at http://www.15926.org/publications/general-discussions/pid-take-off/index.htm

Please shoot at it, if so required.


Mon Aug 20, 2012 12:46 pm
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Joined: Tue May 15, 2012 8:48 am
Posts: 77
HansTeijgeler wrote:
Software for the take-off and mapping from a P&ID is essential fo the success of ISO 15926.

I have done it manually for a P&ID snippet showing the anti-surge controls of a centrifugal compressor, just for my education. As Victor assured me, that shouldn't be done manually. So the software folks are invited to chip in.

The results of my hard labo(u)r can be found at http://www.15926.org/publications/general-discussions/pid-take-off/index.htm

Please shoot at it, if so required.


This is good stuff and I am happy to help move this further.

General Comments

A P&ID is a schematic not a physical diagram and of course
the objects modelled on it are Functional rather than Physical.

Equipment Items and Pipes often appear on more than P&ID
so we need to be aware of that.

Plant Items

Showing drivers on P&ID's is frequently either not done at all
or only done for major power users. There is no hard and fast rule
on this its a policy that is often set at company or even manager
level. Its actually more common in my experience to derive power
requirements from Equipment Lists and Data Sheets than from
P&ID's. Generally the Electrical Design Group rely on their
own electrical schematic in the form of the Single Line Diagram.

Major Plant Items are sometimes ordered before the P&ID even exists
and are typically specified and purchased from data sheets rather
than the P&ID

Control Systems

Instrument and Loop tags usually follow the tagging schemes
laid down by ISA or KKS pretty closely but it is certainly true
that there is no one to one relationship between the schematic
representation and the physical Instrument loop. As you mention the
loop may actually contain more devices than are shown on the P&ID
but its equally the case that with modern digital technology
the physical Indicator may be nothing more than a readout
on a shared LCD screen while recorders are often multichannel
devices shared by many instruments. Some apaprent instruments
end up as nothing more physical than a software signal in fact

Streams

In my experience stream naming is more often derived from the
process simulation than the line segments and naming reflects that

A given line segment will typically have a single stream but
equipment items may have multiple streams. A simple tank or vessel
would only have a single stream but a pump or compressor would
have inlet and outlet streams while a heat exchanger would have
tubeside and shell side outlet stream. A distillation column could
have many more. While streams are rarely shown on P&ID's there
are systems such as Aspen Basic Engineering and Autoplant where they
are modelled in the database and relationships set between
Equipments, Lines and Valves to the stream

One problem that needs to be considered with streams is that
the apparent connectivity differe between the simulation/PFD
and the P&ID.

The simulation and the PFD will typically be modelling the
Unit Operation such as PUMPING , HEATING, COOLING etc.

This means that Pumping Unit Op P-100 may become 3 pumps
P-100A, P-100B and P-100C all of which share the same
inlet and outlet Streams Similarly a Heater and Cooler may be
combined into a single Heat Exchanger.


Wed Aug 29, 2012 4:32 pm
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Joined: Sun Jan 22, 2012 10:02 pm
Posts: 283
Hi Keith,

Thanks for your response!

Is there a possibility for Bentley to draft this little P&ID and build some software to achieve the same mapping results?
This would be an important step forward!

Regards,
Hans


Wed Aug 29, 2012 9:09 pm
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Joined: Tue May 15, 2012 8:48 am
Posts: 77
HansTeijgeler wrote:
Hi Keith,

Thanks for your response!

Is there a possibility for Bentley to draft this little P&ID and build some software to achieve the same mapping results?
This would be an important step forward!

Regards,
Hans


We could manage something I'm sure

As part of the Geometry SIG and MIMOSA effeors we are essentially doing much the same thing and I have already had one crack at documenting the PID Data Model


Thu Aug 30, 2012 3:39 pm
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Joined: Tue May 15, 2012 7:06 am
Posts: 12
Very interesting!

Are there any artifacts for typical PID characteristics of this system including piping material characteristic (diameter and wall thickness) and process characteristic (pressure, temperature, fluid)?


Thu Jan 17, 2013 7:10 am
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Joined: Sun Jan 22, 2012 10:02 pm
Posts: 283
Hi Pavel,

I had done that in another context: http://www.infowebml.ws/mapping/line-list.htm

Regards,
Hans


Thu Jan 17, 2013 7:49 am
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Joined: Tue May 15, 2012 7:06 am
Posts: 12
Hans,

I think what there is a missing point - a process case, because in fact this system could be used in many regimes, so set of streams have to be process case.

And about material characteristics - as I know PID are usually designed using piping specification. Piping specification contains only specified sets of pipes (this is clear classification pattern).

So this is open question for me.


Fri Jan 18, 2013 5:32 am
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Joined: Sun Jan 22, 2012 10:02 pm
Posts: 283
A P&ID as such doesn't deal with streams, and hence also not with process cases (modes). Process modes usually require different line-ups (stream paths) and controller setpoints. Some people may annotate P&IDs with such information, but to me that doesn't seem to be a solid basis for mapping.


Fri Jan 18, 2013 11:24 am
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