12 replies to this topic

[fui]

hey frens,

i need to summarize some standard symbol of engineering instrument (chemical engineering), such as, pumps, valve, column, indicators, meters and so on. if possible anyone can send me relevant ISO standard symbols?

[Andree]

I found this a few months ago in internet
Hope this helps
A.

Attached Files

•  Process_Diagrams.pdf   1.58MB   1077 downloads

[aanita]

Andree
I can not dwnload the file you give the link.
Can you please verify it is working?
Regards.

[fui]

thanks andree

[rxnarang]

Can I suggest PIP ?

[url="http://www.pip.org/d...ample-PID.pdf"]

This is a grossly underutilized practice, primarily because one has to pay to access.

It would be wonderful if PIP practices could be free to access.

Regards

[binzee]

You may also refer to this book
"CHEMICAL ENGINEERING DRAWING SYMBOLS" BY D.G. AUSTIN

HALSTED PRESS LONDON 1979

REGARDS,

[Juicexlx]

I had the same exact question not long ago... What I've found is this: you go on the ISO web site and pay for the REAL document (expensive and quoted in Euro. Believe me, that's a lot of money they are asking for... OR you go on the web site: scribd.com, you register and you search for and download (free) the DOE (Departement of Energy, USA): <u>Engineering Symbology</u> volume 1. Hope that helped. <img src="http://www.cheresour...IR#>/ph34r.gif" style="vertical-align:middle" emoid="" border="0" alt="ph34r.gif" />

[JLMONTREAL]

I am confused for the instrument symbols. Please help to clarify.
We may use pressure controller as an example. If we need the trend curve in the PLC or DCS display, I am used to the method by indicating as PRC in P&ID, or PIC if no trend curve is needed. I believe this is the process requirements for the instrument function. These functions can be configured in PLC and DCS only as per such kind of requirement. And also this type of expression can tell the reader directly the function of the instruments.

Recently some other engineers told me this is an old method. PC is good enough to imply indicating or recording function. They think PLC or DCS can indicate or show the curves by default. R only refers to the old controller with the record paper. The same reason is for TI only (no TR needed), LI only (no LR needed), etc.

I don’t agree but I don’t have some supporting documents with me. Even in these threads and internet, the two expressions exist. Could anybody clarify which method is correct?

[djack77494]

JL,
I was brought up in "the old method", but I agree with the folks telling you that PC is good enough. With modern instrumentation you can always get instantaneous indications as well as trends, so all PLC or DCS instruments have the "I" and "R" functions.
Doug

[JLMONTREAL]

Thanks, Doug

I used DCS Honeywell2000 five years ago. What I knew was that the DCS did have the function to create curves for all the parameters (if there was enough memory.). However, if the trend curve was not required by process people, there was no logged data or curves by default, only real-time indication. This helps to decide how many memory cards or other hardware needed. The <u>PRCA</u> or <u>PICA</u> tells if trend curve or alarm is needed in this controller. The same instrument symbol philosophy apllied everywhere in the P&ID developmed by Fostwheeler in 1991.

If we thought the trend curve or alarm was needed for certain parameters, we had to request extra configuration from the software/instrument engineers. Sometimes, even extra memory cards had to be added.

Does today's DCS/PLC log all the parameter data and create curves by default?

Thanks. JL

[djack77494]

JL,

I think that the answer to your question, especially if we're talking about DCS systems, is "yes". These are powerful full-fledged computer systems having lots of resources available. All I've seen have lots of storage and the ability to retrieve and analyze historical data. That to me satisfies the "recorder" function of old. As the technology has advanced, I think there are very few remaining issues with adequate memory or storage.

[JLMONTREAL]

Thanks

[denizen360]

internationally accepted p&id symbols..the below article will help you to familiar with p&id symbols..
p&id symbols