Looking For A P&ID Standard With Industry Standardized Symbols

What is missing from ANSI/ISA 5.1 that you require? This Standard contains everything I have ever seen on a Piping and Instrumentation Drawing (P&ID), and many...many more.

If you have some specialized equipment or components, you may need to develop symbols for them yourself. This is not uncommon as many companies have their own set of drawing symbols and conventions. This is especially true if they do a lot of In -House design work

Why not make a "Standard" drawing with all the symbols that you use. Put all the symbols from Auto-CAD on it that you use plus the ones you create for your non-standard equipment/components. Reference this dwg. on all of you P&ID's, e.g. For symbols used on this dwg. Ref. XXX-XX. That should free up drawing space and provide the standard symbols you need.

40 years later and the discussion continues! (I'm assuming you're in the chemical/refining realm.) I once had a flow-sheet pencil template, and it didn't draw all the symbols the way my company did.

As far as I know, there is no industry-standard (API, AIChE or ASME) recommended practice for what you're looking for. So much process equipment is custom built (pressure vessels, for example). It took ISA years to get where they are.

I would try to get a look at ISO 14617. I don't have access to the standards but, referring to Wikipedia, ISO 10628 seems to relate to Process Flow Diagrams and ISO 14617 to P&I Diagrams. 14617 has several sections, including several relating to instrumentation which probably conflict with ISA 5.

Regardless, I recommend you maintain a separate legend sheet, instead of referring to standards directly. (I hope if you purchase a copy of the standard, you have the right to incorporate the symbols into your legend drawing.) You also need to incorporate your line numbering, size, spec, insulation, equipment numbering, etc. into the legend. If you don't have a legend, when the standards change, all your P&ID drawings may have conflicts.

By the way, if you have distillation towers/columns, do you number the trays starting from the top or the bottom? Everybody in the company? All your suppliers?

● ANSI/ISA 5.1 Instrumentation Symbols and Identification is very important source for instrumentation symbols used at P&ID drawings.

● And for any oil & gas project, the 1^st step of design is preparing a separate drawings as a legend sheets, instead of referring to standards directly to avoid any conflicts. These drawings shall include symbols of equipment (mechanical, electrical, process, instruments, … etc.), abbreviations, flow diagrams symbols legend, fluid symbols, piping components symbols, valve coding and symbols, line numbering system, instrument function and symbols, … etc.

● For equipment, there are a lot of handbooks includes its symbols and legend.

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Or this link:

https://www.mediafire.com/file/whu7m4y157ab3ci/1._Enppi_-_Piping_Symbols_%26_Legend.pdf/file