This Instrument Symbols Legend CAD sheet is a detailed reference for P&ID and process drawings. It includes standard instrument bubbles, tag abbreviations, and common measurement device symbols—helping your diagrams remain consistent and easy to interpret for engineering, operations, and commissioning teams.
The legend typically covers:
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Instrument bubbles and locations (panel/central/local/behind control)
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Common tag types such as:
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Pressure: PI, PT, PR, PC, PIC, PRC
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Temperature: TI, TT, TR, TC
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Flow: FI, FT, FR, FC, FE
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Level: LI, LT, LR, LC, LA, LG
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Analyzer / transducer / specialty items
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Meter symbols and elements including orifice/venturi/v-cone, wedge meter, target meter, weir meter, ultrasonic meter, turbine meter, rotameter, vortex sensor, flow nozzle meter
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Accessories and drawing items such as quick change, straightening vanes, diaphragm meter, pitot tube/averaging pitot tube, thermometers, pressure gauges, connecting elements
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Simple logic items shown on the sheet (e.g., AND/OR/NOT gate symbols) where used in control diagrams
Use this CAD legend for:
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P&ID documentation sets and control schematics
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Standard symbol templates for drafting teams
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Training and QA review to avoid symbol/tag mistakes
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Faster instrument tagging and clearer drawings