P&ID symbol cheat sheet PDF.
The shapes a P&ID draws, each named: instrument bubbles, valve bodies, primary elements and the off-page connector.
- Field-mounted instrument
- Panel-mounted instrument
- Shared-display BPCS function block
- Globe valve
- Control valve
- Pressure safety valve
- Orifice plate
- SIS logic solver function
- Off-page connector
The symbols, one by one.
Shape only: the letters inside a bubble are read with the ISA 5.1 letter card. Each symbol opens its own page, with its variants and the shapes it is mistaken for.
Instrument mounting symbols
Actuated valve symbols
Primary element symbols
Connector symbols
Common questions
What does the shape of an instrument bubble tell you.
Where the instrument lives and what reads it. A plain circle is field mounted, a circle with a line across it is panel mounted, a dashed line means behind the panel, a hexagon is a shared display or control system, and a square around the bubble is the safety system.
Does the card cover tag letters too.
No, deliberately. This page is geometry: bubbles, valve bodies, primary elements and connectors. The letters inside the bubble are on the ISA 5.1 cheat sheet, so each page stays readable at a glance.
Will it match my drawings.
It covers the common ISA 5.1 shapes. Facilities and EPCs vary, and a drawing's own legend sheet always wins over any printed card, which is the first thing to check on an unfamiliar set.
We run it on your drawings.
The page is a reference you read at the drawing table. From your drawing set the register comes back built, each row traceable to the sheet it came from.