Pressure gauge symbol
Also called Pressure indicator, PI
A pressure gauge shows the pressure locally on a dial, with no signal sent anywhere.
What the pressure gauge symbol means
A pressure gauge shows the pressure locally on a dial, with no signal sent anywhere.
How it is drawn
A field instrument circle tagged PI, connected to the process line by a thin line, often with an isolation valve.
The pressure gauge symbol in each standard
Drawn as ISA 5.1 defines it, as on most US and international legends.
ISO 10628-2 does not cover instruments. On ISO-based P&IDs they are drawn as IEC 62424 PCE requests, or to ISA 5.1 on many international projects.
German (DIN): Manometer. See DIN P&ID symbols.
Where you see it on a P&ID
On pump discharges, vessels, filters and utility headers.
Tag codes
The pressure gauge is commonly tagged:
- PI
- PG
Tag formats follow the project numbering procedure. For instruments, the letters follow ISA 5.1, explained on the instrument symbols page.
Related symbols
Frequently asked questions
What does the pressure gauge symbol look like on a P&ID?
A field instrument circle tagged PI, connected to the process line by a thin line, often with an isolation valve.
What is a pressure gauge used for?
A pressure gauge shows the pressure locally on a dial, with no signal sent anywhere. You will find it on pump discharges, vessels, filters and utility headers.
What tag does a pressure gauge have?
It is commonly tagged PI, PG. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the pressure gauge symbol the same in ISA and ISO?
ISO 10628-2 does not cover instruments. On ISO-based P&IDs they are drawn as IEC 62424 PCE requests, or to ISA 5.1 on many international projects. Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the pressure gauge called in German?
Manometer. On a German R&I-Fließschema it is drawn to DIN EN ISO 10628-2 and DIN EN 62424.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016