Open tank symbol
Also called Atmospheric tank, Sump, Pit
An open tank is open to the atmosphere at the top.
What the open tank symbol means
An open tank is open to the atmosphere at the top.
How it is drawn
A rectangle with no top line.
The open tank symbol in each standard
Drawn as on most US-style legend sheets.
Container, tank, cistern. Drawn the same way: open at the top.
German (DIN): Offener Behälter. See DIN P&ID symbols.
Where you see it on a P&ID
As sumps, open drain tanks, settling basins and chemical make-up tanks.
Tag codes
The open tank is commonly tagged:
- T
- TK
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 open tank symbol look like on a P&ID?
A rectangle with no top line.
What is a open tank used for?
An open tank is open to the atmosphere at the top. You will find it as sumps, open drain tanks, settling basins and chemical make-up tanks.
What tag does a open tank have?
It is commonly tagged T, TK. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the open tank symbol the same in ISA and ISO?
Yes, ISO 10628-2 draws it the same way (2061). Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the open tank called in German?
Offener Behälter. On a German R&I-Fließschema it is drawn to DIN EN ISO 10628-2.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016