Steam trap symbol
A steam trap drains condensate from steam lines and equipment while holding the steam in.
What the steam trap symbol means
A steam trap drains condensate from steam lines and equipment while holding the steam in.
How it is drawn
A circle or square in the line with a T inside.
The steam trap symbol in each standard
Drawn as on most US-style legend sheets.
Self-operating release valve (steam trap). A circle in the line, half filled across the diagonal.
ISO SVG
German (DIN): Kondensatableiter. See DIN P&ID symbols.
Where you see it on a P&ID
At low points of steam lines, on heaters, tracers and steam users.
Tag codes
The steam trap is commonly tagged:
- ST
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 steam trap symbol look like on a P&ID?
A circle or square in the line with a T inside.
What is a steam trap used for?
A steam trap drains condensate from steam lines and equipment while holding the steam in. You will find it at low points of steam lines, on heaters, tracers and steam users.
What tag does a steam trap have?
It is commonly tagged ST. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the steam trap symbol the same in ISA and ISO?
No. A circle in the line, half filled across the diagonal. The ISO 10628-2 registration number is 2181. Always check the legend sheets at the front of the P&ID set.
What is the steam trap called in German?
Kondensatableiter. 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