Heat traced line symbol
Also called Traced line, Steam traced line
A heat traced line has an electric cable or small steam tube along it to keep the fluid from freezing or becoming too viscous.
What the heat traced line symbol means
A heat traced line has an electric cable or small steam tube along it to keep the fluid from freezing or becoming too viscous.
How it is drawn
The process line with a dashed line running alongside it, marked ET for electric tracing or ST for steam tracing.
The heat traced line symbol in each standard
Drawn as on most US-style legend sheets.
Tracer for heating or cooling. A second line along the pipe with a dash and dots in it. Insulated lines (X322) are hatched.
ISO SVG
German (DIN): Rohrleitung mit Begleitheizung. See DIN P&ID symbols.
Where you see it on a P&ID
On water, heavy oil, wax-prone and freeze-prone lines.
Tag codes
The heat traced line is commonly tagged:
- ET
- 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 heat traced line symbol look like on a P&ID?
The process line with a dashed line running alongside it, marked ET for electric tracing or ST for steam tracing.
What is a heat traced line used for?
A heat traced line has an electric cable or small steam tube along it to keep the fluid from freezing or becoming too viscous. You will find it on water, heavy oil, wax-prone and freeze-prone lines.
What tag does a heat traced line have?
It is commonly tagged ET, ST. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the heat traced line symbol the same in ISA and ISO?
No. A second line along the pipe with a dash and dots in it. Insulated lines (X322) are hatched. The ISO 10628-2 registration number is C0106. Always check the legend sheets at the front of the P&ID set.
What is the heat traced line called in German?
Rohrleitung mit Begleitheizung. 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