Process line symbol
Also called Major process line, Main process piping
A process line is a pipe carrying the main process fluid between equipment.
What the process line symbol means
A process line is a pipe carrying the main process fluid between equipment.
How it is drawn
A thick solid line with flow arrows, labelled with a line number giving size, service, number and piping specification.
The process line symbol in each standard
Drawn as on most US-style legend sheets.
Pipeline. A solid line, as in every standard.
German (DIN): Hauptrohrleitung. See DIN P&ID symbols.
Where you see it on a P&ID
For all main process piping on the P&ID.
Tag codes
The process line is commonly tagged:
- Line number, e.g. 6"-P-1001-A1A
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 process line symbol look like on a P&ID?
A thick solid line with flow arrows, labelled with a line number giving size, service, number and piping specification.
What is a process line used for?
A process line is a pipe carrying the main process fluid between equipment. You will find it for all main process piping on the P&ID.
What tag does a process line have?
It is commonly tagged Line number, e.g. 6"-P-1001-A1A. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the process line symbol the same in ISA and ISO?
Yes, ISO 10628-2 draws it the same way (405). Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the process line called in German?
Hauptrohrleitung. 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