Hydraulic signal line symbol
A hydraulic signal line carries a hydraulic pressure signal, for example to a hydraulic valve actuator.
What the hydraulic signal line symbol means
A hydraulic signal line carries a hydraulic pressure signal, for example to a hydraulic valve actuator.
How it is drawn
A thin line with small L shapes at intervals.
The hydraulic signal line symbol in each standard
Drawn as ISA 5.1 defines it, as on most US and international legends.
Signal lines are not part of ISO 10628-2. They come from IEC 62424 or ISA 5.1.
German (DIN): Hydraulische Signalleitung. See DIN P&ID symbols.
Where you see it on a P&ID
On hydraulic actuators, wellhead control panels and subsea systems.
Tag codes
The hydraulic signal line is commonly tagged:
- ISA 5.1
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 hydraulic signal line symbol look like on a P&ID?
A thin line with small L shapes at intervals.
What is a hydraulic signal line used for?
A hydraulic signal line carries a hydraulic pressure signal, for example to a hydraulic valve actuator. You will find it on hydraulic actuators, wellhead control panels and subsea systems.
What tag does a hydraulic signal line have?
It is commonly tagged ISA 5.1. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the hydraulic signal line symbol the same in ISA and ISO?
Signal lines are not part of ISO 10628-2. They come from IEC 62424 or ISA 5.1. Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the hydraulic signal line called in German?
Hydraulische Signalleitung. 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