Butterfly valve symbol
A butterfly valve opens and closes with a disc that rotates a quarter turn in the line. It is compact and light, and common on large-diameter lines.
What the butterfly valve symbol means
A butterfly valve opens and closes with a disc that rotates a quarter turn in the line. It is compact and light, and common on large-diameter lines.
How it is drawn
The two-triangle valve body with a vertical line through the middle, standing for the disc. Some legends draw two end bars with a diagonal disc instead.
Variants
- Two end bars with a slanted disc
The butterfly valve symbol in each standard
Drawn as on most US-style legend sheets.
Valve, butterfly type (form 1). Form 1 is the valve body with a bar and a solid dot in the middle. Form 2 is a rectangle with a diagonal and a dot.
ISO SVG
German (DIN): Absperrklappe. See DIN P&ID symbols.
Where you see it on a P&ID
On large water, cooling water, air and low-pressure gas lines, and as control valves on large flows.
Tag codes
The butterfly valve is commonly tagged:
- HV
- FV or TV when used for control
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 butterfly valve symbol look like on a P&ID?
The two-triangle valve body with a vertical line through the middle, standing for the disc. Some legends draw two end bars with a diagonal disc instead.
What is a butterfly valve used for?
A butterfly valve opens and closes with a disc that rotates a quarter turn in the line. It is compact and light, and common on large-diameter lines. You will find it on large water, cooling water, air and low-pressure gas lines, and as control valves on large flows.
What tag does a butterfly valve have?
It is commonly tagged HV, FV or TV when used for control. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the butterfly valve symbol the same in ISA and ISO?
No. Form 1 is the valve body with a bar and a solid dot in the middle. Form 2 is a rectangle with a diagonal and a dot. The ISO 10628-2 registration number is X8075. Always check the legend sheets at the front of the P&ID set.
What is the butterfly valve called in German?
Absperrklappe. 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