Diaphragm valve symbol
A diaphragm valve closes by pressing a flexible diaphragm down onto a weir or the body. The fluid only touches the body and the diaphragm, so it suits corrosive, sterile and slurry services.
What the diaphragm valve symbol means
A diaphragm valve closes by pressing a flexible diaphragm down onto a weir or the body. The fluid only touches the body and the diaphragm, so it suits corrosive, sterile and slurry services.
How it is drawn
The two-triangle valve body with a curved line over the top, standing for the diaphragm.
The diaphragm valve symbol in each standard
Drawn as on most US-style legend sheets.
ISO 10628-2 has no separate symbol for this. Check the project legend sheet.
German (DIN): Membranventil. See DIN P&ID symbols.
Where you see it on a P&ID
In chemical, pharmaceutical, water treatment and food plants.
Tag codes
The diaphragm valve is commonly tagged:
- HV
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 diaphragm valve symbol look like on a P&ID?
The two-triangle valve body with a curved line over the top, standing for the diaphragm.
What is a diaphragm valve used for?
A diaphragm valve closes by pressing a flexible diaphragm down onto a weir or the body. The fluid only touches the body and the diaphragm, so it suits corrosive, sterile and slurry services. You will find it in chemical, pharmaceutical, water treatment and food plants.
What tag does a diaphragm valve have?
It is commonly tagged HV. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the diaphragm valve symbol the same in ISA and ISO?
ISO 10628-2 has no separate symbol for this. Check the project legend sheet. Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the diaphragm valve called in German?
Membranventil. 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