P&ID valve symbols
Valve symbols are the most common symbols on a P&ID. Almost all are built from the same body: two triangles meeting at their points, drawn in the line. What is added inside or on top of that body tells you the valve type.
- Gate valveA gate valve opens and closes by lifting a flat gate out of the flow path.
- Globe valveA globe valve controls flow with a plug moving onto a seat inside a globe-shaped body.
- Ball valveA ball valve opens and closes with a quarter turn of a ball with a hole through it.
- Check valveA check valve lets fluid flow in one direction only and closes automatically if the flow reverses.
- Butterfly valveA butterfly valve opens and closes with a disc that rotates a quarter turn in the line.
- Plug valveA plug valve opens and closes with a quarter turn of a tapered or cylindrical plug with a port through it.
- Diaphragm valveA diaphragm valve closes by pressing a flexible diaphragm down onto a weir or the body.
- Needle valveA needle valve has a long tapered needle that gives very fine flow adjustment.
- Angle valveAn angle valve has its inlet and outlet at 90 degrees, so it turns the flow as well as controlling it.
- Three-way valveA three-way valve has three ports.
- Four-way valveA four-way valve has four ports and switches flow between two pairs of them.
- Normally closed valveA normally closed valve is shut during normal operation and only opened for start-up, maintenance or emergencies.
Valves in ISO 10628-2
About ISO 10628-2- Gate valveValve, gate typeX8074
- Globe valveValve, globe typeX8068
- Ball valveValve, ball typeX8071
- Check valveCheck valve (general)X8077
- Butterfly valveValve, butterfly type (form 1)X8075
- Needle valveValve, needle typeX8076
- Angle valveValve, angle type (general)2102
- Three-way valveValve, three way type (general)2103
A plain body is a gate valve. A dot in the middle makes it a globe valve, a circle a ball valve, and a filled half a check valve. Three or four triangles meeting in the middle make a three-way or four-way valve.
Valves drawn filled in solid black are normally closed. Valves with an actuator on top are covered under control valve symbols.
The cards at the top use the forms of US legend sheets (PIP PIC001 practice). The grids below them show the same symbols as ISO 10628-2 or IEC 62424 draw them. See ISA vs ISO P&ID symbols for the differences.
Frequently asked questions
What are valve symbols on a P&ID?
Valve symbols are the most common symbols on a P&ID. Almost all are built from the same body: two triangles meeting at their points, drawn in the line. What is added inside or on top of that body tells you the valve type.
How many valve symbols are there?
This legend covers the 12 most common ones: gate valve, globe valve, ball valve, check valve, butterfly valve, plug valve, diaphragm valve, needle valve, angle valve, three-way valve, four-way valve, normally closed valve. Project legends may add company-specific variants.
Can I download these symbols?
Yes. Each symbol page has a free SVG and PNG, and the whole legend is available as a printable PDF chart on the P&ID symbols page.