Ball valves are widely used in piping systems for their reliable shut-off capability and simple operation. To effectively interpret technical drawings like P&ID (Piping and Instrumentation Diagrams), ISO schematics, or hydraulic diagrams, understanding ball valve symbols is essential. This guide provides a comprehensive overview of ball valve symbols, including 2-way, 3-way, actuated, and check types.
Common Ball Valve Symbols
1. Ball Valve Symbol in P&ID
In a P&ID, a basic ball valve is usually shown as a circle with two triangles pointing toward it, indicating the direction of flow. Variations exist depending on the valve’s actuation method and port configuration.
- Manual Ball Valve Symbol: A simple circle with a horizontal line.
- Actuated Ball Valve Symbol: Includes a square or oval actuator icon above the valve.
- Normally Closed Ball Valve Symbol: Often labeled or shaded to indicate default closed position.
2. 2-Way Ball Valve Symbol
A 2-way ball valve controls flow in a straight line with an open/close function. Its symbol consists of a ball icon in the center and two flow lines at both ends.
3. 3-Way Ball Valve Symbol
3-way ball valves, which can divert or mix flow, have more complex symbols:
- L-Port (Diverting): Usually shown with three connection lines forming an L shape.
- T-Port (Mixing): The T-port symbol has three lines forming a ‘T’.
Specialized Ball Valve Symbols
Ball Valve Hydraulic Symbol
In hydraulic schematics, a ball valve is represented by a solid circle intersecting a flow path, often according to ISO 1219 standards.
Ball Valve Pneumatic Symbol
When used in pneumatic systems, the symbol may incorporate actuator control symbols and directional arrows to show airflow control.
Ball Valve Icons and Drawing Symbols
In CAD drawings or plumbing schematics, ball valve symbols might appear as:
- Simple line drawings with handle icons
- Annotated with size and material
- ISO standard symbols with labeled ports (A, B, C)
Comparison with Other Valve Symbols
To avoid confusion, it’s important to distinguish ball valves from other common valve types:
- Gate Valve P&ID Symbol: Wedge-shaped gate inside a rectangle.
- Globe Valve P&ID Symbol: Shows a flow path that curves upward and then downward.
Conclusion
Understanding ball valve symbols—whether for a 2-way, 3-way, actuated, or check configuration—is critical when reading technical diagrams. Whether you’re reviewing a P&ID, ISO schematic, or hydraulic circuit, correctly identifying these symbols ensures accurate design and maintenance decisions.
Need help selecting the right valve or interpreting your project’s schematics? Contact us for expert support and product recommendations.
