Ball Valve Symbol (NC)

What is a Ball Valve?

A ball valve is a type of shut-off valve that uses a rotating ball with a hole to control the flow of fluids. To open it, a handle or actuator is used to turn the ball 90 degrees (quarter-turn) so that its bore aligns with the flow path, letting the fluid flow freely.

In this position, the handle is held parallel to the pipe, indicating that it is open. By contrast, the valve is closed by turning the handle back to its original position (perpendicular to the pipe) so the bore is perpendicular to the flow path, effectively blocking the fluid.

What does the Ball Valve NC symbol represent on a P&ID?

The Ball Valve NC (Normally Closed) symbol shows a valve that stays in the closed position when not actuated. It only allows flow when operated, making it useful for controlled start-up, shutdown, and safety applications.

What is the difference between Ball Valve NC and Ball Valve NO symbols?

• Ball Valve NC (Normally Closed): Default state is closed, requiring actuation to permit flow.
• Ball Valve NO (Normally Open): Default state is open, requiring actuation to block flow.

This difference is critical in process control, safety systems, and emergency shut-off designs.

Do Ball Valve NC symbols change based on ISO, ISA, or ANSI standards?

Yes. While Capital X Panel Designer's library follows ISO 14617 P&ID standards, other standards such as ISA S5.1 and ANSI, may present slight variations in symbol design. Always confirm the drafting standard your project requires.

Where are Ball Valve NCs commonly used in process design?

Normally Closed Ball Valves are typically used in:

• Emergency shutdown systems
• Process isolation during maintenance
• Controlled start-up sequences in industries such as chemical, oil & gas, and water treatment

Where can I find Ball Valve NC and other valve symbols for CAD and P&ID drawings?

You can access a full set of ISO-compliant symbols, including Ball Valve NC, directly from Capital X Panel Designer's Symbol Library. Using standardised symbols saves drafting time, ensures accuracy, and keeps diagrams consistent.

Skip Drawing Ball Valve P&ID Symbols With Capital X Panel Designer!

Skip the tedium of drawing symbols with Capital X Panel Designer! Just drag and drop the ball valve symbol you need wherever you desire. This easy-to-use electrical CAD software will ensure your workflow moves faster than ever.

Learn more about how to create custom electrical symbols.