Ball Valve Glossary

This comprehensive glossary provides clear definitions of common terms used in ball valve design, selection, installation, operation, and maintenance. It is intended as a helpful reference for engineers, technicians, and anyone working with ball valves.

Key Terms and Definitions (A–Z)

• Actuator: A device used to operate a valve remotely or automatically (electric, pneumatic, hydraulic, or manual).
• Anti-Static Device: A feature that prevents static electricity buildup between the ball, stem, and body.
• Ball: The spherical component inside a ball valve that rotates to control flow through the valve.
• Ball Valve: A quarter-turn valve that uses a hollow, perforated, and pivoting ball to control flow.
• Blow-Out Proof Stem: A stem design that prevents the stem from being forced out of the valve body by internal pressure.
• Cavity: The space between the ball and the valve body.
• Cavity Filler: A material placed in the valve cavity to reduce dead space and prevent media buildup or contamination.
• Dead Leg: A section of piping with little or no flow that can lead to contamination, stagnation, or bacterial growth.
• Double Offset: A butterfly valve design with two offsets (stem and disc) that reduces seat wear and operating torque.
• Fire Safe: A valve design tested to maintain sealing integrity during and after exposure to fire.
• Float Ball / Floating Ball: A ball valve design where the ball is held in place by the seats and floats slightly downstream under pressure.
• Full Port / Full Bore: A ball valve design where the bore diameter matches the pipe diameter, minimizing pressure drop and allowing pigging.
• ISO 5211 Mounting Pad: A standardized mounting interface on a valve for easy and secure actuator attachment.
• L-Port: A 3-way ball valve configuration with an L-shaped flow path, typically used for diverting flow.
• Live-Loaded Packing: A stem sealing system that uses springs or Belleville washers to maintain consistent packing pressure over time.
• Metal Seated: A valve design that uses metal-to-metal contact between the ball and seats for sealing.
• Multi-Port Valve: A valve with more than two ports (commonly 3-way or 4-way ball valves).
• One-Piece Ball Valve: A valve design with a single-piece body, typically non-serviceable without cutting it out of the line.
• Packing: The sealing material around the stem that prevents leakage to the atmosphere.
• Piggable: A valve design that allows pipeline pigs (cleaning or inspection devices) to pass through without obstruction.
• Reduced Port / Reduced Bore: A ball valve design where the bore is smaller than the pipe diameter.
• Resilient Seated: A valve design that uses a soft (elastomeric or polymeric) seat for bubble-tight shut-off.
• Seat: The sealing surface inside the valve that contacts the ball to stop or control flow.
• Stem: The shaft that connects the ball to the handle or actuator.
• T-Port: A 3-way ball valve configuration with a T-shaped flow path, commonly used for mixing or selecting between flow paths.
• Three-Piece Ball Valve: A valve design consisting of three body sections that allows easy in-line maintenance and seat/seal replacement.
• Trunnion Mounted: A ball valve design where the ball is mechanically supported by a trunnion (upper and lower shafts) for better performance in high-pressure applications.
• Triple Offset: A butterfly valve design with three offsets that creates a cone-shaped sealing surface, typically providing zero leakage with metal seats.
• Two-Piece Ball Valve: A valve design with two body sections, generally more serviceable than one-piece designs.
• Zero Offset: A traditional concentric butterfly valve design with no offsets between the stem, disc, and seat.

Do you need help understanding specific valve terms or selecting the right ball valve for your application? Call 908.362.9981 or submit the inquiry form and we’ll be happy to assist.