Basic Structure
- Valve Body: Typically made of materials like stainless steel (e.g., 304, 316), brass, or carbon steel. Stainless steel offers excellent corrosion resistance, suitable for various corrosive media; brass provides good thermal conductivity and moderate corrosion resistance, often used for water, gas, etc.; carbon steel has lower costs, ideal for non-corrosive or weakly corrosive media. The valve body features internal or external threads for easy connection to threaded pipelines.
- Ball: Mostly crafted from stainless steel or cemented carbide, ensuring high strength and wear resistance. A circular through-hole in the ball controls medium flow-rotating the ball opens/closes the valve.
- Valve Seat: Common materials include PTFE (polytetrafluoroethylene), RPTFE (reinforced PTFE), or rubber. PTFE/RPTFE seats boast chemical stability and sealing performance for diverse chemicals; rubber seats offer elasticity for good sealing in water/air systems.
- Pneumatic Actuator: The silver-gray upper component uses compressed air as power. Two types prevail: double-acting (air pressure drives piston to open/close) and single-acting (spring-return) (springs reset the valve to a safe position, e.g., closed, during air failure for system safety).
Working Principle
Compressed air enters the actuator's inlet, pushing internal pistons/diaphragms. A linkage rotates the valve stem, turning the ball:
- Open: Ball's through-hole aligns with the pipeline axis, allowing unobstructed medium flow.
- Closed: Ball rotates 90°, blocking the pipeline axis to stop medium flow.
Performance Features
- High Sealing: Tight contact between the ball and seat prevents leakage, even under pressure differences-ideal for gas/chemical fluid control.
- Easy Operation: Fast-response actuators enable quick open/close actions. Precision control is achievable via air pressure/flow adjustments.
- Simple Installation: Threaded connections simplify setup/removal, reducing labor/time costs.
- Low Flow Resistance: The ball's through-hole minimizes pressure loss, ensuring smooth medium flow for high-flow applications.
- Broad Adaptability: Operates in temperatures from -40ºC to 180ºC (varies by material) and pressures up to PN16-PN40.
Application Fields
- Chemical Industry: Controls corrosive, flammable media (e.g., acids, alkalis, solvents).
- Food & Beverage: Uses food-grade materials (316L stainless steel, sanitary seals) for milk/juice production.
- Plumbing & Sanitary: Manages water flow in household/commercial systems (e.g., water heaters, faucets).
- Gas Transmission: Safely regulates natural gas, compressed air, etc.
Maintenance and Servicing
- Routine Checks: Verify actuator air pressure, valve sealing (no leaks), and stem lubrication (reapply grease for smooth rotation).
- Cleaning: Remove internal/external debris to prevent seat-ball damage-critical for media with particles.
- Actuator Upkeep: Inspect/replace worn seals; check solenoids/filters to ensure clean air supply and reliable operation.




