How does the floating ball design of a flange ball valve ensure leak-free sealing?

When discussing how the floating ball design of a flange ball valve ensures leak-free sealing, it can be expanded upon in the following detailed aspects:
Optimization of Seal Surface Contact: The floating ball design allows the ball to have a certain degree of freedom within the valve seat, enabling it to automatically adjust its position to fit the seat. When the valve is closed, the ball is pressed tightly against the valve seat by the media pressure, creating a uniform seal surface contact. This tight contact helps prevent media leakage from the valve. Compared to a fixed ball design, the floating ball design can better adapt to imperfections and wear of the valve seat, maintaining long-term sealing performance.
Automatic Compensation Function: Due to the floating ball design, the ball can automatically compensate for valve seat wear or misalignment caused by temperature changes, pressure fluctuations, or installation errors. When these changes occur, the ball can adaptively adjust its position to ensure close contact with the valve seat, thus maintaining sealing performance. This automatic compensation function significantly reduces the frequency of maintenance and valve replacement, improving valve reliability and service life.
Selection of Valve Seat Materials: The valve seat of a flange ball valve is typically made of materials with good elasticity and wear resistance, such as polytetrafluoroethylene (PTFE) or reinforced rubber. These materials have excellent sealing performance and corrosion resistance, maintaining stable sealing effects under various media and operating conditions. Appropriate selection of valve seat materials not only ensures sealing performance but also reduces friction and wear, extending the valve's service life.
Dual Seal Design: Some advanced flange ball valves adopt a dual seal design, which involves setting two sealing surfaces between the ball and the valve seat. When media pressure acts on the ball, both sealing surfaces are pressurized simultaneously, enhancing the reliability and safety of sealing. The dual seal design provides additional protection under extreme operating conditions, ensuring that the valve remains leak-free under various conditions.
Other Auxiliary Measures: To further improve sealing performance, flange ball valves can also employ other auxiliary measures, such as installing packing glands or adopting fire-safe designs. Packing glands provide an additional sealing layer to prevent media leakage from the packing. Fire-safe designs can maintain valve sealing performance during emergencies such as fires, preventing the spread of flames.
In summary, the floating ball design of a flange ball valve ensures leak-free sealing through optimized seal surface contact, automatic compensation functions, appropriate selection of valve seat materials, and dual seal designs. This design enables the flange ball valve to maintain good sealing performance under harsh operating conditions such as high pressure, high temperature, or corrosive media, making it an essential fluid control equipment in industrial applications.