While offering good sealing, the entire load of the working medium on the ball is transferred to the outlet sealing ring. Therefore, it's crucial to consider whether the sealing ring material can withstand the working load of the medium on the ball. Under high pressure impact, the ball may shift. This structure is generally used in medium and low-pressure ball valves.
In a fixed ball valve, the ball remains stationary under pressure. Fixed ball valves typically have a floating seat; under medium pressure, the seat moves, pressing the sealing ring tightly against the ball to ensure a seal. Bearings are usually mounted on the upper and lower shafts of the ball, resulting in low operating torque, suitable for high-pressure and large-diameter valves.
To reduce the operating torque of ball valves and increase sealing reliability, oil-sealed ball valves have emerged. These valves inject special lubricating oil between the sealing surfaces to form an oil film, enhancing sealing performance and reducing operating torque, making them even more suitable for high-pressure, large-diameter ball valves.
