The ball of the pneumatic ball valve is fixed and does not move after being pressed. The fixed ball valve has a floating valve seat. After receiving the pressure of the medium, the valve seat will move, so that the sealing ring is pressed tightly on the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the sphere, and the operating torque is small, which is suitable for high-pressure and large-diameter valves. In order to reduce the operating torque of the pneumatic ball valve and increase the reliability of the seal, the oil-sealed ball valve appeared, which not only injects a special lubricant between the sealing surfaces to form an oil film, which enhances the sealing performance and reduces the operating torque. Suitable for high pressure and large diameter ball valves.
According to the pressure, the nature of the medium and the different sealing requirements, the ball valve selects the front and back seal layout of the ball, or the front and rear double seal layout. The seat material of medium and high temperature ball valves can be para-polystyrene and metal materials. The power source of the pneumatic ball valve is gas, which is generally at a pressure of 0.2-0.8MPa, which is relatively safe. If the pneumatic ball valve leaks, compared to hydraulic and electric, the gas can be discharged directly, which does not pollute the environment and has high safety at the same time.
