Introduction to the main principles and characteristics of pneumatic regulating valve ball valve

Explain the main principles and characteristics of ball valve
Pneumatic regulating valve ball valve is a rotary valve with a rotation angle of 0-90 °. It has excellent sealing performance, large flow coefficient, small flow resistance coefficient, simple structure, long service life and easy maintenance. Equipped with a cylinder-type actuator, the ball valve is divided into single-acting and double-acting models. Products are widely used in chemical, petroleum, textile, power, food and pharmaceutical, refrigeration, and paper industry system control.
When the ball valve of the pneumatic regulating valve is opened, the wedge block drives the wedge block to move up. It sags due to its own weight, the wedge spool assembly shrinks, and the sealing surface is separated without friction damage. When the pneumatic valve is closed, the valve stem moves downward, acts on the wedge block, expands the wedge block assembly, generates two horizontal thrusts, and presses the floating circular gate plate against the valve seat to seal the two-way blocking of the inlet and outlet media. Sealing performance Stable and leak-free. The material of the wedge block valve core is larger than the self-locking angle, which not only has small resistance due to movement factors, but also saves effort when opening and closing the valve stem. Therefore, the selected actuator has a smaller driving force. The sealing surfaces of the valve seat and valve stem are sealed with surfacing alloy to make the sealing surfaces have good resistance to medium erosion. It can ensure that the valve uses high temperature, medium containing hard particles and impurities.
功能 Actuator function of pneumatic regulating valve ball valve:
Pneumatic actuator adopts cylinder-piston structure, which has small volume, large output force, stable performance and reliable work. Equipped with a manual device, it has both pneumatic and manual conversion functions. It provides users with emergency operation on the spot when external electrical and gas failures occur. The conversion is flexible and the operation is simple and convenient. The valve is equipped with control elements such as solenoid valve, which can realize the functions of remote control, collective control, automatic control and field operation. The valve position switch is used to send the valve status signal. A retractable indicator rod is installed on the top of the actuator to indicate the opening and closing status of the valve. When the ascending zui is high, it means that the valve is fully open, and when it goes down, it means that the valve is fully closed.
的 Characteristics of pneumatic regulating valve ball valve:
1. Low fluid resistance, ball valve is one of all valves with low fluid resistance. Even a reduced diameter ball valve has relatively small fluid resistance.
2. Thrust bearing reduces the frictional torque of the valve stem, which can make the valve stem balanced and flexible in long-term operation.
3. The valve seat has good sealing performance. The sealing ring made of polytetrafluoroethylene and other materials has a structure that is easy to seal, and the valve sealing capacity of the ball valve increases with the increase of the medium pressure.
4. Stem seal is reliable. Because the stem only performs rotary motion without lifting movement, the packing seal of the stem is not easy to break, and the sealing capacity increases with the increase of the pressure of the medium.
5. Because materials such as polytetrafluoroethylene have good self-lubrication, the friction loss with the ball is small, and the service life of the ball valve is long.
6. Bottom-loading stem and stem head convex step prevent the stem from spraying out. If the valve stem seal is damaged due to fire, metal contact can be formed between the convex step and the valve body to ensure the stem seal.