The manual booster structure of the pneumatic pneumatic ball valve introduces that there are many valves in the gas pipeline that need to be closed and opened quickly, so the valves driven by the gas-liquid system meters can also be controlled remotely. Because the medium pressure in the transmission gas pipeline fluctuates greatly, when the pressure is relatively high, It is difficult to open and close the valve when the friction torque of the ball rotation is very large. A large driving force must be required, which requires an emergency mechanism to input energy to the driving system to increase the pressure of the working medium.

What requirements does the pneumatic butterfly valve have for the application environment
1. Temperature
The rated operating pressure of the pneumatic butterfly valve used at high temperature must be lowered according to the modification coefficient of the operating pressure and temperature of the pneumatic butterfly valve at high temperature, so as to ensure that the valve is stopped under safe conditions.
2. Corrosion
The raw material of pneumatic butterfly valve is usually stainless steel, and the active anions (such as chloride ion and sulfur ion) in the medium are easy to damage the stainless steel passive film, showing small corrosion holes on the bottom metal, which is the active center generated by pitting corrosion. The external potential of the metal inside the etch hole is relatively negative, and the external potential of the metal outside the etch hole is relatively positive, so an active passive micro galvanic corrosion cell is formed inside and outside the etch hole. The cell has a structure of large cathode and small anode area ratio, and the anode current density is large, and the etch hole deepens quickly. The strength of corroded pneumatic butterfly valve drops, and it is easy to form failure when receiving internal pressure and tensile load. Therefore, for pneumatic butterfly valves used in corrosive environments, relevant information should be selected, and protection methods should be added to improve corrosion resistance.
3. Fatigue failure
Under dynamic operation, the pneumatic butterfly valve is usually damaged by fatigue cracks due to cyclic load effect. Such damage is normal failure. In order to extend the service life, it is necessary to ensure that the hose design and selection are correct, the device is accurate, and no additional stress such as twisting of the hose occurs.
4. Water hammer phenomenon
Water hammer is a pressure transient process caused by sudden change of medium activity and sudden change of fluid momentum in the pipe. It is a special oscillation phenomenon caused by unstable activities in the pipe. When the pressure wave with sharp rise and fall is transmitted through the pipeline, it will produce a noise like that announced when the pipeline is hit with a hammer, so it is also called "water hammer with two edges and one edge". When water hammer occurs, the impact on the bend section of the pipeline becomes more severe. Therefore, the user should follow the requirements of the operating procedures, such as slowly warming, steadily pressurizing, and lowering the instantaneous flow and pressure changes to avoid water hammer.
5. Transport media
If the delivery medium in the pneumatic butterfly valve has chemical characteristics (acidic or alkaline), which is prone to electrochemical reaction, the raw materials for each part of the hose shall be selected reasonably according to the corrosion resistance function parameter table of the hose raw materials.
In addition to the above, thermal shrinkage, external oscillation and shock, alternating operating conditions, short and regular monitoring and maintenance, and inadequate handling in the pneumatic butterfly valve pipe will also affect the life of the pneumatic butterfly valve.