The main features of the pneumatic telescopic butterfly valve are as follows: novel and reasonable design, unique structure, light weight, convenient operation, quick opening and closing; The telescopic butterfly valve can not only adjust and intercept the flow, but also compensate for the expansion and contraction caused by the temperature difference of the pipeline, and also provide convenience for installation, replacement and maintenance of the valve. The sealing part can be adjusted and replaced, and the sealing performance is reliable.

Design and selection of pneumatic butterfly valve
The pneumatic butterfly valve has the functions of reducing the device stress of the pipeline, compensating the displacement of the pipeline, absorbing the vibration of the pipeline system and the noise of the pipeline system, and is widely used in aerospace, locomotive and ship and other fields. The following mainly introduces several aspects that should be considered in the design and selection of pneumatic butterfly valves.
1. Quality of original data
Austenitic stainless steel (304, 316L), Cr, Mo, Ni and other elements are selected for the data and wire mesh of ordinary hoses, which can make them have good pitting corrosion resistance. With the decrease of C content in steel, the pitting corrosion resistance will improve. The manufacturer shall select materials that meet the requirements of the specification to ensure the corrosion resistance and stress corrosion resistance of the product.
2. Dimensions
The size of the hose determines its service life at a certain level. If the pneumatic butterfly valve is too short, the purpose of compensation, vibration reduction and noise elimination may not be achieved; However, if the hose is too long, instability, increased flow resistance, additional mechanical damage and vibration will occur. Therefore, in the process of application, the choice of the stop length of the radius of curvature should be in accordance with C13/T14525-2010.
3. Flange mode
Both ends are fixed flanges, which is easy to form hose changes in local application places, reducing its service life. One end welding flange and one end loose flange can be selected, which can reach the state of no torque after the hose device, and increase the service life.