4、 Maintenance of pneumatic ball valve
Only when the pressure before and after the ball valve is removed can the pneumatic ball valve be disassembled.
During the disassembly and reassembly of the ball valve, it is necessary to protect the sealing parts, especially the non-metallic parts, such as the O-ring and other parts, with special tools.
When reassembling the valve body of the pneumatic ball valve, the bolts must be tightened symmetrically, gradually and evenly.

It has been found after previous earthquakes abroad that in earthquakes, the storage tank and the pipeline connected to it experienced absolute displacement, resulting in great stress, which caused the pipeline to bear excessive force and torque at the equipment, pipe fittings, fixed supports, etc. connected with the pipeline. In serious cases, the tank body could be damaged, resulting in an accident of liquid storage leakage. In order to increase the stress, the pipeline system must be designed to be flexible enough to overcome the above damage. The pneumatic butterfly valve is flexible enough to reduce the stress in the pipeline, increase the thrust of the pipeline on the tank and support, and thus maintain the tank.
1. If the steel temporarily alternates cold and hot tasks, then under the thermal stress caused by the temperature difference change outside the material, large cracks will occur and expand from time to time, initially leading to splitting. Therefore, the thermal fatigue function of steel should be considered for structures and pipelines under the condition of rough temperature changes.
2. Under the action of low temperature, the cementite in the carbon steel will migrate and gather due to the energy obtained, forming the cementite with coarse grains and inclusion in the ferrite. The cementite will gradually change from lamellar to spherical, which is called spheroidization. Because the strength of graphite is extremely low and it is presented in sheet form, the strength of the material is greatly reduced. The addition of brittleness is called graphitization of materials. The carbon steel will be graphitized in the environment above 425 ℃ for the time being. It is more clear when the temperature is higher than 475 ℃. The maximum operating temperature of SH3059 regular carbon steel is 425 ℃, and the maximum operating temperature of GB150 regular carbon steel is 450 ℃.