The Way to Improve the Quality of Sealing Pair of Pneumatic Ball Valve
1. Ball of pneumatic ball valve The ball of pneumatic ball valve can be divided into floating pneumatic ball valve and fixed pneumatic ball valve. However, no matter what kind of ball, especially large pneumatic ball valve, the way to improve the quality of the sealing pair of pneumatic ball valve The dead weight of the ball will have an adverse impact on the sealing performance and service life of the valve. For example, the ball of the floating ball has no supporting shaft, so the fitting surface of the seal seat bears its dead weight. Therefore, under the same working condition, the greater the dead weight of the ball, the greater the wear on the sealing fitting surface in its dead weight direction, which greatly reduces the service life of the pneumatic ball valve. At the same time, once the preload of the bath towel between the sphere and the seal seat disappears, the greater the mass of the ball, the greater the differential pressure necessary to reduce the sealing, which greatly reduces the low-pressure sealing performance. Similarly, if the pneumatic ball valve is equipped with a pneumatic device for quick opening and closing, its inertia torque will be several times, dozens of times increased. Therefore, how to think of ways to reduce the dead weight will have considerable social and economic benefits for the performance and life of products, inertia torque and even manufacturing costs. Cast thin wall balls and hollow balls are used abroad, and cast balls are also used domestically. However, the casting quality cannot pass the standard. Even as a qualified part, it is far from meeting the technical requirements for the quality of the sphere. The other is the ball welded with multiple plates. The single weld has multiple processes, which is not suitable for batch production. Shanghai Shenyuan Valve Co., Ltd. has explored a unique processing method, called plate balling process. With this method, the utilization rate of plate is up to 60%, the weight is reduced by 50%, and there is only one weld, which is at a less critical fitting surface.

Analysis of life of compensator and welding of pneumatic butterfly valve
The life of the compensator is the shortest working period or cycle times that can ensure normal operation when it is used under working conditions. The elastic sealing system composed of bellows often works under the condition of accepting more cycles of variable load and larger displacement, so it is of great significance to confirm the service life of the compensator. Due to the different functions of compensators, the requirements for their service life are different.
1、 When the compensator is used to compensate for the position deviation caused by the device in the pipeline system, its life request only needs several times.
2、 The compensator is used in the thermostatic controller with high switching rate, and its service life must reach 10000 times before it can meet the application requirements.
3、 When the compensator is used as a vacuum seal for the vacuum switch, its service life must reach 30000 times to ensure normal operation.
It can be seen from the above three application examples that due to different application conditions, the service life of compensator requests varies greatly. The life of the compensator is related to the fatigue characteristics of the selected data, and also depends on the size of the residual stress of the forming compensator, the condition of stress concentration and the appearance quality of the bellows.
Step 1: nozzle size. During welding, the pipe length shall be measured first, and then the pipe knife shall be used to cut the pipe size.
Step 2: Clean the pipeline. Due to the metal nature of the pipe, some waste slag will be generated due to oxidation in the pipe, and some waste slag will affect the welding effect. Therefore, before welding, we should use emery cloth or paper to grind away the waste slag in the pipe.
Step 3: Clean the fittings with a pipe brush. Cleaning the fittings ensures that the welding hose is bonded to the tin plating.
Step 4: Control the welding time. Generally speaking, the length of the weld bead you need depends on the length of the solder.
Step 5: Use flare heat pipe. The torch heat pipe is mainly used to ensure the average heating at the welding point of the pipe. It is worth noting that when using the torch, ensure that the flame is close enough to cover the diameter of the entire pipeline.