4. Calculation of total friction torque The friction torque of the valve is calculated according to the following formula: MF=MQZ+MFT+MFC (N-M) (4), where: friction torque of MQ ball in the valve seat; Friction torque between MFT packing and valve rod; Friction torque analysis of MFC valve stem head The force generated by pneumatic ball valve shows that under the action of medium, the floating ball moves towards the outlet end, and the force generated is all borne by the valve seat seal ring at the outlet. The valve seat seal ring in front of the ball does not bear the force and does not affect the friction torque.

How to improve the quality of plastic coated pneumatic butterfly valve
The external improvement of the product can be carried out from time to time. When we stop the improvement of the plastic coated pneumatic butterfly valve, what aspects should we stop from? Now let's make a comprehensive understanding of this aspect. When you really find the direction of our improvement, you will find that many things will be improved.
When we improve the quality of plastic coated pneumatic butterfly valves, we should really make the products functional, and various functions can really satisfy different industries. When you really understand the overall things, you will find how critical it is to improve the overall performance of the products, We should pay attention to this aspect ourselves.
In addition to functional improvement, we also need to know how to improve the external material of plastic coated pneumatic butterfly valve. Different materials will be very different when used. When you really improve the material from time to time, how to ensure the anti-corrosion effect of pneumatic butterfly valve
The pneumatic butterfly valve will form an oxide film on the surface after reacting with the oxygen in the atmosphere. The iron oxide formed on ordinary carbon steel continues to stop oxidation, so that the corrosion will expand from time to time and eventually form holes. It is possible to apply paint or oxidation resistant metals (such as zinc, nickel and chromium) to stop electroplating to ensure the appearance of carbon steel, but, as people know, this maintenance is just a film. If the maintenance layer is destroyed, the steel below will begin to rust.
The corrosion resistance of pneumatic butterfly valve depends on the chromium content. When the chromium content reaches 10.5%, the atmospheric corrosion resistance of steel increases significantly, but when the chromium content is higher, although the corrosion resistance can still be improved, it is not obvious. The reason is that when the steel is alloyed with chromium, the type of external oxide is changed to be similar to the external oxide formed on pure chromium metal. This tightly adhered chromium rich oxide maintains the appearance and avoids further oxidation. This kind of oxide layer is extremely thin, through which you can see the natural luster of the stainless steel surface, so that stainless steel has a common appearance. Moreover, if the surface layer is damaged, the exposed steel surface will stop self repairing with the atmospheric reaction, and form this "passivation film" again to continue to play a maintenance role.