3.2 The sealing mechanism of the floating pneumatic ball valve is shown in Figure 1 (a). Since there is no fixed support at the lower end of the ball, when the floating pneumatic ball valve is closed, the ball will produce a certain amount of floating (displacement) under the effect of the medium pressure, leave the sealing seat at the inlet end and press it against the sealing seat at the outlet end, so that the medium will be blocked at the sealing seat at the outlet end. That is to say, the floating pneumatic ball valve actually only has the sealing seat at the outlet end to play a sealing role, while a small floating gap is kept between the sealing seat at the inlet end and the ball.

1. In terms of appearance, the color of the valve shaft body is the outstanding point for identification. The appearance and color of the valve can fully reflect the material condition of the valve products. For most counterfeit valve products, the selection of steel is generally discussed. As we all know, the price of steel is also an important reason for determining the price of valve products. Therefore, some Jian merchants have made great efforts in the use of steel, reducing the model of steel and passing inferior products off as superior ones. Use ordinary steel, carbon steel, malleable steel and other materials, and even use iron pipes to replace steel products. Therefore, the color of the valve is very different from that of the product. Most of these low-cost materials are white in appearance, which is obviously different from the green color of the valve steel.