The working principle of the three piece pneumatic ball valve is as follows:
1、 When the opening process is in the closed position, the ball is pressed on the valve seat by the mechanical pressure of the valve stem. When the hand wheel is turned counterclockwise, the valve rod moves in the opposite direction, and the angular plane at its bottom makes the ball detach from the valve seat. The valve rod continues to lift and interacts with the guide pin in the spiral groove of the valve rod to make the ball begin to rotate without friction. When it reaches the fully open position, the valve rod is lifted to the limit position, and the ball rotates to the fully open position.

The Common Use of Non metallic Compensators and the Causes of Their Easily Damaged
The non-metallic compensator is widely used in iron and steel plants, smelters, petrochemical plants, thermal power plants, cement plants, atomic power plants and other equipment such as flue gas desulfurization, dust removal equipment, air heating, flow assist blower and other equipment at the entrance and exit. It is much better than the metal expansion joint, so it is deeply criticized by users and vigorously promoted. characteristic:
⑴ It can compensate multi-dimensional direction. Various ways, large compensation amount and long service life;
⑵ It can effectively compensate or eliminate the device error;
⑶ Low rigidity and small elastic reaction force;
⑷ High temperature range and good corrosion resistance;
(5) The elastic elements that can effectively isolate vibration and reduce noise constitute the working main body are non-metallic materials, usually fiber fabrics, so they are also called fabric compensators (contraction joints, expansion joints). There is also rubber material, which can replace fiber fabric under various working conditions except that it can not meet the application conditions under ultra-high temperature (above 400).