③ The lubrication of the liquid medium is poor, coupled with overload operating pressure, the tracking and rotation of the two sealing surfaces are not synchronized. For example, a high-speed pump with a speed of 20445r/min and a center diameter of 7cm on the sealing surface has a linear speed of up to 75m/s after operation. When one of the sealing surfaces lags behind and cannot track rotation, the instantaneous high temperature causes damage to the sealing surface.