Abstract:A dynamic model of the work process of a new type rotating ball valve with double direction metal sealing was established. And the dynamic model was simulated and analyzed by using Gear PredictorCorrector Algorithm. The results of dynamic simulation and analysis revealed that the torsion of turning on the new type rotating ball valve was less than the torsion of closing up the new type rotating ball valve. And in order to avoid water hammer, the torsion of turning on the new type rotating ball valve should be less than or equal to 5 500 N·m, and the torsion of closing up the new type rotating ball valve should be less than or equal to 4 650 N·m, when the velocity of flowing water was 5 m/s.