Trunnion mounted ball valve has been designed with two floating seats, which are movable under the pressure of medium. Under the bottom of seats, seat loading springs are positioned to ensure two floating seats can attach the ball’s surface tightly, othermore, pressure of medium also can push seats to attach ball tightly to ensure sealing more reliable.
The fixed ball valve is equipped with a movable valve seat seal ring which can generate displacement under the pressure of medium. The seal ring is always pressed onto the ball under the preti ghtening force of the preloaded spring equipped at the bottom of the valve seat seal ring. In case that any medium pressure exists, the pressure will press the valve seat seal ring onto the ball tightly, guaranteeing the sealing performance of the ball valve.