TRUNNION BALL VALVE -Bidirectional sealing design feature
According to some special working conditions and customers’ requirement, ARAN has provide the trunnion mounted ball. Valve with the double-sealing design structure, i.e. seat sealing in front of the ball and seat sealing behind the ball, thus the reliable sealing of the valve is ensured because the valve can perform normally even if one of the effective sealing designs becomes lost due to the abnormal condition.
Regarding the seat in front of the ball, the piston effect formed by the area difference between D1 and D2,plus the pre-tightended force of a spring would cause the seat in front of the ball by the pressure difference of the medium before and after the valve to touch the ball closely to form the tightness ,of
Regarding the seat after the ball, the piston effect formed by the area difference between D2 and D3, plus the pretightened force of a spring would cause the seat behind the ball to touch the ball closely to form the tightness, of which the sealing force will become bigger as the pressure difference gets higher.
ARAN’s turnnion mounted ball valve features the front ball sealing design structure.Each seat of the ball valve can separately cut off the medium at both inlet and outlet of the valve to realize double-block functions.When the ball valve is closed,body cavity and two of the body ends can be blocked with each other even if both the inlet and outlet are under pressure,when the medium left in the body cavity might be bled through the relief valve.