Trunnion mounted ball valves are based on a system that provide a fixed ball and floating seat rings, moving along the valve axis.
The side load given by the pressure acting on the ball is absorbed by the bearings. At low pressure, the sealing on the seats is obtained by the spring action on the seat rings. The more the pressure increases, the more it pushes the seats against the ball.
the trunnion mounted valves are available from ½” to 36” – ASME class 150 to 2500 – as well as API 6A 5000 and 15.000 – in several combinations of materials and execution to cover all possible service application from low temperature to high pressure