Ball of trunnion ball valve is fixed

Ball of trunnion ball valve is fixed, it does not move with medium pressure. Trunnion ball valve has floating seats.  The seats move with the medium pressure to tight the ball and seal ring to ensure sealing reliability. Bearings could be mounted in top shaft and bottom shaft, which reduces operation torque. This is widely used in valves with high pressure and big sizes. To decrease the operation torque and increase sealing reliability, lubricated ball valves are adopted in recent years. A special sealant is injected between sealing faces of lubricated ball valve to create a layer. This increase the sealing reliability while decreasing the operation torque, which is better for high pressure, big sized ball valves.