Trunnion or guided ball valves
Guided ball valves have a trunnion that prevents the ball from moving at the bottom. This guide or trunnion is connected to the lower end of the valve body. This allows the ball to rotate without friction and provides a better seal. Guided or trunnion ball valves are commonly used in high pressure and high temperature applications. In this publication we want to show you up to 8 types of ball valves.
Trunnion mounted ball valves work the same way as floating ball valves, but in this case the ball is anchored by a second shaft at the bottom of the shutter, called trunnion. This prevents the ball from moving from its axis. trunnion mounted ball valves can keep proper sealing on both sides at once. This is suitable for 3- or 4-way valves and valves in very low pressure applications where the flow is not enough to push the ball into its seat downstream.
These valves are effective in low and high pressure applications, and require less torque than floating ball valves.