Trunnion Mounted ball valves mean the valve ball is fixed in position by the stem and the trunnion which are supported in the bearings fixed in the valve body. Indeed, in this type of valves the shaft, the ball, and the supporting trunnion act as a single solid assembly able to withstand the heavy loads generated by balls of large dimensions.The disc design of butterfly valve and some check valves are also in the trunnion mounted type.

The seat is spring-loaded onto the ball, giving reliable sealing at low pressures and the line pressure forces the upstream seat onto the ball to cause it to seal.

Besides a size flexibility advantage, a trunnion valve features a lower operating torque compared to a floating valve design (which can become a benefit when the valve needs to be actuated, as smaller and economical actuators can be fitted to operate the valve).

Full Welded Trunnion Mounted Ball Balve

Trunnion Mounted Ball-Valve

Trunnion Mounted Valve