Trunnion Mounted Ball Valve is a fixed bai fixed type b […]
Trunnion Mounted Ball Valve is a fixed bai fixed type ball valve, which has some differences in working principle with floating du type zhi ball valve (Floating type).
The floating ball valve has only one upper stem and no lower stem. When the valve is closed, the fluid will push the valve ball, and the valve ball will have a certain displacement in the direction of the fluid force, so that the valve ball will be squeezed in Above the valve seat, a seal is formed between the ball and the valve seat, which is a one-sided seal, also called a post-valve seal. It can be said that the ball valve seat does not move.
When the valve diameter increases, the weight of the valve ball increases, and the floating ball will easily squeeze the valve seat and increase the torque. With fixed ball valve structure, the lower valve stem can be used to push up the ball, reducing the burden on the valve seat. The working principle of the fixed ball is that when the valve ball is closed, the upper and lower stems fix the position of the ball, so the ball does not move, and the valve seat closes the valve under the preload of the spring to achieve a seal. It is a double-sided seal, that is, the valve seats on both sides play a role of sealing.
In addition, under high pressure conditions, there are more applications for fixed balls, but the structure of fixed balls is more complicated. In small-caliber, medium and low pressure situations, floating balls are more cost-effective.
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