Traditional ball valve designs can contribute to performance challenges triggered by corrosion. Additionally, in both the two-piece and one-piece traditional designs, side loading often creates a weakness, which increases the risk of leaks in-line or to the environment.
The plastic-to-plastic joint between ball and stem can lead to “play” between the stem and the ball during opening or closing of the valve.
When the media is under pressure the torque applied through the stem to the ball can increase and be transferred to the drive slot in the ball. This often results in the outer edges of the ball liner being heavily loaded. As the polymer is subjected to flows under pressure, the thickness of the polymer is reduced. With intensive use, the liner may become too heavily worn and corrosive material can attack the metal, leading to a potential failure.
Side-loading is another design challenge that directly impacts the lining and sealing capabilities. When a spherical ball is in the closed position, the face of the ball is subjected to pressure generated by the media and can create side loading. In both the two-piece and one-piece traditional ball valve designs, side loading creates a weakness, which increases the risk of leaks in-line or to the environment.
TYPICAL CHALLENGES:
High wear and exposure to excessive torque on the ball & stem joint area cause the lining to creep, which thins the lining, risking static deformation or destruction of the lining between the ball and the stem, potentially leading to corrosion of the ball and stem core and catastrophic valve failure
