When the ball moves downstream to enhance the in-line seal, the pressure between the spherical surface of the stem and seal remains constant leading to a consistent and lasting atmospheric seal.
When the ball moves downstream to enhance the in-line seal, the pressure between the spherical surface of the stem and seal remains constant leading to a consistent and lasting atmospheric seal. The seal itself offers an x-shaped cross-section to create a tight seal between the media and environment. As pressure increases, the seal is forced against the valve body and stem without damage or deformation. The seal is mechanically energized by an adjustable wedge ring, which creates a secondary sealing back-up and eliminates the need for springs and multilayer stem packing. In previous one-piece designs, pressure variations caused the ball’s axis to move slightly, resulting in seat or liner deformation which can lead to fugitive emissions. This patented seal and stem combination has the ability to handle heavy side-load effects without releasing the lateral forces into the stem packing. This valve design offers significant advantages including a longer lifespan, greater leak prevention, and improved safety when handling hazardous media.
The body assembly has metal-to-metal connections that offer resistance against forces due to misalignment that may be created in the pipeline. This feature is designed to alleviate deformation and damage to the lining, even under pressure-induced stresses. Furthermore, the body parts have a broad, angled contact surface. The advantage of this is that during thermal cycles the plastic liner maintains its seal.
Lastly, the design reduced the cavity around the ball, where debris or contaminants can collect and affect the performance of the valve. This change extends the valve life in applications where solids are present.
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