Britval fully welded ball valves are used mainly in Gas transmission and distribution pipeline (Mid-stream), typical for underground and buried installation The ball is fixed and the seat rings are floating, free to move along the valve axis.Side load generated by pressure acting on the ball is absorbed by bearings.At low pressure the seat sealing acting is achieved by the thrust of the springs acting on the seat. As the pressure increases the fluid pressure pushes the seat rings against the ball, making the sealing more reliable.Upstream Sealing At low pressure, seat-to-ball contact is maintained by Belleville springs. At higher pressures, seat contact is reinforced by line pressure.

Automatic Internal Relief of Body Pressur Relief of excess body cavity pressure is automatic, avoiding dangerous pressure buildup. Any pressure exceeding downstream line pressure by approximately 200 psi pushes the downstream seat away from the ball, allowing the pressure to relieve into the pipeline.Rotating Seat Rings The exclusive rotating seat feature is standard in the Britval fully welded ball valve sizes 14” (350 mm) and larger. Both seats rotate 15 degrees each time the valve is closed, exposing a new pinch point and evenly .