Though floating ball valves have numerous applications, their purpose is essentially just to control how liquids flow through pipelines, though these aren’t the only type of ball valve used for this purpose. The other major type – a trunnion ball valve – is also used for such purposes, and a bit later we’ll compare it to the floating variety.A floating ball valve gets its name from the hollow, ball-like sphere that “floats” freely inside the valve’s body, which is compressed between two flexible seats while suspended in liquid.

What a floating ball valve normally does during operation is float slightly downstream, which causes the seating mechanism to compress under the ball. Should the seating disintegrate, the ball floats to the metal stem to seal it. This provides a failsafe within the design.The system also involves a stem in the valve’s body that connects it to a slot at the top of the ball and allows the ball to rotate 90 degrees. This stem allows the ball to move laterally when upstream pressure acts on it, while the other downstream seat improves the tightness of the valve’s seal.

This allows the valve to close when liquid flows in either direction.The ball itself has a hole through which liquids pass freely when it’s correctly aligned with both ends of the valve. This hole, when perpendicular, seals the valve. When this hole is in any other position, liquid will continue to flow through it. The floating ball valve can stop, distribute and alter the direction liquids flow within a pipeline, with its main features being the sealing design of the seats, which automatically relieve pressure, reliably sealing when flows reverse and acting as a locking device.

Pressure acts on the closed Plastic Valve valve on the backside of the upstream seat as well as the ball, which forces the ball in the direction of the downstream seat. This force both deforms and limits the valve seats. This temporary deformation is engineered into the seats’ design, using stored energy to temporarily change its shape in order to keep the seal when temperatures or pressure changes.