With the pipeline in operation, the advancing slurry column increases the positive pressure in the pipeline and raises the ball to its seating position, effectively sealing the valve.
Should a pump or power failure cause the slurry pipeline to go down, so it is not in operation, the ball will drop to the bottom of the valve housing, allowing air to enter around it and rush into the pipeline, effectively breaking the vacuum.
Our valve requires no heat tracers for tailings lines. By close coupling the valve to the slurry pipeline, the latent heat in the slurry will prevent freezing. The ball floats in water, so it works even when priming the line.