What causes 'ring fly-out' and how can it be diagnosed in a failure analysis?

'Ring fly-out' is the premature exit of the ring from the groove during operation. In a failure analysis, the first step is to check for 'groove rounding' or deformation. If the groove wall is slanted, it indicates the thrust load exceeded the groove material's yield strength. Another cause is insufficient 'cling'—if the ring's ID/OD wasn't properly sized for the groove. If the ring itself is intact but found outside the groove, it likely failed due to centrifugal forces or high-frequency vibration that caused the ring to 'walk'. Examination of the ring's edges for wear patterns can indicate if it was fully seated prior to the event.