Gap extrusion is a type of damage to sealing elements. It belongs to the category of damage caused by mechanical stress. In the case of gap extrusion, pressure is the cause of the damage. The sealing element is pressed into the sealing gap, especially with pulsating pressures. This is located between the two surfaces to be sealed. During this gap migration, characteristic peeling occurs where the sealing element touches the edge of the groove. This fully or partially sheared material is also known as an extrusion flag. The loss of material can lead to a reduction in the sealing effect.
#1 Definition of column extrusion
Gap extrusion is the pressure-induced migration of a sealing element into the sealing gap on the side facing away from the pressure. The groove edge shears off material from the sealing element.
#2 Meaning of the column extrusion
Gap extrusion is a common damage pattern in sealing technology. Damage often does not occur over the entire circumference of the sealing element, but at the point with the greatest diameter clearance. In order to avoid the damage pattern, the pressure conditions are already taken into account in the design.