Some O-Ring compounds that present appreciable elastic properties and good compatibility with many fluids, result in being sensitive to air and light. Their sensitivity increases in a considerable way if the exposure to such agents comes when the O-Ring is taut. The direct and pro-longed exposure to air and light provokes quick ageing in these O-Rings During the assembly and usage phases, the presence of a thin layer of lubricant exerts a noticeable protective action. The damaged O-Rings present the characteristics aspect of figure 9.2. The surface presents slits in a radial direction that increase in depth with extended exposure. The elasticity and the torsion resistance are reduced considerably.
Damaged O-Ring by direct exposure to air and light
This is one of the most typical cases of damage that can be compared. Particular care must be given to the protection of the O-Rings that are assembled on particulars for which could be managed by the warehouse: a long storage period can make the damage process easier.