Which of the following has the longest shelf life?

• A. O-ring
• B. V-ring
• C. Viton O-ring
• D. Gasket

Answer: (C)

Shelf life for elastomer seals depends on how well the material resists aging processes like oxidation, heat, ozone, and chemical attack. Viton O-rings, made from fluorocarbon elastomer (FKM), have superior resistance to heat, fuels, oils, and solvents and show excellent oxidative stability. That combination means their properties degrade much more slowly during storage, so they stay functional for a longer period under typical aerospace storage conditions. With proper storage—cool, dry, and away from direct sunlight—they generally outlast other common elastomer seals such as nitrile-based O-rings, V-rings, and gaskets, which are more susceptible to aging and chemical attack. Hence, the longest shelf life among the options is the Viton O-ring.