In many gasketing applications, rubber is the most effective sealing material because of its fluid non-permeability, chemical resistance, heat resistance and capacity for withstanding pressure.
All rubber products are elastomers, and elastomers are characterized by elasticity. This quality of elasticity is what makes rubber such an ideal material for gasketing applications. Most rubber products, when compressed and then relieved, will return to their original shape fairly quickly, assuming extreme temperatures and the presence of corrosive chemicals are not factors.
If, for example, a simple O-shaped rubber gasket is used to seal the lid of a ceramic pot, the rubber pushes against the pot and its lid, which creates a seal. This is how all rubber gaskets create seals.
Different rubber materials perform in different ways when used in gasketing applications. Because gaskets are used to prevent chemicals and gasses from leaking, the material used to create the gaskets must resist degradation caused by contact with those materials.
Gasoline and other petrochemicals can degrade many rubber varieties. In response to the demand for rubber materials that could resist corrosion despite contact with petrochemicals, synthetic rubber materials like EPDM, Viton, Neoprene and silicone were developed.
Heat and corrosion resistance are key considerations when applying gaskets in a given context. Viton, the first fluoroelastomer ever developed, is an excellent material for the sealing of fuel lines and other avenues through which petrochemicals are transmitted. Viton cannot, however, come into contact with ketones, acetone and other organic acids.
EPDM displays excellent compatibility with ketones but poor compatibility with petrochemicals. Because gaskets contribute to the safe and stable operation of machines with which people come into constant contact, the importance of carefully selecting gasketing material cannot be overstated.
Improperly selected or maintained gaskets can cause catastrophic failure in the equipment in which they are applied; when carefully chosen and periodically checked for signs of stress or degradation, they contribute very significantly to equipment’s safe and effective operation.