Viton® and EPDM are elastomers that are commonly used for O-rings. Both are types of rubber polymers that are compounded for low compression set. This means that they will recover well after a fixed time under specified squeeze at a given temperature. Both elastomers are also highly flexible and can be stretched to a great extent, without breaking. Such elastomers are commonly used as gasket material, but are also employed for making valves, pumps, and related components.
Viton® rubber is a fluoro elastomer, whereas epdm rubber is ethylene-propylene-diene-monomer. The primary differences between Viton® and EPDM is in their chemical resistance and temperature ranges. Both have different properties and applications for general industrial use. Having sufficient knowledge of the differences between the two can help you make a better-informed decision. Differences between Viton® Properties and EPDM rubber properties:
- Temperature - Viton® temperature resistance ranges from -20°C to 210°C, while EPDM temperature resistance ranges from -45°C to 145° This means that both are excellent for extreme temperatures, but EPDM has a slight edge in colder temperatures, while Viton® is better for heat resistance at higher temperatures.
- Chemical resistance: Viton® is resistant to mineral and vegetable oils, gasoline, most alkalis and aromatic hydrocarbons. . EPDM, on the other hand has good resistance to hot water and steam, silicone oils, polar solvents like ketones and alcohol and glycol based brake fluids, however, EPDM shows poor resistance to mineral oils, greases and fuels. Both these compounds show very good oxygen, ozone and weather resistance.
- Applications: After NBR (nitrile) o rings are most commonly available in Viton® polymer which has excellent oil and chemical resistance and is used extensively in the petrochemical, chemical and food industries. EPDM is good in steam applications and has moderate chemical resistance, but should be avoided with petroleum agents and solvents.
- Cost: As an approximate guide, Viton® compound is eight times more expensive than EPDM. However, due to the large amount of Viton o rings and seals being produced and stocked, the former is available in myriads of sizes, and you may not find significant differences in cost between the seals made from these compounds if your requirement is small (say up to a few hundred pieces)
When choosing between Viton® vs epdm, it highly recommended that you verify their compatibility with the fluids likely to be encountered in the desired application. You can also consult our chemical compatibility guides or call Polymax on 022-65645424 for more information
Viton® is a registered trade mark of Du Pont Dow Elastomers