what is Viton and EPDM O-ring?

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: from -20°C to 210°C,

EPDM temperature : from -45°C to 145°C

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.

 


Post time: Jun-11-2019