EPDM and Viton are both widely used elastomers for mechanical gaskets or O-rings. Elastomers are one of the several types of rubber polymer with very high yield strength. Yield strength means the point wherein the material will not go back to its initial shape after applied with stress. In general, an EPDM or Viton gasket, such as the ones sold at Blaylock Gasket & Packing, may be stretched a lot without breaking or getting damaged. The most widely preferred use for these elastomers are as gaskets. Valves, pumps, and other equipment use these elastomers to avoid leaks.
EPDM is ethylene propylene diene monomer . It comes with a temperature range from -70 up to 300 degrees Fahrenheit. It is highly resistant to damage due to heat, compression, alkalis, sunlight, and ozone. It has low resistance to acids, petrol substances, and hydrocarbons. The ethylene composition starts from 45 percent to 75 percent. The higher the ethylene content the higher the chance of better mixing, loading of the polymer, and extrusion. Curing these polymers using peroxide provides a higher crosslink density as opposed to the amorphous counterparts.
Viton is a proprietary fluoroelastomer designed and manufactured by DuPont, the inventors of Teflon. It comes with a temperature range from -15 up to 400 degrees Fahrenheit. It is highly resistant to damage due to heat, compression, alkalis, acids, sunlight, petrol-based substances, ozone, and salt solution.
The main dissimilarity between an EPDM and Viton gasket is the temperature range. Viton handles hotter temperatures, whereas EPDM deals with cooler temperatures. In addition, a Viton gasket is more resistant to oils and chemicals. However, if you acetones are present, you will want to pick an EPDM gasket.