O-Ring Selection
Selecting the correct o-ring material can offer you better chemical resistance while others can offer better heat resistance or cold flexibility within your application. Some guidelines for the different types of o-rings:
Buna-N
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The most common o-ring because of its fuel and oil resistance. It has a temperature range of -30◦ to 250◦ F. |
FKM
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Well known for its outstanding resistance to heat, oxidation, weathering, and ozone. The temperature range is -15◦ to 400◦ F. |
EPDM
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Ethylene-propylene-diene rubber (EPDM, also sometimes referred to as EPR) is a chemically resistant family of compounds. Colder uses high quality peroxide cured EPDMs that provide exceptional resistance to temperatures with a wide range of chemicals. |
FFKM (Chemraz®, Simriz®, Kalrez®)
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Broadest range of chemical resistance of any elastomeric material, combining the resilience and sealing force of an elastomer with chemical resistance approaching that of PTFE. |
PFA & FEP Encapsulated Seals
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Encapsulated seals combine the resiliency of the elastomer with the superior chemical resistance of the fluoropolymer to achieve a seal that is lower cost than a pure fluoroelastomer FFKM seal. |
Food-grade
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Commonly used when food, beverages or potable water is going through the coupling. |
Silicone
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Seals have good temperature resistance. The temperature range is -70◦ to 400◦ with special compounds can reach 175◦ to 450◦ F. Silicone can also be supplied with Class VI requirements for life sciences applications. |