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Which Seal is Best for Your Application?

Viton vs. Buna

Viton and Buna are two of the most commonly used elastomers for sealing applications and for good reason. Both of these rubbers serve as great general-purpose sealing options. These seals offer excellent compression set resistance, and both are designed to resist most oils and lubricants, especially petroleum-based lubricants. Viton and Buna seals also tolerate moderate temperature applications between 5°F and 250°F, making them optimal for general industrial use. However, choosing between the two becomes more imperative for specific applications.

Temperature Ranges for Viton Seals vs. Buna Seals

Viton and Buna seals have several crucial differences that make them well-suited to certain applications. While each brand serves as a great sealing option at moderate temperatures, Viton is superior to Buna for high-temperature applications.

Viton Temperature Rating

Viton seals provide an indefinite seal for temperatures up to 400°F. This brand also delivers an excellent seal for temperatures up to 600°F for longer than 48 hours.

Buna Temperature Rating

Buna seals are effective up to 250°F. However, they provide a low-temperature sealing option effective down to temperatures of -22°F.  Temperatures below 5°F render Viton seals ineffective because they become hard and inflexible.

Key Differences Between Viton Seals and Buna Seals

Other environmental conditions differentiate these seals. An exceptionally broad range of chemical resistances makes Viton seals an option for most applications involving oils, fuels and mineral acids. Viton seals are also resistant to oxidation, ozone, UV exposure, weather, fungus and mold.

Buna seals offer some chemical resistance but may degrade from weather and ozone exposure, which is not a common issue. Buna seals have superior abrasion and tear resistance, making them more suitable for heavy-duty industrial applications.

Both seals are suitable for various applications and serve as excellent general-purpose seals. It’s important to consider the advantages and disadvantages of each to optimize your seal selection.

Contact Humphrey Products for Information on Viton Seals and Buna Seals

Humphrey Products is an industry-leading valve manufacturer. For more info on Viton and Buna seals contact us at 1-800-477-8707 or email us at

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