Buna vs. Viton® O-Rings: What Are the Differences?

By Smart Products USA

valves in buna and viton orings

O-rings are essential components in countless applications, providing reliable sealing abilities in diverse products and being made from many different materials. Two of the most commonly used materials for O-rings are Buna and Viton®. While both offer unique advantages, they also differ in terms of performance, cost, material composition, and more.

We’ve created this guide so you can explore the key distinctions between Buna and Viton® O-rings and determine the right material selection for your specific project’s needs.

Understanding Viton® and Buna O-Rings

When selecting the right O-ring for your application, having an understanding of each type of material is crucial. Viton® and Buna O-rings are two widely used options, each offering unique benefits depending on factors such as the operating environment, exposure, and performance needs. Let’s examine the key capabilities and properties of each.

What Are Buna O-Rings?

Buna O-rings, also referred to as Buna-N O-rings, are known for their versatility, being a reliable choice for applications involving moderate temperatures and are compatible with a wide range of materials, making them one of the most popular O-ring types.

What Are Viton® O-Rings?

Viton® O-rings are engineered to perform in demanding environments. Their high resistance to extreme temperatures, aggressive chemicals, and fuels makes them a top choice for industries that require reliable sealing solutions in harsh environments.

Comparing Buna and Viton® O-Rings

Below, we outline the key differences between Buna and Viton® O-rings and the factors that matter most in making your decision.

Composition

  • Buna O-rings – Made from nitrile rubber (Buna-N), offering strong resistance to petroleum-based oils and fuels, and performing well with silicone greases and ethylene glycol fluids
  • Viton® O-rings – Composed of fluoropolymer elastomer, which is resistant to compression set and permeation, and suitable for use with silicone oils, greases, and halogenated hydrocarbons

Durability

When choosing between Viton® and Buna O-rings, considering durability is key, as it plays a crucial role in performance across various sealing applications. Here’s how their durability compares:

  • Buna O-rings – Reliable for general-purpose use, but less resistant to harsh chemicals and extreme wear
  • Viton® O-rings – Designed for challenging conditions, offering resistance to chemicals and wear

Temperature

It’s important to consider how well the O-ring you choose performs under your operating conditions. Here’s how Buna and Viton® O-rings’ temperature ranges compare:

  • Buna O-rings – Ideal for applications with moderate temperatures, operating from -35 °F to 250 °F
  • Viton® O-rings – Capable of withstanding more extreme environments, in a temperature range of -15 °F to 400°F

Cost

Cost is another important consideration when deciding between Viton® and Buna O-rings. Here’s how their pricing compares:

  • Buna O-rings – A cost-effective option for general use, especially in moderate environments
  • Viton® O-rings – A higher upfront cost, but the durability can save money over time by reducing replacements

Applications of Viton® vs. Buna O-Rings

We’ve compiled a breakdown of the best uses for both Buna and Viton® O-rings, helping you determine which is most appropriate for your needs.

Best Uses for Buna O-Rings

Buna O-rings are commonly used in applications that require moderate resistance to a variety of fluids, including water, oils, and chemicals. Some specific sealing uses include:

  • Fuel lines in automotives
  • Refrigeration systems
  • Water pumps
  • Hydraulic systems using water-based fluids
  • Washers
  • Dishwashers
  • Pneumatic tools

Best Uses for Viton® O-Rings

Viton® O-rings are typically beneficial for demanding environments that require resistance to more aggressive conditions and are often used in applications that require more specialized sealing solutions. Some specific uses for sealing include:

  • Fuel systems in high-performance engines
  • Aerospace equipment exposed to extreme temperatures
  • Hydraulic systems in high-pressure chemical environments
  • Valves in chemical reactors
  • Automotive and industrial fluid handling systems
  • Oil drilling or offshore equipment

FAQs About Buna and Viton® O-Rings

Are Buna O-rings the same as Nitrile O-rings?

Yes. Buna O-rings are often referred to as nitrile O-rings, and they are synonymous. Both terms describe O-rings made from nitrile rubber, a synthetic material known for its resistance to oils, fuels, and other chemicals.  

Can Viton® O-rings be used in underwater applications?

Yes, Viton® O-rings are a good choice for underwater applications. However, it’s important to consider the specific water temperature, pressure, and chemical composition of the water to ensure optimal performance.

So, which O-ring is right for me?

To keep it simple, here are some things to consider when deciding between Buna and Viton® O-rings.

Choose Buna O-rings if your application involves:

  • Moderate temperatures
  • Less aggressive chemicals
  • General-purpose use

Choose Viton® O-rings if your application requires:

  • High-temperature resistance
  • Chemical resistance
  • Long-term reliability in extreme conditions

What industries commonly use Buna and Viton® O-rings?

Both of these forms of O-rings are commonly used in similar industries for a wide variety of sealing applications, with each offering unique advantages depending on specific requirements. Some industries that commonly use both types of O-rings include:

Use Viton® and Buna O-Rings in Our Air Pumps

At Smart Products USA, we offer our customers the option to choose between Buna-N and Viton® O-rings with our Series 800 Air Pumps, allowing for customization based on application requirements. So, whether you need the oil and fuel resistance of Buna or the high-temperature and chemical resistance of Viton®, we provide flexibility to ensure your pump performs optimally in a variety of environments.

Additionally, we also offer Viton® and Buna O-rings in a range of other products. Our Buna-N O-rings are available in the following products:

Our Viton® O-rings are available in the following products:

Ready to Find the Right O-Ring? Contact Smart Products Today!

Still have questions on which O-ring to choose for your project? Get in contact with the team at Smart Products USA today. We look forward to assisting you.