If you’re searching for a highly resilient O-ring with broad temperature ranges and exceptional compression set durability, you may find hydrogenated nitrile butadiene rubber (HNBR) O-rings to be an ideal solution.

What Is an HNBR O-Ring?

HNBR O-rings are synthesized from polymers formed by infusing hydrogen into the double bonds of nitrile butadiene until saturation. This hydrogenation process yields a multitude of double bonds that strengthen the NBR polymers to a superior level. Besides augmenting durability and abrasion resistance, it also enhances the HNBR O-rings' resistance to ozone, heat, mechanical stress, and chemicals. Consequently, HNBR O-rings are emerging as one of the most resilient, cost-effective choices for engineers requiring durable seals.

HNBR O-Ring Material Information

When choosing HNBR O-rings for your specific use, it's important to grasp the diverse performance attributes tied to the range of acrylonitrile content (ACN) - here, 17 to 49 percent. The material's performance in low temperature applications tends to decrease as the ACN content increases. Conversely, higher ACN values exhibit improved resistance to polar lubricants and fuels. Wyatt Seal also carries standard durometers of 70, 80, and 90 in HNBR O-rings. As such, there is a wide array of potential HNBR O-ring solutions to meet your specific application needs.

If you’re unsure of what ACN or durometer value is appropriate for your application, the experts at Wyatt Seal can assist. Simply contact us with any questions you have, and we’ll gladly guide you to the right HNBR sealing solution.

Benefits of HNBR O-Rings

HNBR O-rings surpass standard nitrile rubber (NBR) O-rings in performance. The “N” in HNBR stands for “Nitrile”, while the “H” indicates the addition of hydrogen to the chemical compound. This hydrogenation process significantly enhances the nitrile rubber's toughness and temperature resilience, even in severe environments. HNBR O-rings possess a wide temperature range (- 23ºF to 300ºF), and exhibit greater resistance to wear, tear, and compression than their NBR counterparts. HNBR O-rings also exhibit excellent weathering resistance.

Common Uses and Applications of HNBR O-Rings

HNBR O-rings are commonly found in automotive, air conditioning, and oil and gas products. They are particularly efficient in modern coolant systems that employ R134a coolant. Traditional neoprene O-rings tend to degrade and break down faster in these systems. However, HNBR O-rings excel under such conditions, proving to be an optimal choice for hydrochlorofluorocarbon (HCFC) coolant systems. It's worth noting that the type of lubricant used is also critical in these systems; R134a is incompatible with older PAG lubricants but synergizes well with mineral oil and HNBR O-rings.

More specifically, HNBR O-rings demonstrate superior longevity and durability in industries and applications including:

  • Petroleum
  • Fuels
  • Oils
  • Aliphatic hydrocarbons
  • Alcohols
  • Di-ester base lubricants
  • Silicone oils
  • Grease
  • H2S
  • R134a refrigerant gas
  • Animal & vegetable fats
  • Ethylene glycol
  • Salt solutions
  • Bases
  • Diluted acids
  • Steam
  • Hot water up to 300F

While ideal for several diverse applications, use with strong acids, ethers, esters, ketones, aldehydes, chlorinated hydrocarbons, UV rays, ozone, direct sunlight, brake fluids (especially glycol-based), polar solvents, aromatic or chlorinated hydrocarbons, and aromatic fuels is not recommended.

Find the Right HNBR O-Ring for Your Application

In today's high-paced engineering landscape, speed, accuracy, and agility in design are more critical than ever. Finding the precise O-ring to meet your requirements can become a tedious challenge unless you're collaborating with seasoned industry experts.

Choosing the perfect O-ring is paramount to avoiding product failure or machine inefficiencies. Wyatt Seal, with over fifty years of O-ring proficiency, is your reliable partner in this process. Our comprehensive industry connections, combined with an extensive inventory of standard O-rings of all sizes and compositions, enable us to deliver sealing solutions promptly and cost-effectively.

Should we not have your desired product in stock, our team of experts stands ready to leverage their extensive industry knowledge to fabricate custom O-rings tailored to your exact specifications. If you're in immediate need of HNBR O-rings, we invite you to get in touch with us. Let's discuss.