What is an O-ring NBR?

NBR (Nitrile Butadiene Rubber) is a synthetic elastomer that is commonly known in the market under trade names such as Perbunan®, Europrene N®, and Krynac®. At VanyTol, we manufacture premium NBR sealing solutions that meet or exceed these industry standards. It is a highly popular choice because of its excellent resistance to oils, greases, and fuels.

Its mechanical properties, flexibility, and broad temperature range (-30°C to +120°C) make the NBR O-ring one of the most widely used seals in various industries. This material offers a perfect balance between durability, price, and chemical resistance. It is used in hydraulic systems, pneumatics, fuel lines, and HVAC installations. While the NBR O-ring has limited resistance to ozone and UV radiation, it remains one of the most popular sealing solutions globally due to its versatility and reliability.

How is the NBR O-ring made?

The NBR O-ring, also known as a nitrile o-ring, is a synthetic elastomer produced by the copolymerization of butadiene and acrylonitrile. This entire process results in a material that is strong and flexible. It also makes the material resistant to oils, greases, and hydrocarbons.

The acrylonitrile content can vary from 18% to 50%. A higher content improves oil resistance but reduces flexibility. Thanks to the double bonds in the polymer structure, the NBR O-ring can be vulcanized with sulfur, enhancing its mechanical strength and wear resistance. These characteristics make the nitrile butadiene rubber O-ring widely used in seals, hoses, and industrial materials.

Composition and production process

The acrylonitrile content directly influences the rubber’s properties. A higher acrylonitrile content increases resistance to oils and fuels but reduces flexibility at low temperatures. Vulcanization with sulfur further strengthens the compound (often compared to properties found in Perbunan®). The final product is an elastic and wear-resistant material. These features make the VanyTol NBR O-ring the right choice for industrial use.

Chemical and mechanical properties

The NBR O-ring is also known for its chemical and mechanical performance. It offers high resistance to oils, greases, and hydrocarbons making it a preferred choice in industrial sectors. It features excellent wear resistance, tensile strength and compression set resistance. These qualities contribute to a long service life.

Advantages of the NBR O-ring

NBR O-ring products offer many advantages, making them a popular choice in industrial applications. One of their key strengths is their resistance to oils, greases, and fuels, making them ideal for machinery and hydraulic systems.

Applications of the NBR O-ring

The NBR O-ring is a commonly used seal in a variety of industries. Thanks to its resistance to oils, greases, and hydrocarbons, it’s a reliable choice for hydraulic and pneumatic systems.

• Hydraulic and pneumatic systems: Ensures reliable sealing even under high pressure and fluctuating temperatures. Used in cylinders, valves, and pumps to prevent leakage.
• HVAC systems and industrial use: Widely used in heating, ventilation, and air conditioning thanks to its excellent resistance to coolants and sealants.

Drawbacks and limitations of the NBR O-ring

While the NBR O-ring offers many advantages, there are also some limitations:

• Limited resistance to ozone and UV radiation: Not ideal for outdoor applications. Prolonged exposure can cause hardening and cracking.
• Limited chemical resistance: It does not hold up well against strong acids, halogenated hydrocarbons, ketones, or solvents.
• Temperature limitations: At temperatures above +120°C, the material can harden, become brittle, and lose its sealing capability.

Alternatives to the NBR O-ring

Although the NBR O-ring is versatile, there are cases where it falls short. Choosing the right material increases sealing effectiveness and extends lifespan.

• EPDM O-rings: Better suited for outdoor and water applications due to their high resistance to ozone, UV radiation, and weathering.
• FKM (Viton®) O-rings: If you need a seal for extreme conditions involving high temperatures (over +200°C) and harsh chemicals, FKM (Viton® is a registered trademark of Chemours) is a much better option.