Parker Buna Nitrile (NBR) O-rings | Sealing Devices (2024)

FAQs

What is the difference between nitrile and Buna O-rings? ›

Buna, also referred to as nitrile or Buna-N, is an NBR rubber that displays excellent resistance to all petroleum-based oils and fuels, as well as water, various alcohols, silicone greases, and hydraulic fluids. It offers such other advantages as good tear resistance and non-polar solvent resistance.

Nitrile rubber (NBR) o-rings, also known as Buna-N, are one of the most commonly used sealing elastomers due to their resistance to petroleum-based fuels and lubricants and their relatively low price. Nitrile elastomers are copolymers of acrylonitrile and butadiene.

Crucial Differences

Viton® standard compounds can withstand temperatures up to 446℉, while Buna o-rings can only handle up to 257℉. Conversely, when it comes to low temperature applications, Buna outperforms Viton®—withstanding temperatures down to -40℉ while standard Viton® can only handle down to -13℉.

The main difference between buna and EPDM is that buna is known for its superior oil resistance whereas EPDM is known for its superior environmental resistance properties. Nitrile and EPDM sheeting are both extremely strong and durable rubber materials that can stand up well against impacts and abrasions.

The main disadvantage of nitrile rubber is its poor performance when exposed to UV, general weathering and ozone. It is therefore not advisable for outdoor applications. Nitrile offers relatively poor steam resistance and an unremarkable operational temperature range of -25 °C to +100 °C.

Depending on the construction and grade of the seal, a Viton seal can withstand temperatures as low as -20ºC and as high as 210ºC. On the other hand, NRB can withstand temperatures as low as -30ºC and as high as 100ºC. NRB seals can't compete with Viton seals in situations with high temperatures.

Nitrile 'O' rings – best 'O' ring material for general-purpose reliability.

A: Nitrile rubber, Buna-N and NBR are all different names for the same thing. They are used interchangeably.

Buna O-Rings (NBR, Nitrile)

This form of synthetic rubber is generally chemical-resistant, standing up to oil, fuel, and other harsh compounds.

Buna o-rings feature a wide variety of benefits that make them highly desirable for many applications. Buna-N offers excellent chemical resistance to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water and alcohol.

What are Buna o-rings used for? ›

Buna-N o-rings are commonly used in fuel tanks and other components for automotive and aerospace applications where ordinary rubber cannot be used due to its reactivity with fuel/oil/etc.

Buna Temperature Rating

Buna on the other hand is only effective up to 250°F. However, Buna seals provide a low-temperature sealing option with effective sealing down to temperatures of –22°F, while temperatures below 5°F render Viton seals ineffective as they become quite hard and inflexible.

EPDM roofing is vulnerable to damage in high temperatures. The rubber membrane can shrink, stretch, or crack if exposed to extreme heat for long periods. It is important to keep the EPDM roof cool by providing adequate shading and ventilation.

NBR has better chemical resistance than EPDM and is resistant to a wide range of oils, fuels, and chemicals, making it suitable for automotive and industrial applications. On the other hand, EPDM is not as resistant to chemicals, but it has good resistance to ozone, weathering, and UV radiation.

Nitrile, also commonly referred to as Buna-N or NBR, is a copolymer of Acrylonitrile and Butadiene. Nitrile is the most commonly used elastomeric material for molded and extruded products. This material offers relative low cost, good mechanical properties, and resistance to many common oils, fuels and lubricants.

Buna-N O-Rings Typical Applications and Products:

NBR is often used for gaskets and o-rings in pneumatic, hydraulic, and fuel systems. V-packings and backup rings made from high-hardness Nitrile compounds are common in high pressure environments in the Oil and Gas industry.

Nitrile 'O' rings – best 'O' ring material for general-purpose reliability.

Benefits of Nitrile O Rings

Nitrile butadiene rubber, also known as NBR, is a synthetic rubber copolymer that offers superior resistance to oils, acids and other chemicals. The material's most high-profile use is the gloves used by doctors, nurses, lab techs and cleaners. It also resists punctures well.

Nitrile rubber, also known as nitrile butadiene rubber, NBR, Buna-N, and acrylonitrile butadiene rubber, is a synthetic rubber derived from acrylonitrile (ACN) and butadiene. Trade names include Perbunan, Nipol, Krynac and Europrene. This rubber is unusual in being resistant to oil, fuel, and other chemicals.