This is a quick overview of the various O-Ring materials that are available for applications and found at select UK O-Ring suppliers. When it comes to Specialist Sealing Products, it is a good idea to be clued into every option that is on the market. The materials can range from the common O-Ring with Shore 70A hardness to more complex elastomeric items.
This list will give any engineer a brief understanding of how to make the correct O-Ring selection for their application.
O-Ring Requirements
Some of the factors to take into consideration when choosing the right O-Ring are:
- Temperatures to which the application will be subjected
- Pressure, the seals, will encounter
- If the application chemicals will be compatible with the O-Ring material
- What size and budget restraints are required
- Durometer readings
Once the engineer knows these key points, it will be possible to determine the correct O-Ring material that is suitable. If there is any doubt that the standard materials aren’t acceptable for an application that demands extreme performance or environment, a customised specialist material can be designed.
Common O-Ring Materials
All O-rings are manufactured from an elastomeric material. However, they have many different formulaic compositions that change the function specifications.
The more common O-Ring materials are:
- Nitrile, or NBR
- Viton®, or FKM
- Silicone
- Neoprene
- EPDM
Nitrile/NBR/Perbunan: If there is one substance O-Rings must be able to tolerate, it is lubricants. Nitrile was developed for sealing systems that encounter large quantities of oils and fuels. This is the O-Ring material of choice for gasket manufacturers. Even though it has been around since the 1930s, it remains a fundamental, popular choice.
Viton®/FKM/Fluoroelastomer: A synthetic rubber developed for high performance, Viton® is the O-ring of choice for any application that demands a high tolerance to chemicals and fuels. Harsh corrosive chemicals can erode or damage an O-ring after a continued interaction. FKM performs well under high temperatures, making it a good choice for combustibles like gas. Strict tests have indicated that Viton® is not suitable for any applications using steam.
Silicone: This ubiquitous synthetic rubber remains durable in most temperature extremes. Unique compounds have been added to the silicone O-Ring gum stock to make it more tear-resistant. It comes in a variety of colours and can withstand fluctuations in weather.
Neoprene®/Chloroprene: Neoprene® has been around for many decades because it is well-priced and has overall solid performance. Some of the outstanding qualities of Neoprene® is its ability to be customised for certain specifications. In its commercial uses, it is fuel and lubricant resistant, durable in all weathers and performs well in dynamic applications.
EPDM: This material is made of synthetic rubber that is resistant to long periods of exposure to weather and harsh conditions. This gives EPDM a solid rating when added to its excellent performance against fuels, oils and lubricants.
