ALLIANCE'S WORLD OF SEALS
YOUR SEAL SPECIALIST
What is an oil seal?
Seals are essential to protecting the bearings of any rotating shaft assembly -They prevent contaminants such as dirt, dust and water, while also preserving the system’s lubricant.
Choosing the right oil seal
Oil seals come in many different types and materials depending on their application. Determining the material is vital to ensuring your equipment is operating at its best performance. For example, your equipment may need to run at higher temperature applications, such as an engine seal for a jet engine, you may need to choose a specific material for your oil seals to run properly.
Materials for Oil Seal
NBR is recommended for the majority of standard applications and is the most commonly used rubber (elastomer) material. This is because of Nitrile's compatibility with most environments as well as its relatively low cost. Generally nitrile is used for disposable non-latex gloves, footwear, automotive transmission belts, synthetic leather, hoses, o-rings, gaskets, oil seals, and more.
The temperature range of nitrile is −35° to 120 °C (−30° to 250 °F). Due to this wide range, NBR seals can be used for gas oil, silicone oil, animal/vegetable oils and fat, hydraulic liquid as well as hot and cold water. In addition, NBR is oil resistant and has an excellent abrasion resistance, so for any application that demands shock absorbers, NBR is a perfect choice to go with.
Some disadvantages of NBR are poor ozone, sunlight and weather resistance as well as limited high temperature and flame resistance. For higher temperature resistance, a much better material to use is Silicone.
Silicone compounds or “VMQ” offers a wide range of traditional operating temperatures starting at -60°C to 200°C (-140°F to 392°F).
In addition to its excellent temperature resistance, it is also resistant to ozone, light, and weather conditions. Silicone can be typically found in the food and medical industry as well as in hydraulics and pneumatics. It is often the preferred material for o-rings, moulded parts and flat seals but is also commonly used for electric insulators due to the material’s translucency and flexibility.
Although extremely flexible, silicone does have some disadvantages. Many silicone compounds have poor tensile strength, tear resistance, and abrasion resistance. If you are looking for a material that offers a higher tensile strength, while still offering high temperature resistance, look no further than Viton®.
Viton®, a trademarked name of The Chemours Company, is a specific brand of synthetic rubber commonly used in o-rings, oil seals, gaskets, chemical resistant gloves, and other molded products.
Due to having a higher density, Viton has the widest temperature range of -40°F to over 400°F (-40°C to over 240°C) making it a perfect choice for higher temperature applications. Viton® also has the largest range of chemical resistance, i.e., it is resistant to silicone oil and grease, mineral/vegetable oil and grease, aliphatic, aromatic, and chlorinated hydrocarbons, non-flammable hydraulic fuels as well methanol fuels, and more.
While Viton offers a superior temperature and chemical range than other materials, it can be more expensive than the others as well.