When it comes to compound deterioration, heat is one of the most destructive forces. Therefore, understanding “what is the best high temperature O-ring” is a crucial factor. If you are working with temperatures over 150°C then there are a number of materials you can consider such as FKM, FVMQ, and FFKM to name but a few.

O-Rings for Automotive Oils, Fuels And Gases

Viton is one of the best all-round materials available, particularly when used with oils, greases and fuels at high temperatures. An alternative to this is the Polyacrylate or ACM as it is known has resistance against mineral oils as well as engine, gearbox and transmission fluids. ACM O-rings have the ability to withstand temperatures of 150°C.

Hydrogenated Nitrile or HNBR has a top temperature of 140°C and again, this is compatible with automotive fuels, oils and gases although it is not suitable for use with chlorinated hydrocarbons or strong acids.

TFE/P or Aflas has the ability to handle the majority of chemical mediums that are used in automotive sealing. It has the ability to withstand a temperature of up to 204°C.

Silicone or VMP O-rings offer temperature resistance of up to 230°C and some variants of this material can handle up to 300°C. These are commonly used where there is high exposure to UV, ozone and weathering although they are not suitable for use in hot water, chemical or dynamic applications.

PTFE O-Rings have the ability to handle temperatures of up to 250°C and offer chemical resistance to acids, alkalis and solvents. In actual fact, it also has the ability to withstand temperatures as low as -200°C.

FEP comes from the same range of materials as PTFE. While it has many of the same characteristics, it can only work to a temperature of 204°C. These seals are both chemical and heat resistant, much like PTFE although they do offer an increased level of flexibility.

FFKM is also known under brand names such as Perlast, Perflour and Simriz. This is available for use in a range of applications and so, they are available in a range of material grades and this enables them to operate at temperatures that range from 230°C to 320°C.