Frequently Asked Questions — FKM O-Rings
What is FKM (Viton) rubber?
FKM, commercially known as Viton®, is a fluoroelastomer with exceptional chemical and thermal resistance. Its high fluorine content (65–71 % by weight) makes it stable in aggressive media — fuels, mineral oils, aromatic hydrocarbons, and chlorinated solvents — where most other elastomers fail. FKM is the default choice for high-performance sealing wherever temperature or chemical exposure is demanding.
What temperature range can FKM o-rings handle?
Standard FKM o-rings operate reliably from −20 °C to +200 °C in continuous service, with short excursions possible to +230 °C. Special low-temperature FKM grades (GF, GLT) extend the lower limit to −40 °C. This broad range covers most industrial, automotive, and aerospace sealing scenarios.
What chemicals is FKM resistant to?
FKM has excellent resistance to fuels (petrol, diesel, biodiesel, aviation fuel), mineral oils, hydraulic fluids, aliphatic and aromatic hydrocarbons, chlorinated solvents, and ozone. It is not recommended for use with ketones (MEK, acetone), esters, ethers, or hot water above 100 °C where hydrolysis can occur.
What are typical applications for FKM o-rings?
FKM o-rings are used in automotive fuel injectors and pumps, aerospace hydraulic systems, chemical processing equipment (pumps, valves, reactors), oil and gas wellhead and downhole tools, and any industrial machinery exposed to aggressive fluids or sustained high temperatures above 120 °C.