Fluoroelastomers (FKM) for Sealing

The latest developments regarding fluorocarbon polymer technology has offered a number of possibilities for the seal designers. Fluorocarbons are now available with much more resistance against chemicals and temperature, have a lower volume swell and various other advantages that render them perfect in extreme sealing conditions. Though one needs to be careful while choosing the fluorocarbon for specific sealing applications.

Following is a fact sheet which can help you make the right material choice for fluoroelastomers:

A or E Form of FKM

It is the oldest and one of the most common elastomers amongst the FKMs product line. These most often have a fluorine content upto 66% and are supplied for the common aerospace specifications. The A or E type show low compression set with non-resistance to flex fuels having high-levels of alcohol or MBTE. Also, these grades are known to be the general purpose FKMs. `

B Form of FKM

B form of FKM was basically developed to increase the fluorine content so as to provide better fluid resistance against acids and flex fuels as compared to A or E types. These comprise of 67% of fluorine content and are used in situations where resistance against flex fuels with alcohol or MTBE is required.

GF or F Form of FKM

It is an extended wing of B form of FKM along with increased fluorine content for better fuel and solvent resistance. With 70% fluorine content, these are extensively used in agricultural sector where strong chemicals are used on a daily basis.

GLT Form of FKM

This type was developed to improvise the low temperature flexibility in comparison to age old A or E type FKMs. The flexibility of low temperature generally reaches 40 degree Fahrenheit. These comprise of 65% of fluorine content and are unfit for aggressive solvents or flex fuels.

GFLT Form of FKM

GFLT form of FKM is appropriate for flex fuel applications as these have 68% of fluorine content and 35 degree Fahrenheit of rating.

Check out our article FFKM Performance and Application for more information on FFKM.