FKM gaskets, also known by their trademark name Viton®, are fluorocarbon rubber gaskets that have excelled resistance to high temperatures, ozone, mineral oil, synthetic fluid, aromatics, and organic solvents and chemicals. They are one of the most commonly used gaskets in extraction due to their solvent resistance and durability. Though not as long lasting as PTFE, they are softer which makes them far easier to seal.

These gaskets feature a mesh which is sealed into the gasket. The mesh allows for filtering of certain sized particles, holding them back while smaller particles can flow through. It’s important to filter in steps, if you go to the finest mesh first you will have issues with clogging.

Note that the higher the mesh number, the finer the particles. For example, 10 mesh will allow a 1999 micron particle through, but 100 mesh will only let a 149 micron particle through. See the chart below for reference.