Everything You Need To Know About FKM Seals

Nov 26, 2020 Industrial seals | Material

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FKM seals, also known as fluorocarbon seals are industrial seals made of fluorocarbon elastomer material. Commonly, these seals are used in aviation and aerospace, food and pharmaceutical, semiconductor manufacturing applications, etc. Due to properties like high-temperature sustainability, chemical resistance, mechanical strength, etc these types of seals are highly preferred in the aforementioned industries. However, the fluorocarbon elastomers are responsible for the excellence of the FKM seals. Therefore, before utilizing these seals in industrial applications, one must be well-versed with the material, fluorocarbon rubber, and its properties. This post introduces fluorocarbon rubber, its material properties, and the advantages of FKM seals.
                                                     

An Overview of FKM (Fluorocarbon Rubber)

FKM is an elastomer from the family of fluorocarbon elastomers. It was designated by ASTM International under the standard D1418. It was initially introduced by DuPont under the name of Viton®, however, now it is being manufactured by several manufacturers like Daikin Chemical, HaloPolymer, and many more. It is an equivalent material of FPM as both the materials feature the same base material that is a fluorocarbon rubber. 

These highly fluorinated carbon-based synthetic rubber polymers were first introduced in the 1950s due to the demand for high temperature sustaining seals, O-rings, and gaskets for the aerospace industry.

FKM polymer is made from vinylidene monomers with a high concentration of fluorine and carbon-based elastomers. The crosslinking mechanism between the monomers, fluorine molecules, and carbon make this material highly suitable for applications exposed to chemicals and high temperature.

Owing to the excellent properties, FKM fluorocarbon elastomers are being utilized for manufacturing seals, O-rings, gaskets, etc for industries like automobile, aeronautical, petroleum, etc.

The following are the two grades of FKM fluorocarbon rubber.

• General Grade: The general grade FKM material has a temperature range between -20˚C to 230˚C and it offers high resistance to chemicals and hydraulic fluids, and high compression resistance. These properties are commonly found in the general grade FKM fluorocarbon elastomers. This type of FKM seals, O-rings, and gaskets are suited for automobile, energy, and manufacturing industries, however, are not approved for food and beverage, medical and pharmaceutical industries.
• FDA Grade: The FDA grade of FKM elastomers are approved for applications related to consumable goods. Therefore, this grade of FKM is used to manufacture seals for industries like food and beverages, pharmaceutical, etc.

Also, based on chemical composition, there are four fundamental types of FKM available, listed as follows.

1. Type 1 FKM
2. Type 2 FKM
3. Type 3 FKM
4. Type 4 FKM

There are several properties of this fluorocarbon rubber that makes it suitable for complex industrial applications. Let us discuss the same.

Properties of Fluorocarbon Elastomers

The following are the significant properties of FKM elastomers that make this material a great choice for applications exposed to high temperatures and chemicals.

• FKM elastomers are highly tolerant to the temperature and offer thermal stability. The tolerable temperature range of FKM is between -40˚C to 225˚C.
• Being a carbon-based synthetic polymer, it offers high endurance to external impacts like mechanical stress, bombarding forces, etc. Therefore, the compression resistance of the FKM polymer is high.
• It offers excellent resistance to chemicals, hydro-fluids, and fuels. Therefore, under the exposure of mineral oils and fats, this material does not suffer chemical or physical degradation.
• It offers high oxygen stability and a limited impact on aging. Therefore, the lifespan of FKM is about 5000 hours at 200˚C.
• It offers low gas permeability, therefore, the material is immune to interruption of gaseous media, air bubble formation, porosity, etc.
• Under influence of non-polar media, the properties of FKM remain unchanged.

Learn About Few Specific Properties of FKM Seals

Owing to the above-mentioned properties of the material, the FKM seals are widely preferred in several industrial applications. The following are the benefits of using these seals instead of other types of seals like metal, or cartridge seals.

• Due to high-temperature tolerance and thermal stability, heat leakage is reduced in FKM seals.
• The longer lifecycle of these seals reduces the need for frequent seal or gasket replacement.
• Due to high compression resistance, the deformation is minimum for these seals, which also enhances the durability of the system.

In order to reap the mentioned benefits of these seals in industrial applications, it is essential to invest in quality seals. Only experienced manufacturers like SSP Seals can ensure the authentic quality, and performance of FKM seals in compliance with ISO, ASTM, and DIN standards. The company utilizes FDA approved FKM to manufacture seals for several industries.