Viton® FKM FPM Rubber - Fluorine Rubber
Viton® rubber is a specific product of the copolymerization process of fluorinated rubber monomers. It is also known by other names on the market, such as fluororubber, FKM, and FPM. The name of this material has been trademarked by DuPont. Viton is a high-quality product known for its exceptional resistance. It has high mechanical strength and resistance to damage, extreme temperatures, and aggressive substances.
It is an uncompromising solution in the range of rubber products - this fluoroelastomer has the highest possible parameters, which will prove its resistance in the toughest and most demanding working conditions.
What does the acronym FKM and FPM stand for?
Viton is a fluorine-based rubber produced in a chain reaction of copolymerization of monomers containing fluorine molecules. Specifically, it consists of vinylidene fluorides and hexafluoropropylenes, alternated with vinylidene fluorides and trichloroethylenes. Viton is known for its exceptional resistance to extreme temperatures and non-flammability. Fluorine vulcanizates also exhibit partial gas permeability. In a vacuum environment, Viton may slightly lose mass. Most rubber blends have similar mechanical properties to Viton.
Viton-type vulcanizates are labeled as FPM. On the other hand, fluorine rubbers or fluorine-based rubbers are designated as FKM.
At first glance, one can distinguish the materials present in fluororubber seals being observed by the buyer. Viton O-rings are typically black, while FKM FPM seals are green or black with a green mark at the outer edge. They can also be found in brown or in any other color upon request.
Viton® History
The history of Viton dates back to the 19th century. In 1802, Éleuthère Irénée du Pont de Nemours founded a company initially focused on producing black powder. It is hard to believe that today this company is a publicly traded entity listed on the New York Stock Exchange. Today, it is also one of the largest chemical companies globally. Interestingly, its founder was the son of the secretary of the king of Poland, Stanisław Poniatowski. The company was born in Brandywine Creek, USA. Throughout the 19th century, DuPont invested in the chemical market, but it was in the 20th century that the company truly flourished. It was during this time that scientists working for DuPont invented very durable materials, including teflon, kevlar, nylon, and the aforementioned Viton. DuPont was responsible for a revolution in polymer materials.
In 2012, Viton was introduced to the market and officially presented at the DKT (Deutschen Kautschuk-Tagung) conference in Nuremberg.
Applications of Viton® Rubber
Among many available vulcanized materials, this highly durable rubber stands out due to its valuable industrial properties:
- Vacuum resistance
- UV radiation resistance
- Durability in ozone environments
- Resistance to oils and mineral greases, even those with additives
- Resistance to inorganic acids such as sulfuric, hydrochloric, phosphoric, and nitric acids
- Excellent durability against non-flammable hydraulic fluids with phosphoric esters and chlorinated hydrocarbons, designated as HSC
These material characteristics make it highly valued in demanding industries. Coal and even nuclear power plants utilize it. Companies in the gas, oil, and petrochemical industries also benefit from the resilient nature of this rubber. Notably, even the oil industry relies on Viton for production processes and transportation methods. Its unique properties are widely used in transporting various chemical substances, machinery involved in transfer, and desulfurization systems. Viton is also present in the aerospace, space, and food industries.
Due to its minimal gas permeability, this synthetic rubber also finds applications in vacuum sealing.
Viton is a reliable material, protecting various surfaces from aggressive chemicals in challenging environments. These conditions, classified as unusual, primarily include high temperatures generated during engine or turbine operations and low temperatures requiring elasticity. Viton's temperature range is from -25 to 210 degrees Celsius. However, it has been observed that even at 230 degrees Celsius, short-term seals also remain undamaged. This rubber is dimensionally stable and exhibits self-lubricating properties, which are utilized in the automotive industry for fuel systems and engines. Its shape retention property has also found applications in various pumps, valves in pneumatic and hydraulic systems.
FKM FPM Rubber - Temperature Range for FKM FPM Rubber
Fluorine-based rubber compounds, commonly known as fluororubbers due to the addition of Fluorine increasing resistance and providing working properties at high temperatures, have a specific temperature range.
This range typically spans from -25°C to +210°C. Depending on the application, some mixtures can even withstand temperatures up to +230 and +250°C.
This temperature range makes these compounds suitable for high-temperature applications, such as high-temperature O-rings used in engines and high-pressure fuel injectors.
Viton® - Material for Many Generations!
Synthetic rubber Viton, also known as a fluoropolymer elastomer, is commonly used in O-rings. Viton fluoroelastomers are classified under designations such as:
- FKM ASTM D1418
- ISO 1629
These include:
- Tetrafluoroethylene (TFE) terpolymers
- Vinylidene fluorides (VDF, or VF2)
- Hexafluoropropylene (HFP) and its copolymers
- Perfluoromethylvinyloether (PMVE)
To classify rubber materials under Viton, the fluoride content must be between 66 to 70%. Viton is commonly green or brown in color. However, color may not be the most accurate way to identify it. It is better to subject it to density tests, where Viton will have a density higher than 1800 kg/m3, significantly greater than other rubbers with densities ranging around 1.010 - 1.520 kg/m3.
Viton® can be divided into 4 families:
- Viton A® - VF2/HFP dipolymers - universal sealing, resistant to fuels and mineral oils, fluoride content around 66%
- Viton B® - VF2/HFP/TFE terpolymers - used in chemical plants and as electrical seals, fluoride content at 68%
- Viton F® - VF2/HFP/TFE terpolymers - effective against oxidized automotive fuels, concentrated inorganic acids, water, steam, fluoride content at 70%
- Special types include: GLT, GBLT, GFLT, and Viton Extreme, concerning TFE/propylene and ethylene/TFE/PMVE copolymeric materials, used in the automotive industry, oil extraction, and specialized seals.
The chemical resistance of Viton material to aggressive substances depends on the type of base polymer and the ingredients used in the final product processing. O-rings are a good example of this. Of course, material performance may vary as there are many facilities producing Viton polymers.
When working with synthetic rubber with fluorine additives, caution must be exercised in case of very high temperatures or direct exposure to fire. Fluoroelastomers can decompose and release toxic hydrogen fluoride. Residues and waste materials in contact with Viton under such conditions should be removed using specifically designed protective equipment.
Viton® Seals - POWER Rubber
Viton seals made of fluorine rubber produce a highly durable material - Viton. O-rings, flat sealing mats, or custom-shaped gaskets are made from it. Available in the market are gaskets, flat seals, O-rings, profiles, cords, and simmerings. With a laser plotter, appropriate Viton forms can be cut and trimmed to meet demand.
Viton O-Rings Better Than NBR O-Rings
Commonly used rubber O-rings are made of a nitrile blend, NBR. This material exhibits oil resistance within a basic range. Additionally, the working temperature range is up to +100°C - POWER Rubber recommends usage up to +90°C.
However, what if one needs greater chemical resistance and higher temperature tolerance for O-rings?
Here, FKM FPM O-rings come into play, often known as high-temperature O-rings. They allow operation up to +220°C. They exhibit chemical resistance to mineral oils, even synthetic ones, greases, continuous contact with fuel, oil, and their derivatives. They are often known as oil-resistant O-rings. Seals made from this material also feature dedicated resistances, such as contact with food - FDA Viton®.
FKM FPM and Viton® Rubber Sheets
Oil rubber sheets are precisely sheets made from fluorine mixtures. Their main advantage is very high resistance to continuous contact with greases, oils, gasoline, and diesel.
The oil sheets are available in thicknesses:
- 1 mm
- 1.5 mm
- 2 mm
- 3 mm
- 4 mm
- 5 mm
- 6 mm
- 8 mm
- 10 mm
- 12 mm
- 15 mm
Technical Data for FKM FPM Sheets
Hardness: The most common hardness of sheets is 75 ShA (Shore A Scale). However, production capabilities allow obtaining sheets with hardnesses of 70 ShA.
Recommended temperature range: From -20°C to +220°C, and in high-temperature versions, even up to +275°C
Tensile strength: 200%
Chemical resistance: High resistance to ozone and continuous contact with mineral and vegetable oils, HFD hydraulic fluids. They meet ASTM-1 and IRM 902 and 903 standards.
FKM O-rings with NORSOK M-710 certification
The NORSOK M-170 standard was developed by the Norwegian Oil Industry. It defines the qualification requirements for non-metallic sealing materials and manufacturers. **Why is the NORSOK M-710 certificate so important?** The NORSOK standard is internationally recognized and implemented by the Norwegian Oil Industry. Meeting the standards allows for: - unique performance properties - improved production efficiency - extended lifespan of seals in critical conditions on oil fields The standard specifies requirements for non-metallic (polymeric) sealing materials, sockets, and supports for permanent offshore use, including well completions, control systems, heads, and valves. It also covers seat and backrest elements for permanent use in subsea water. The NORSOK M710 specification also applies to top-side valves in extreme gas constructions. The standard consists of two sections: Annex A - Research methods, conditions, and procedures for aging elastomeric materials Annex B - Resistance to Rapid Gas Decompression (RGD) Elastomers meeting the requirements of the NORSOK M710 standard have been designed for demanding conditions on oil fields. The materials have undergone rigorous testing and have been approved based on various criteria such as: - rapid gas decompression (RGD) - also known as explosive decompression (ED); Occurs when compressed gas is released very quickly and can cause (not always visible) failure of rubber seals inside the device. - aging in sour and sweet gas (simulates test conditions characteristic of the sealing installation environment, both in sour and sweet working conditions) - compression resistance tests - material property tests The NORSOK standard aims to ensure safety, therefore it requires that each individual element (not the entire assembly) meets the established criteria and specifications. **FKM O-rings with NORSOK M710 certificate - benefits and properties** O-rings used in the oil industry for subsea applications must comply with the NORSOK M710 standard. O-rings resistant to explosive decompression are most commonly made of fluororubber FKM / Viton®. Furthermore, this type of rubber has excellent physical properties. FKM O-rings with NORSOK M710 certificate offer performance and protection in applications involving rapid pressure loss, providing resistance to high temperatures and explosions. They are most commonly used in high-pressure applications in the oil and gas industry. Seals and technical components used in the oil and gas industry include oil and natural gas distribution, offshore production platforms, natural gas production, and energy generation. To meet the constantly growing demands of our Customers, we use advanced production technology and specialized knowledge in processing. For a detailed discussion of the requirements, please contact us. Viton® FDA O-rings made of FKM elastomers with FDA class are a popular choice for producing seals in industries requiring high quality, especially in food and beverage, pharmaceutical, and medical device industries. Viton® FDA O-rings are made of a special fluoroelastomer compliant with Food and Drug Administration requirements. They can come into contact with food, drugs, and medical devices. The FDA ensures that the products do not contaminate food products and are safe for consumers. Viton® FDA O-rings are: - odorless, tasteless - resistant to microbial growth - non-toxic - non-staining - non-allergenic - durable for the intended environment **Viton® FDA O-rings - properties and benefits** Discover the benefits of using Viton® FDA sealing rings, here are some of them: - ideal for use in industries where contact with drugs, food, medical devices is possible - provide long-lasting and reliable sealing - suitable for high-temperature applications - resistant to a wide range of chemicals, including oils, fuels, acids, and bases - suitable for use in challenging conditions where contact with chemicals is a risk Fluoroelastomers cope well with high temperatures, are chemically resistant, and do not absorb water. The operating range varies from -20°C to +204°C. You can read more about the FDA certificate [here](/certyfikat-fda/) If broadly defined rubber products for contact with food items are needed, FFKM compounds are also suitable for such applications. However, it is worth remembering that in professional applications, rubber articles should be FDA certified. FDA certification (source: Food and Drug Administration [https://www.fda.gov/]), the American equivalent of the Food and Drug Administration. It confirms the permissibility of seals for contact with food items - food, and even potable water.
Viton® USP Class VI"
USP (United States Pharmacopeia) is a non-profit organization that supports public health. It focuses on the pharmaceutical and biotechnological industries. The United States Pharmacopeia establishes standards to protect the quality of drugs and other healthcare-related technologies.
USP sets standards for quality, purity, strength, and consistency through a series of rigorous tests to assess their suitability. The testing standards are defined by the United States Pharmacopeia and the National Formulary (USP-NF). It is a non-profit organization responsible for the quality and safety of medical products and food.
USP Classes:
USP defines six classes of plastics I-VI, with Class VI being considered the most stringent. To meet USP Class VI criteria, a product must demonstrate very low toxicity levels. USP Class VI products undergo a series of biological tests to evaluate the reactivity of different types of plastics in vivo. Chapter 88 sets standards for testing and certifying materials used in the production of medical products.
Biocompatibility Testing of Plastics in Medical Applications
USP Class VI testing is conducted on plastics that come into contact with injectable drugs and liquid substances encountered at various stages of drug manufacturing.
Biocompatibility is a characteristic that all rubber components used in medical equipment and surgical devices must possess when in contact with living tissue.
USP Class VI Testing Methods
In the laboratory, testing is carried out by creating an extract from the product with various extracting fluids such as polyethylene glycol and vegetable oil. To observe the biological reaction, the extract of the product is injected in vivo (live) into test subjects (rabbits and mice). The main aim of the research is to identify the absence of toxic chemical substances that may migrate from elastomeric materials, causing harmful health effects.
Testing is done in accordance with USP 88, which requires three types of tests:
- Systemic injection test (this test is designed to monitor the extract sample injected intravenously for abnormal toxic reactivity; observation period is 72 hours)
- Subcutaneous test (results determine if the medical device causes local skin reactions; observation period is 72 hours)
- Implantation test (involves embedding a sample material and observing the reaction of live tissue to direct contact with the material; observation period is at least 120 hours)
After passing the three tests mentioned above, elastomeric materials are also subjected to various temperature tests for a specified duration, such as +55°C (72 hours), +70°C (24 hours), +121°C (1 hour).
USP Class VI Testing Benefits
Here are the major benefits of conducting tests according to USP Class VI:
- USP Class VI standard confirms the absence of harmful reactions
- Biocompatibility testing confirms that medical products do not cause long-term effects due to chemical substances released from plastics
FKM O-rings of USP VI class
The pharmaceutical, biopharmaceutical, and biotechnological industries require elastomeric materials of high quality, characterized by reliability, and meeting strict requirements for biocompatibility and biological purity. Rubber compounds certified as USP Class VI have a high level of biocompatibility, making them ideal for use in the medical and pharmaceutical industries.
FKM/Viton® USP Class VI sealing rings are recommended for high-temperature applications (e.g. pumps, agitators).
USP Class VI - Applications
- medical and pharmaceutical industries
- pumps and sanitary seals
- in medical facilities (fluid handling and transport components)
- hygienic (aseptic) diaphragm valves
- single-use process components (e.g. tubing)
- direct applications (e.g. tissue implants)
If you need more information about our products, please contact us.
Viton® rubber with UL94 V0 certification
UL (Underwriters Laboratories) is an independent organization that develops safety standards and issues certifications for products that meet specific norms and requirements.
UL 94 is a flammability standard widely used in the rubber industry. It involves testing the flammability of polymeric materials through combustion tests to evaluate their ability to extinguish after ignition.
Flame ratings according to the UL standard include:
- Vertical burning tests (V-0, V-1, V-2, 5VA, 4VB, VTM-0, VTM-1, VTM-2)
- Horizontal burning tests (HB, HBF, HF-1, HF-2)
UL 94 V0-rated Fluoroelastomer FKM indicates that the material was tested in a vertical position and self-extinguished within a specified time after removal of the ignition source. The vertical position also indicates whether flaming particles dripped from the sample and ignited a cotton indicator placed below the sample. Fire-resistant materials prevent flame propagation during a fire.
For more information about the UL94 certification, you can read here.
If you need flame-retardant materials with a UL 94 V0 rating, please contact us.
Fluororubber FKM compliant with EN549 standard
Rubber materials used for seals and membranes in gas devices and gas installation equipment are subject to strict requirements regarding material, geometry, construction, and durability. They must comply with the EN549 standard.
Rubber materials with the EN549 standard are often used in industrial natural gas installations or natural gas transmission lines. The above standard also applies to rubber seals used, for example, in central heating boilers, gas stoves, and natural gas stoves.
EN549-compliant FKM fluorinated rubber meets rigorous standards that apply almost throughout Europe. A faulty seal can have catastrophic consequences, which is why Viton® EN549 rubber has successfully passed rigorous tests that examine, among other things, the aging properties of the material under the influence of hot air, n-pentane, and ozone.
For more information on the EN549 standard, visit here
Viton® A
Viton® Type A is a general-purpose fluoroelastomer with a fluorine content of about 66%. It is suitable for seals and molded products, applications related to extrusion, and solution coating. It includes three different ranges of vinylidene fluoride/hexafluoropropylene copolymer viscosities:
- A-35 (extrusions, semi-finished products with high hardness)
- A (calendared products, molded parts)
- A-HV (gaskets, O-rings)
Viton® A is composed of dipolymers of hexafluoropropylene (HFP) and vinylidene fluoride (VF₂). It has a monomer structure that polymerizes upon heating, creating a rigid crystalline structure with high tensile strength. Its structure is linear, with each atom arranged regularly, and the chain length is almost equal to a single bond. Viton® A is characterized by exceptional thermal resistance and chemical stability (resistant to oils, fuels, greases, most mineral oils). Moreover, it is resistant to many aliphatic hydrocarbon fluids. It performs excellently in contact with ozone, strong acids (except hydrofluoric acid), strong bases, weak oxidants, organic compounds, and many solvents. It exhibits excellent resistance to atmospheric conditions, abrasion, heat, as well as fungi and mold.
Viton® A is an FDA-approved material, making it suitable for applications involving food contact. It is often used as a material for food packaging (protecting products from moisture, oxygen, contaminants). It also finds application in the pharmaceutical industry.
Sample products produced using Viton® A:
- O-rings
- V-rings
- Gaskets
- Fuel hoses
- Fuel lines
- Valve stem and shaft seals
- Solution coatings for chemical containers, among others
Viton® B
Viton® B fluoroelastomer is a type B rubber polymer consisting of hexafluoropropylene (HFP), vinylidene fluoride (VF₂), and tetrafluoroethylene (TFP) with a fluorine content of about 67%. The addition of TFE to Viton® B provides greater chemical resistance compared to Viton® A, including resistance to acids, amines, and steam.
Viton® B is made from kalafonia monomers (soft resin derived from natural sources) that polymerize upon heating, creating a flexible material with lower density than Viton® A. Its structure is branched.
Viton® B is oil-resistant, resistant to abrasion, compression, and permeation, and:
- resistant to high temperatures (can withstand high temperatures with a maximum continuous operating temperature of about 250°C)
- resistant to acids
- resistant to atmospheric conditions
- resistant to UV radiation and ozone
- has excellent resistance to degradation
- resistant to most mineral acids
- stands out from other types of rubber in its resistance to aliphatic and aromatic hydrocarbons
- has exceptional oxidation resistance, sunlight, wind
- exhibits excellent resistance to fungi and mold
This type of material is FDA approved for food contact applications. Similar to Viton® A, it is used for food packaging.
Viton® B is preferred in applications where increased chemical resistance and resistance to higher temperatures are required. It is commonly used in industries such as aviation, automotive, oil, and gas, and chemical processing.
The material is used in the production of:
- Gaskets
- O-ring seals
- Valve covers
- Shaft seals
- Lining for rubber hoses
Viton® G
Viton® G is a peroxide-cured fluorinated rubber consisting of Viton® GF polymer. Viton® G provides greater resistance to concentrated acids than Viton® B.
Only G-type fluoroelastomers are suitable for work in sulfuric acid. Viton® G contains more fluorine than other types of Viton®, significantly improving the material's resistance to hot, concentrated sulfuric acid.
Viton® GF
Viton® GF is a high-performance grade of Viton® with low viscosity, peroxide-cured, containing 70% fluorine. It consists of hexafluoropropylene (HFP), vinylidene fluoride (VF₂), tetrafluoroethylene (TFE) with a monomer cured by peroxide.
Viton® GF exhibits excellent resistance to aromatic hydrocarbons, alcohols, water vapor (up to 140°C), water, many chemicals and solvents, including strong acids.
Viton® GF also has other unique properties, including:
- easy to process
- excellent heat resistance
- resistance to low temperatures
- excellent resistance to compression set
- provides resistance to some of the most corrosive chemicals
- characterized by higher resistance to cleaning agents used in the pharmaceutical and food industries
- increased durability
Viton® GF surpasses Viton® A and B in chemical resistance. It provides resistance to fluids and low permeability even in extreme conditions, making it suitable for various industries that use chemical mixtures and oxidized fuels.
The material is used in the production of rubber seals, fuel hoses, molded parts requiring flexibility at low temperatures, O-rings, crankshaft oil seals, turbocharger rubber hoses, and more. It is also suitable for the production of sanitary components.
Viton® GLT
Viton® GLT is a low viscosity peroxide-cured grade of Viton® containing 64% fluorine. It consists of polytetrafluoroethylene ether perfluoro-3,6-ethylidene-vinyl ether (PMVE), vinylidene fluoride (VF₂), and tetrafluoroethylene (TFE) with peroxide-cured monomer.
Introduced to the market in 1976, Viton® GLT excels in exceptional low-temperature flexibility for molding applications. It also features:
- excellent low-temperature resistance
- excellent compression set resistance
- excellent resistance to fluids, chemicals, and high temperatures
- does not swell in water
Viton® GLT is a highly specialized grade that performs well in areas where challenging environmental conditions prevail, such as the automotive sector, oil exploration systems. The material is used in the production of seals, O-rings, molded parts requiring flexibility at low temperatures, elastomeric diaphragms, turbocharger rubber hoses, dynamic seals for diesel fuel injectors, among others.
Viton® GFLT
Viton® GFLT is a peroxide-cured grade of Viton®, containing 67% fluorine, consisting of polytetrafluoroethylene ether perfluoro-3,6-ethylidene-vinyl ether (PMVE), vinylidene fluoride (VF₂), and tetrafluoroethylene (TFE). Viton® GFLT, a low viscosity peroxide-cured fluoroelastomer, exhibits exceptional curing speed and low-temperature flexibility. Additionally, it features excellent resistance to fluids, oils, low compression set, as well as water resistance (reduced swelling in water).
Other properties of Viton® GFLT include:
- heat resistance
- high-temperature endurance (up to 225°C)
- excellent resistance to swelling and permeation
- resistance to degradation when in contact with motor oils, gasoline, biofuels, etc.
- compared to other fluorocarbon elastomers, it provides better fluid resistance (similar to Viton® GF)
Due to its properties, Viton® GFLT is well-suited for use in fuel systems utilizing gasoline and alcohol blends and/or "oxygenated" fuels. It is used in the production of seals, O-rings, rubber hoses, rubber diaphragms, fuel injector rubber parts.
Viton® GFLT has a wide range of applications in areas where high flexibility in low temperatures is required, such as in automotive and aviation industries.
Viton® ETP
Viton® ETP was developed to address critical sealing issues. Viton® Extreme ETP consists of polytetrafluoroethylene ether perfluoro-3,6-ethylidene-vinyl ether (PMVE) and tetrafluoroethylene (TFE) with peroxide-cured monomer. It contains 67% fluorine and provides improved chemical resistance compared to standard fluoroelastomers like Viton® A.
Discover the additional properties of Viton® ETP, here they are:
- offers excellent resistance to low molecular weight esters, ketones, and aldehydes, as well as high-pH liquids
- excellent resistance to volume swell and property loss in the presence of highly corrosive substances
- longer service life
- does not swell
- compression-resistant when in contact with aggressive solutions, amines, hot water
- resistant to ozone and very high temperatures (up to 220°C)
- the elastomer's flexibility is maintained at low temperatures
- well-suited to environments with high pressure, strong acids, petroleum products, synthetic and mineral greases, silicone oils, polar fluids, and more
Viton® ETP finds applications wherever high-temperature resistance and resistance to aggressive media are required. It is most commonly used in the gas, oil, automotive, and aviation industries. It is also excellent for the production of sanitary components.
We meet our customers' expectations. We design and produce custom Viton technical seals on individual order.
Feel free to contact us here.
Viton® is an official registered trademark of the DuPont® rubber compound. www.dupont.com