Viton® A — FKM Type 1 Fluoroelastomer (66 % F), Raw Gum for Vulcanization

Description

Viton® A is the original type 1 fluoroelastomer (FKM) — a binary copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP). Its 66 % fluorine content is the standard fluorination level, providing the baseline set of FKM elastomer characteristics: resistance to high temperatures, aggressive media, UV, ozone, oils and fuels. Supplied as raw gum for subsequent vulcanization into finished seals and molded parts.

FKM elastomers are divided into 4 types by fluorine content and composition: type 1 (66 %, VDF/HFP — Viton® A) — the standard; type 2 (68 %, terpolymer with TFE) — improved oil resistance; type 3 (69 %) — maximum fuel resistance; type 4 (64 %, with ethylene) — low-temperature flexibility. Viton® A is the most widely used type for general sealing applications where the priority is a balance of price and performance.

Typical parameters (after vulcanization): density 1.85 g/cm³, Mooney viscosity ML(1+10) 100 °C ≈ 80 MU, continuous service temperature 200 °C (peak 250 °C), Tg ≈ −20 °C (standard Viton® A is not intended for applications below −15 °C; see type 4 for cryogenic use), Shore A hardness 70–75, tensile strength 10–15 MPa, elongation at break 250–300 %, compression set 25 % at 200 °C / 70 h (ISO 815).

Key advantages

• Continuous service temperature of 200 °C (peak 250 °C for short periods) — exceeds NBR, EPDM and silicone
• Resistance to all fuel types: gasoline, diesel, kerosene, JP-8 aviation fuel, ethanol blends E10/E20/E85, biodiesel B100
• Resistance to mineral and synthetic oils, hydrocarbon-based hydraulic fluids, brake fluids (NOT DOT 3/4)
• Resistance to aromatic (benzene, toluene, xylene) and aliphatic hydrocarbons
• Resistance to ozone, UV and weathering — suitable for decades of outdoor service
• Inherent flame resistance without additives (self-extinguishing once the flame source is removed)
• Low outgassing in vacuum — suitable for UHV and semiconductor processes
• Biological inertness — suitable for food and pharmaceutical equipment (after appropriate vulcanization and certification)

Limitations and incompatible media

• Do not use with: ketones (acetone, MEK), esters (ethyl acetate), amines, concentrated alkalis, hot steam above 150 °C (for steam — type 4 FKM or EPDM)
• Limited use in hot water and steam up to 100 °C — for continuous hot-water service consider EPDM
• DOT 3/4/5.1 brake fluids (glycol-based) — incompatible
• Not recommended for applications below −15 °C — standard Viton® A loses elasticity (for low-temperature use — Viton® GLT, GFLT, ETP series)

Applications

• Automotive fuel systems: injector seals, fuel pump gaskets, hoses in contact with E85 biofuel — a gradual transition from NBR to FKM driven by the growing ethanol share in fuels
• Aerospace: hydraulic system seals, hydraulic transmission gaskets, fuel fittings for aircraft engines, static and dynamic seals for JP-8 / Jet-A systems
• Oil and gas (downhole/upstream): seals for packers, ESP pumps, production manifolds, plungers; temperatures up to 200 °C at depths of 5–6 km
• Chemical process equipment: pump and valve seals for hot acidic and alkaline solutions (up to the concentrations specified for the particular FKM type), reactor equipment
• Semiconductor industry: high-purity gas line seals, gate valves, vacuum system components (Class 100 cleanroom-certified products)
• Food, pharmaceutical and biotech: seals for CIP/SIP equipment, bioreactors, dosing systems (after FDA / USP Class VI certification of the finished part)
• Military and defense equipment: seals and hoses for fuel and hydraulic systems, special applications

Global market counterparts: Daikin Dai-El® G-7 series, 3M Dyneon™ FT-2230, Solvay Tecnoflon® FOR-435, AGC AFLAS® (special types). When selecting an alternative FKM type (1/2/3/4), consider the specific requirements for media, temperature and compression load.

The stated values are typical for the vulcanized material and may vary depending on the compound formulation, the type of curing agent and the vulcanization conditions. This information is provided for reference only and does not constitute an official batch data sheet. Please request the TDS and MSDS for the specific batch before industrial use.