The Viton GB/GF series fluororubber belongs to the family of vinylidene fluoride-hexafluoropropylene copolymers (FKM) and its terpolymers. It is a high-grade grade within the Viton brand, featuring balanced comprehensive performance, excellent processing performance, and outstanding resistance to media. Specifically, the GB series focuses on general-purpose high-performance oil and heat resistance, while the GF series further enhances the chemical resistance (especially to alcohol-containing fuels and acidic gases) and low-temperature flexibility based on the GB series.
Viton GB/GF exhibits excellent high-temperature resistance, with a typical operating temperature range of -25℃ to +220℃, and the GF series can be extended to -30℃ for low temperatures. Its long-term continuous operating temperature can reach 205℃, and intermittent use can reach 250-300℃. It has excellent heat aging resistance, maintaining its elasticity even after thousands of hours in air at 200℃.
The excellent oil and chemical resistance of this series of materials is its core advantage:
GB series: It exhibits excellent resistance to mineral oil, gear oil, hydraulic oil, fuel oil (gasoline, diesel, kerosene), lubricating oil, aromatic hydrocarbons (benzene, toluene), chlorinated hydrocarbons, as well as dilute acids and alkalis.
GF series: Based on GB, it exhibits enhanced resistance to alcohol-containing fuels (such as E10 and E85 gasoline), acidic oil and gas containing hydrogen sulfide, amine preservatives, high-concentration ozone, and superheated steam (intermittent). Its fluorine content is typically higher (>68%).
Viton GB/GF exhibits good mechanical strength, with tensile strength reaching 12-18MPa. Its tear strength and wear resistance surpass that of general fluororubber. Its compression set performance is excellent, especially the GF series, which utilizes a peroxide vulcanization system. The compression set can be controlled at 20%-30% at 200℃, ensuring the reliability of long-term dynamic sealing.
In addition, the GB/GF series exhibits excellent resistance to ozone, ultraviolet radiation, and atmospheric aging, making it virtually unaffected by any outdoor environment. Its electrical insulation properties are moderate, making it unsuitable for high-frequency and high-voltage electrical sealing. The GF series typically boasts better mold release properties and scorch resistance, making it suitable for manufacturing complex-shaped or high-precision seals.
However, Viton GB/GF is not resistant to low molecular weight organic acids (such as formic acid, glacial acetic acid), overheated alkali solution (>80℃), high-temperature steam (continuous >150℃), phosphate ester hydraulic oil (Skydrol type), and some amine-based brake fluids. Its cost is significantly higher than that of nitrile rubber and acrylate rubber, but lower than that of perfluoroether rubber (FFKM).
VITON GB/GF seals, specifically the sealing rings made of Viton GB or GF fluororubber, play a pivotal role in demanding high-temperature applications such as automotive powertrains, industrial hydraulic systems, oil and gas equipment, and aerospace due to their exceptional high-temperature oil resistance, remarkably low compression set, and outstanding resistance to complex chemical media.
Automotive engine and fuel system: In the sealing of high-pressure fuel pumps for gasoline direct injection (GDI) engines, turbocharger oil circuits, diesel high-pressure common rail systems, injector O-rings, and quick connectors for fuel lines, the Viton GF series exhibits excellent resistance to gasoline containing alcohol (ethanol, methanol), biodiesel, and high-temperature engine oil, significantly outperforming the GB series. The GB series, on the other hand, is widely used for general engine seals such as valve oil seals and crankshaft oil seals.
Industrial hydraulic and pneumatic systems: In high-pressure hydraulic cylinder piston seals, gear pump end cap seals, proportional valve cartridge seals, accumulator seals, and pneumatic actuator diaphragms, the low compression set characteristics of Viton GB/GF ensure the maintenance of sealing force after millions of reciprocating cycles, making it particularly suitable for mineral oil-based and non-flammable hydraulic oil (excluding phosphate esters) systems.
Oil, Natural Gas, and Chemical Processing: In applications such as valve sealing for Christmas tree systems at wellheads, flange gaskets for equipment handling acidic gases (including H₂S/CO₂), auxiliary components for mechanical seals of chemical process pumps, and joint sealing for solvent delivery pipelines, the Viton GF series stands out as an upgraded alternative to the standard FKM due to its superior chemical resistance and resistance to acid gas corrosion. The GB series, on the other hand, is suitable for conventional media such as crude oil, refined oil products, and natural gas liquids.
Aerospace: In the sealing of aircraft engine accessory gearboxes, fuel system connectors, hydraulic system pipelines (mineral oil-based), and landing gear shock absorber air chambers, Viton GB/GF meets the stringent requirements of aviation standards for resistance to high-temperature fuel, low temperature (high-altitude environment), and ozone aging. It is a typical material for aviation O-rings.
Semiconductor and electronic equipment: In the sealing of vacuum coating equipment chambers, auxiliary gas pipelines for plasma etching machines, high-temperature oven door seals, and explosion-proof valve seals for power batteries, Viton GF’s resistance to high-temperature plasma and corrosive gases helps reduce particulate contamination.
General industry and household appliances: In seals for high-temperature dyeing machines, compressor shaft seals, oven conveyor belt chain seals, high-pressure waterway seals for coffee machines (intermittent steam), and gearbox seals for power tools, Viton GB/GF offers a lifespan far exceeding that of nitrile rubber and silicone rubber, reducing the frequency of maintenance.
Special attention is required:The GB series is suitable for most mineral oil, fuel oil, and dilute acid and alkali conditions, but it has limited resistance to alcohol-containing fuel, acidic gases, and high-temperature steam.
The GF series is more recommended for applications involving alcohol-based fuels (biofuels), acidic oil and gas, high-temperature ozone, and high requirements for low-temperature flexibility. However, its resistance to water vapor is still limited, making it unsuitable for continuous high-temperature hot water or steam sealing.
Both series are not resistant to phosphate ester hydraulic oil (such as Skydrol, EPDM or fluorosilicone rubber should be used) and overheated alkali solution.
Selection recommendation: For applications involving alcohol-based fuels, acidic media, and higher heat resistance requirements, Viton GF is preferred; for conventional fuel oils/fluids, where cost and processability are important, Viton GB is recommended.In summary, the Viton GB/GF series fluororubber materials and their seals represent top-tier high-performance fluororubber sealing solutions in fields demanding high sealing reliability, such as automotive, industrial hydraulics, petrochemical, aerospace, and precision equipment, due to their excellent high-temperature oil resistance, extremely low compression set, superior resistance to complex chemical media, and wide operating temperature range.