VITON seal. Description and characteristics of the sealing materials used Sale of Viton seals

Types and names of fluorine rubbers: SKF, FKM, FPM, Viton and others

Fluorine rubbers (FC, organofluorine rubbers, fluoroelastomers) are a large family of synthetic rubbers obtained by copolymerization of fluorine-containing monomers. Due to the fluorine content, these materials have outstanding heat resistance, non-flammability and are resistant to many aggressive environments. The general disadvantages of fluorine rubbers are their high cost and the danger of releasing toxic gases and vapors when exposed to ultra-high temperatures. Among rubbers, FCs occupy the same place as the most famous fluoropolymer, Teflon, among polymers.

These materials have been actively developed and patented since the 40s of the 20th century by large chemical corporations such as DuPont. Commercial names of new materials became widespread and became household names. Let's look at the most common notations:

SCF, fluorinated synthetic rubbers is a general designation for a family of fluoroelastomers, adopted in the USSR and Russia. Belonging to a particular group is indicated by a digital index, the brand is specified by letters. For example: SKF-26, SKF-260 MPAN.

Name SKF	International designation, commercial names
	FKM (FPM) A or E, Viton A (VF2/HFP), Viton A
	FKM (FPM) GLT, Viton GLT
	FFKM, Kalrez (Kalrez), Parofluor
	VF2/CTFE, Kel-F 3700 (Kel-F 3700), Dyneon 31508

FPM, Fluorinated propylene monomer (ISO designation), FKM, Fluorocarbon (ASTM designation, American Society for Testing Materials) is a general designation for a number of fluoroelastomers based on vinylidene fluoride (1,1-Difluoroethylene, vinylidene fluoride, VDF, VF2). The first such material was Viton A, synthesized by DuPont, a copolymer of VF2 with hexafluoropropylene (HFP), followed by Viton B and Viton F, which also contain tetrafluoroethylene (TFE), and a number of special grades on the same basis. Nowadays, the collective name “Vitons” most often means FPM rubbers and a similar classification is often used, i.e. FPM A or FKM GLT corresponds to the properties of Viton A or Viton GLT from DuPont. Many manufacturers are developing their own brands, for example Dyneon (3M), Dai-El (Daikin), Solef (Solvay Specialty Polymers). For some of them there is no analogue in the Viton family, for example VF2/CTFE (SKF-32, Dyneon 31508). However, DuPont produces Viton Extreme (ETP), which does not contain VF2 and is therefore not an FPM.

Viton® (Viton) is a trademark of DuPont. This brand produces a wide range of rubbers based on vinylidene fluoride (VF2) and tetrafluoroethylene (TFE). Viton types A, AL, B, GBL, F, GF, GLT, GBLT, GFLT are VF2 copolymers and belong to FPM (FKM) fluorine rubbers. Viton Extreme is a copolymer of ethylene, tetrafluoroethylene (TFE), and perfluoromethylvinol ether (PMVE), does not contain VF2 and is therefore not classified as FPM (FKM). This rubber is also designated as ETP (ethylene, tetrafluoroethylene (TFE), perfluoromethylvinylether (PMVE)). The range of original Vitons is very wide; the types mentioned above are divided into grades, each of which has characteristics in terms of temperature, mechanical or chemical properties.
.

FFKM, Perfluoroelastomer, a copolymer of tetrafluoroethylene (TFE) with perfluoromethyl vinyl ether (PMVE). Chemically related to FKM (FPM). Domestic designation - SKF-460. Also known by manufacturer brands such as Kalrez (Kalrez) from DuPont, Parofluor (Parker Hannifin), Simriz (Freudenberg Simrit GmbH), Neofton (FSUE "NIISK").

AFLAS is a trademark of Asahi Glass Co (Japan). Under this name, two types of materials are produced: copolymer of tetrafluoroethylene and propylene (TFE/P, series 100, 150 and others) and terpolymertetrafluoroethylene, propylene and vinylidene fluoride (TFE/P/VF2, series SP, MZ201). After Asahi Glass Co was the first (1975) to introduce TFE/P-based fluorine rubbers to the market, the name “AFLAS” began to be used as a commonly used name, including in Russian - Aflas. Usually in this case a TFE/P copolymer is meant.

Characteristics of FPM (Vitone, Viton), compatibility with media

Fluororubbers FPM based on vinylidene fluoride have outstanding properties in terms of thermal and chemical resistance. However, different types of FPM have certain features.

FPM type A or E, vinylidene fluoride-hexafluoropropylene copolymer (VF2/HFP), is the oldest and most common fluoroelastomer in general use. Typically contains 66% fluoride. The main properties of the material are:

• high heat resistance (up to +250°C), exceeding the heat resistance of all known rubbers, except siloxane;
• high weather resistance and ozone resistance;
• chemical and biological inertness, superior to these characteristics of all other elastomers;
• good wear resistance and abrasion resistance;
• satisfactory dielectric properties;
• non-flammability;
• resistance to aging at high temperatures.

This material exhibits good resistance to the accumulation of residual deformation during compression. This type of FPM is applicable in the operating temperature range from -20°C to +250°C, resistant to oxidizing agents and other aggressive media, oils, gasoline and solvents. Not resistant to esters and ketones, flex-fuels with high bioethanol or MBTE content, and some acids.

FPM type B, a vinylidene fluoride terpolymer with hexafluoropropylene and tetrafluoroethylene (VF2/HFP/TFE), differs from type A in its TFE content and a higher (67%) mass fraction of fluorine and exhibits better chemical resistance to acids and biofuels than type A/E.

FPM type GF or F, a VF2/HFP/TFE terpolymer, differs from type B in its higher fluorine content (70%). It has the highest resistance to biofuels and other particularly aggressive environments for FPM for general use.

FPM type GLT– Designed to improve low temperature properties compared to traditional A/E type FPMs. This type of FPM is applicable in the operating temperature range from -50°C to +250°C. Typically contains 65% fluorine and is not resistant to biofuels or aggressive solvents.

FPM type GFLT– combines the ability to operate at low temperatures (from -35°C) and greater chemical resistance to biofuels and other aggressive solvents than GLT. Contains, as a rule, 68% fluorine.

FPMVF2/CTFE, copolymer of vinylidene fluoride (VF2) with trifluorochloroethylene (CTFE). Previously produced and became widely known under the brand name Kel-F 3700 (Kel-F 3700). After the Kellogg company was absorbed by the 3M corporation, this material became part of the Dyneon brand line. In the USSR and Russia it is known under the brand name SKF-32. Like other FPM rubbers, it is characterized by high heat resistance, non-flammability and resistance to many aggressive environments. Operating temperature range from -20°C to +200°C. In terms of the basic mechanical properties of resistance to temperature and aggressive environments, VF2/CTFE is inferior to other FPM. At the same time, this material exhibits excellent resistance to concentrated acids, including fuming nitric acid (solution with an HNO₃ concentration >86%).

Below is a table of properties and compatibility of materials under the Vitone brand manufactured by DuPont. The “–S” marking on DuPont products indicates that the material is manufactured using Advanced Polymer Architecture (APA) technology. Vitone Extreme (ETP-S) is not an FPM material, but is part of the Vitone product line. You can familiarize yourself with the decoding of the Vitone brand article.

FPM rubbers from other manufacturers usually have a similar labeling system or provide a correspondence table with DuPont materials.

Relative chemical compatibility and mechanical properties of Viton® fluoroelastomers

	Viton® general purpose			Viton® special purpose
Chemical environment
Automotive and aviation fuel
Automotive fuel containing ethanol, methanol, MTBE, etc.
Engine oil type SE and SF
Engine oil type SG and SH
Aliphatic hydrocarbons, liquids and chemicals
Aromatic hydrocarbons, liquids and chemicals
Water-based liquids, steam, mineral acids (H2SO4, HNO3, HCl, etc.)
Amines, strong bases (KOH, NaOH, etc.)
Low molecular weight carbonyl compounds (MTBE, MEK, MIBK, etc.)
Compression Set and Low Temperature Capability
Resistance to the accumulation of permanent deformation during compression
Adaptability to low temperatures
Symbol: 1 = Excellent; 2 = Good; 3 = Poor; 4= Not recommended

Application of FPM (Vitons)

Fluororubbers are used in many industries where work in particularly difficult conditions and aggressive environments is necessary. Main consumers of FPM:

• Aerospace industry.
• Automotive industry.
• Chemical industry and transport.
• Food and pharmaceutical industry.
• Equipment for working in undeveloped areas and in difficult operating conditions.
• Exploration and production in oil and gas fields.
• Oil refining and transportation.

Fluororubbers are used for the manufacture of such parts as oil seals, cuffs, sealants, coatings, vibration dampers, vibration compensators (vibration inserts), gaskets, membranes, plugs, diaphragms, heat-resistant O-rings, rod seals. Our assortment of this material includes a VITEX rubber compensator. Fluororubbers are used in the production of sleeves, hoses and tubes for hot aggressive liquids and gases, wire and cable insulation, fuel storage tanks, valves and other products that come into contact with oils, oxidizers and other aggressive media at 200°C and above. Fluororubbers can be used to make adhesives and sealants. Sealing films on this basis do not deteriorate under prolonged exposure to oxygen and ozone, retain elasticity at low temperatures, and have high water resistance.

When choosing an FPM type, it is necessary to take into account many factors, such as mechanical and chemical properties, operating characteristics and extreme operating conditions, required fault tolerance, repairability and replacement. Depending on all the conditions, the optimal option with a suitable balance of cost and characteristics is selected.

DuPont provides the following table for the applicability of Viton rubber types

Viton type	Basic Applications
A, AL, GAL-S, GLT-S	General purpose seals: fuels and lubricants used in automotive, aviation and astronautics.
B,GBL-S	Chemical industry, energy, utilities. Seals and gaskets.
SKF-32	Oil refining, exploration and production. Special seals for particularly harsh conditions.

FPM rubbers can be co-vulcanized with natural rubber, styrene butadiene rubber, chloroprene rubber, silicone rubber and other rubbers. Adding fluorine rubber to cheaper rubbers produces a compound with better chemical resistance than the original rubber. The characteristics of such mixtures are lower than those of “pure” FPM, but this is compensated by lower cost.

FPM production technology (Vitons)

FPM fluororubbers are usually produced by emulsion copolymerization of vinylidene fluoride with trifluorochloroethylene or hexafluoropropylene at temperatures from 20°C to 100°C. Although fluoromonomers are easily emulsified in water even without an emulsifier, its use increases the rate of polymerization and improves the uniformity of the resulting rubbers. Most often, salts of fluorinated liquid acids, such as ammonium perfluoroctoate, are used as an emulsifier.

Fluorine rubbers differ from other synthetic rubbers in their increased viscosity and rigidity, which creates certain difficulties during their processing. The increased viscosity and rigidity of FPM are due to the peculiarities of their structure - high polarity of chains, high molecular weight of linear or weakly branched macromolecules, as well as the presence of a microgel. In addition, the viscosity of fluorine rubbers containing a noticeable amount of microgel increases under mechanical stress, for example, in the first minutes of rolling as a result of the destruction of the microgel and the resulting strengthening of intermolecular interaction.

ETP, Vitone Extreme

Viton Extreme, ETP, a copolymer of ethylene, tetrafluoroethylene (TFE), and perfluoromethylvinol ether (PMVE), is a brand of rubber manufactured by DuPont and part of the Viton family of rubbers. This material does not contain VF2 and does not formally belong to the FPM (FKM) group. Viton Extreme contains 73.5% fluoride.

Vitone Extreme has the same resistance to temperature, acids and hydrocarbons as VF2-based FPM rubbers (other Vitones). In addition, ETP has unique resistance to a number of media that are incompatible with FPM, including alkalis, amines, ketones, aldehydes, and low molecular weight esters (e.g., methyl tertiary butyl ether, MTBE).

FFKM, Kalrez, Kalrez, SKF-460

Perfluoro rubber, FFKM exhibits unique thermal and chemical resistance even compared to other fluorine rubbers. It is also widely known as Kalrez, a trademark of DuPont, which began producing this material in the 70s of the last century. The main feature of this material is its performance in the range from -25°C to +320°C.

The advantage of rubber based on FFKM is low residual compression deformation even under operating conditions at a temperature of about 250°C. The good mechanical properties of these rubbers do not change after exposure to air at a temperature of about 300°C for 1 month. FFKM contains about 75% fluoride.

FFKM is used in the chemical, food and pharmaceutical industries, and semiconductor production. The extreme durability of FFPM allows it to be used at high temperatures in aggressive environments such as jet engine lubricants, rocket fuel components, and oil wells.

DuPont indicates that Kalrez is compatible with more than 1,800 chemical compounds. Among the environments in which FFKM can operate:

• Aliphatic and aromatic hydrocarbons.
• Chlorinated hydrocarbons.
• Polar solvents (ketones, esters, ethers).
• Inorganic and organic acids.
• Water and steam.
• High vacuum (with minimal weight loss).

FFKM is not compatible with:

• Fluorinated refrigerants (R11, 12, 13, 113, 114 and others).
• Perfluorinated lubricants based on PFPE.
FFKM is produced under the brands SKF-460 (Russia), Kalrez (DuPont), Parafluor (ParkerHannifin), Simriz (Freudenberg Simrit GmbH), Neofton (FSUE NIISK).

Comparison of properties of FPM, ETP, FFKM

Based on information from DuPont, the properties of FPM (Vitone), ETP (Vitone Extreme) and FFKM (Kalrez) materials can be compared. The environments in which all three materials perform well are not specified.

Name		ETP (Vitone Extreme)
Chemical compatibility
Fireproof working fluids
Halogenated solvents
Concentrated acids
Dilute acids
Properties
Maximum constant operating temperature, °C
Glass transition temperature, °C
Tensile strength, MPa
Symbol: 1 = Excellent; 2 = Good; 3 = Satisfactory; 4 = Not recommended *Rating depends on material type.

TFE/P, Aflas, Aflas

AFLAS– a trademark of Asahi Glass Co (Japan) and a commonly used name for fluoroethylene and propylene (TFE/P) based fluoroethylene and propylene rubbers. Two groups of materials are produced: based on TFE/P (AFLAS100, 150, etc.) and based on TFE/P/VF2 (AFLAS SP, MZ201). Aflas contain 58-60% fluorine. AF-15 rubber is offered as a domestic analogue.

Aflas have a unique combination of the following characteristics:

• Resistance to high temperatures, up to +230°C in long-term operation, short-term up to +300°C.
• High chemical resistance to strong acids and alkalis, including at high temperatures.
• High dielectric properties (about 10 15 -10 16 Ohm cm).

Aflases are used in air, hydrocarbon fuels, mineral and synthetic oils in static (various gaskets) or dynamic friction conditions (cuffs, rings, diaphragms). These materials exhibit excellent resistance to concentrated acids (hydrochloric, hydrofluoric, sulfuric, nitric), live steam (at temperatures above 200°C), alcohols, alkalis, hydrogen sulfide and mercaptans. Their resistance in these environments over time is higher than the resistance of vulcanizates based on other fluorine rubbers. Detailed information on the chemical resistance of different AFLAS® grades can be found. These materials can be resistant to low temperatures; the glass transition temperature, depending on the brand of rubber, ranges from -35°C to -2°C. At low temperatures, aflas-based vulcanizates become rigid, but not brittle and do not collapse, which is a unique property of this material.

In oil production, Aflas products work well when exposed to high-sulfur oil and gas, amine corrosion inhibitors, high-alkaline drilling fluids, for pumping into water-based wells, acids, and for hydraulic fracturing. Aflas rubber products are used in steam injection installations and in geothermal areas. In the automotive industry, they can be used in the cooling system at high temperatures of engine coolant with corrosion inhibitors, lubricants, glycol brake fluids and new types of motor oils. Aflases are used in the energy, pulp and paper and chemical industries. Due to their high insulating properties at high temperatures, they are of interest to the cable industry.

Aflases are poorly compatible with aromatic hydrocarbons, ketones, and chlorinated hydrocarbons. An obstacle to the widespread use of elastomeric compositions based on these fluorine rubbers is the difficulty of processing them using traditional technologies.

Viton® is a registered trademark of fluorine rubber owned by DuPont, and today Viton is considered the best of all existing fluorine rubbers. A rubber mixture is made from fluorine rubber, from which a seal is then made. In accordance with various standardization systems, the phrase “fluorine rubber” is denoted by various abbreviations, but the meaning and the material itself do not change.

The abbreviation FPM is in accordance with the guidelines of the International Organization for Standardization (ISO), the abbreviation FKM is in accordance with the designation adopted by the American Society for Testing and Materials (ASTM). Those. FPM is the international name and FKM is the American name for the same material. In Russia, the abbreviation FC is accepted (SKF-26, SKF-32).

Viton® fluorine rubber began to be produced in 1957. The start of production of this material made it possible to solve many problems in major industries such as:

Aerospace industry
· Automotive industry
Chemical industry and transport
· Food and pharmaceutical industry
Equipment for working in undeveloped areas and in difficult operating conditions
· Exploration and production in oil and gas fields
· Oil refining and transportation

The main applications of fluoroelastomers are oil seals, cups, sealants, coatings, vibration dampers, compensators, gaskets, membranes, plugs, diaphragms, heat-resistant O-rings, rod seals, heat-resistant cords and plates.

At the moment, the most common types of rubbers are general purpose rubbers: Viton® A, Viton® B, Viton® F.

Fluorinated rubbers based on these rubbers differ in their resistance to oxygen-containing automobile fuels, motor oils, and water-based liquids.

There are also fluorine rubbers for special purposes - Viton® GLT, Viton® GFLT, Viton® Extreme, Viton® BaseResistant.

Types of fluorine rubbers:

							Base Resistant
Chemical resistance
Durability to high temperature
Durability to low temperature

Note: the more + signs, the better the properties of the rubber.

FPM / FKM / Viton® (Fluoroelastomer) - works well in environments exposed to a variety of aggressive liquids. Systems using Viton® products are more resistant to a wide range of chemicals. It has excellent mechanical and physical properties; the fluorine content in the rubber mixture ensures the non-flammability of this material. Fluorinated elastomers have low gas permeability and minimal weight loss when operating in a vacuum.

Stability data (Viton, FPM, FKM)

Good stability	Medium stability	Low/zero. sustainability
mineral oils and lubricants	hot water
aliphatic hydrocarbons (propane, butane)		skydrol 500
silicone oils and fats		ammonia, amines, alkalis
vegetable and animal oils and fats		superheated water vapor
flammable, also super flammable		Low molecular weight organic acids (formic and acetic acids)
oils with sulfur and highly aromatic oils		hydrofluoric acid, chlorosulfonic acid
highly flammable hydraulic fluids of the HFD-S group (phosphoric acid esters, some types may cause destruction) and HFD-R (chlorinated hydrocarbons)	highly flammable hydraulic fluids of groups HFA, HFB, HFC	polar solvents (acetone, methyl ethyl ketone, dioxane, ethyl acetate)
biodegradable hydraulic fluids		glycol based brake fluids
aromatic hydrocarbons (benzene, toluene)

Application range of viton seals

(Viton, FPM, FKM) is mainly used in areas with high temperature and chemical loads. Moreover, fluoride rubber is used in hydraulic systems with highly flammable HFD hydraulic fluids and as a pre-tensioning element for QH-PUR - chemical resistant polyurethane - seals in biodegradable liquids.

Resistant to:

· fuel
· aging
· aggressive chemical compounds
mineral oils and fats
· silicone oils and fats
· oils with sulfur and highly aromatic oils
biodegradable hydraulic fluids
ozone
aliphatic hydrocarbons (propane, butane, gasoline)
aromatic hydrocarbons (gasoline, toluene)
chlorinated hydrocarbons
ultraviolet radiation

Not resistant to:

· broadcasts
Glycol-based brake fluids
organic acids, such as octic and formic
flux acid
chlorosulfonic acid
Ketones (acetone, acetophenone)
hot water steam
· ammonia
· amines
polar solvents (acetone, methyl ethyl ketone, dioxane)

Operating temperature range of fluorine rubber rings: from -20°C to +200°C, withstands short-term heating up to +230°C. In some cases, properly designed fluorine rubber parts based on special frost-resistant Viton rubber can ensure tightness of fixed joints even at temperatures below -60°C.

It should be taken into account that when the temperature of fluoroelastomer seals increases above +300°C, toxic gases and vapors begin to be released from them, and even after cooling, these materials are unsafe.

Information on the performance of rubber based on Viton fluorine rubber at elevated temperatures:

· 10,000 hours at T=204 °C.
· 3000 hours at T=232 °C.
· 1000 hours at T=260 °C.
· 240 hours at T=288 °C.
· 48 hours at T=316 °C.

Viton® retains good sealing properties after exposure to air for more than 10,000 hours at temperatures up to 204°C.

Basic physical and mechanical characteristics (Viton, FPM, FKM)

Properties	Unit	Meaning	Test standard
Hardness			GOST 263 (ISO 868)
Density			GOST 267 (DIN 53479)
Modulus at 100% elongation	MPa (N/mm 2)		GOST 270 (DIN 53504)
Conditional tensile strength	MPa (N/mm 2)
Elongation at break
Resistance to tearing apart
Compression permanent deformation (air) 100°C/24h			GOST 9.029 (DIN ISO 815)
Rebound elasticity			GOST 27110 (ISO 4662)
Abrasion			GOST 12251 (DIN 53516)
Minimum application temperature
Maximum application temperature
Thermal aging in air 168h/225°C: -change in hardness -change in conditional strength -change in relative elongation	Unit Shore A br>	3 -12 +20	GOST 9.024 (ISO 188)
Aging in oil SZhR-1 70h/150°C: -change in hardness -change in conditional strength -volume change	Unit Shore A % br>	1 + 15 -20 -0,2	GOST 9.030 (DIN ISO 1817)
Aging in oil SZhR-3 70h/150°C: -change in hardness -change in conditional strength -change in relative elongation -volume change	Unit Shore A % br>	2 +6 -20 +1,9	GOST 9.030 (DIN ISO 1817)

Fluoroelastomer is a high quality heat and weather resistant rubber that has excellent resistance to ozone, oxidation, mineral oils, fuels, hydraulic fluids, aromatic and other organic solvents and chemicals.

• Data applicable to seals, O-rings, and hydraulic hoses (not only, of course):

FPM. More details

FPM is a semi-finished product made from bisphenol-crosslinked fluoride rubber (Viton DU PONT). FPM usually colored brown.

Properties

FPM is highly resistant to temperatures and chemicals. Temperature range: from 0 o C to +200 o C (short term up to +230 o C). Due to its rich structure and chemical composition, this material has excellent resistance to ozone, weathering and aging. Swelling in various media is very low, also in aromatic hydrocarbons. This material can also be used in high vacuum conditions.
FPM does not burn.

Resilience data

Good stability	Medium stability	Low/zero stability
Mineral oils and fats	Hot water	-
Aliphatic hydrocarbons (propane, butane, gasoline)	-	Skidrol 500
Silicone oils and fats	-	Ammonia, amines, alkalies
Vegetable and animal oils and fats	-	Hot water vapor
Fuel, also super-flammable	-	Low molecular weight organic acids (formic and acetic)
Oils with sulfur and highly aromatic oils	-	Flux acid, chlorosulfonic acid
Highly flammable liquid group HFD-S And HFD-R	Highly flammable liquid groups H.F.A., HFB, HFC	Polar solvents (acetone, methyl ethyl ketone, dioxane)
Biodegradable hydraulic fluids	-	Glycol-based brake fluids
Aromatic hydrocarbons (gasoline, toluene)	-	-
Chlorinated hydrocarbons	-	-

Application area

FPM Mainly used in areas with high temperature and chemical loads. Moreover, FPM used in hydraulic systems with highly flammable hydraulic fluids of the group HFD and as a pre-tensioning element for polyurethane seals in biodegradable liquids.

Preferred Application:
- special seals in the chemical industry and heating engineering;
- shaft seals;
- O-rings;
- hydraulic seals for HFD-liquids.

Basic physical and mechanical characteristics of FPM

Properties	Unit	Meaning	Test standard
Hardness	SHORE A	85±5	DIN 53505
Density	g/cm 3	2.50±0.03	DIN 53479
Tensile strength	N/mm 2	≥10	DIN 53504
Tensile strength	%	≥90	DIN 53504
Permanent deformation 100 o C/22h	%	≤14	DIN 53517
Wide Tear Strength	N/mm	17	DIN 53515
Rebound Elasticity	%	8	DIN 53512
Abrasion	mm 3	180	DIN 53516
Minimum application temperature	o C	-20	-
Maximum application temperature	o C	+200	-
Thermal aging 24h/230 o C: hardness change change durable to break change durable tensile	SHORE A % %	+3 +11 -18	DIN 53505 DIN 53504 DIN 53504
Behavior in ASTM oil no. 1 n. DIN 53521 70h/150 o C: hardness change change durable to break change durable tensile change volume	SHORE A % % %	-1 +15 -20 -0,2	DIN 53505 DIN 53504 DIN 53504 DIN 53521
Behavior in ASTM oil no. 3 n. DIN 53521 70h/110 o C: hardness change change durable to break change durable tensile change volume	SHORE A % % %	-2 +6 -20 +1,9	DIN 53505 DIN 53504 DIN 53504 DIN 53521

Viton® is a registered trademark of fluoroelastomer owned by DuPont. A rubber mixture is made from fluorine rubber, from which a seal is then made. In accordance with various standardization systems, the phrase “fluorine rubber” is denoted by various abbreviations, but the meaning and the material itself do not change. The abbreviation FPM is in accordance with the guidelines of the International Organization for Standardization (ISO), the abbreviation FKM is in accordance with the designation adopted by the American Society for Testing and Materials (ASTM). Those. FPM is the international name and FKM is the American name for the same material. In Russia, the abbreviation FC is accepted (SKF-26, SKF-32). Viton® fluorine rubber began to be produced in 1957. The start of production of this material made it possible to solve many problems in major industries such as:

• Aerospace industry
• Automotive industry
• Chemical industry and transport
• Food and pharmaceutical industry
• Equipment for working in undeveloped areas and in difficult operating conditions
• Exploration and production in oil and gas fields
• Oil refining and transportation

The main applications of fluoroelastomers are oil seals, radial lip seals, sealants, coatings, vibration dampers, expansion joints, gaskets, O-rings, rod seals, cords and plates. At the moment, the most common types of rubbers are general-purpose rubbers: Viton® A, Viton® B, Viton® F. Fluoride rubbers based on these rubbers differ in their resistance to oxygen-containing automobile fuels, motor oils, and water-based liquids. There are also fluorine rubbers for special purposes - Viton® GLT, Viton® GFLT, Viton® Extreme, Viton® Base Resistant. Types of fluorine rubbers:

Viton®	A	B	F	GLT	GFLT	Extreme	Base Resistant
% fluoride	66	68	70	64	66	56	-
Chemical resistance	++	+++	++++	+	++++	++++	++++
Durability to high temperature	+++	+++	+++	+++	+++	+++	+++
Durability to low temperature	+	0	-	++++	++	+	+

Note: the more + signs, the better the properties of the rubber.

FPM / FKM / Viton® (Fluoroelastomer) - works well in environments exposed to a variety of aggressive liquids. Systems using Viton® products are more resistant to a wide range of chemicals. It has excellent mechanical and physical properties; the fluorine content in the rubber mixture ensures the non-flammability of this material. Fluorinated elastomers have low gas permeability and minimal weight loss when operating in a vacuum.

Properties

Unit change

FPM/FKM (Vuitton)

PTFE (Teflon)

P.O.M. +15%GF +5%MoS2

dark grey

cream

rigidity

rigidity

density

tensile strength

tensile strength

modulus of elasticity - (rupture)

70°C/24h 20% Deformation

permanent deformation pressure

100°C/24h 20% Deformation

recoil elasticity

wide tensile strength

abrasion/wear

Minimum temperature

Maximum temperature

NBR, TPU, MVQ,...

Elastomers- these are materials that, through the application of a small force, can be stretched very strongly. Due to their structure, elastomers have a very high degree of ability to return to their original position. This means that the permanent change in shape of these materials is negligible. In principle, elastomers can be divided into two groups: chemical cross-linking elastomers and thermoplastic elastomers. Chemically cross-linked elastomers or rubber materials are high polymers whose macromolecules are cross-linked in large loops by the addition of a vulcanizing agent. Thanks to such chemical cross-linking, they do not melt and disintegrate at high temperatures. Moreover, such cross-linking ensures that the rubber materials are insoluble and, depending on the environment, swell or contract less or more strongly. Thermoplastic elastomers are materials that exhibit the characteristic properties of elastomers within a high temperature range. However, their cross-linking occurs physically, not chemically. Thanks to this, they melt at high temperatures and can be processed using conventional thermoplastic methods. Thermoplastic elastomers are soluble and have lower swelling properties compared to their chemically cross-linked equivalents.

POM, PA, PTFE + filler, PEEK, ...

Thermoplastics- these are melting high-polymer materials, which in their temperature range of application are much harder and more rigid compared to elastomers. Depending on its chemical composition, the properties of a material can be either brittle and brittle, or viscous and elastic. The morphological composition causes large stretches without returning to the original shape. The shape of the material changes plastically and thus the material is called plastomer. Plastomers are used in sealing technology for solid sealing elements such as support, guide and drive rings.

TPU (green) is a material from the group of thermoplastic polyurethane elastomers. TPU is characterized by particular wear resistance, excellent mechanical properties, extremely low permanent deformation pressure and high tear resistance. In seal technology, TPU is mainly used in the form of sponge rings, wipers, compact seals and chevron seals. The extrusion strength of TPU is far superior to that of rubber plastomers. TPU is suitable for use in special areas such as mineral oils, water with a maximum temperature of up to 40°C and in biodegradable hydraulic fluids at 60°C. Without back-up rings, TPU seals apply up to a maximum pressure of 400 bar, depending on the profile geometry.

TPU (red) is a hydrolysis-resistant thermoplastic polyurethane elastomer. It combines approximately the same mechanical properties of TPU and high stability, unusual for polyurethanes, in hydrolysis environments (with water temperatures up to 90 ° C) and mineral oils. These properties allow application in water hydraulics, tunnel construction, mining and press manufacturing. The gas permeability of TPU (red) is much lower compared to TPU (green), so it is especially used in high pressure gases.

CPU (red) is a molded elastomer produced using a special injection molding process from the same raw materials as TPU (red). It has the same chemical and mechanical properties as TPU (green), but is used for semi-finished products in sizes from 550 mm to 2000 mm and special sizes with extremely thick walls.

TPU (blue)- This is a modified TPU for use at low temperatures. TPU (blue), unlike the TPU (green) material, goes into a state of fluidity at a lower temperature (-42°C) and has higher elasticity and residual deformation (45%). Suitable for use in cold climates (-50°C).

TPU (gray)- This is a completely new thermoplastic polyurethane elastomer, with additives of composite materials that provide constant lubrication. This ensures a constant reduction in friction, increased sliding speed and reduced wear. Used for operation in conditions of poor lubrication (dry running), or lack of oil lubrication: water hydraulics and pneumatics (without oil).

NBR (black) is an elastomer based on cross-linked sulfur acrylic-nitrile-butadiene rubber. It has high hardness and, for rubber elastomers, high abrasion resistance. At high temperatures, especially in an oxygen environment (air 80°C), aging accelerates, the material becomes hard and brittle. When air access is blocked, the aging process slows down significantly. Due to its unsaturated structure, NBR has low resistance to ozone, weathering and aging. Swelling in mineral oils is negligible, but is highly dependent on the composition of the oil. Gas permeability is relatively high, as a result of which there is a danger of explosive decompression, in which parts of the material rupture. It is used in areas where, in addition to high resistance to fuel and mineral oils, high elasticity and permanent deformation are also required (cylinder seals at low pressures).

H-NBR (black)- this is hydrogenated acrylic-nitrile-butadiene rubber and has, compared to NBR, better mechanical properties, high resistance in chemical environments such as propane, butane, mineral oils and fats, with a high percentage of additives, in dissolved acids and alkalis at a wider temperature range (-25°C to +150°C). Also more resistant to ozone, weather and aging. At the same time, it remains highly elastic. Used in engine and gearbox seals, crude oil and natural gas production, etc.

FPM, FKM (brown)- elastomer based on fluoro-rubber cross-linked with bisphenol (Viton - Du Pont trademark). Designed for groove rings, wipers, sponge rings, chevron seals, etc. Highly resistant to temperatures, chemicals, extreme weather conditions and ozone. Temperature range: from -20°C to + 200°C (short-term up to 230°C). Used in hydraulic systems with highly flammable liquids of the HFD group (phosphorus based). Low resistance to ammonia and ammine environments, polar solvents (acetone, methylethylketone, dioxane), and glycol-based brake fluids.

EPDM (black)- an elastomer based on peroxide-crosslinked ethylene-propylene-diene rubber. It has good mechanical properties and a wide temperature range of application: from - 50°C to + 150°C, hot steam up to 180°C. Due to its non-polarity, it is not stable in hydraulic fluids based on mineral oils and carbohydrates. Used in conditions of hot water, steam, alkalis and polar solvents (in washing and cleaning equipment). When used in brake fluids based on glucol, compliance with regional regulations is required. Resistant to weather, ozone and aging.

MVQ (brown) is an elastomer based on methyl vinyl silicone rubber. Free of soot and suitable for electrical insulation. Temperature range from - 60°С to +200°С. Used for O-rings, flat and special seals, in the food and chemical industries. Due to its low mechanical values ​​(compared to other rubber materials) it is used primarily in static seals. Swelling in mineral oils is negligible, but depends on the composition of the oil.

PTFE (white) is a crystalline thermoplastic based on the chemical basis of polytetrafluoroethylene (Teflon). An exceptionally wide temperature range of application (-200°C to +200°C), the lowest coefficient of friction (m=0.1) among all plastic materials and a very high degree of resistance to almost all environments. PTFE has a non-stick surface, does not absorb moisture and has very good electrical properties. It is important to take into account the time-dependent plastic deformation of PTFE even under light load (cold flow). Resistant to almost all chemicals except elemental fluorine, chlorotrifluoride and molten alkali metals. Therefore, it has the widest range of applications in technology.

PTFE + filler (gray)- differs from PTFE in its chemical composition by added fillers (15% glass fiber and 5% molybdenum disulfide), which reduce plastic deformation under loads (reduced cold fluidity, increased extrusion resistance). It is used in sealing elements for low friction with high loads, for sliding and supporting elements, where pure Teflon cannot be used. Due to the presence of fillers, it cannot be used in the food industry.

POM (black)- technical thermoplastic based on polyacetal (polyoxymethylene). It has a high ability to retain shape, high surface resistance, elasticity and low moisture absorption. The tendency to cold flow at temperatures below 80°C is insignificant. POM is an excellent material under sliding and wear conditions and has excellent mechanical properties. POM is used where high hardness and low friction are required, that is, for guides and support elements (at T = 100°C). Not stable enough in acids and alkalis.

PA (black)- thermoplastic based on cast polyamide. Used instead of POM for diameters greater than 250 mm. High ability to retain shape, elasticity and rigidity, but prone to moisture absorption (loss of rigidity and change in volume). Use in watery environments is not recommended. Well suited for sliding operation (support, guide rings).

PEEK (cream)- thermoplastic based on polyaryletherketone from a number of highly temperature-resistant artificial materials. It is used mainly in those areas where, due to high temperatures (up to +260°C), high chemical and mechanical requirements, the use of conventional technical plastic materials is impossible. Universal stability in many chemical environments (with the exception of sulfuric acid, saltpeter) determines the use of PEEK in the oil and gas and chemical industries. Widely used in electrical engineering and electronics due to its good electrical properties in combination with mechanical properties.

This is a polymer based on fluorine-containing synthetic rubber; the fluoride content in the most common VITON brands ranges from 66% to 70%. In general, Viton is very resistant to hydrocarbon compounds, fuels and lubricants, gasoline, synthetic and mineral oils, but incompatible with ketones (such as acetone), organic acids (such as acetic acid). Some modifications are resistant to concentrated inorganic acids, hot steam, and high temperatures.

Taking into account its properties, the range of its use in various industries is very wide, from the chemical and petrochemical industries to large and small energy. It is irreplaceable when operating heat exchange equipment in steam boiler houses and central heating stations.

Viton is highly resistant to temperatures and chemicals. Temperature range: from -20°С to +200°С (short-term up to +230°С). Due to its rich structure and chemical composition, this material has excellent resistance to ozone, weathering and aging. Swelling in various media is very low, also in aromatic hydrocarbons. This material can also be used in high vacuum conditions. Not flammable.

Viton® is a registered trademark of fluorine rubber owned by DuPont, and today Viton is considered one of the best of all existing fluorine rubbers. In accordance with various standardization systems, the phrase “fluorine rubber” is denoted by various abbreviations, but the meaning and the material itself do not change. The abbreviation FPM is in accordance with the guidelines of the International Organization for Standardization (ISO), the abbreviation FKM is in accordance with the designation adopted by the American Society for Testing and Materials (ASTM). Thus, FPM is the international name and FKM is the American name for the same material. In Russia, the abbreviation KF is adopted (SKF-26, SKF-32).

CHEMICAL RESISTANCE CHARACTERISTICS

Good stability	Medium stability	Low/zero stability
mineral oils and lubricants	hot water
aliphatic hydrocarbons (propane, butane)		skydrol 500
silicone oils and fats		ammonia, amines, alkalis
vegetable and animal oils and fats		superheated water vapor
flammable, also super flammable		Low molecular weight organic acids (formic and acetic acids)
oils with sulfur and highly aromatic oils		hydrofluoric acid, chlorosulfonic acid
highly flammable hydraulic fluids of the HFD-S group (phosphoric acid esters, some types may cause destruction) and HFD-R (chlorinated hydrocarbons)	highly flammable hydraulic fluids of groups HFA, HFB, HFC	polar solvents (acetone, methyl ethyl ketone, dioxane, ethyl acetate)
biodegradable hydraulic fluids		glycol based brake fluids
aromatic hydrocarbons (benzene, toluene)

Application area

Mainly used in areas with high temperature and chemical loads. Moreover, fluoride rubber is used in hydraulic systems with highly flammable HFD hydraulic fluids and as a pre-tensioning element for QH-PUR - chemical resistant polyurethane - seals in biodegradable liquids.

Preferred Application

• special seals in the chemical industry and heating engineering
• shaft seals
• O-rings
• hydraulic seals for HFD fluids

Basic physical and mechanical characteristics

Properties	Unit	Meaning	Test standard
Hardness	units Shore A	85±5	GOST 263 (ISO 868)
Density	g/cm W	2.50±0.03	GOST 267 (DIN 53479)
Modulus at 100% elongation	MPa (N/mm 2)	>=5	GOST 270 (DIN 53504)
Conditional tensile strength	MPa (N/mm 2)	>=8
Elongation at break	%	>=90
Resistance to tearing apart	N/mm	>=21	GOST 262
Compression set (air)100°C/24h	%	<=20	GOST 9.029 (DIN ISO 815)
Rebound elasticity	%	>=8	GOST 27110 (ISO 4662)
Abrasion	mm 3	150	GOST 12251 (DIN 53516)
Minimum application temperature	°C	-20
Maximum application temperature	°C	+200
Thermal aging in air 168h/225°C:
-change in hardness	units Shore A	+3	GOST 9.024 (ISO 188)
	%	-12
	%	+20
Aging in oil SZhR-1 70h/150°C:
-change in hardness	units Shore A	-1	GOST 9.030 (DIN ISO 1817)
-change in conditional strength	%	+15
-change in relative elongation	%	-20
-volume change	%	-0,2
Aging in oil SZhR-3 70h/150°C:
-change in hardness	units Shore A	-2	GOST 9.030 (DIN ISO 1817)
-change in conditional strength	%	+6
-change in relative elongation	%	-20
-volume change	%	+1,9