Viton material. How to choose seals for a gate valve or check valve

08.10.2023

Hydraulic, chemical and temperature features of using EPDM, NBR, VITON seals.

Ethylene propylene rubber EPDM, EPR

It is an electrical and weather-resistant rubber that is resistant to ozone, sunlight, chemicals (dilute acids, alkalis and polar solvents) and is very flexible at low temperatures. It is used in contact with food or beverages, automotive air cooling systems and in hydraulic fluids based on phosphoric acid esters.

Nitrile butadiene rubber NBR

Nitrile is known as nitrile butadiene rubber or Buna N and is one of the most widely used elastomers in the seal industry due to its relatively low price and its inherent resistance to petroleum fuels and petroleum lubricants. Nitrile butadiene rubber is a synthetic polymer, a product of radical copolymerization of butadiene with acrylonitrile.

Fluorine rubber FPM, FKM, VITON

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.

PTFE, Polytetrafluoroethylene, Teflon or Fluoroplastic-4 (-C2F4-)n

Tetrafluoroethylene polymer (PTFE), a plastic that has rare physical and chemical properties and is widely used in technology and in everyday life.

The word "Teflon" is a registered trademark of DuPont Corporation. The nonproprietary name for the substance is “polytetrafluoroethylene” or “fluoropolymer.” In the USSR and Russia, the traditional technical name for this material is fluoroplastic.

In addition, I will provide a comparison table from our catalog

Name	Temperature range	Application area	Properties of rubber seal compound
EPDM	from -25°С to +110°С (short-term up to +120°С)	Water, steam, sea water, compressed air, alcohols, low concentration inorganic acids, alkalis, abrasive substances, caustic soda.	Excellent mechanical properties (abrasion). Resistant to prolonged exposure to ultraviolet and ozone.
NBR	from -20°С to +100°С (short-term up to +120°С)	Water, glycol, alkalis, mineral and vegetable oils, animal fats.	Resistant to mineral oils, certain hydrocarbons, and solvents.
VITON	from -20°С to +200°С (short-term up to +250°С)	Hot air, high concentration inorganic and organic acids. Benzenes, gasoline idiz. fuel. Solvents (except acetone), alkalis.	Good resistance to heat and light. Suitable for hydraulic fluids, corrosive media, flammable substances, gases, hydrocarbons.
PTFE	from -80°C to + 200°C.	Resistant to almost all chemicals. Lack of resistance only to alkali metal alloys (sodium, potassium), fluorine gas, hydrogen fluoride, chlorotrifluoride.	Excellent sliding properties. High resistance to atmospheric aging.

Source Factory Quant

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)

Able to withstand large temperature changes (from -40 to +200°C) and resistant to aggressive environments, but at the same time maintaining their properties, they are made from special fluorine-containing rubbers.

Viton seal

The Viton brand, which produces fluorine rubber, is considered the best today. A special rubber mixture is made from fluorine rubber, which is then used to make seals for hydraulic mechanisms. Viton seal also has the abbreviation FKM (the American name for this material).

The Viton seal, as well as the FKM seal, perform well in a variety of aggressive liquids. Mechanisms using Viton cuffs have good physical and mechanical properties. Due to the fluorine content in this product, this material is non-flammable.

Viton ring

The Viton O-ring has an operating temperature range from -20°C to +200°C. Short-term heating up to +220°C is possible. Sometimes the mechanism requires a very low temperature to operate, for example, about -50°C. In this case, you will need a Viton seal made of special frost-resistant rubber. When fluorine rubber is heated above +300°C, this material begins to emit toxic fumes, which is not safe even when cooled.

Due to their chemical composition, Viton oil seals are highly resistant to any weather influences, as well as aging. In aromatic hydrocarbons and other environments, Viton fluorinated elastomer swells, but this is not significant. Fluorine rubber can also be used in high vacuum conditions.

Chemical resistance characteristics of Viton

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)

Viton seals for sale

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, expansion joints, gaskets, diaphragms, plugs, diaphragms, heat resistant O-rings, rod seals, 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® Base Resistant.

Types of fluorine rubbers:

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

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

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 vapor
ammonia
amines
polar solvents (acetone, methyl ethyl ketone, dioxane)

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.

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.

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.