FKM Seals Resist a Wide Range of Chemicals and ... …

1 parco fluorocarbon Seals offer outstanding resistance to aggressive Chemicals and high temperatures . Our high-quality fluorocarbon sealshave a long history of reliable performance in service temperatures from -40 to +400 F. For superior resistance to Chemicals and continuousservice temperatures as high as 600 F, considerParco s perfluoroelastomer American Society for Testing Materials (ASTM)document D1418, Standard Practice for Rubber andRubber Latices Nomenclature, uses the abbreviation FKM for compounds made from fluorocarbon polymer.

2 parco offers fluorocarbon compounds to Resist awide Range of Chemicals and temperatures . Themost common type of fluorocarbon polymer contains 66 percent fluorine and is a copolymer ofvinylidene fluoride (VF2 or VDF) and hexafluoropropylene (HFP). Other types of fluorocarbon polymer contain tetrafluoroethylene(TFE) for improved chemical resistance. Some typesof fluorocarbon polymer contain perfluoromethylvinyl ether (PMVE) for improvedflexibility at low fluorocarbon polymers are commonlydivided into three types: A, B, and F, in order ofincreasing fluorine content.

3 In general, higher fluorine content provides improved chemical resistance but decreased low-temperature flexibility. Specialty fluorocarbon polymers are alsoavailable for applications requiring improved performance in caustic fluids and lowtemperatures. Specialty fluorocarbons include GLT,GFLT, LTFE, and you are unfamiliar with the different elastomersused for Seals , refer to parco s Elastomer SelectionGuide. That guide will help you to select the correct elastomer for your application. If you determine that fluorocarbon Seals are right foryour application, this guide will help you select thecorrect , B, and F are popular types of fluorocarbon polymer originally developed by DuPont Performance Elastomers.

4 Other fluorocarbon polymer suppliers use different names fortheir equivalents. GLT, GFLT, and ETP are Genuine Viton fluorocarbon polymers made by DuPont. Viton is a registered trademark of Dupont Performance Elastomers. LTFE is afluorocarbon polymer made by Dyneon, a 3M s fluorocarbon Seals have a long history of reliable performance in service temperatures from -40 to +400 F. For continuous service temperatures as high as600 F, consider parco s Seals Resist a Wide Range of Chemicals and TemperaturesCharacteristics ofFluorocarbon TypesBelow is a brief description of the various types offluorocarbon polymer.

5 Figure 1 compares the resistance to common fluids among the fluorocarbon types. Low temperature resistancealso varies based on the fluorocarbon type, asshown in Figure FluorocarbonsStandard fluorocarbon compounds typically use abisphenol cure system, which provides fast curecycles and improved resistance to compression standard fluorocarbons use a peroxide curesystem to improve resistance to steam, acid, andaggressive automotive lubricating oils. A-Typefluorocarbons or dipolymers, are used forgeneral-purpose sealing.

6 A-Type offers the bestresistance to compression set among all fluorocarbons. A-Type is not recommended foruse in amines, low molecular weight carbonyls, orflex fuels. (Fluorine content of polymer is about66%)B-Type fluorocarbons offer better chemical resistance than A-Type. B-Type has improvedresistance to aromatic hydrocarbons and automotive fuels containing alcohols and etherssuch as methyl tertiary butyl ether (MTBE).(Fluorine content of polymer is about 68%)F-Typefluorocarbons provide excellent resistance to flex fuels.

7 F-Type has the best fluidresistance of all the standard fluorocarbons.(Fluorine content of polymer is about 70%)Specialty FluorocarbonsSpecialty fluorocarbon polymers use a peroxidecure system for improved resistance to steam andacid. Specialty fluorocarbons generally have better low-temperature flexibility than standard fluorocarbons. Specialty fluorocarbon polymersGLT, GFLT, and ETP are Genuine Viton .GLTfluorocarbons offer excellent low-temperature flexibility and fluid resistance similarto A-Type.

8 Compounds using GLT typically have atemperature retraction value (TR-10) of -22 F.(Fluorine content of polymer is about 64%)GFLT fluorocarbons combine excellent low-temperature flexibility and fluid resistancesimilar to F-Type. Compounds using GFLT typicallyhave a TR-10 value of -11 F. (Fluorine content ofpolymer is about 67%)LTFE fluorocarbons have the best low-temperature flexibility of any fluorocarbon andfluid resistance similar to GFLT. Compounds usingLTFE typically have a TR-10 value of -40 F.

9 (Fluorine content of polymer is about 67%)ETPfluorocarbons were developed as a cost-effective alternative to fluorocarbons offer similar reliable service inaggressive Chemicals , but at a fraction of the fluorocarbons also have excellent resistanceto low molecular weight carbonyls, amines, andcaustic bases. (Fluorine content of polymer isabout 67%) Flex-fuel vehicles can use various blends ofgasoline and alcohol as fuel. Flex fuels refer to those blends and typically have alcohol content of 15 percent or more.

10 Parcorecommends its Seals made from F-type polymer for use in flex of Popular ParcoFluorocarbon CompoundsBelow is an overview of parco s most popular fluorocarbon compounds areblack unless stated otherwise. For help choosingthe appropriate parco compound for your application, please refer to the Selection Diagramin Figure 3. Compounds for Applications with Service Pressures up to 1,500 psi9066-75375-durometer fluorocarbon; excellent resistance tocompression set; improved low-temperature flexibility (TR-10 value of -25 F); meets the requirements of Aerospace Material Specification(AMS) R 83485.