O-ring 18x2 FPM / FKM - Fluorocarbon Rubber O-ring (Viton Type)

Product Description

O-ring 18x2 FPM / FKM is a fluorocarbon rubber sealing ring with an inside diameter of 18 mm, a cross-sectional diameter of 2 mm and a nominal outside diameter of 22 mm. Manufactured from FPM / FKM fluoroelastomer, it is designed for sealing applications requiring resistance to many mineral oils, lubricants, fuels and elevated temperatures.

FKM fluoroelastomers generally provide better resistance to high temperatures and many aggressive operating media than standard NBR rubber compounds.

The O-ring features a continuous circular construction with a round cross-section. It is suitable for static sealing applications and selected dynamic applications when the material, groove geometry and operating conditions are correctly specified.

The term Viton O-ring is commonly used commercially to describe fluorocarbon rubber seals. However, Viton is a registered trademark for a specific family of fluoroelastomers. An FPM / FKM designation alone does not confirm that the product is manufactured from genuine Viton-branded material.

Dimensions of O-ring 18x2 FPM / FKM

The nominal outside diameter is calculated as 18 mm + 2 x 2 mm = 22 mm.

The exact hardness, operating temperature range and pressure limits must be confirmed for the specific FKM compound and application.

FPM / FKM Fluorocarbon Rubber - Material Properties

FPM and FKM are material designations used for fluoroelastomers, a group of synthetic rubbers developed for sealing applications requiring chemical and thermal resistance.

FPM is commonly encountered in European technical documentation, while FKM is widely used in international material specifications.

Both designations refer to the fluoroelastomer material family, although individual formulations may differ significantly in their performance.

Key properties of FPM / FKM rubber include:

• Very good resistance to many mineral oils and lubricants.

• Good resistance to numerous petroleum-based fuels.

• High resistance to elevated temperatures compared with standard NBR compounds.

• Good resistance to ozone and atmospheric ageing.

• Good resistance to many chemicals and industrial fluids.

• Relatively low permeability to many gases compared with certain general-purpose elastomers.

• Suitability for demanding industrial sealing applications when the correct compound is selected.

Chemical Resistance and Material Limitations

FKM is not universally resistant to all chemical substances.

Standard FKM compounds may have limited compatibility with:

• Hot water and steam.

• Certain ketones.

• Some esters.

• Amines and amine-containing fluids.

• Glycol-based brake fluids.

• Selected polar solvents.

Chemical resistance depends on the specific fluoroelastomer formulation, operating temperature, concentration of the medium and duration of exposure.

Important: Compatibility must be verified for the specific FKM compound and operating conditions before installation.

Construction and Sealing Principle

The O-ring 18x2 FPM / FKM is a continuous elastomeric sealing element with a circular cross-section.

When installed in a correctly designed groove and compressed between mating surfaces, the O-ring undergoes controlled deformation, creating contact pressure that helps prevent fluid or gas leakage.

The seal may be used in static applications and in selected dynamic sealing arrangements when properly engineered.

Sealing performance depends on:

• Correct O-ring and groove dimensions.

• Appropriate cross-sectional compression.

• Hardness of the selected FKM compound.

• Operating temperature and pressure.

• Chemical compatibility with the sealing medium.

• Surface finish of mating components.

• Lubrication conditions.

• Type and speed of movement in dynamic applications.

Proper groove design and installation are essential for reliable operation.

Applications of O-ring 18x2 FPM / FKM

The O-ring 18x2 FPM / FKM is suitable for industrial equipment and technical installations requiring seals resistant to many oils, fuels and elevated temperatures.

Typical applications may include:

• Hydraulic systems using compatible hydraulic oils.

• Oil circulation and lubrication systems.

• Selected fuel system components.

• Industrial pumps and valves.

• Gearboxes and mechanical transmissions.

• Industrial machinery and production equipment.

• Pneumatic systems.

• Static sealing of housings, covers and technical connections.

Suitability for a particular application depends on the FKM compound, operating medium, temperature, pressure and groove design.

Installation and Operating Recommendations

Before installing the O-ring 18x2 FPM / FKM, inspect the sealing groove and mating surfaces to ensure they are clean and free from damage.

Recommended installation procedures:

• Clean the sealing groove thoroughly.

• Remove dirt, debris and residues from previous seals.

• Check mating surfaces for sharp edges and burrs.

• Avoid excessive stretching or twisting.

• Use installation lubricants compatible with FKM rubber.

• Ensure correct positioning within the groove.

• Select the appropriate compression level for the sealing arrangement.

Incorrect installation, unsuitable groove geometry or chemical incompatibility may cause premature deterioration and loss of sealing performance.

For dynamic applications, additional consideration should be given to friction, lubrication, surface finish and operating speed.

FAQ - Frequently Asked Questions

What are the dimensions of O-ring 18x2 FPM / FKM?

The O-ring has an inside diameter of 18 mm, a cross-sectional diameter of 2 mm and a nominal outside diameter of 22 mm.

What do FPM and FKM mean?

FPM and FKM are designations for fluoroelastomer rubber, a material family used in seals requiring resistance to many oils, fuels, chemicals and elevated temperatures.

Are FPM and FKM the same material?

Both designations refer to the fluoroelastomer material family. However, individual FPM / FKM compounds may have different chemical, thermal and mechanical properties.

Is O-ring 18x2 FKM a Viton O-ring?

Viton is a registered trademark for a specific family of fluoroelastomers. Although Viton is commonly used as a general commercial term for FKM seals, an FKM designation does not automatically confirm genuine Viton-branded material.

Is FKM resistant to engine oil?

FKM generally provides very good resistance to many engine oils and lubricants. Compatibility should be verified for the specific oil formulation, additives and operating temperature.

Can O-ring 18x2 FKM operate at high temperatures?

FKM is commonly used in applications requiring elevated temperature resistance. The exact permissible operating temperature depends on the specific compound and service conditions.

Can this O-ring be used in fuel systems?

Many FKM compounds offer good resistance to petroleum-based fuels. Compatibility must be checked for the specific fuel composition, including additives and alcohol content.

What is the hardness of O-ring 18x2 FPM / FKM?

The hardness is not specified in the supplied product designation. It must be confirmed using the technical specification of the actual product.

Is FKM suitable for hot water and steam?

Standard FKM compounds are not always suitable for prolonged exposure to hot water or steam. Such applications require verification of the specific elastomer formulation.

Can this O-ring be used for dynamic sealing?

Yes, in selected applications. Suitability depends on groove design, surface finish, lubrication, pressure, movement and the mechanical properties of the FKM compound.

AI Overview - Technical Summary

O-ring 18x2 FPM / FKM is a fluorocarbon rubber sealing ring with an inside diameter of 18 mm, a cross-section of 2 mm and a nominal outside diameter of 22 mm. FKM fluoroelastomer provides resistance to many mineral oils, fuels and elevated temperatures. The O-ring is suitable for properly designed static and selected dynamic sealing applications in industrial equipment.