AFM seals

AFM gaskets are used wherever industrial seals need to withstand high thermal, mechanical and chemical loads over the long term. They are among the proven flat gasket materials in mechanical and plant engineering and are used when reliability, process safety and a long service life are the priority. This article provides a structured overview of the structure, properties, areas of application and selection criteria of AFM gaskets and supports you in making a well-founded material decision.

What are AFM gaskets?

AFM gaskets are high-quality fibre-reinforced flat gaskets that have been developed for demanding industrial applications. They consist of a combination of aramid fibres, mineral fillers and an elastomer binder. This material structure provides high mechanical strength, temperature resistance and media resistance.

AFM stands for Aramid Fiber Material and describes a modern further development of classic fibre gaskets. AFM gaskets are used wherever reliable sealing under pressure, under temperature fluctuations and in contact with chemical media is required.

Structure and material properties

AFM gaskets are characterised by a multi-layer, homogeneously compressed structure. The individual components perform clearly defined functions:

• Aramid fibres provide tensile strength and dimensional stability
• Elastomer binders ensure elasticity and recovery behaviour
• Mineral fillers improve temperature and media resistance

This combination produces a gasket material that reliably withstands both static and dynamic loads.

Typical technical characteristics

The exact characteristics vary depending on the AFM type. Typical properties are:

Property	Typical range
Temperature resistance	up to approx. 250–400 °C
Pressure resistance	up to approx. 100 bar
Media resistance	oils, fuels, water, gases, chemicals
Surface pressure	high, even under varying load

These values make AFM gaskets a versatile solution for numerous industrial applications.

Areas of application of AFM gaskets

AFM gaskets are used across industries, particularly where classic elastomer gaskets reach their limits.

Typical areas of application are:

• Mechanical and plant engineering
• Chemical industry
• Energy and power plant technology
• Pump and valve manufacturing
• Oil and gas industry
• Vehicle and engine technology

Thanks to their high adaptability, AFM gaskets are suitable both for flange connections and for special designs.

Advantages over classic gasket materials

Compared with simple rubber gaskets or older fibre materials, AFM gaskets offer several advantages:

• High temperature and pressure resistance
• Low relaxation under long-term load
• Good chemical resistance to many media
• Dimensional accuracy even under varying operating conditions
• Long service life when correctly designed

These properties help to extend maintenance intervals and reduce operational downtime.

AFM gaskets compared with alternative gasket materials

AFM gaskets are often used where other materials reach technical or economic limits. The following overview shows typical differences in direct comparison:

Material	Typical advantages	Typical limitations	Suitable applications
AFM gasket	High temperature and pressure resistance, good media resistance, low relaxation	limited elasticity compared with pure rubber gaskets	flange connections, industrial plants, chemicals, energy
Rubber gasket	Very good elasticity, simple installation	limited temperature and media resistance	low temperatures, simple seals
PTFE gasket	Very high chemical resistance	low recovery behaviour, tendency to creep	aggressive media, low surface pressure
Graphite gasket	Very high temperature resistance	higher costs, sensitive to installation errors	high-temperature applications, energy and power plant technology

The selection of the right gasket material should always be based on the real operating conditions.

Typical errors in the selection and application of AFM gaskets

In practice, leaks often arise from design or application errors. The most common causes include:

• Insufficient surface pressure, as a result of which the gasket does not seal completely
• Incorrect media assumptions, for example with changing or unknown process media
• Unsuitable elastomer binder for the temperature or chemicals
• Unfavourable flange surfaces with excessive roughness or damage
• Errors in bolt tightening, such as uneven preload

Careful material selection and professional installation significantly increase operational safety and extend the service life of the gasket.

Selecting the right AFM gasket

The selection of a suitable AFM gasket always depends on the specific operating conditions of the application. The decisive factors are initially the continuously applied operating temperature and the system pressure, as these determine the mechanical load and the recovery behaviour of the gasket. The medium to be sealed is equally relevant, since oils, fuels, gases or chemical substances place different demands on the elastomer binder and the fibre structure. In addition, the flange type used and the surface condition of the sealing surfaces influence the required surface pressure and the long-term sealing effect. In many industrial applications, specific approvals, standards or internal plant specifications also play a role. A professional design based on these parameters ensures that the AFM gasket fulfils its sealing function permanently and reliably.

Cut pieces and custom-made products

AFM gaskets are available as sheet material and can be precisely cut to the required dimensions. In addition to classic ring and flat gaskets, individual contours, complex hole patterns and special geometries to drawing or sample can be realised. This is particularly advantageous for older plants, special flanges or customer-specific designs where standard dimensions are not sufficient.

Modern cutting and punching processes allow tight tolerances to be maintained, ensuring consistent quality and fit accuracy. Made-to-measure AFM gaskets help to shorten installation times, avoid rework and secure the sealing effect in the long term. Both single pieces for repair and maintenance cases and series cuts for ongoing operation can be produced economically.

In summary

AFM gaskets offer a technically mature solution for demanding seals in industry and plant engineering. They combine high mechanical stability with reliable recovery behaviour and broad media resistance. As a result, they are suitable for applications in which temperature changes, pressure loads and chemical influences must be mastered over the long term.

Thanks to the possibility of individual cuts and custom-made products, AFM gaskets can be flexibly adapted to different installation situations. In combination with professional design and installation, they make a significant contribution to operational safety, reduced maintenance effort and a long service life of the entire plant.

Frequently asked questions about AFM gaskets

What distinguishes AFM gaskets from rubber gaskets?

AFM gaskets offer higher temperature and pressure resistance and are suitable for industrial applications with increased mechanical and chemical requirements.

Are AFM gaskets suitable for chemicals?

Many AFM types are resistant to oils, fuels, gases and selected chemical media. Suitability depends on the elastomer binder and the respective process conditions.

Can AFM gaskets be manufactured individually?

AFM gaskets can be produced as cut pieces or special shapes exactly to drawing, sample or technical specification.

What role does surface pressure play with AFM gaskets?

Even and sufficiently high surface pressure is decisive for the sealing effect. Deviations often lead to leaks or increased material stress.

Are AFM gaskets suitable for use at varying temperatures?

AFM gaskets are well suited to temperature changes, as they remain dimensionally stable and show reliable recovery behaviour.

How long is the service life of AFM gaskets?

The service life depends on the medium, temperature, pressure and installation. With professional design, long operating times are achieved in practice.

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