Klingersil® seals

What are Klingersil® seals?

Klingersil® is the brand name for sealing sheets from the manufacturer Klinger. Among them are various materials in standard and high-performance quality. They are particularly suitable for high-pressure applications and for use in the chemical industry. There are both fiber-reinforced and PTFE-based sealing materials under the brand name Klingersil®. The different materials cover a very wide range of applications, each with specific requirements.

Klingersil® materials consist of various fibers, such as aramid fibers, synthetic fibers, or carbon fibers, which are bonded with various elastomers, such as NBR (acrylonitrile-butadiene). As a rough guide, Klingersil gaskets consist of approximately 25% elastomers and approximately 30% fibers. The remainder consists of fillers. Elastomers are primarily considered a key component of fiber-reinforced seals because they influence sealing performance, temperature resistance, mechanical properties, elasticity, and chemical resistance.  The fibers in Klingersil gaskets, in turn, influence temperature resistance, chemical resistance, and tensile strength. Active and highly active fillers have a reinforcing effect on sealing performance, mechanical properties, and chemical resistance.

Some specialty high-pressure seals, such as Klingersil® C-8200, are based on glass fibers bonded with acid-resistant elastomers. One of the highest-performance grades is Top-Chem-2000, a silicon carbide (SiC)-filled PTFE.

Klingersil gaskets are characterized by high adaptability and very good sealing properties. They have very good handling properties, so that simple production and assembly of the respective flat gasket is ensured. Another advantage of Klingersil gasket materials is the wide variety of materials, so that the manufacturer can cover a large number of media resistances for a wide range of applications.
A major disadvantage of Klingersil gaskets is embrittlement and loss of bolt force due to settling behavior at high temperatures (>150 °C).

Basically, it can be said that various Klingersil gasket materials exist as alternatives to certain gasket materials from the manufacturer Frenzelit. For Novapress Basic and Novapress Universal, for example, the Klingersil C 4400 gasket material can be regarded as an equivalent substitute. All the materials mentioned are fibrous materials based on aramid fibers bonded with NBR. In addition, the three fiber materials are considered to be versatile high-pressure seals. With regard to existing approvals, both Novapress Basic, Novapress Universal and C 4400 have the elastomer guideline and are consequently suitable for contact with drinking water.

Also comparable to Novapress Universal is Klingersil C 4430, which is based on synthetic fibres and glass fibres and bonded with NBR. There are also overlaps between Novapress Multi II and Novatec Premium XP and the C 4430 and C4500 fibre materials in terms of mechanical, thermal and chemical resistance.

Given the wide variety of materials described, flat gaskets and flange gaskets made of Klingersil can be used in a variety of applications.
Gaskets made from Klingersil® materials exhibit very low wear and can withstand high pressures. As such, they are particularly well-suited for use as high-pressure gaskets in pneumatics, hydraulics, and mechanical engineering. Thanks to their chemical resistance, they can also be used in the chemical industry. The materials are food-grade compliant and are therefore used as sealing materials in food processing as well.

Thanks to the “Elastomer Leitilinie” and W-270 approvals, the C-4400 and C-4430 sealing materials are used in drinking water supply systems. Based on the DVGW DIN 3535-6 and HTB VP401 approvals, we are also aware that both Klingersil materials are used in (natural) gas supply systems. In the field of power generation, C-4400 is suitable for applications involving cooling water and lubricants.
Finally, Klingersil seals are often used as flanges for piping and equipment, as well as seals for heat exchangers.