Modified PTFE solutions

PTFE is an indispensable base material for many areas of sealing technology. PTFE is characterized by outstanding physical and chemical properties. Here are just a few of the advantages:

  • Thermal application range from - 260 °C to + 300 °C (short-term)
  • Almost universal chemical resistance
  • Light and weather resistance
  • Resistant to hot water vapor
  • Very good gliding properties
  • anti-adhesive behavior
  • non-flammable
  • No water absorption
  • physiologically safe (food approval according to BGA 1935/2004 and FDA)

Only some disadvantageous properties, such as cold flow behaviour, poor bonding behaviour and a lack of wear resistance, need to be minimized through targeted modification of the material. Various fillers such as glass fibers, carbon, graphite, metal reinforcements and minerals are used for this purpose.

With their NOVAFLON® and TOP-CHEM® product ranges, FRENZELIT and KLINGER have designed modified PTFE-based materials that cover a wide range of possible applications.
Expanded PTFE grades further extend the range of applications. PTFEs and hybrids are also used as adhesive tapes.

We are happy to offer you specific advice on selecting the right compound for your application!

Graphite seals

Our range of graphite flat seals is designed for operating conditions where higher temperatures prevail and therefore soft fiber materials are no longer an option.

FRENZELIT offers both laminated and unlaminated product variants. The Novaphit product range was designed to meet the requirements of the so-called TA-Luft. Today, it has become the standard in many areas of industry. Modifications with different objectives extend the range considerably (XP technology).

KLINGER has developed various graphite products which are also based on both laminated (spit plate and smooth plate) and unlaminated technologies. High-purity graphites cleaned of oxidizing impurities are used.

Our product range also includes graphite tapes as maintenance products. They are used, for example, as a quick aid in revisions to cover other sealing elements.

High-temperature seals

For high-temperature applications above 750° C, such as in fuel cell technology, reactors, ovens and other applications, materials of mineral origin can be considered. When selecting the right material, it is important to clarify the pressure conditions and the media.

FRENZELIT has developed the ISOPLAN® insulation product range for high-temperature applications. The very high application limit temperatures and the low thermal conductivity values determine a wide range of possible applications at low pressures.

FRENZELIT novaMICA® THERMEX is the high-pressure seal material for applications in the hot gas or exhaust gas sector and where continuous temperatures of up to 1000 °C occur. For media that are sealed at low to medium pressures.

KLINGERmilam PSS is a special high-temperature sealing material for temperatures up to 900°C and higher. Together with its extensive resistance to chemical substances such as solvents, aggressive acids, bases and mineral oils, it can be used for a wide range of applications at low to medium pressures.

Other insulation materials, such as the NEFALIT product range, complete our range.

Metal seals

Metal seals are generally used when the operating conditions (pressure, medium, temperature, leakage rates, etc.) mean that component seals are no longer sufficiently reliable. Here, the edge area of sealing technology is covered by varying the shape while taking physical and chemical limits into account.

Common materials:

1.4541 (321), 1.4571 (316TI), 1.4401 (316), 1.4404 (316L), 1.4301 (304) or St37, among others

Possible areas of application:

TA-Luft, Fire Safe certification, food approval

Lens seals

Lens seals are used as absolute high-pressure seals. Their main advantage lies in their reusability. Lens seals can practically not be overpressed, as their shape means that the sealing surface increases with increasing pressure, but the surface pressure increases at a lower rate. This type of seal can also be used as a dummy lens, for example for bypasses.

Ring Joint seals

The RTJ is a metallic seal that must be precisely machined and requires a well-prepared flange. The corresponding Brinel hardness of the material used must be taken into account, as the receiving flange must be about 20% harder than the seal. Ring-joint seals are mainly used in the petrochemical industry, in pipeline and apparatus construction and are intended for the highest pressure loads

A distinction is made between:

OKTAGONAL ring joint seals (dimensions according to ASME B16.20, API Standard 6A for flanges according to ASME B16.5 and ASME B16.47 Series A) and OVAL ring-joint seals (dimensions according to ASME B16.20, API Standard 6A for flanges according to ASME B16.5 and ASME B16.47 Series A)


  • Low leakage values according to the installation conditions
  • Extreme compressive strength
  • Easy handling
  • High dimensional stability and prevention of pushing out

Weld ring seals

Weld ring seals are used in absolutely critical areas. They guarantee maximum operational reliability and continuity with large diameters and pressures thanks to the firm welding of the diaphragm halves. Despite the welding, the sealing connection can be repeatedly loosened (depending on the material) permanently. In addition to the standard shape, all other shapes are possible after clarification of the technical details (nature of the sealing strip and other installation conditions).

Separating plate seals

Our quality in separating plate seals ensures reproducible sealing properties. This guarantees plant safety and availability. MMT type separating plate gaskets are mostly used in tank construction, where they seal the gap between the tank wall and the longitudinal separating plate. Separating plate seals are the seals for heat exchangers and ensure efficiency when separating the media. Correct use of the separating plate gasket can significantly reduce power losses in heat exchangers. The sealing effect is achieved by 4 spring lamellas, which are mounted in the carrier profile like a fan.

Soft metal seals

Metal composite seals are generally used when, due to operating conditions (pressure, medium, temperature, leakage rates, etc.), soft fiber seals no longer offer sufficient safety. They are used in combinations of suitable metals in conjunction with soft materials such as graphite, PTFE, rubber or even heat-resistant mineral fibers.

Depending on the application, comb profile seals with overlays, spiral wound seals, corrugated seals, rubber-steel seals, jacketed or encased seals are used in the force main seal. In some cases, these seals are also manufactured for the force shunt.
Soft metal seals generally have very low leakage rates, so that they usually meet the requirements of TA Luft and other immission regulations. Our range includes all common designs of this type of seal.

Rubber-steel seals, which combine different elastomers reinforced with a steel core, are also suitable for simple applications.
Typical representatives of this type of sealing principle are rubber-steel seals, comb profile seals, spiral wound seals and corrugated ring seals. Many other forms, which are precisely tailored to the application, complement the basic types mentioned.

We will be happy to advise you on the selection of the appropriate seal

Soft material seals

Our range of soft fiber seals is designed for standard operating conditions. Materials have been optimized for different process conditions by adding functional fillers. For example, materials are geared towards chemical resistance, pressure resistance or temperatures:

With its KlingerSil series and related hybrids, KLINGER has developed a very wide range of products that are optimized for various applications through the use of additives.

FRENZELIT also offers product variants geared towards a wide range of applications, which are designed for both high resilience and good chemical resistance.

We will be happy to advise you on the selection of the appropriate seal.

Seal cutters and tools

KLINGER ring cutting machine: "Quickly cut your own rings". You can produce rings from 80 to 1250 mm, in any thickness and in no time at all. KLINGER ring cutter spare parts. We stock various spare parts for Klinger ring cutters, such as pointed blades and round blades