Share this page by mail Gasket Sheets for High Temperature
Final Advanced Materials cuts and produces high-temperature gasket sheets from soft materials, from prototypes to large series.
From -200°C to over 900°C, our product range covers most industrial applications.
Gasket sheets are recommended for producing flat sealing pieces intended to be compressed between two other parts. The seals can also be used to optimise the contact area between two parts.
Principal selection criteria for gasket sheets
- Temperature (maximum, continuous, etc.)
- Fluid pressure
- Chemical environment
- Mechanical resistance
Applications of gasket sheets for high temperatures
- Sealing with hot gases
- Heat exchangers
- Burner seals
- Exhaust manifolds
- Thermal insulation
- Food industry
- Chemical industry
Please do not hesitate to contact us and send us your specifications so that we can help determine which product will best meet your requirements.
Used materials for gasket sheets
Silicate fibre
Very good quality P.T.F.E. sheet loaded with silicate fibres. This mixture provides the product with excellent mechanical characteristics, complementing the excellent properties of the P.T.F.E. facing the most aggressive environments. Available in thicknesses of 0.5 to 3 mm.
Applications: Chemical, petrochemical, pharmaceutical and food industries, with very good resistance to strong acids and alkalis (except fluoride and molten alkali metals).
Glass fibre
Fibreglass sheet with NBR elastomeric binder. This mixture allows a higher temperature resistance and a greater resistance to pressure. It is blue in colour on both sides and available in thicknesses of 0.5 to 3 mm. A reinforced version is also available made from stainless steel sheet or a fibreglass/aramid blend.
Applications: Water, oil, air, fuel, gas, steam, oxygen, organic & inorganic acids. General applications for all industries.
Graphite
Flexible expanded graphite gasket sheet (purity 99%) with stainless steel reinforcement. Other graphite items are available on request. Available in thicknesses of 1 to 3 mm.
Applications: Water, oil, air, fuel, gas, steam, chemistry, thermal and mechanical shocks. Applications under high temperatures and associated pressures.
Mica
Gasket sheet made of (90%) phlogopite mica flakes and a silicone binder. Brown/green in colour on both sides and available in thicknesses of 1 to 3 mm. A reinforced version with 316L pins and a stainless-steel insert is also available.
Applications: Very high temperatures, even in the presence of oxygen. Burner seals, exhaust manifolds, exchangers.
Comparative table
|
Composition |
Silicate fibre + PTFE |
Aramid glass fibre + NBR (4430) |
Glass fibre + NBR |
Expanded graphite G + stainless-steel sheet |
Mica + Silicone |
|
Peak operating temperature °C |
270 |
400 |
440 |
800 |
1100 |
|
Continuous operating temperature ˚C |
260 |
300 |
350 |
530 |
1000 |
|
Steam temperature ˚C |
260 |
250 |
250 |
/ |
/ |
|
Minimum temperature ˚C |
-200 |
-150 |
/ |
-240 |
-200 |
|
Pressure (bars) |
/ |
80 |
120 |
150 |
5 |
|
Density g/cm³ |
2.2 |
1.75 |
1.75 |
1 |
1.9 |
|
Compressibility % |
4 to 7 |
9 |
7 |
35 |
15 |
|
Elastic recovery % |
>50 |
> 50 |
55 |
15 |
40 |
|
Stress relaxation N/mm² at 300°C |
20 (150°C) |
35 |
33 |
49 |
40 |
|
Gas permeability ml/min |
<0.02 |
< 0.1 |
0.03 |
0.6 |
/ |
This list of materials is not exhaustive but represents the composition of the most frequently used seals. Please do not hesitate to contact us so we can suggest the best material for you.
FAQs that can help you in this category
Final Advanced Materials will use the following criteria to recommend the material best suited to your needs: temperature, pressure, and environment (gaseous, liquid).
If you are seeking a material with high compressibility (>40%) and excellent chemical resistance, graphite is the perfect solution for your needs. It is resistant to over 60 bars of pressure, 550°C in a normal atmosphere, and up to 3,000°C in an inert atmosphere.
However, if you are seeking a material which can resist temperatures ranging between 900–1,000°C in a normal atmosphere and 6 bars of pressure, mica will be a better option. It is both an effective electrical insulator (20 to 80 kV/mm) and an effective thermal insulator (≈ 0.3 to 0.7 W/m·K).
Expanded graphite gaskets have excellent thermal resistance. However, their temperature resistance depends heavily on the working environment.
In a non-oxidising atmosphere (vacuum or inert gases), expanded graphite can be used at temperatures of up to approximately 3,000°C. However, in the presence of oxygen (air) graphite is subject to oxidation, which lowers its maximum service temperature to around 450–500°C. Above this temperature, degradation will be accelerated.
Mica sheets have a good resistance to many solvents, oils and organic chemical agents, as well as high-temperature oxidising environments, making them particularly effective for extreme thermal applications.
However, their resistance is generally limited in the presence of strong bases and strong acids, which can attack the mica structure and degrade the gasket's mechanical properties.
In summary, mica gasket sheets have an excellent overall chemical resistance, especially in moderately acidic environments, but their compatibility depends on concentration or temperature.
Generally, the more irregular the surfaces, the thicker the gasket must be to ensure proper conformability and a tight seal.
However, increasing the thickness also reduces the rigidity of the gasket and may require a higher tightening load to achieve a satisfactory seal. Therefore, it is important to find a balance between defect compensation capability and mechanical strength.
Furthermore, at high temperatures it is important to take both creep and relaxation processes into account: it is often preferable to choose a moderate thickness combined with a compressible and thermally stable material, rather than excessively increasing the thickness.
If the irregularities are too important, Final Advanced Materials can advise you on a textile solution.