Mica & high-temperature materials

When temperatures exceed the capabilities of fibre sheets, elastomers or certain graphite constructions, materials specifically developed for severe thermal service are required.

European Sealing Technology supplies several mica- and vermiculite-based families, including:

• rigid mica;
• EST-Temp;
• EST-MCSS;
• Thermiculite® 715;
• Thermiculite® 815.

Selection must never be based on maximum temperature alone: pressure, atmosphere, thermal cycling, oxidation, flange rigidity and installation constraints must also be considered.

The EST range includes flexible and reinforced mica materials, including EST-Temp and EST-MCSS, together with Thermiculite® 715 and 815 and rigid mica in sheets or tubes.

Solutions based on phlogopite mica and high-temperature binders provide cuttable sheets for thermal applications. Compressibility and construction depend on the grade.

Adding a perforated stainless-steel reinforcement improves rigidity, handling and mechanical strength.

Thermiculite® 715 is a sheet material without a metal core, based on exfoliated vermiculite, aramid/synthetic fibres and a nitrile binder.

The current Flexitallic® data sheet specifies:

• use in many general and demanding industrial applications;
• good resistance to many chemical media;
• API 607 Fire-safe;
• recommended maximum temperature of 454 °C;
• standard sheet size of 1.5 m × 1.5 m.

These values are taken from Flexitallic® documentation; final selection also depends on pressure, fluid, gasket construction and actual assembly conditions.

Thermiculite® 815 is a high-temperature material comprising a perforated/tanged 316 stainless-steel core faced with a vermiculite-based sealing material.

The current Flexitallic® data sheet specifies:

• high-pressure superheated steam, strongly oxidising media and high-temperature gas/exhaust applications;
• API 607 Fire-safe;
• recommended maximum temperature of 1000 °C;
• 316 stainless-steel reinforcement.

Temperature and pressure limits must never be combined or interpreted independently of actual assembly conditions.

Rigid mica sheets are suitable for cut parts used in electrical or thermal insulation and high-temperature applications, depending on grade and construction.