High Temperature Insulation Covers & Blankets

This article was written by Chuck Murphy of Thermaxx Jackets

Thermaxx Jackets manufactures insulation jackets to insulate very hot applications, ranging from 600°F to 2500°F. These temperatures are encountered with:

  • High pressure steam
  • Furnaces
  • Kilns
  • Turbines
  • Cogen sites
  • Exhausts
  • Utility plants
  • Refining/petrochemical plants
  • Various industrial processes

Depending upon the temperature of the application, specific designs and materials need to be employed in manufacturing of a high temperature insulating jacket.

Before High Temperature Insulation is Applied

Before High Temperature Insulation is Applied to Component

After High Temperature Insulation is Applied

After High Temperature Insulation is Applied to Component


Traditional materials and designs fail when used at high temperature. The first step in the hot jacket design is the materials selection. This requires an understanding of the hot component, the components environment and the design of the jacket. Factors that effect the materials used in a hot jacket are; location (inside, outside, steam pit/vault), environment (steam, chemical, water) and hot component design (flanged, NPT, piping, lubrication ports). Typical materials used to manufacture hot jackets are:

Jacket Cover

Vermiculite Coated Fiberglass Cloth Good to 1500°F
Silica Cloth Good to 1800°F
Wire Mesh Good to 2300°F

Cold Side

Teflon Coated Fiberglass Cloth Good to 550°F
Silicone Coated Fiberglass Cloth Good to 500°F

Jacket Insulation

Ceramic Good to 2400°F
Pyrogel Good to 1200°F
Needled Fiberglass Good to 1200°F

Sewing Thread

Kevlar Good to 750°F
Fiberglass Good to 1000°F
Kevlar Inconel Good to 1800°F
Quartz Good to 2000°F
Al2O3, SiO2, B2O3 Good to 2500°F


The next step in the design of a hot insulation jacket is analyzing the temperature of the hot component to be insulated, the ambient temperature where the hot component is located, and the desired surface temperature (touch temperature) of the insulating hot jacket using a computer program developed by the National Insulation Association. This program calculates the thickness of insulation needed to get a specific surface temperature for the jacket. For example, if the customer desires a surface temperature of under 125°F for a 600°F component, the program will tell the designer how thick of a specific insulation is needed.

Design of the jacket is next. Depending upon the location, environment and hot component to be insulated, the design will vary greatly. Proprietary designs protect the materials from overheating as well as insulate the component. Proper placement of materials is critical to avoid thermal degradation.

Finally, the hot jacket is manufactured with a high temperature thread using a quality manufacturing process that warranties Thermaxx Hot Jackets for 5 years.

Learn more about Thermaxx Hot Jackets or contact us!

Read more from our blog about common insulation materials.

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