Recrystallized Silicon Carbide (R-SiC) Thermocouple Protection Tube

Recrystallized Silicon Carbide (R-SiC) Thermocouple Protection Tubes are designed for continuous temperature measurement in demanding high-temperature industrial environments. Manufactured from over 99% high-purity silicon carbide without any sintering additives, these tubes provide excellent oxidation resistance, outstanding thermal shock performance, and superior resistance to sulfur-containing atmospheres.

With a maximum continuous service temperature of 1650°C, R-SiC protection tubes are widely used in glass melting furnaces, precious metal processing, industrial incinerators, and other applications exposed to corrosive flue gases.

• Excellent High-Temperature Resistance
  • Continuous operating temperature up to 1650°C.
• Outstanding Oxidation Resistance
  • Maintains stable performance during long-term exposure to oxidizing atmospheres.
• Superior Sulfur Corrosion Resistance
  • Ideal for furnaces containing sulfur-bearing flue gases.
• Excellent Thermal Shock Resistance
  • Handles rapid heating and cooling cycles with minimal risk of cracking.
• High Purity Material
  • Manufactured from >99% SiC without binders or sintering additives.
• Long Service Life
  • Excellent dimensional stability under prolonged high-temperature operation.

R-SiC protection tubes are manufactured using carefully graded high-purity silicon carbide powders without any binders or sintering aids. After extrusion forming and controlled drying, the green body is pressurelessly sintered at 2200–2400°C under an inert atmosphere.

During sintering, silicon carbide particles bond through a recrystallization mechanism, forming a stable interconnected structure while maintaining controlled open porosity. The result is an exceptionally pure material with outstanding oxidation resistance, sulfur corrosion resistance, and excellent thermal shock performance.

R-SiC thermocouple protection tubes are widely used in high-temperature industrial processes where excellent oxidation resistance and sulfur corrosion resistance are required.

Typical applications include:

• Glass melting furnaces
• Float glass production lines
• Precious metal melting furnaces
• High-temperature heat treatment furnaces
• Industrial waste incinerators
• Sulfur-containing flue gas systems
• Laboratory high-temperature furnaces

Although R-SiC provides exceptional resistance to oxidation and thermal shock, it has a naturally porous microstructure.

For applications requiring complete gas sealing—particularly when using Pt-Rh thermocouples—an inner alumina protection tube or double-wall protection system is recommended to prevent corrosive gases from reaching the thermocouple.

R-SiC protection tubes are therefore best suited for applications where corrosion resistance and high-temperature durability are more critical than absolute gas tightness.

Compared with conventional ceramic protection tubes, R-SiC offers several important advantages:

• Excellent resistance to oxidation at temperatures up to 1650°C
• Outstanding durability in sulfur-containing furnace atmospheres
• Better thermal shock resistance than many traditional ceramics
• High thermal conductivity for faster temperature response
• Long service life in aggressive industrial environments
• Available in customized dimensions for various furnace designs

A reliable thermocouple protection tube should provide:

• Long-term stability at elevated temperatures
• Resistance to acids, alkalis, molten salts, and sulfur compounds
• Good thermal conductivity for rapid temperature response
• Excellent thermal shock resistance during heating and cooling cycles
• Chemical compatibility with thermocouples and insulating materials
• Adequate mechanical strength throughout its service life

R-SiC protection tubes meet these requirements in many demanding industrial applications where oxidation resistance and thermal durability are critical.

We supply customized Recrystallized Silicon Carbide (R-SiC) Thermocouple Protection Tubes in various diameters, lengths, and wall thicknesses to meet different furnace designs and operating conditions.

Contact our engineering team for technical support, custom dimensions, or application recommendations