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.
| Property | Value |
|---|---|
| Material | Recrystallized Silicon Carbide (R-SiC) |
| SiC Purity | >99% |
| Maximum Service Temperature | 1650°C |
| Bulk Density | 2.70 g/cm³ |
| Apparent Porosity | 15% |
| Flexural Strength (Room Temperature) | 90 MPa |
| Flexural Strength (1400°C) | 80 MPa |
| Elastic Modulus | 240 GPa |
| Thermal Conductivity (1000°C) | 25 W/m·K |
| Coefficient of Thermal Expansion | 4.8 × 10⁻⁶ /°C |
| Thermal Shock Resistance | Excellent |
| Standard Outside Diameter | Φ20–60 mm |
| Standard Inside Diameter | Φ10–40 mm |
| Standard Length | Up to 1200 mm |
| Corrosion Resistance | Excellent resistance to oxidation and sulfur-containing atmospheres |
| Gas Tightness | Semi gas-tight |
| Custom Sizes | Available upon request |
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
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