Silicon Carbide Thermocouple Protection Tubes
Oxide Bonded | Nitride Bonded | Isopressed
Silicon carbide thermocouple protection tubes are available as oxide bonded, nitride bonded and carbon bonded (isopressed) varieties. Note the characteristics of each type before choosing one for your application.
Oxide Bonded Silicon Carbide Protection Tubes
Oxide bonded silicon carbide thermocouple protection tubes (SC) have a maximum service temperature of 2730°F or 1500°C. These tubes are not gas tight. They are about 14% porous. This material has good thermal shock and corrosion resistance. Oxide bonded tubes also have excellent thermal conductivity. Because of this they are best used as a secondary protection tube to protect Mullite or Alumina primary thermocouple tubes from direct flame impingement. Oxide bonded protection tubes are also frequently used in oxygen atmosphere furnaces with molten non-ferrous metals such as Aluminum, since they are very resistant to oxidation and slag attack.
Composition - 89.6% Silicon Carbide (Black, course grained Alpha / Beta mix), 8.5% Silicon Dioxide, .7% Aluminum Oxide, .7% Iron Oxide.
Tube Configurations
Specifications - Oxide Bonded
- Maximum Service Temperature of 2730°F or 1500°C
- Excellent Thermal Conductivity
- Excellent for Flame Protection
- Tube sizes from 1 3/4" to 2.0" O.D.
- Available with Bushings, Collars, Steel Fittings, Couplings, or Mounting Flanges.
- Lengths from 6" to 48"
- Closed One End or Open Both Ends
Nitride Bonded Silicon Carbide Protection Tubes
Nitride bonded silicon carbide thermocouple protection tubes (SCN) have a maximum service temperature of 2800°F or 1550°C and have the same characteristics as Oxide bonded tubes but with a few exceptions. Nitride bonded tubes are more dense and less porous that oxide bonded tubes. They also have slightly better thermal shock and corrosion resistance, with twice the crushing strength of the oxide bonded protection tubes.
Composition - 75.0% Silicon Carbide (Black, course grained Alpha / Beta mix), 23.4% Silicon Nitride, .5% Silicon Dioxide, .3% Aluminum Oxide, .3% Iron Oxide.
Specifications - Nitride Bonded
- Maximum Service Temperature of 2800°F or 1550°C
- More Dense Than Oxide Bonded Tubes
- Excellent Crushing Strength
- Tube Sizes Range From 1 3/4" to 2.0" O.D.
- Available With Bushings, Collars, Steel Fittings, Couplings, or Mounting Flanges.
- Lengths Available From 6" to 48"
- Closed One End or Open Both Ends
Isopressed Silicon Carbide Protection Tubes
Isopressed or carbon bonded silicon carbide protection tubes (SCI) are less porous (8%) than nitride bonded but not as dense as oxide bonded tubes. Isopressed silicon carbide tubes have a maximum service temperature of 2800°F or 1550°C.
Composition - 78.2% Silicon Carbide (Black, course grained Alpha / Beta mix), 18.7% Silica, 2.1% Sodium Oxide, 1.43% Aluminum Oxide, .44% Iron Oxide. Note: Isopressed protection tubes are coated with a silicon carbide glaze to reduce open porosity and the reactive surface area of the protection tube. This glaze is used to help prolong the service life of the tube.
Specifications - Isopressed
- Maximum Service Temperature of 2800°F or 1550°C
- Glazed Outer Surface to Prolong Service Life
- Excellent for Molten Aluminum Applications
- Tube size 2.0" O.D.
- Available with 1/2" or 3/4" NPT Threaded Nipples.
- Available in Lengths From 12", 18", 24", 30", 36", 42", and 48"
Specifications
- Installation flexibility