Protection Tubes - Silicon Carbide

 

oxide bonded | nitride bonded | isopressed | Hexoloy®

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. Silicon carbide tubes are not gas tight. They are about 14% porous. Silicon carbide also has good thermal shock and corrosion resistance. Oxide bonded silicon carbide also has 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.

oxide bonded silicon carbide tube Specifications

  • 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 silicon carbide 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.

nitride bonded silicon carbide tube Specifications

  • 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
Silicon Carbide Protection Tubes | SC | SCN
Silicon Carbide Thermocouple Tube
Part Number O.D.
(Inches)
I.D.
(Inches)
O.D.
(mm)
I.D.
(mm)
Silicon Carbide
Type
Mounting
SCP-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Plain Tube
SCNP-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Plain Tube
SCB-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Bushing 2" x 3/4" NPT
Cemented on Tube
SCNB-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Bushing 2" x 3/4" NPT
Cemented on Tube
SCC-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Collar
3" O.D. x 1" Thick
SCF-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Fitting 3/4" NPT Female
Held by 3 set screws
SCNF-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Fitting 3/4" NPT Female
Held by 3 set screws
SCRB-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Reverse Bushing
cemented on tube
2" Male NPT
SCRNB-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Reverse Bushing
cemented on tube
2" Male NPT
SCCP112-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Cemented Coupling
1 1/2" Female NPT
SCCP114-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Cemented Coupling
1 1/4" Female NPT
SCCNP112-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Cemented Coupling
1 1/2" Female NPT
SCCNP114-* 1 3/4" 1" 44.5 25.4 Nitride Bonded Cemented Coupling
1 1/4" Female NPT
SCFL-* 1 3/4" 1" 44.5 25.4 Oxide Bonded Steel Mounting Flange
attached to collar on tube
Note: * Specify the protection tube length (P) in inches.

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.

isopressed silicon carbide tube Specifications

  • 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"
Silicon Carbide Protection Tubes | Isopressed
Isopressed Silicon Carbide Thermocouple Tube
Part Number O.D.
(Inches)
I.D.
(Inches)
O.D.
(mm)
I.D.
(mm)
Silicon Carbide
Type
Mounting
SCI12-* 2" .62" 50.8 15.7 Isopressed
Carbon Bonded
Steel inner tube
1/2" NPT
SCI34-* 2" .82" 50.8 20.8 Isopressed
Carbon Bonded
Steel inner tube
3/4 " NPT
Note: * Specify the protection tube lenght (P) in inches.

Hexoloy® silicon carbide protection tubes

Hexoloy® silicon carbide protection tubes have a maximum service temperature of 3000°F or 1650°C. ain both oxidizing and corrosive atmospheres. It can be used in chemicals including strong acids and abases. Hexoloy® is chemically inert and has excellent thermal shock resistance ten times superior to Alumina. It is also very hard, second only to diamonds, with excellent wear and abraision resistance. Hexoloy® has five times the thermal conductivity of Alumina. Unlike other forms of silicon carbide, Hexoloy® can be used as a single primary thermocouple protection tube since it is gas tight.

Composition - 99% Sintered Fined Grained Green Alpha-Silicon Carbide.

Hexoloy® silicon carbide tube Specifications

  • Maximum Service Temperature of 3000°F or 1650°C
  • Excellent Thermal Shock Resistance Ten Times Superior to Alumina
  • Excellent Wear and Abrasion Resistance.
  • Tube sizes 3/8" to 1 1/4" O.D.
  • Available with Bushings, Collars, Steel Fittings, or Couplings
  • Available in Lengths From 12", 18", 24", 30", 36", 42", and 48"
Silicon Carbide Protection Tubes | Hexoloy®
Hexoloy Silicon Carbide tube
Part Number O.D.
(Inches)
I.D.
(Inches)
O.D.
(mm)
I.D.
(mm)
Silicon Carbide
Type
Mounting
SCHX0604-* 3/8" 1/4" 9.5 6.4 99% fine grained green alpha SC 1/2" O.D.
3/8" Wide
SCHX1006-* 5/8" 3/8" 15.9 9.5 99% fine grained green alpha SC 5/8" O.D.
1/4 " Wide
SCHX1208-** 3/4" 1/2" 19.1 12.7 99% fine grained green alpha SC 5/8" O.D.
1/4 " Wide
SCHX1608-** 1.0" 1/2" 25.4 12.7 99% fine grained green alpha SC 5/8" O.D.
1/4 " Wide
SCHX2012-** 1 1/4" 3/4" 31.8 19.1 99% fine grained green alpha SC 1" O.D.
3/8" Wide
Note: * Specify the protection tube lenght (P) in inches. 6" to 26"
** Specify the protection tube lenght (P) in inches. 6" to 48"