Oxide Bonded Silicon Carbide Thermocouple Protection tubes (SC) have a maximum
service temperature of 2730°F (1500°C). Silicon carbide tubes are not gas
tight. They are about 14% porous. Silicon carbide also has good thermal shock
and corrosion resistance. It also has excellent thermal conductivity. Because
of this they are best used as a secondary protection tube to protect Mullite
or Alumina primary tubes from direct flame impingement. Silicon carbide tubes
are also frequently used in oxygen atmosphere furnaces and molten non-ferrous
metals such as Aluminum, since they are very resistant to oxidation and slag
attack.
Composition - 89.6% Silicon Carbide (Black, coarse grained Alpha / Beta mix)
, 8.5% Silicon Dioxide, .7% Aluminum Oxide, .7% Iron Oxide.
Nitride bonded silicon carbide tubes (SCN) have the same characteristics as
Oxide bonded silicon carbide with a few exceptions. They have a maximum service
temperature of 2800°F (1550°C). Nitride bonded tubes are more dense and less
porous than oxide bonded tubes. They also have slightly better thermal shock,
corrosion resistance, and twice the crushing strength of the oxide bonded
tubes.
Composition - 75.0% Silicon Carbide (Black, coarse grained Alpha / Beta mix),
23.4% Silicon Nitride, .5% Silicon Dioxide, .3% Aluminum Oxide, .3% Iron Oxide.
Isopressed or Carbon bonded silicon carbide tubes (SCI) are less porous
(8%) than Nitride bonded silicon carbide but not as dense as Oxide or Nitride
bonded tubes. They have a maximum service temperature of 2800°F (1550°C).
Composition - 78.2.0% Silicon Carbide (Black, coarse grained Alpha / Beta
mix), 18.7% Silica, 2.1% Sodium Oxide, 1.43% Aluminum Oxide, .44% Iron Oxide.
Note: Protection tubes are coated with a silicon carbide glaze to reduce open
porosity and reactive surface area of the protection tube. This glaze is used
to help prolong the service life of the tube.
Hexaloy® Silicon Carbide has a maximum service temperature of 3000°F (1650°C)
in both oxidizing and corrosive atmospheres. It can be used in chemicals including
strong acids and bases. Hexaloy® is chemically inert and has excellent thermal
shock resistance ten times superior to Alumina. It is very hard, second only
to diamonds, with excellent wear and abrasion resistance. Hexaloy® has five
times the thermal conductivity of Alumina. Unlike other forms of silicon carbide,
Hexaloy® can be used as a single primary protection tube since it is gas tight.
Composition - 99% Sintered fined grained green Alpha-Silicon Carbide.
PLAIN END-SILICON
CARBIDE  |
| Silicon Carbide (SC) and Nitrate Bonded Silicon Carbide (SCN) for use to 1650 C or 3000 F. |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| OD | ID | OD | ID | |||
| SCP-* SCNP-* |
1 3/4 1 3/4 |
1 1 |
44.5 44.5 |
25.4 25.4 |
Plain | PLAIN, open one end, closed other end |
BUSHING-SILICON CARBIDE
 |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
SCB-* SCNB-* |
1 3/4 1 3/4 |
1 1 |
44.5 44.5 |
25.4 25.4 |
BUSHING, outside thread-NPT | BUSHING (forward) on open end, closed other end |
| 2" X 3/4" NPT Cemented on Tube |
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COLLAR-SILICON
CARBIDE  |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| SCC-* | 1 3/4 | 1 | 44.5 | 25.4 | Collar 3" OD, 1" Width | Collar on open end, closed other end |
| Collar |
||||||
FITTING-SILICON
CARBIDE  |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| SCF-* SCNF-* |
1 3/4 1 3/4 |
1 1 |
44.5 44.5 |
25.4 25.4 |
Fitting-3/4" NPT Female Held by 3 set screws |
Fitting on open end, closed other end |
| Fitting |
||||||
Carbon bonded silicon carbide tubes (SCI) are less porous (8%) than Nitride
bonded silicon carbide but not as dense as Oxide or Nitride bonded tubes.
They have a maximum service temperature of 2800°F (1550°C).
Composition - 78.2.0% Silicon Carbide (Black, coarse grained Alpha / Beta
mix), 18.7% Silica, 2.1% Sodium Oxide, 1.43% Aluminum Oxide, .44% Iron Oxide.
Note: Protection tubes are coated with a silicon carbide glaze to reduce open
porosity and reactive surface area of the protection tube. This glaze is used
to help prolong the service life of the tube.
ISOPRESSED-SILICON
CARBIDE  |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| SCI12-* SCI34-* |
2 2 |
.62 .82 |
50.8 50.8 |
15.7 20.8 |
1/2" or 3/4" NPT steel inner tube |
Isopressed Steel inner tube |
| 1/2" NPT 3/4" NPT |
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REVERSED BUSHING-SILICON
CARBIDE  |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| SCRB-* SCNBRB-* |
1 3/4 1 3/4 |
1 1 |
44.5 44.5 |
25.4 25.4 |
REVERSED BUSHING, outside thread-NPT | BUSHING (reversed) on open end, closed other end |
| 2" NPT Cemented on tube |
||||||
COUPLING (Female)-SILICON
CARBIDE  |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| SCCP112-* SCCP114-* SCNBCP112-* SCNBCP114-* |
1 3/4 1 3/4 1 3/4 1 3/4 |
1 1 1 1 |
44.5 44.5 44.5 44.5 |
25.4 25.4 25.4 25.4 |
Coupling Cemented on Tube NPT | COUPLING (Female) Cemented on open end, closed other end |
| 1 1/2 1 1/4 1 1/2 1 1/4 |
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Hexaloy® Silicon Carbide has a maximum service temperature of 3000°F (1650°C)
in both oxidizing and corrosive atmospheres. It can be used in chemicals including
strong acids and bases. Hexaloy® is chemically inert and has excellent thermal
shock resistance ten times superior to Alumina. It is very hard, second only
to diamonds, with excellent wear and abrasion resistance. Hexaloy® has five
times the thermal conductivity of Alumina. Unlike other forms of silicon carbide,
Hexaloy® can be used as a single primary protection tube since it is gas tight.
Composition - 99% Sintered fined grained green Alpha-Silicon Carbide.
SILICON CARBIDE-Hexaloy®
 |
| Silicon Carbide for use to 1650 C or 3000 F. |
| Silicon Carbide Part Number |
INCHES | MILLIMETERS | MOUNTING | CONSTRUCTION | ||
| O.D. | I.D. | O.D. | I.D. | |||
| Lengths 6" to 26" SCHX0604-* SCHX1006-* Lengths 6" to 48" SCHX1208-* SCHX1608-* SCHX2012-* |
3/8 5/8 |
1/4 3/8 1/2 1/2 3/4 |
9.5 15.9 19.1 25.4 31.8 |
6.4 9.5 12.7 12.7 19.1 |
Most standard fittings are available |
Plain or most fittings are available on open end, closed other end |
| 1 1/2 1 1/4 1 1/2 1 1/4 |
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Hexaloy® is a trademark of Carborundum Co.
| © Copyright 2005 Arklay S. Richards Co., Inc. |