001 Front Cover

Ceramic Protection Tubes-

Silicon Carbide and Hexaloy@ Silicon Carbide - Oxide Bonded

Silicon carbide protection tubes (SG) 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. lt also has excellent ther- mal 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 met- als such as Aluminum, since they are very resistant to oxidation and slag attack. Composition - 89.6"/o Silicon Carbide (Black, coarse grained Alpha / Beta mix) , 8.5"/o Silicon Dioxide, .7% Aluminum Oxide, .7o/o lron Oxide. Silicon Carbide - lUitride Bonded Nitride bonded silicon carbide tubes (SCN) have the same characteristics as Ox 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.Oo/o Silicon Carbide (Black, coarse grained Alpha / Beta mix), 23.4% Silicon Nitride, .5% Silicon Dioxide, .3% Aluminum Oxide, .3% lron Oxide.

scP-* SCNP.*

25.4 25.4

1 314 1 314

44.5 44.5

1

Plain Tube

1

PIaIn Tube

Bushing 2" x 314" NPT Cemented on the Tube

SCB.* scNB-*

44.5 44.5

25.4 25.4

314 314

1

1

1

1

Collar 3" O.D. x 1" Wide

scc-*

25.4

44.5

1 314

1

Fitting 314" NPT Female held by three set SCTEWS

SCF.* SCNF-*

44.5 44.5

25.4 25.4

314 314

1

1

1

1

FIfrIng

lsopressed around a steel tube

P

1/2" NPT 314" NPT

sc112-* scl34-*

50.8 50.8

15.7 20.8

.62 .82

2 2

Isopressed

. Add length (P) as the suffix, multiples of 6 inches (152.4mm) are stocked.

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