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Ceramic Protection Tubes are used in
applications where contamination from hostile environments or the cutting action
of concentrated and direct flame impingement are factors. Such conditions
usually require a noble metal thermocouple such as platinum and platinum alloys.
When selecting assemblies using ceramic components, the expected maximum
temperatures must be considered. At elevated temperatures, some ceramic
materials go through a glass phase. As silica is a prime contaminant of
platinum, alumina protecting tubes and insulators are recommended for
temperatures exceeding 2000ºF (1093ºC).
| Material | Maximum Operating Temperature |
Thermal
Shock Characteristics |
Maximum Available Length (in) |
Typical Applications |
Remarks |
| Alumina (99.5%) |
3350ºF (1843ºC) |
Fair (preheating to 900ºF (482ºC) recommended |
84 | Iron, Barium, crown glass: Non-ferrous metals; gas-tight protection for noble metal thermocouples in excess of 2400ºF (1316ºC) |
Sags at 2900ºF (1593ºC) Prevents dry hydrogen penetration |
| Porcelain (Mullite) |
2900ºF (1593ºC) |
Poor (preheating to 900ºF (482ºC) recommended |
84 | Non-ferrous metals;
gas-tight protection for noble metal thermocouples to 2400ºF (1316ºC) |
Sags at 2900ºF (1593ºC) Prone to attack by halogen gases; Some penetration of dry hydrogen. Contains silica. |
| Alumina (99% Min. Purity) | |
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Protecting Tubes |
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Protecting Tubes with Collar |
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| Part Number |
I.D. x O.D.^ | Construction | Length | Price US Dollars |
| APT-101-__ | 1/4" x 3/8" | Plain End | 12" thru 48" in 6" increments | |
| *APT-102-__ | 7/16" x 11/16" | Plain End | 12" thru 60" in 6" increments | |
| APT-103-__ | 3/4" x 1" | Plain End | 12" thru 72" in 6" increments | |
| APT-104-__ | 1" x 1-1/4" | Plain End | 12" thru 72" in 6" increments | |
| APT-105-__ | 1/4" x 3/8" | With Ferrule 7/8-27 Threads | 12" thru 48" in 6" increments | |
| APT-106-__ | 7/16" x 11/16" | With Ferrule 7/8-27 Threads | 12" thru 60" in 6" increments |
 |
Complete the Part
Number with 3 digits indicating length in whole inches.
Example: = APT-105-012 is
12" long and PPT-107-048
is 48" long. * Available with brass or steel reducing fitting -- 3/4" NPT x 1/2 NPT ^ Dimensional tolerance: Up to 1" ± 5% or .025", whichever is greater Over 1" ± 4% or .050", whichever is greater |
| Porcelain |
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|
|
Protecting Tubes |
|
|
Protecting Tubes with Ferrule |
|
|
| Part Number | I.D. x O.D.^ | Construction | Length | Price US Dollars |
| PPT-101-__ | 1/4" x 3/8" | Plain End | 12" thru 84" in 6" increments | |
| *PPT-102-__ | 7/16" x 11/16" | Plain End | ||
| PPT-103-__ | 3/4" x 1" | Plain End | ||
| PPT-104-__ | 1" x 1-1/4" | Plain End | ||
| PPT-105-__ | 1/4" x 3/8" | w/Collar Approx. 5/16" x 3/4" | ||
| PPT-106-__ | 7/16" x 11/16" | w/Collar Approx. 5/16" x 1-1/16" | ||
| PPT-107-__ | 3/4" x 1" | w/Collar Approx. 5/16" x 1-3/8" | ||
| PPT-108-__ | 1" x 1-1/4" | w/Collar Approx. 5/16" x 1-5/8" | ||
| PPT-109-__ | 1/4" x 3/8" | w/Ferrule 7/8-27 Threads | ||
| PPT-110-__ | 7/16" x 11/16" | w/Ferrule 7/8-27 Threads |
|
Complete the Part
Number with 3 digits indicating length in whole inches.
Example: = APT-105-012 is
12" long and PPT-107-048
is 48" long. * Available with brass or steel reducing fitting -- 3/4" NPT x 1/2 NPT ^ Dimensional tolerance: Up to 1" ± 5% or .025", whichever is greater Over 1" ± 4% or .050", whichever is greater |
