U and W Shaped Radiant Tubes
U and W shaped radiant tubes for tube temperatures up to 1250°C (2280°F). The radiant tubes includes nickel-chromium (NrCr) alloys or iron-chromium-aluminium (FeCrAl) alloys for extremely demanding environments, of combinations of the two material types.
High-temperature corrosion properties
Material | In Air / Oxidizing | Oxidizing Sulphur | Reducing Sulphur | Carburizing | Nitriding |
ASTM 310 | 0 | 0 | 0 | 0 | 0 |
253 MA1) | + | + | ++ | + | 02) |
353 MA1) | + | - | 0 | ++ | ++ |
SD Consults APM | ++ | ++ | ++++ | +++ | +3) |
SD Consults APMT | ++ | ++ | ++++ | +++ | +3) |
- 253 MA and 353 MA are trademarks owned by Outokumpu OY
- Nitriding may occur at very low dew point (<-60°C/-51°F)
- Severe nitriding may occur at low dew point (<-20°C/-29°F)
Oxidation properties at 1100ºC (2040ºF) | Carburization rate for various alloys |
Radiant tubes for tougher conditions at the burner leg
In some furnaces not all parts of a radiant tube is exposed to extreme temperatures. In these cases, an alternative is to use Kanthal APM or Kanthal APMT iron-nickel-chromium (FeCrAl) alloy for the burner leg and a nickel-chromium (NiCr) alloy for the bend and the return tube.