| ENGINEERING DATA SHEET SUBJECT : HEAT EXCHANGER MATERIALS
ALUMINIZED STEEL
Armco Type 1 Aluminizes Steel is cold-rolled steel with
silicone-aluminum fused to both sides by a patented hot-dip process. Both the aluminum
alloy bond are highly resistant to temperature and corrosion in normal service, making
aluminized steel much superior to ordinary or ceramic-coated steel as a heat exchanger
material.
409 STAINLESS STEEL
"409" is an improved Type 410 stainless now
successfully used in automobile mufflers. It is low carbon steel containing about 12%
chromium and a small amount of nickel for corrosion resistance. "409" also
contains titanium, silicon, and molybdenum, which improve its mechanical characteristics.
Although its resistance to high temperature and corrosion
is not as great as Type 321 stainless, "409" is much lower in price. It may,
therefore be used where cost must be kept down, where strong corrosive elements are not
expected, or where the longer guarantee of #321 stainless is not required.
321 STAINLESS STEEL
Type 321 is a titanium stabilized stainless
containing 18% chromium and 10% nickel for extremely high resistance to temperature and
corrosion. No commercially used metal can even approach it as a heat exchanger material.
HEAT EXCHANGER GUARANTEE
Applies to gas unit heaters, duct furnaces
and indirect-fired heating systems.
| Application |
Type of Heat Exchanger |
| Aluminized |
Stainless Steel |
| Type 409 |
Type 321 |
| Normal Space Heating |
10 Years |
10 Years |
10 Years |
| Furnace Upstream from Cooling Coil |
1 Year |
10 Years |
10 Years |
| Furnace Downstream from Cooling Coil |
1 Year |
5 Years |
10 Years |
| Make-up Air |
1 Year |
5 Years |
10 Years |
| Heating and Ventilating |
1 Year |
5 Years |
10 Years |
| Process Heating |
1 Year * |
1 Year * |
1 Year * |
* 1-Year warranty covering
defects in material and workmanship only.
DIVISON OF ERIC INC. |
