Tubular Heaters – Sheath Materials

Incoloy 840

Nickel 18-20%, Chromium 18-22%, Iron balance.

Has about 10% less nickel than Incoloy 800. Used in many air heating applications, where it has exhibited superior oxidation resistance at less cost than Incoloy 800.

Incoloy 800

Nickel 30-35%, Chromium 19-23%, Iron balance.

The high nickel content of this alloy contributes to its resistance to scaling and corrosion. Used in air heating and immersion
heating of potable water and other liquids.

316/316L Stainless Steel

Chromium 16-18%, Nickel 11-14%, Iron balance.
(316L – Low Carbon)

Modified with the addition of Molybdenum (2-3%) to improve corrosion resistance in certain environments, especially those which would tend to cause pitting due to the presence of chlorides. Applications include deionized water.

Maximum Sheath Temperature: 1200°F / 649°C

304/304L Stainless Steel

Chromium 18-20%, Nickel 8-11%, Iron balance.
(304L – Low Carbon)

Used in the food industry, medical, and chemical heating.

Maximum Sheath Temperature: 1200°F (649°C)

321 Stainless Steel

Chromium 17-20%, Nickel 9-13%, Iron balance.

Modified with the addition of Titanium to prevent carbide precipitation and resulting intergranular corrosion that can take place in certain mediums when operating in the 800-1200°F
(427-649°C) temperature range.

Copper

Standard Copper Alloy

A low temperature, inexpensive material used mainly for clean water heating.

Maximum Sheath Temperature: 350°F / 177°C

Steel

Low Carbon

Used for high to low viscosity oils, asphalt, tar, wax, molten salt, heat transfer liquid media and other compatible solutions.

Inconel 600

Iron 6-10%, Chromium 14-17%, Nickel balance

Maximum Sheath Temperature: 1800°F / 982°C

Incoloy 825

Nickel 38-46%, Chromium 19.5-23.5%, Molybdenum 2.5-3.5%, Iron balance

Excel Automation Inc.