There are many kinds of tubular heater materials, the most commonly used this four kinds.
Copper Sheath | Water heating, water solutions non-corrosive to copper. |
Stainless Steel Sheath | Immersion in oils, molten salt baths, alkaline cleaning solutions, tars and asphalt. Also suitable for clamping to metal surfaces and casting into aluminum. Corrosive liquids, food processing equipment. Stainless steel 304 is the normal material. |
Incoloy Sheath | Air heating, radiant heating, cleaning and degreasing solutions, plating and pickling solutions, corrosive liquids. Usually for high temperature. |
Titanium tube | corrosive environment. |