Sheath Materials for Flanged Immersion Heaters

Electric flanged immersion heaters offer superior efficiency. This is achieved through both advanced technology and a high level of customization to match specific project needs. Designs, heater element configurations, and wattages, are all customizable. 

In addition, one of the most important customizations is selecting the right sheath material. How temperatures and mediums involved in industrial heating processes interact with sheath materials directly impacts efficiency and longevity. 

To keep heaters running at peak performance and prevent premature repairs or failure, careful sheath material selection is important for flanged immersion heaters.

How Sheath Materials Are Chosen

There are three main factors to consider when choosing sheath materials for heaters. Temperature, the corrosivity of the medium, and budget.


The target temperature and operational range of a heating process determine which materials are appropriate. Some metals and alloys can be damaged at high heat, especially over a sustained period of time. This can mean premature failure or inefficiency.

Corrosivity of Medium

While materials like steel are budget-friendly, they can end up costing more in the long run. When heating a corrosive medium, you need a sheath material that can withstand the corrosivity. Otherwise, the equipment and sheath can become damaged, requiring replacement and repair. 

As well, degrading material caused by corrosion can lead to sediment buildup. This reduces efficiency, can cause overheating, and requires more frequent maintenance. The initial savings when using a non-corrosive resistant material can quickly add up with repair, replacement, and maintenance costs.


It is essential that the flange heater sheath material is suitable for operational temperatures and corrosion-resistance needs. But, budget still plays a pivotal role. There is a careful balance between the best available option and keeping costs reasonable.

Our team of engineers helps select the materials best suited to your project’s needs, without compromising on quality or performance.


Common Sheath Materials

Most projects only require the most common sheath materials, steel, stainless steel, and copper. These are more budget-friendly than specialty materials and are suitable for most applications.


Steel is one of the most commonly used materials for immersion heater sheaths and flanges. It is capable at high temperatures and is a mainstay for oil and gas industry operations. While its capability and pricepoint make steel a popular material, it has limited corrosion resistance. As such, it is not suitable for heating anything more than mildly corrosive liquids.

Common uses of steel sheath heaters include:

  • Inline Gas Heating
  • Low Flow Gas Heating
  • Oils – Light, Medium, and Heavy Oils
  • Stagnant Oils


Stainless Steel

Stainless steel, like steel, contains iron. This makes it a strong, durable metal. Stainless steel, however, is capable of handling greater corrosivity than steel. This makes it suitable in processes involving demineralized and deionized water.

Because its cost is a little higher, steel is more often used unless the added corrosion resistance is necessary. Common stainless steel sheath heater applications include:

  • Process Water, Demineralized Water, Deionized Water
  • Mildly Corrosive Solutions
  • Soap & Detergent Solutions
  • Soluble Cutting Oils



Unlike steel and stainless steel, copper is a non-ferrous metal. That means that it doesn’t contain iron or steel. Non-ferrous metals and alloys have superior corrosion resistance. As such, copper offers the best corrosion protection of the common sheath materials.

Common applications of copper sheath immersion heaters include:

  • Boiler & Water Heaters
  • Clean Water
  • Cooling Towers
  • Hot Water Storage
  • Freeze Protection
  • Solutions (that are not corrosive to copper)


Specialty Sheath Materials

Where common materials are too heavy, susceptible to corrosion, or otherwise unsuitable for applications alloys and specially treated metals can be used. Sheath materials like Inconel, Hastelloy, and titanium come at a higher price but are ideal for extremely corrosive environments.

Incoloy sheath heaters, for instance, are common in processes involving:

  • Corrosive Solutions in Spray Washers and Rinse Tanks
  • Demineralized Water
  • Hot Water
  • Severe Corrosive Solutions
  • Steam Boilers


Flanged Heater Quotes & Design

Wattco custom engineers electric flanged immersion heaters for all major industries. Our team of engineers works with your project’s specifications and budget to select the optimal design, materials, settings, and heater types for superior performance. Working with electric heaters, we supply future-forward and innovation-first technologies that deliver precise and efficient results.

Contact us today for flanged heater quotes and information.