How to select the right flanged immersion heater for your application?


Selecting the right flanged immersion heater for your application is crucial to ensuring efficient heating and optimal performance. In this blog post, we will discuss what a flanged immersion heater is, how to choose the right one, and the advantages it offers. We will also provide information on how flanged immersion heaters work. We introduce Marathon Heater as a reputable manufacturer of these heating solutions.

What is a Flanged Immersion Heater?

A flanged immersion heater is a type of electric heating element that is immersed in a liquid or gas for heating. It consists of a heating element, typically made of high-quality stainless steel, encased in a flange assembly. The flange assembly allows for easy installation and removal of the heater from the tank or vessel.

Different alloys and materials can be used to suit specific applications. Steel flanges are used for deionized water, lubricant oils, heavy and light oils, waxes, mildly corrosive liquids, low-flow gas, and water tank heating. Stainless steel flanged heating elements are used with mild and severe corrosive solutions and in military applications. The sheath materials used can be steel, 304 stainless steel, and copper, as well as exotic alloys such as Incoloy.

The immersion heaters are broadly sub-divide as below:

How to Select the Right Flanged Immersion Heaters?

Determine the heating requirements:

Start by assessing the specific heating requirements of your application, such as the desired temperature range, required heating capacity, and the medium being heated.

Consider the Material:

The material of the heating element and the flange assembly should be compatible with the liquid or gas being heated. Stainless steel is a common choice because of its corrosion resistance and durability.

Size and Watt Density:

Select a flanged immersion heater that matches the size and watt density requirements of your application. Watt density refers to the amount of power the heating element delivers per unit surface area. It is important to choose a heater with an appropriate watt density to avoid premature failure or damage.

Environmental Factors:

Consider the operating environment of the heater, including ambient temperature, humidity, and corrosive substances. This information will help determine the insulation and protective coatings required for the heater.

Safety Features:

Look for flanged immersion heaters that come with safety features such as built-in thermal cutouts, pressure relief valves, and overheat protection. These features ensure safe operation and prevent damage to the heater and the system.

Different sheath materials used have different operating temperatures and watt densities. While selecting the material, these values must match your criteria. The table shown below will help you make an ideal selection.

Take some precautions while selecting an immersion heater:

  •  Selection of the right material for the wet parts to avoid potential corrosion from the fluid to be heated.
  • Proper cold length and active length ratios need to avoid hot spots and dry heating.
  • Element skin temperature within the flash point limit of the fluid to avoid any hazards. Proper thermal design is very necessary whenever heating a flammable fluid or in hazardous area installations.
  • Fixing method and support for the bundle by considering the turbulence during the inflow and outflow.
  •  Control system for both element skin and fluid temperatures. 


What are the advantages of flanged immersion heaters?

Flanged immersion heaters offer several advantages, including:

  • Efficiency: Flanged immersion heaters offer high efficiency in heating applications. Since the heating element is directly immersed in the medium, there is minimal heat loss during transfer, resulting in efficient and rapid heating.
  • Versatility: Flanged immersion heaters are versatile and used in a wide range of industrial applications. They are suitable for heating high viscous fluids (bitumen, HFO etc.) and reduce the viscosity before pumping out. This versatility makes them a popular choice for industries like oil and gas, chemical processing, food and beverage, pharmaceuticals, and more.
  • Easy Installation and Maintenance: Flanged immersion heaters are designed for easy installation and maintenance. The flange assembly allows for straightforward mounting and dismounting from tanks or vessels, facilitating quick and hassle-free heater replacement or cleaning.
  • Compatibility: These heaters are available in different materials, such as stainless steel, Incoloy, titanium, and more, to suit the compatibility requirements of various liquids and gasses. This ensures that the heater remains resistant to corrosion and chemical reactions, prolonging its lifespan.
  • Heating Large Volumes: Flanged immersion heaters can heat large volumes of fluid. Used in applications where a substantial amount of liquid or gas needs to be heated, such as in industrial tanks, boilers, heat exchangers, and process systems.
  • Customization Options: Flanged immersion heaters customized to meet specific application requirements. Manufacturers like Marathon Heater offer options for wattage, voltage, flange size, sheath material, and other features, allowing users to tailor the heater to their exact needs.

How does a Flanged Immersion Heater work?

Flanged immersion heaters work by converting electrical energy into heat through a heating element. The heating element is inserted into the liquid or gas, and the electrical current flowing through it generates heat. The heat is then transferred to the surrounding medium, raising its temperature to the desired level.

These heaters operate on the principle of electrical resistance heating. The heating element is made of a material with high electrical resistance, such as stainless steel. When electrical current flows through the element, it encounters resistance, which generates heat. This heat is then transferred to the surrounding medium, raising its temperature.       

The flange assembly, which houses the heating element, provides a secure and sealed connection to the tank or vessel being heated. It ensures that the heater remains immersed in the medium while maintaining electrical insulation and preventing leakage.

Flanged Immersion Heaters Manufacturers: Marathon Heater

For reliable and high-quality flanged immersion heaters, Marathon Heater is a leading manufacturer to consider. With years of experience in the industry, Marathon Heater offers a wide range of flanged immersion heaters that meet the diverse needs of different applications.

Marathon Heater is a reputable manufacturer of flanged immersion heaters. Their heaters undergo testing and quality control processes to meet industry standards and customer expectations.

By choosing Marathon Heater as your flanged immersion heater manufacturer, you can benefit from their reliability, technical expertise, and commitment to delivering heating solutions that meet your specific requirements.


Selecting the right flanged immersion heater is crucial for efficient heating in various industrial applications. By considering factors such as heating requirements, material compatibility, size, watt density, environmental factors, and safety features, you can choose a heater that meets your specific needs. With reputable manufacturers like Marathon Heater, you can trust the quality and performance of your flanged immersion heater.

Remember, selecting the right flanged immersion heater is essential for achieving optimal performance and efficiency in your heating application. Consulting with experts and manufacturers like Marathon Heater can help you make an informed decision and ensure a successful heating solution for your industrial needs.

Explore more about Flanged Immersion Heaters at Marathon Heater and experience the innovation driving heating and sensing technologies forward.

Please feel free to contact us at if you require assistance with your needs for flanged immersion heaters.