What Is an Immersion Heater? Working Principle and Selection Guide
An immersion heater is an electric heating element designed to directly heat liquids inside tanks, containers, boilers, and process equipment. The heating element transfers heat directly into the liquid, providing efficient and reliable heating for industrial and commercial applications.
Proper selection depends on the tank size, liquid type, required temperature, heating time, installation method, and sheath material. Choosing the right heater helps achieve stable heating performance and longer service life.
What Is an Immersion Heater?
An immersion heater uses an electric resistance heating element to generate heat inside a liquid. The heating tubes are immersed directly in water, oil, chemical solutions, or other compatible liquids, allowing heat to transfer efficiently from the element to the surrounding medium.
Immersion heaters are commonly used for water heating, oil heating, chemical processing, cleaning systems, boilers, storage tanks, and industrial liquid heating.
Explore our complete range of industrial immersion heaters for different tank sizes and heating requirements.
Screw Plug vs Flanged Immersion Heater
The two common installation methods are screw plug and flanged designs. The right choice depends mainly on the tank connection, required heating capacity, available installation space, and application requirements.
Screw Plug Immersion Heater
Screw plug heaters are commonly used for smaller tanks, water containers, and process equipment with threaded openings. The heater is installed by directly screwing the threaded fitting into the tank connection, making installation and maintenance relatively simple.
They are a practical choice for compact systems and applications requiring moderate heating capacity.
Learn more about our Screw Plug Immersion Heater .
Flanged Immersion Heater
Flanged immersion heaters are designed for larger tanks, boilers, and industrial process equipment requiring higher heating capacity. Multiple heating tubes can be mounted on one flange to provide higher power output and effective heat distribution.
This design is commonly selected when the equipment has a suitable flange connection and requires higher heating capacity or multiple heating elements.
Explore our Flanged Immersion Heater solutions.
Common Sizes and Power Options
Immersion heater dimensions and power ratings depend on liquid volume, target temperature, heating speed, and installation conditions. The following ranges can be used as general references for industrial applications.
| Type | Tube Diameter | Power Range | Typical Applications |
|---|---|---|---|
| Screw Plug Heater | Φ10mm–Φ12mm | 1kW–9kW | Small tanks, water heating, process containers |
| Flanged Heater | Φ10mm–Φ14mm | 3kW–30kW+ | Storage tanks, boilers, industrial systems |
Custom lengths, voltages, wattages, terminal configurations, and sheath materials are available according to application requirements.
How to Choose the Right Immersion Heater
Before selecting an immersion heater, consider these key factors:
- Installation connection: Threaded tank openings generally suit screw plug heaters, while larger industrial tanks may use flanged designs.
- Required heating power: Power selection depends on liquid volume, target temperature, required heating time, heat loss, and operating conditions.
- Liquid compatibility: The sheath material must be compatible with the liquid. Stainless steel 304, 316L, Incoloy, titanium, or other materials may be selected depending on corrosion conditions.
- Heating environment: Consider liquid circulation, heater position, available installation space, and the risk of dry running or localized overheating.
For a detailed comparison of common sheath materials and their applications, see our Immersion Heater Materials & Sheath Selection Guide .
Water Heating Applications
Immersion heaters are widely used for boiler feed water, hot water tanks, industrial cleaning, and commercial sanitation systems. Screw plug and flanged immersion heaters provide efficient, reliable heating for tanks and process vessels where stable water temperature and dependable operation are required.
Common Industrial Applications
Immersion heaters are also used in chemical processing, food production, water treatment, oil heating, cleaning systems, and industrial liquid heating equipment.
See our Immersion Heater Applications page for more application examples and heating solutions.
Need a Custom Immersion Heater?
The best immersion heater should match the actual working conditions rather than simply use the highest available power. Tank size, liquid type, temperature, heating time, installation method, and material compatibility should all be considered before selecting a heater.
EaseWise provides customized immersion heating solutions for industrial and commercial liquid heating applications, including different power ratings, dimensions, installation methods, and sheath materials.
Amy – Sales
Email:
amy-easewise@tzheater.com
WhatsApp:
+86 188 8318 8154
Hanna – Sales
Email:
hanna-easewise@tzheater.com
WhatsApp:
+86 173 5163 6811