Immersion Heaters

Electric Immersion heaters are heating elements used to directly heat liquids found in a variety of industries from process heating, power, chemical, oil and gas, pharmaceuticals, metals processing to the food & beverage industry.

Durex Industries has over 35 years of experience in the application, design, and manufacture of robust industrial immersion heaters and process assemblies for immersion heating applications.

Industrial Immersion Heaters from Durex Industries

Our screw plug, flange, and over-the-side immersion heaters are designed to provide a quick and efficient way to reach and maintain required temperatures to prevent liquids from freezing in colder conditions, maintain production flow at a constant temperature, provide precise heat distribution, and allow fluids to transfer effectively.

Durex process immersion heaters are constructed from hairpin bent tubular heating elements brazed or welded into threaded screw plugs or flanges and typically inserted horizontally through the side of a tank or vessel directly into the fluid.

Using direct heating allows for the fluid to quickly reach the desired temperature and ensure optimized high performance results.

Contact Durex Industries for Process Immersion Heaters

We have thousands of standard designed immersions heaters for quick field replacements and convenient ordering. Durex also has extensive experience with custom designed electric immersion heaters for storage tanks, reservoirs, and circulation flow applications.

Buy screw plug immersion heater standard designs directly from our online storeQuick ship!

Buy flange immersion heater standard designs directly from our online store.

Request a quote or contact us for assistance.

----Screw Plug Immersion Heaters.jpg

Screw Plug Style Heaters

3-5 Day Lead Time on standard designed screw plug immersion heaters with general purpose or GRC style enclosures.

----Flange Immersion Heaters.jpg

Flange Style Heaters

Flanged immersion heaters are constructed of hairpin bent tubular heater elements brazed or welded into ANSI standard flanges or plate flanges of various shapes and sizes. ANSI flange heaters are typically used for large volume, high power and/or higher pressure applications.

Over The Side Immersion Heaters.jpg

Over-The-Side Style Heaters

Over-the-side immersion heaters are designed for the robust requirements of corrosive chemicals, viscous (potentially contaminated) fluids, and rinse and process water heating.

----Pipe Insert-Dry Well Heaters.jpg

Pipe Insert (Dry Well) Heaters

Screw plug and flanged immersion heaters can be used to heat a "dry well" in a tank. This provides tank heating while facilitating easy removal of the heater without draining the tank contents.

Tubular Immersion Heaters

Tubular Style Heaters

Tubular immersion heaters are commonly used in radiant and immersion heating applications such as infant incubators where a formed tubular heater warms the air flow and an immersion tubular heater assembly vaporizes water to provide humidity.

Immersion Cartridge Heaters

Immersion Cartridge Heaters

Immersion cartridge heaters are compact, high-powered liquid heating products. They are mounted into a coupling on the side of a tank or pan.

Industrial tubular immersion heating elements are used for direct liquid heating applications. They are constructed of one or more heater elements brazed or welded into various types of mounting fittings. Standard and custom engineered electric heater designs are available for tailored solutions to your thermal application requirements.

Request a quote or contact us for assistance.

Application Guidelines

The goal is to optimize the heater configuration to ensure the longest life possible while minimizing overall product and life cycle costs. The general temperature, sheath material and watt density guidelines below can aid in proper heater selection for some common liquids. Contact Durex for further assistance.

Liquid Max. Operating Temps °F (°C) pH Level and/or Concentration Recommended Sheath Material Typical Plug Material Max. Watt Density W/in2(W/cm2)
Clean, Potable Water
212 (100) Neutral (pH 6 to 8) Copper Brass 60-90 (9.5-14)
Process Water & Weak Solution 212 (100) pH 5 to 9; 2-3% Incoloy®, 304SS Steel or 304SS 48 (7.5)
Demineralized, Deionized Water 212 (100) Neutral 304SS or 316SS (passivated) 304SS or 316SS 60 (9.5)
Weak (Acidic) Solutions* 210 (100) Up to 5-6% Incoloy®, 316SS Steel 48 (7.5)
Mildly Corrosive (Acidic) Solutions* 180 (80) 5-15% Incoloy®, 316SS 304SS or 316SS 20-30 (3.5)
Severely Corrosive (Acidic) Solutions* 180 (80) >15% Incoloy®, titanium, Teflon® 304SS or other 15-16 (2.5)
Caustic Soda 10% 200 (100) pH 14; 10% Incoloy® Steel 20-23 (3.5)
Caustic Soda 50% 250 (120) pH 14; 50% Incoloy® Steel 16 (2.5)
Fuel Oil 1 & 2; Kerosene Lube Oil SAE 10 to 30 200-250 (95-120) - Steel Steel 20-23 (3.5)
Fuel Oil 4 & 5; Lube Oil SAE 40 to 50 200-250 (95-120) - Steel Steel 15-16 (2.5)
Fuel Oil 6 & Bunker C 160 (70) - Steel Steel 6-8 (1.2)
Hydraulic Oil 100 (40) - Steel Steel 15-16 (2.5)
Ethlyene Glycol 300 (150) - Steel Steel 23-30 (3.5-4.5)
Glycerine 500 (260) - Incoloy® Steel 8-10 (1.5)
Molton Salt Bath 800 (425) - Steel, 321SS, Monel® Steel 23-30 (3.5-4.5)
Paraffin Wax 150 (65) - Steel or 304SS Steel 15-16 (2.5)
Molasses 100 (40) - 304SS or 316SS 304SS 4-5 (0.7)

* Sheath material and watt density dependent on type of acid, concentration, temperature, aeration, movement, etc.

  • Please note that the user accepts full responsibility for validating that a heater is suitable for a given liquid or gas heating application.
  • Ensure that heater elements are completely covered in liquid AT ALL TIMES. Failure to do so may cause the heater elements to operate in open air and fail prematurely, or worse, lead to ignition of flammable vapor mixtures, causing serious personal injury and equipment damage. Liquid level sensors are highly recommended.
  • Durex recommends the use of a thermostat or process controller as well as a high limit sensor and FM approved safety controller to prevent unexpected over temperature conditions.

Typical Heating Applications

Pharmaceuticals, Food and Beverage Industries:

  • Batch processing
  • Brew kettles
  • Heat transfer systems and reactors
  • Milking & dairy systems
  • Ovens
  • Packaging equipment
  • Spray dryers and drying systems
  • Sterilizers
  • Transfer lines
  • Vats

Oil, Gas, Petrochem, Chemical Industries:

  • Air dryers
  • Heat transfer systems
  • Lube and pump systems
  • Process gas heating
  • Process plants
  • Reactors
  • Storage Tanks
  • Reservoirs
  • Waste Oil

Power Industry:

  • Fuel gas and fuel oil heating
  • Flue gas and ESP heating
  • Storage Tanks
  • Reservoirs
  • Water wash systems

Primary and Secondary Metals Processing:

  • Autoclaves
  • Heat transfer systems
  • Heat treat baths
  • Primary and secondary metals furnaces

Request a quote or contact us for assistance.

Manufacturing Capabilities

  • Quick ship on standard immersion heater designs
  • Standard and custom designed immersion heaters
  • C-UL heating element component recognition available
  • ASME Section VIII Div 1 manufacturer with “R” stamp capability
  • CSA hazloc certified terminal enclosures available

Considerations When Selecting a Type of Immersion Heater

Choosing the right type of immersion heater for your application is important. The goal is to optimize the heater configuration to ensure the longest life possible while minimizing overall product and life cycle costs.

Durex Industries’ team of engineers will assist you in providing the best and most efficient heating solution required for you application.

Consider the below factors when ordering your immersion heater:

  • Hazardous location installation
  • Voltage rating, phase and kW power rating
  • Available Amps at site of installation
  • Time required to reach desirable temperature setting
  • Temperature control and sensing scheme
  • Quantity of liquid being heated and if flowing or mixing
  • Viscosity and thermal conductivity of the fluid
  • Corrosive nature of the fluid
  • Tank or heating vessel insulation thickness and type
  • Space limitations for installation or heater removal
  • Outdoor or indoor installation
  • Ambient environment operating conditions

Request Info