Durex Industries has over 30 years of experience in the application, design, and manufacturer of robust industrial tubular immersion (submersible) heaters and process assemblies. We have thousands of immersion heater standard designs 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.
Industrial immersion heaters are used for direct liquid immersion 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 immersion heater designs are available for tailored solutions to your thermal application requirements.
- Shop Online for standard designed Screw Plug Heaters. 2" & 2 1/2" NOW WITH 5 DAY LEADTIME. Flanged Immersion heaters also available.
immersion heater types
typical immersion heater applications
Pharmaceuticals, Food and Beverage Industries:
- Batch processing
- Brew kettles
- Heat transfer systems and reactors
- Milking & dairy systems
- Packaging equipment
- Spray dryers and drying systems
- Transfer lines
Oil, Gas, Petrochem, Chemical Industries:
- Air dryers
- Heat transfer systems
- Lube and pump systems
- Process gas heating
- Process plants
- Storage Tanks
- Fuel gas and fuel oil heating
- Flue gas and ESP heating
- Storage Tanks
- Water wash systems
Primary and Secondary Metals Processing:
- Heat transfer systems
- Heat treat baths
- Primary and secondary metals furnaces
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.
DOWNLOADS related to immersion heaters
Process Heater Brochure - 7MB (PDF)
Standard Screw Plug Immersion Heater Designs - 520KB (PDF)
ASME Section VIII Division 1 Certificate - 50KB (PDF)
National Board "R" Stamp Repair Certificate - 99KB (PDF)