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Industrial Flange Immersion Heater Manufacturer | Custom Electric Heating Solutions
ELEKHEAT manufactures custom flange immersion heaters for oil tanks, water treatment, chemical processing and industrial heating systems. ANSI, DIN, JIS flange designs with SS316L and Incoloy materials.
- ANSI Flanges 2"-24"
- Incoloy & SS316L Sheath
- 480V/600V 3-Phase
What Is a Flange Immersion Heater?
A flange immersion heater is an industrial electric heating device designed for direct installation into tanks, vessels, and process equipment. It consists of multiple tubular heating elements welded onto a flange plate, allowing direct heat transfer into liquids or process fluids.
Available with ANSI, DIN, or JIS flange designs, flange immersion heaters can be customized with different power ratings, voltages, flange sizes, and sheath materials such as stainless steel 304/316L and Incoloy.
With high heating capacity, compact structure, and easy installation and replacement, flange immersion heaters are widely used for heating water, oil, chemicals, and other industrial process fluids.
Flange Heater Engineering Calculator
Calculate required power, watt density, and amperage for your immersion heating application.
Classification by Heating Medium
This is the most critical classification, as the medium determines the watt density ($W/cm^2$) and the sheath material of the heating elements.
Water Heating Flange Heaters
- Characteristics: High watt density (typically 6-10 W/cm^2).
- Materials: Usually Stainless Steel 304 or 316L.
- Applications: Industrial boilers, cleaning systems, water storage tanks.
Oil Heating Flange Heaters
- Characteristics: Extremely low watt density (usually 1-2.5 W/cm^2) to prevent oil carbonization caused by localized overheating.
- Materials: Carbon Steel or Stainless Steel.
- Applications: Thermal oil furnaces, hydraulic oil heating, lubricant preheating.
Corrosive Chemical Heating
- Characteristics: High resistance to chemical attack.
- Materials: Incoloy 800/840, Titanium, or PTFE (Teflon) coatings.
- Applications: Electroplating baths, phosphating tanks, strong acid/alkali heating.
Classification by Protection Rating
This relates directly to the design of the Terminal Box, a key focus for engineers during technical reviews.
General Purpose
NEMA 1 rated, suitable for standard indoor industrial environments.
Moisture/Weather Resistant
NEMA 4/4X rated, featuring gaskets to prevent rain or spray from entering the housing.
Explosion-Proof
NEMA 7 rated. These feature heavy-duty, flame-proof enclosures designed to contain internal sparks and prevent the ignition of external flammable gases.
Flange Immersion Heater Construction
A flange immersion heater consists of five main components: flange mounting assembly, tubular heating elements, electrical enclosure, temperature monitoring system, and safety protection devices.
Terminal Enclosure
Protects electrical connections and power terminals.
- IP54/IP65 waterproof enclosure
- Explosion-proof option available
- Terminal blocks and grounding connection
Flange Plate
Mounting and sealing base connecting the heater to tanks and vessels.
- Carbon steel, SS304/316L, titanium options
- ANSI, DIN, JIS flange standards
- Provides mechanical fixing and sealing
U-Type Tubular Heating Elements
Core heating component transferring heat directly into process fluids.
- NiCr or FeCrAl resistance wire
- High purity MgO insulation
- SS304/316L or Incoloy sheath
Temperature Sensor
Provides accurate temperature monitoring and control.
- Thermocouple or PT100 sensor
- PID temperature control integration
Safety Protection System
Additional protection for reliable operation.
- Over-temperature protection
- Low liquid level protection
- Dry-run protection
Technical Specifications
Voltage & Power
- Voltage Range: 120V – 690V AC (Customizable)
- Power Range: 3kW – 1500kW (Customizable)
Engineering Support: Need help calculating power requirements? [View Power Selection & Calculation Guide]
Heating Medium & Temperature Limits
| Medium Type | Application Detail | Max Temperature |
|---|---|---|
| Gas / Air | Normal Air / Inert Gas | Low-Mid: ≤350°C | High: Up to 600°C |
| Special Atmospheres | Customized based on flow rate | |
| Liquid | Water / Cleaning Systems | ≤100°C |
| Thermal Oil / Lubricants | ≤350°C | |
| Corrosive | Acids, Alkalis, Chemical Baths | Low-Temp: ≤60°C | Mid-High: ≤100°C |
Dimensions & Mounting Standards
Flange immersion heaters are typically designed with ANSI, DIN, or JIS flange connections. For smaller tanks or limited installation spaces, screw plug and tri-clamp immersion heaters are alternative configurations.
- Tube Diameters: φ8mm, φ10mm, φ12mm, φ14mm, φ16mm, φ18mm, φ20mm
- Flange Standards (Flat): ANSI, DIN, JIS (DN25 to DN150+)
- Screw Plug Immersion Heater Sizes: 1″, 1.5″, 2″ (NPT/BSP)
- Tri-Clamp Immersion Heater Sizes: 1.5″, 2″, 2.5″
- Custom Features: Cold zone length, lead wire length, thermowells, insulation layers.
Accessories & Options
Common Structural Types of Flange Heaters
Standard Flanged Structure
- The heater is mounted to the equipment using a bolted flange connection
- Most widely used industrial configuration
- Suitable for high temperature and high pressure applications
Key features: Stable, universal, widely applicable
Threaded (Screw-In Flange) Structure
- Installed by directly screwing into a threaded opening (e.g., G thread / NPT)
- Compact design suitable for small to medium power systems
Key features: Easy installation, low cost, flexible usage
Quick-Release Clamp Structure (Sanitary Type)
- Uses tri-clamp or similar sanitary quick-connection system
- Designed for fast installation and removal
- Common in hygienic processing systems
Key features: Fast maintenance, easy cleaning, high hygiene level
Explosion-Proof Flange Structure
- Equipped with explosion-proof terminal housing and reinforced sealing
- Complies with Ex-rated safety standards (e.g., Ex d / Ex e)
Key features: High safety level, suitable for hazardous environments
Removable / Maintainable Structure
- Heating elements and flange are designed for partial disassembly
- Individual heating tubes can be replaced without replacing the whole unit
Key features: Easy maintenance, lower repair cost, reduced downtime
How to Select a Flange Immersion Heater?
Selecting the correct flange immersion heater requires evaluating the heating medium, required power, flange specification, material compatibility, electrical requirements, and safety protection.
Heating Medium
Select sheath material according to the heating medium.
- Water: SS304 / SS316L
- Oil: SS316L / Incoloy 800
- Corrosive chemicals: Titanium or special alloys
Heating Power
Calculate required kW based on liquid volume, temperature rise and heating time.
- Tank heating: P = m × Cp × ΔT / time
- Safety factor: normally 1.2–1.3
Flange Specification
Confirm flange size, pressure rating and installation standard.
- DN80 / DN100 / DN125 / DN150
- ANSI, DIN, JIS standards
- PN10 / PN16 / higher pressure options
Sheath Material & Watt Density
Choose suitable material and surface load to improve heater life.
- Water: 1.0–1.5 W/cm²
- Oil: 0.8–1.5 W/cm²
- Air: 0.5–1.0 W/cm²
Electrical Parameters
Select voltage and connection according to power requirements.
- 220V / 380V / 400V / 480V
- Single phase or three phase
- Star or Delta connection
Protection Requirements
Select suitable protection according to operating environment.
- IP65 waterproof enclosure
- Explosion-proof ATEX / IECEx options
- Temperature and liquid level protection
Quick Selection Guide
| Application | Recommended Configuration |
|---|---|
| Water Tank Heating | SS304/316L tube + IP65 enclosure + liquid level protection |
| Thermal Oil Heating | Incoloy 800 sheath + low watt density design |
| Chemical Heating | SS316L / Titanium / special alloy materials |
| Hazardous Area | Explosion-proof enclosure + ATEX/IECEx certification |
Example: Electric Heating Element Selection for a Water Tank
Project Requirement:Heat an open water tank (3 × 3 × 2 meters) from 20°C to 80°C within 3 hours.
1. First, determine the total power:
Heating 18 tons of water from room temperature (20℃) to 80℃ within 3 hours.
Specific heat capacity of water at room temperature: 4.2 kJ/(kg·℃)
Temperature difference: 80 – 20 = 60℃
Substituting into the formula, the theoretical thermal power is calculated as: 18000 * 60 * 4.2 / 3600 / 3 ≈ 420 kW
Considering the thermal efficiency in actual use, a coefficient of 0.8-0.9 is generally used, resulting in an approximate power of 470-520 kW.
2. Determine Heater Structure and Installation Method
1) For power ranges of 470-520KW, a flange-type electric heating element structure with concentrated power is suitable.
2) Flange-type electric heating elements are commonly used in water tanks for both horizontal side mounting and vertical mounting. The dimensions of the heating element will vary depending on the installation method.
3. Determine the dimensions, material, and power of the electric heating element:
1) Dimensions:
- Tank size: 3 × 3 × 2 meters
- For horizontal installation, the element length must be < 3 meters
→ Recommended length: 2.5–2.7 meters
2) Material Selection:
- Clean water / purified water / softened water → SUS304 stainless steel
- Groundwater / wastewater / sewage → SUS316L stainless steel
3) Power per Element:
Based on size and medium, select an appropriate power rating.
→ Example: 75 kW per flange heater
4. Determine the number and arrangement of electric heating elements
1) Based on the total power (470-520KW) and the power of a single electric heating element (75KW), 6-7 electric heating elements are required.
2) The above installation method is a side-mounted horizontal installation; therefore, 6-7 electric heating elements can be evenly or crosswise distributed on all four sides of the enclosure.
Installation Example
Size confirmation
Before purchasing, confirm whether the flange size, the center distance of themounting holes and the pipe length from the flange to the bottom are appropriate.
For the first installation, you need to purchase the matching flange
For top-mounted installation, pay attention to the length of the cold zone to avoid local hightemperature that may burn the heating tube
Flange Immersion Heater Applications
Flange immersion heaters are widely used for heating liquids and process fluids in industrial tanks, vessels, and heating systems. Customized solutions are available for different temperatures, materials, and operating conditions.
Water & Process Heating
Flange immersion heaters are widely installed in industrial water tanks, boiler systems, and process heating equipment.
- Industrial hot water tanks
- Boiler feed water heating
- Cleaning systems
- Water treatment equipment
Material Selection & Application Guide
Selecting the right sheath and flange material is critical for the longevity of your heating element. Our engineering team recommends the following configurations:
| Heating Medium | Sheath Material | Flange Material | Recommended Watt Density (W/cm2) |
| Clean Water / Process Water | SS304 / Copper | Carbon Steel | 8 – 10 |
| Deionized / Demineralized Water | SS316L / Incoloy 800 | SS316L | 6 – 8 |
| Light Fuel Oil / Lube Oil | Steel / SS304 | Carbon Steel | 2 – 3 |
| Heavy / Crude Oil | Steel / SS304 | Carbon Steel | 1 – 1.5 |
| Corrosive Chemicals / Acids | Titanium / PTFE Coating | SS316L | 2 – 4 |
| Food Equipment / Sanitary | SS316L (Passivated) | SS316L | 4 – 6 |
Explosion-Proof Option
Explosion-proof flange heaters are designed for hazardous areas with flammable gases or dust.
Explosion-proof enclosure: Ex d / Ex e
Hazardous area: Zone 1 / Zone 2
Temperature class: T3 / T4 / T5
Compliant with ATEX / IECEx standards
Support non-standard customization
It can be customized according to customer requirements and drawings, and we can also provide customers with thoughtful solutions
Why Engineers Choose Elekheat
Built for Performance. Verified for Safety.
Corrosion Resistance
We use premium Incoloy 800/840 and SS316L seamless tubing to withstand harsh chemical environments and high-temperature oxidation.
Precision TIG Welding
Designed for integration with industrial tanks and pressure vessels according to customer pressure requirements.
Safety Compliance
Available with NEMA 4 (Moisture) and NEMA 7 (Explosion Proof) terminal housings for hazardous locations (Class I, Div 1).
Quality & Manufacturing Capability
Certified manufacturing, strict quality control, and proven export experience for explosion-proof flange heaters used in hazardous industrial environments.
Factory & Workshop
Our flange heaters are manufactured in a dedicated industrial facility with specialized workshops for heating element fabrication, welding, assembly, and explosion-proof enclosure installation.
Production Process
Quality Control & Testing
100% routine testing before shipment
Incoming Material Control
All incoming materials are inspected and verified to ensure compliance with technical specifications and certification requirements.
In-Process Quality Control
- Welding inspection
- Dimensional and assembly checks
- Electrical wiring verification
Final Testing
| Test Item | Description |
|---|---|
| Insulation Resistance Test | Ensure electrical safety |
| Dielectric Strength Test | High-voltage withstand test |
| Power & Performance Test | Rated power verification |
| Temperature Control Test | Safety temperature limitation |
| Explosion-Proof Inspection | For ATEX / IECEx models |
Compliance & Certification
Stop Production Downtime Caused by Heater Failure
In heavy-duty industrial applications, generic off-the-shelf heaters often fail due to improper watt density or material incompatibility. This leads to carbonization in oil tanks or rapid scaling in water systems.
Elekheat’s Flanged Immersion Heaters are built differently. We calculate specific watt density (W/cm²) based on your exact medium viscosity. Whether you need a replacement for a boiler or a custom solution for a petrochemical tank, our heaters are engineered to last.
Frequently Asked Questions (FAQ)
Price depends on power, material, and customization. Send your requirements for a quotation.
Standard models: 7–15 days
Custom models: 15–30 days
Yes, we provide engineering drawings for approval.
Oil & gas, chemical, water treatment, marine, and industrial manufacturing.
Yes, full OEM/ODM service is available.
At ELEKHEAT, we’re here to provide the answers you need. Whether you’re looking for product information, technical specifications, or need assistance with maintenance, our team of experts is ready to help. Don’t hesitate to reach out—we’re committed to ensuring you get the support you need for the best heating solutions.
