Caldor Engineers and Manufactures Tubular Heating Elements in Any Required Shape

Caldor tubular heating elements are designed for reliable operation in a wide range of liquids, gases, and solid materials. Proper selection of watt density, sheath material, and tube diameter is essential to ensure long service life, corrosion resistance, and thermal stability.

• Stagnant water: 8–12 W/cm² · Copper, AISI 321, AISI 316L
• Circulating water: 10–16 W/cm² · Copper, AISI 316L, Incoloy® 800 / 825
• Boric water: up to 8 W/cm² · AISI 316L
• Boiler water: 8–16 W/cm² · AISI 316L, Incoloy® 800 / 825
• Chlorinated water: up to 6 W/cm² · Incoloy® 825
• Sea water: 3.5–6 W/cm² · Incoloy® 825, Inconel® 600
• Demineralized / deionized / distilled water: 4–6 W/cm² · AISI 316L, Incoloy® 800 / 825
• Domestic hot water: 4–8 W/cm² · Copper, AISI 316L, Incoloy® 825
• Caustic water (2%–70%): 2.3–7 W/cm² · AISI 316L, Incoloy® 825, Inconel® 600

• Fuel oil pre-heating / light fuel oil: 1–2 W/cm² · AISI 321, AISI 316L
• Heavy fuel oil: 0.5–3.5 W/cm² (depending on grade) · AISI 316L
• Gasoline / kerosene: 3.0–3.5 W/cm² · AISI 316L
• Machine oils (SAE 10–50): 2.0–3.5 W/cm² · AISI 316L
• Mineral oils: 0.5–3.5 W/cm² · AISI 321, AISI 316L
• Lubricating oils: up to 2.3 W/cm² · AISI 321, AISI 316L

• Acetic acid: up to 6 W/cm² · AISI 316L, Incoloy® 825
• Boric acid: up to 6 W/cm² · Incoloy® 825
• Chloric, hydrofluoric, nitric, sulphuric acids: up to 1.5 W/cm² · PTFE-coated sheath
• Alkaline baths: up to 6 W/cm² · AISI 321 (non-corrosive), AISI 316L
• Phosphate baths: up to 4 W/cm² · AISI 316L, Incoloy® 825

• Ethylene / propylene glycol: 4–8 W/cm² (depending on concentration) · AISI 321, AISI 316L

• Air (static or circulating): 0.1–8 W/cm² · AISI 321 / AISI 309
• Natural gas: 0.1–8 W/cm² · AISI 321, AISI 316L
• Argon / nitrogen: Load depends on sheath temperature · AISI 321, 316L, Incoloy® 825, Inconel® 600
• Propane / butane: Load depends on sheath temperature · AISI 321, AISI 316L
• Oxygen / hydrogen: Load depends on sheath temperature · AISI 316L

• Aluminium, brass, bronze (cast-in): 4–15 W/cm² · AISI 309
• Copper-nickel cast-in: 5–10 W/cm² · AISI 309
• Oxychlorination: up to 3 W/cm² · Incoloy® 800 / 825
• Calcination processes: up to 3 W/cm² · Incoloy® 800 / 825
• Hydrocarbon regeneration: up to 2 W/cm² · Incoloy® 800 / 825

Watt density, tube diameter, and sheath material are selected to optimize reliability, corrosion resistance, and temperature performance.

• Tube diameters: 6.5 / 8.5 / 10 / 13.5 / 16 mm
• Sheath materials: AISI 321, AISI 316L, AISI 309, Incoloy® 800 / 825, Inconel® 600, Titanium
• Optional coatings: PTFE (Teflon™), Halar
• Tube types: Sealed tube (standard), seamless tube (on request)

• Maximum voltage: Ø6.5 → 400 V · Ø8.5 → 415 V · Ø10 → 500 V · Ø13.5 → 690 V · Ø16 → 750 V
• Resistance tolerance: −5% / +10%
• Power tolerance: <100 W: ±10% · >100 W: +5% / −10%

• Sheaths: Rolled, welded, or seamless tubes manufactured to ASTM / DIN standards
• Forming: Straight or custom-bent geometries according to specifications
• Diameter tolerance: ±0.1 mm
• Length tolerance: ±1% (minimum +5 mm)

Selecting the correct watt density and sheath material according to the heated medium is essential to prevent overheating, corrosion, and premature failure. Caldor engineering support ensures each tubular heating element is optimized for safe, reliable, and long-term operation.

Caldor tubular heating elements are designed for heating liquids, gases, and solid materials. They are used in process equipment where reliable heat transfer is required, including tanks, vessels, pipelines, air heating systems, tooling, and custom industrial machinery.

Tubular heating elements consist of a metallic sheath with a resistive coil embedded in MgO insulation. This construction provides efficient thermal conductivity, dielectric strength, and long-term mechanical stability.

• Engineered coil layout for uniform or application-specific heat distribution
• Optimized watt density selection based on the heated medium and heat dissipation
• Consistent thermal output for continuous-duty industrial operation

• Cold ends can be designed as short, medium, or long according to installation constraints
• Supports safer terminal temperatures and improved connection durability
• Helps protect seals and terminals in high-temperature zones

Sheath material selection is defined by the working medium, corrosion risk, and admissible temperatures. Typical options include stainless steels and high-temperature / corrosion-resistant alloys, as well as special materials for aggressive environments.

• Stainless steels: balanced performance for general industrial environments
• High-temperature alloys: improved oxidation and residue resistance at elevated temperatures
• Corrosion-focused materials: optimized for chemical media and demanding applications

• Voltage and wattage tailored to the application
• Stable dielectric strength enabled by MgO insulation
• Power tolerance and electrical safety checks defined by the selected class and project requirements

• Robust sheath for mechanical durability in industrial environments
• Design support for vibration, thermal cycling, and continuous-duty operation
• Custom lengths, diameters, and mounting interfaces available

• Multiple terminal types available (threaded studs, fast-on tabs, lead wires, ceramic heads)
• Connection materials and insulation selected according to temperature and environment
• Custom terminal configurations available for OEM integration

Caldor can bend tubular heating elements to match required geometries, including complex shapes. Bending is engineered to preserve electrical integrity, heat distribution, and mechanical strength.

• U-shapes, hairpins, coils, multi-bends, and custom contours
• Geometry defined according to installation space and heat transfer requirements
• Design support available based on drawings or application sketches

• Mounting and fixing accessories (depending on application)
• Sealing systems to reduce moisture and contaminant ingress
• Protection components for terminals and connection areas

Certification and documentation can be prepared according to project scope. For hazardous environments, ATEX-related configurations may be offered depending on the application requirements.

• Electrical safety testing (dielectric strength and insulation checks)
• Dimensional verification according to project tolerances
• Power and resistance validation based on design specifications

For custom products, test parameters are defined during engineering to match the application and required compliance.

• Various dimensions (Ø / length) and custom geometries
• Voltage and wattage variations
• Cold zones and application-specific power distribution
• Multiple terminal and lead configurations
• Material and sealing selection according to the working medium

Caldor tubular heating elements are supplied to industrial customers where reliability and quality are essential. As a critical “engine” of the final equipment or process, our heaters are engineered for dependable operation and long service life.

Caldor tubular heating elements are designed for heating liquids, gases, and solid materials. They are used in process equipment where reliable heat transfer is required, including tanks, vessels, pipelines, air heating systems, tooling, and custom industrial machinery.

Tubular heating elements consist of a metallic sheath with a resistive coil embedded in MgO insulation. This construction provides efficient thermal conductivity, dielectric strength, and long-term mechanical stability.

• Engineered coil layout for uniform or application-specific heat distribution
• Optimized watt density selection based on the heated medium and heat dissipation
• Consistent thermal output for continuous-duty industrial operation

• Cold ends can be designed as short, medium, or long according to installation constraints
• Supports safer terminal temperatures and improved connection durability
• Helps protect seals and terminals in high-temperature zones

Sheath material selection is defined by the working medium, corrosion risk, and admissible temperatures. Typical options include stainless steels and high-temperature / corrosion-resistant alloys, as well as special materials for aggressive environments.

• Stainless steels: balanced performance for general industrial environments
• High-temperature alloys: improved oxidation and residue resistance at elevated temperatures
• Corrosion-focused materials: optimized for chemical media and demanding applications

• Voltage and wattage tailored to the application
• Stable dielectric strength enabled by MgO insulation
• Power tolerance and electrical safety checks defined by the selected class and project requirements

• Robust sheath for mechanical durability in industrial environments
• Design support for vibration, thermal cycling, and continuous-duty operation
• Custom lengths, diameters, and mounting interfaces available

• Multiple terminal types available (threaded studs, fast-on tabs, lead wires, ceramic heads)
• Connection materials and insulation selected according to temperature and environment
• Custom terminal configurations available for OEM integration

Caldor can bend tubular heating elements to match required geometries, including complex shapes. Bending is engineered to preserve electrical integrity, heat distribution, and mechanical strength.

• U-shapes, hairpins, coils, multi-bends, and custom contours
• Geometry defined according to installation space and heat transfer requirements
• Design support available based on drawings or application sketches

• Mounting and fixing accessories (depending on application)
• Sealing systems to reduce moisture and contaminant ingress
• Protection components for terminals and connection areas

Certification and documentation can be prepared according to project scope. For hazardous environments, ATEX-related configurations may be offered depending on the application requirements.

• Electrical safety testing (dielectric strength and insulation checks)
• Dimensional verification according to project tolerances
• Power and resistance validation based on design specifications

For custom products, test parameters are defined during engineering to match the application and required compliance.

• Various dimensions (Ø / length) and custom geometries
• Voltage and wattage variations
• Cold zones and application-specific power distribution
• Multiple terminal and lead configurations
• Material and sealing selection according to the working medium

Caldor tubular heating elements are supplied to industrial customers where reliability and quality are essential. As a critical “engine” of the final equipment or process, our heaters are engineered for dependable operation and long service life.

Caldor provides multiple terminal styles to match installation constraints, service requirements, and temperature limits. Typical terminal families include:

• Flat terminals for compact electrical connections
• Threaded terminals for robust mechanical retention and serviceability
• Screw-type terminals for simple wiring and maintenance
• Pin terminals for defined connector-style interfaces
• Steatite / ceramic terminals for demanding temperature and insulation requirements

“●” indicates standard compatibility. If you require a non-standard combination, contact our engineering team.

• r = minimum bending radius
• The heated section must never start within the bending radius.
• The start of the heated zone must be located at least 15 mm before or after the bend.
• The minimum bending diameter depends on sheath material and diameter.

If you provide a drawing (2D/3D) or a bending sketch, Caldor can confirm feasibility and recommend the most reliable geometry.

• CE compliance for the European market (as applicable to the scope of supply)
• ATEX / IECEx certification for component or system (project-dependent)
• EAC (CU TR) and cCSAus (NEC 505) where required by the project

Certification scope depends on the complete assembly and installation conditions. For ATEX/IECEx projects, please share zone classification, temperature class / max surface temperature, medium, and control concept.

Electrical tests

• Power verification by cold resistance measurement (allowed tolerance: −5% to +10% of nominal value)
• Insulation test: DC 500 V, minimum cold value > 100 MΩ
• Dielectric test: (2U + 1000 V) × 1.2 for 1 second
• Stray current and hot dielectric strength can be measured on a sample at operating temperature (on request)
• 100% of heating elements are tested before shipment

Mechanical & dimensional checks

• Visual inspection
• X-ray test (if required)
• Verification of critical dimensions

• Customer-specific marking on each heating element
• Project-specific connection terminals (on request)
• Fixing parts such as connectors (on request)

Caldor supplies custom-bent tubular heating elements to industrial customers where reliability and quality are mandatory. As a critical “engine” within process equipment, our heaters are engineered for dependable operation, stable performance, and long service life.