parallax background

Cast-in heaters

Electrical cast-in heaters are designed for heating solids or indirect heating

The cast-in heating plates and heating bands consist of one or several electrical resistances embedded in a block of aluminum, brass, bronze or cupronickel alloy providing excellent thermal conductivity.

Cast-in heating elements are ideal for applications requiring homogeneous indirect heat.

Cast-in heaters are often used in plastics industry, packaging industry, food industry and many others.

Usual applications:  heating plates for presses, extruder dies and sheaths, heating plates for homogeneous heating (rubber, aerated concrete curing), sealing on packaging lines, mills.

Product overview

  • Indirect heating
  • Block of aluminum, brass, bronze or cupronickel alloy
  • Process temperature up to +400°C (aluminium), +650 °C (cupronickel). Maximum +750°C
  • Max Watt density 20 w/cm² on the heating element
  • Maximum weight: aluminium 400kg / cupronikel 300kg
  • Can be equipped with cooling circuits to optimize the industrial process


  • Gravity moulding ensures an excellent material homogeneity and thus a perfect heat transfer.
  • Constant surface temperature is achieved through appropriate forming.
  • As this is indirect heating, the heating resistance is protected. The solid or fluid to be heated is not in contact with the resistance.
  • High protection against corrosion
  • The end-to-end control of the design and production chain allows us to deliver a product which suits your process perfectly
  • Resistance in severe industrial surroundings (impacts, vibration)

Operating conditions

  • Normal (non-ATEX)
  • Hazardous areas (ATEX/IECEx) and NEC 505
  • Extreme environments: – 60°C to + 80 °C
  • Onshore / Offshore environment
  • Salt atmosphere


  • Aluminium, brass, Bronze cast in, max load 4 – 15W/cm², material: 309
  • Copper-nickel cast in, max load 5 – 10W/cm², material: 309

Technical description

The Watt density, tube diameter and the tube sheath are chosen to optimize the reliability and robustness (corrosion, temperature) of CETAL equipments.


  • Tubular heating element (most fo the cases)
  • Heating rods into sleeve

Tube diameter & material

  • Tube diameter: 6.5 / 8.5 / 10 / 13.5 / 16 mm
  • Tube material: Stainless steel AISI 321 (1.4541) / AISI 316L (1.4404) / AISI 309 (1.4828)
  • Tube type: sealed tube, seamless tube (on request)


  • 100% of the components come from our high-quality suppliers from Europe
  • 100% manufacture within CETAL factory

  1. Connection terminals
  2. Tube
  3. Insulation : magnesia oxyde (Mg O), to secure optimized heat transfer and electrical insulation.
  4. Resistance wire: Made of Nickel Chrome 80/20, it is the active part of the heating element (Joule effect)
  5. Cold length
  6. Sealing material: Keeps out external moisture. Different types (silicon, resins, cement) are used depending on the industrialapplication, the external medium and temperature.
  7. Output insulation: Made of steatite ou corundum, it provides dielectric insulation (creepage distance, distance in the air).
  • Heating elements can be fixed on a screw or flange or simply fixed to mechanical structure such as for cast-in plate as illustrated.
  • Aluminium : Up to temperatures of 400 °C, the most widely used alloy.
  • Brass (600°C), bronze (650°C) or cupronickel (650°C – 750°C) for higher temperatures or in case of mechanical stress.
  • Heating elements can be fixed on a screw or flange or simply fixed to mechanical structure such as for cast in plate as illustrated.
  • The elements can be supplied without enclosure for cabling on the customer’s premises.


  • Non ATEX connecting box
    • IP 54 / IP 66 / IP 67
    • Material: painted steel, stainless steel, aluminium
    • Polyamide or nickel-plated
  • ATEX/IECEx connecting box
    • Explosion-proof connecting box, aluminium, stainless steel or painted steel, Ex d IIC
    • Stainless steel increased security enclosure,Ex e IIC
    • Nickel-plated brass cable gland (stainless steel as option)
  • Fluid temperature <110°C, no offset
  • Fluid temperature >110°C, offset between the protecting box and the tank is recommended
  • Temperature sensors (thermostat, limiter, thermocouple or PT100) in the alloy block (process control) or on the heating elements (safety control).
  • Voltage: VAC or VCC
  • Cabling according to main voltage VAC/VCC 1PH + N or 3PH
  • Power : a few Watt to several Megawatts
  • Standard documentation
    • Certificate of conformity to the order
    • Heater wiring diagram
    • Instruction manual
  • On-request documentation
    • Supplied according to directives, standard and construction code
    • Welder qualifications (QS)
    • Welding qualifications (QMOS)
    • PED documentation
    • Material certificate 3.1 according to NF EN 10204
  • The heating assemblies are machined according to technical drawings and take into account tolerance values and surface finishing requirements.
  • Manufactured according to specifications in small or medium-sized production runs.

  • According to CE European directives and CE market (for Europe)
  • ATEX/IECEx certificate for component or system
  • EAC CU TR, c CSA us (NEC 505)

Electrical tests

  • Power test by cold resistance measurement. Allowed tolerance: -5% and +10% of the nominal resistance value.
  • Insulationtest, direct voltage 500 V, mini cold value is > 100 Megohms
  • Dielectric test, (2U + 1000 V)  x 1,2 during 1 second
  • The stray current and the hot dielectric rigidity can be measured on a sample at operating temperature (on request).
  • 100% of the heating elements are tested before shipment (Final control)

Mechanical tests

  • Visual inspection
  • X-ray test (if required)
  • Liquid penetrant test
  • Pressure control test

Dimensional test

  • Critical dimension are tested

Other tests / operations

  • Degreasing
  • Argon cleaning

Third party

  • Third party inspection (on request)
  • Temperature control : Temperature sensors (thermostat, limiter, thermocouple or PT100) in the medium (process control) or on the heating element (safety control), on the flange or in the connecting box.
  • Separate connecting box for temperature control out of the power connecting box
  • Stainless steel material for ATEX/IECEx cable gland
  • Space heaters against moisture inside the connecting box
  • Coating for the connecting box customized specifications and colors
  • Tropicalization: Adapted materials and components, heat-shrink insulated terminals, for extreme atmospheres (moisture, temperature)
  • Insulation: according to design if needed




Standard power control panels

CETAL offers a large range of cost-effective power control panels.

Injection / extrusion applications


In addition to heater design, the use of specifically developed connection boxes allows to install the products in hazardous areas.

The increased safety protection mode “e” (EN60079-7) or the explosion-proof protection mode “d” (EN 60079-1), together with temperature control acc. to EN 60079-0, make it possible to operate the equipments in hazardous area (zone 1 and zone 2) for gases of the A-B-C groups.

Type of protection “d” explosion-proof housing

With this method, the housing (casing):

  • Must contain the explosion within the enclosure
  • Make sure that the ignition cannot reach the hazardous area
  • Always keep an external temperature lower than the auto-ignition temperature of any surrounding

The following factors are selected depending on the internal free volume of the enclosure and the gas present in the area.

  • Type of seal (cylindrical, flat, threaded)
  • Seal length
  • Gap length

The power and temperature control circuits can be accommodated in separate housings

Type of protection “e” increased safety

Method: To prevent the occurrence of any accidental ignition source (electric arcs, heating).

This mode of protection is achieved by:

  • Selecting high-quality insulating material
  • Defining the right creepage distances
  • Ensuring the quality of electrical connection
  • For all classes of gases and vapours
  • Suitable for connection housings