Fast adjustment and removal system.

The expandable cartridge Heaters solve two major problems with conventional high density heaters , poor durability and proper fit extraction improving the accuracy of the temperature with hundreds of attachments and exits for all kind of processes .

With the expandable cartridge heaters we join for the first time the best of the common cartridge heater with cartridge and an adaptive tuning quick and easy removal.


Self-expanding cartridge heater

Longer life
Easy removal
More compact terminations.
Longer length without arching.
More drilling tolerance.
Without cold areas
Hundreds of finishes and terminations.

Working system

The expandable cartridge consists of a high performance compressed cartridge with the highest quality materials, with the particularity of being able to expand on its own, thanks to the fork shape tensioned at a point that allows the expansion and retraction of the cartridge.

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In the dilatation process the expandable cartridge adjusts to the walls of its housing, facilitating the correct transmission of the temperature and avoiding the oven effect, which occurs in other types of cartridge poorly sized with respect to diameter and housing. The bores, which due to circumstances are oversized with the expandable cartridges have the best solution by allowing more adjustment tolerance.
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In the process of contraction the expandable cartridge returns to its initial state facilitating its easy removal from the hole, with the consequent advantages such as: no need to re-drill the mold, no need to destroy the cartridge, easy cleaning of the mold, reuse of the cartridge in other locations, reduction of stock by having the same diameter for different holes, etc.

The purity of materials

Expan cartridges are manufactured through an internal compacting process of all their components, in order to increase their useful life. The N'quel/Cromo 80/20 conductor wire is introduced in the cavities of a ceramic body that centers it, obtaining the ideal separation for a better insulation. All coated with high purity magnesium oxide and controlled granulometry to ensure the complete filling of the Expan cartridge. Later, the surface is compacted and rectified until it is calibrated to the desired size. Finally, it undergoes a rigorous quality control that guarantees the best performance of the cartridge. We do not use these 4 types of materials: Tantalum, Tin, Gold and Tungsten.

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  1. Heating wire Nickel/Chromium 80/20 melting point 1400ºC
  2. Pure magnesium oxide of controlled granulometry
  3. Refractory hard dough
  4. Conductor cable
  5. Stainless steel AISI 304/316/321/ INCOLOY
  6. Ceramic core
  7. Hard ceramic head
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The installations and the unique construction system guarantee maximum purity inside the plant, ensuring a longer service life.

Hundreds of terminations

acabados especiales
All possible terminations for all the applications you require: submersible, anti-vibration, high temperature, special power supply, saline or corrosive environments, compensated, etc.

The best complement: thermocouples

The cartridges can be built with a probe incorporated at any point of the cartridge at the customer's request. The advantages of incorporating probes are innumerable, for example: extends the life of the cartridge considerably, localized temperature accuracy, energy saving, adaptable to where a conventional probe cannot be housed due to space problems.

Technical Data

Voltage (V) 120 - 130 - 240 - 380 - 400
Power tolerance (w)* + 5 % - 10 %
Power Depending on dimensions
Lenght tolerance ± 3% maximum 20mm
Standard diameter tolerance -0.10 to -0.15 mm
Leakage current <=0.5mA to 253 v.
Aislamiento* >=5 MΩ to 500 V
High-voltage cartridge* 1500V to > 24V operating voltage
500V to > 24V operating voltage
Pipe material Stainless Steel
Thread NiCr 8020
Melting temperature 750º C

*tested at ambient temperature

Uniform heat

Expan heaters are built with a single spring-shaped heating wire, which contains more heating wire than any other cartridge heater model. This results in a more uniform heat all around the perimeter, without any cold spots or temperature variations.

High-charge compressed cartridge thermography
Different cold zones are observed, especially in the center of heaters from 250 mm and above.
Common bipartite cartridge thermography
Cold spots are observed at the end of the connections, so it does not evenly heat the mold or application.
Expan Thermography
The absence of cold zones is clearly noticeable, thanks to its exclusive construction system, which allows placing more heating wire in the whole area of the cartridge, including the connection zones.

Cardrige that molds to the hole

Expansion around the entire perimeter of the cartridge makes the Expan cartridge the best solution for larger diameter holes caused by wear, expansion or made to tight tolerances.

Maximum adjustment
Improved heat transmission.
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Adjustment tolerance

The cartridge setting tolerance is referred to as the distance obtained between the surface of the cartridge and the wall of the internal bore, which must be uniform throughout its linear perimeter.

Faster and easier removal, even on long lengths

Expan cartridges, due to their unique construction system, allow easy extraction when the cartridge is cold, saving considerable time and effort, reducing machine downtime and human resources to a minimum. No adjustment paste is required and you will not have to drill, destroy or perform costly operations to remove the cartridge. You will be able to reuse Expan heaters in other molds you need to heat.

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Long lengths, will not arch, which is the main problem of conventional cartridges, thanks to the shape of the tubes, which serve to reinforce the structure of the Expan cartridge lengthwise, facilitating its removal. By expanding equally around the entire perimeter, heat transfer will be uniform without creating curvatures that produce cavities that overheat, causing the cartridge to break.

Precision in expansion

Maxiwatt's expandable cartridges are designed to have the widest range of tolerances of all quality cartridges on the international market.

ejemplo bipartida
We have a 12.5D bore with a tolerance between 12.52 and 12.48, the expandable cartridge has a real diameter of 12.30 +/- 0.05, so we would have a maximum clearance between the surface of the cartridge and the wall of the hole of 0.37 and minimum 0.12, more than enough space to extract the expandable cartridge without any problems, always ensuring good contact with the entire inner surface of the hole.

All intermediate sizes in diameter and length, volts, wattage distribution, cold zones, special finishes, terminations, etc. can be manufactured.

Ø Drill Ø real Zona fría Minimum
Maximum amperes
according to length
3/8'' 9,52 ±0,1 9,3 20 100 1000 15 15
10 10 ±0,1 9,8 20 100 1000 15 15
12 12 ±0,1 11,8 20 100 1500 25 25
12.5 12.5 ±0,1 12,3 20 100 1500 30 25
1/2'' 12.7 ±0,1 12,5 20 100 1500 30 25
15 15 ±0,1 14,8 30 100 1500 40 25
5/8'' 15,88 ±0,1 15,68 30 100 1500 40 25
16 16 ±0,1 15,8 30 100 1500 40 25
3/4'' 19,05 ±0,1 18,85 30 100 1500 40 25
20 20 ±0,1 19,8 30 100 1500 40 25
25 25 ±0,1 24,6 30 100 1500 40 30
1'' 25,4 ±0,1 25 30 100 1500 40 30

Longer useful life the Diference

Expan cartridges have more heating wire (Nickel/Chromium 80/20) than bipartite cartridges or compressed cartridges with the same compression. The principle is key; the more heating wire, the larger the diameter has to be for the same watts. The larger diameter reduces heating wire fatigue and wear, which translates into longer life.

Section of an Expan cartridge with more heating wire per cartridge.

Bipartite Expan
bipartida expan
Basic bipartite
bipartida normal

Patent pending.

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