Maxiwatt C/ Marie Curie, 31
03203 Elche (Alicante)
Phone: (+34) 965 45 26 19
Fax: (+34) 965 45 33 45
Made to order 24-hour dispatch on-line shop


The resistance of self-expanding cartridge

Longer lasting
Easy removal.
More compact terminations.
More free tonnage length.
More drilling tolerance.
No cold zones.
Hundreds of terminations and endings.

bipartite cartridge heater

The adjustment and fast extraction system.

The expandable cartridge Heaters solve two major problems with conventional high density compressed heaters, poor durability fit and proper fit extraction, improving the accuracy of the temperature with hundreds of termination and finishes for all types of industry.

Acabados, Ends Protecciones, Protections

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

resistencias bipartidas Hot

The system

The Expandable Heaters consist of a compressed cartridge heater of a high performance and made with the best materials with the particularity of being able to expand itself thanks to the fork-shaped tensioned in a point that allows the expansion and retraction of the cartridge.

bipartite cartridge heater In the expansion process the expandable cartridge fits the walls of its housing, providing the correct transmission of the temperature, and avoiding the "oven effect" that occurs in other types of cartridges poorly dimensioned with respect to diameter and housing. The drills that for any other circumstances are oversized have with the expandable heaters the best solution to allow more adjustment tolerance.
resistencias bipartidas At the contraction processthe Expandable Heaters come back to their original status, facilitating a smooth removal from the orifice, with the subsequent advantages like not having to drill the mould again, reuse them in other locations, reduce the stock since it will have the same diameter for different drills, etc.

The quality of the materials

The Expandable Heaters are manufactured with an internal compacting system of all its components in order to increase their lifetime. The Nickel/Chrome 80/20 conductor wire is introduced into the cavities of a ceramic body which focuses the suitable separation in order to obtain a better insulation. Fully coated with magnesium oxide of high purity grain sized controlled to ensure the complete cartridge Expan fill. Later comes a compacting process and a rectification of the surface until calibrate the desired size. And finally, a rigorous quality control that guarantees the best operation of the cartridge

bipartite cartridge heater
  1. Nickel/Chrome 80/20 conductor wire, melting point 1400ºC
  2. Grain sized Magnesium oxide
  3. Hard refractory paste
  4. Conducting wire
  5. Stainless Steel AISI 304/316/321/INCOLOY
  6. Ceramic core
  7. Hard ceramic head
  resistencias de cartucho The facilities and the unique building system ensure the maximum purity inside guaranteeing a longer lifetime.

Hundreds of different endings

acabados especiales All  possible ending you may require for all underwater applications, vibration, high temperatures, special food use, corrosive saline environment, graded etc.

Thermocouples, the best complement

The cartridge heater can be manufactured with a probe built into the cartridge sensor, at any point  request. The advantages of incorporating sensors are countless, for instance considerable longer cartridge life, localized temperature accuracy, energy saving, where you cannot accommodate a conventional sensor due to space problems.

Technical data

Voltage (V) 120 - 130 - 240 - 380 - 400
Power tolerance(w)* +5% to -10%
Power Depends on the dimensions
Length Tolerance ± 3% maximum 20mm
Standard Diameter's Tolerance -0.10 to -0.15 mm
Leakage current* <=0.5mA a 253 v.
Insulation* >=5 MΩ a 500 V
High voltage heaters* 1500V to > 24V Operating voltage
500V to > 24V Operating voltage
Tube material Stainless Steel
Wire NiCr 8020
Melting temperature 750º C
*tests have been done at room temperatures

The uniform heating

The Expandable Heaters are made with just one heating wire spring shaped that has more quantity of wire than any other model of cartridge heater. We obtain, this way, an uniform heating around the whole perimeter, without any kind of cold areas or temperature variations.

Compressed high charge cartridge heater thermography.
Several cold zones observed, especially in the centre of the heater from 250 mm.
Ordinary bipartite cartridge heater thermography
It is observed cold spots at the end of the connections .This does not uniformly heated mould or application.
Expandable Heaters thermography
Clearly shows the absence of cold zones thanks to its unique construction, which allows more heating wire in the whole area of the cartridge included in the connection areas.

The heater that conforms to the hole

The expansion around the perimeter of the cartridge makes of the Expandable Heater the  best solution for large diameter holes, caused by attrition, expansion or made with little tight tolerances.

Maximum adjustment
Better heat transfer.
resistencias bipartidas

Fitting tolerance

The adjustment tolerance of the heater is obtained from the distance between the surface of the cartridge and the inner wall of the hole, which must be uniform throughout its lineal perimeter.

The extraction, faster and easier even in long lengths

Expandable heaters, for its unique construction, allow the easy removal when the cartridge is cold, saving time and considerable effort, minimizing machine stop time and human resources. Needs no adjustment paste and you will not have to drill, destroy or perform expensive operations to remove the cartridge. You can reuse the Expandable Heaters in other moulds need to be heated. bipartite cartridge heater
bipartite cartridge heater Long lengths, will not bend, which is the main problem with conventional cartridges, thanks to the shape of its tubes which perform the function to reinforce the structure of expandable heaters longitudinally, facilitating its removal. By expand evenly around the perimeter, heat transmission will be uniform without creating curvatures which produce cavities producing overheat and breaking of the resistance.

Accuracy in expansion

The Expandable Heaters of Maxiwatt are designed to have the widest range of the high quality heater tolerances of all international market.

Example bipartite cartridge heater Example.
We have a drill with a tolerance between12.5 D 12.52 and 12.48, the expandable cartridge has an actual diameter of 12.30 +/- 0.05, which gives us a maximum clearance between the surface of the cartridge and the the hole wall of 0.37 and minimum 0.12 more than enough room to extract the expandable cartridge without any problems, always ensuring good contact with the entire inner surface of the hole.

All of the intermediate sizes can be made in diameter and length, volts, watts distribution, cold areas, special finishes, finishing, etc.

Ø Drill Real Ø Cold zone Minimum
Maximum amps
according to the 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 Service Life: The Difference

More Nickel/Chrome 80/20 heating wire at the Expandable Heaters than in a bipartite heater or a compressed cartridge heater with the same compression, The Expandable Heater have more heating wire (nickel / chromium80/20) than the bipartite heaters or compressed cartridges with the same compression, The principle key is the more heating wire, the larger has to be its diameter for the same amount of watts. The larger diameter reduces fatigue and wear of the heating wire, resulting into a longer service life.

Section of a Expandable heater with more heating wire per cartridge Bipartite Expan
bipartite expan
Basic Bipartite
Basic Bipartite
Patent pending.


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