Maxiwatt Brickell Ave. Suite 1550
33133 Miami (Florida)
Phone: 1-866-MAXIWAT
Phone: 1-866-629 4928


The resistance of self-expanding cartridge

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

bipartite cartridge heater

EXPAN: 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 finishes and terminations for all types of industry.

Acabados, Ends Protecciones, Protections

With the expandable cartridge heaters we combine for the first time the best features 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, high performance cartridge heater and made with the best materials with the particularity of being able to expand itself thanks to the fork-shaped point 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 thermal transfer, and avoiding the "oven effect" that occurs in other types of poorly dimensioned heaters with respect to diameter and fit. Bores that for any other circumstances are oversized, can benefit from our expandable heaters- the best solution to allow more adjustment tolerance
resistencias bipartidas At the contraction process the Expandable Heaters return to their original form, facilitating a smooth removal from the orifice, with the subsequent advantages like not having to drill the mold again, reuse them in other locations, reduce the stock since it will have the same diameter for different drills, etc.


Quality of the materials

The Expandable Heaters are manufactured with an internal compacting system of all its components in order to increase their usable life. 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 inspection that guarantees the best operation of the cartridge

bipartite cartridge heater
  1. Nickel/Chrome 80/20 conductor wire, melting point 2552ºF
  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 terminations

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

Thermocouples, the best accessory

The cartridge heater can be manufactured with a probe built into the cartridge sensor, at any point requested. 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 % - 10 %
Power Depends on the dimensions
Length Tolerance ± 3% maximum 0.787inch
Standard Diameter's Tolerance -0.0039 to -0.0059 inch
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 1382º F
*tests have been done at room temperatures

The uniform heating

The Expandable Heaters are made with just one spring shaped heating wire that has a greater quantity of wire than any other model of cartridge heater. This way we obtain 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 center of the heater from 9.843 inches.
Ordinary split sheath cartridge heater thermography
It is observed cold spots at the end of the connections .This does not uniformly heated mold 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 bore.

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

Maximum adjustment.
Better heat transfer.
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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 molds 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.

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'' 3/8'' ±0.004 0.366 0.787 3.937 39.37 15 15
0.394 0.394 ±0.004 0.386 0.787 3.937 39.37 15 15
0.472 0.472 ±0.004 0.465 0.787 3.937 59.055 25 25
0.492 0.492 ±0.004 0.484 0.787 3.937 59.055 30 25
1/2'' 1/2'' ±0.004 0.492 0.787 3.937 59.055 30 25
0.59 0.59 ±0.004 0.583 1.181 3.937 59.055 40 25
5/8'' 5/8'' ±0.004 0.617 1.181 3.937 59.055 40 25
0.63 0.63 ±0.004 0.622 1.181 3.937 59.055 40 25
3/4'' 3/4'' ±0.004 0.742 1.181 3.937 59.055 40 25
0.787 0.787 ±0.004 0.78 1.181 3.937 59.055 40 25
0.984 0.984 ±0.004 0.969 1.181 3.937 59.055 40 30
1'' 1'' ±0.004 0.984 1.181 3.937 59.055 40 30

Longer Service Life "The Difference"

More Nickel/Chrome 80/20 heating wire in the Expandable Heaters than in a typical split sheath heater or a swaged cartridge heater with the same compression, The Expandable Heater have more heating wire (nickel/chromium 80/20) than the split 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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