Continuous to 150 °C, wound for 110-380 V, built to UL 499 / IEC 60335 / RoHS. Set the outline, the voltage and the wattage on the drawing below and it redraws to them.
Epoxy Immersion and Tank Heaters are continuous to 150 °C, wound for 110-380 V, watt density 0.3 W/cm² in free air and 2 W/cm² bonded to a heat sink, about 8 mm to 20 mm thick. The outline is cut to your drawing, up to 300 x 800 mm in one piece. It does not limit its own temperature: a thermostat, a thermal cutoff or a control loop with an independent over-temperature channel belongs in the design.
Continuous temperature
to 150 °C
Supply voltage
110-380 V
Watt density
0.3 W/cm² free air / 2 W/cm² bonded
Thickness
8 mm to 20 mm
Maximum one-piece size
300 x 800 mm
These are the process limits for this construction, not the rating of a finished part. The ratings of your heater come from the drawing it is built to, and the watt density it can carry depends on what it is bonded to.
Outline & Specification Builder
Set the outline, the size, the voltage and the power you have in mind. The drawing
redraws to match, and the panel works out the heated area, the watt density and the current — then checks
that watt density against what this construction survives in free air and bonded to a heat sink. Those two
limits are different by several times, and it is the difference that decides whether a heater lasts.
Fills in the form below; attach your outline drawing or DXF there.
Request a Quotation for Epoxy Immersion and Tank Heaters
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Every row below is a starting point for the customizer above — pick any size and the drawing will redraw to that row.
Parameter
Specification
Limit / note
Construction
Resistance wire or foil element potted in thermally conductive filled epoxy on a metal plate
Cured under vacuum so there are no voids in the heat path
Plate material
Titanium, 316L stainless or PTFE-clad
Aluminium for spreading, stainless where the chemistry demands it
Total thickness
8 mm to 20 mm
Plate plus encapsulation
Maximum size, one piece
300 x 800 mm
Larger plates are built as multiple circuits on one plate
Dimensional tolerance
u00b10.5 mm on the plate, u00b11 mm on the encapsulation
Supply voltage
110 V, 220 V, 380 V
Wound to order
Resistance tolerance
u00b110%
At 20 u00b0C
Watt density
0.3 W/cmu00b2 typical, 2.0 W/cmu00b2 maximum
Against a load in contact; free-standing operation runs far lower
Continuous working temperature
-40 u00b0C to +150 u00b0C
Set by the epoxy, not by the element
Dielectric strength
2500 V AC, 1 minute
Element to plate
Insulation resistance
greater than 100 Mu03a9 at 500 V DC
Also after 48 hours humidity conditioning
Ingress protection
IP65 as standard, IP67 with a moulded lead entry
The encapsulation is the seal
Mounting
Tapped holes, clearance holes, studs or bonded
Machined into the plate before potting
Sensor options
NTC, PT100 or thermostat potted into the same plate
Reads the plate, which is what the load actually sees
Certifications available
UL 499, IEC/EN 60335, RoHS, REACH, CE, IATF 16949
Construction level
Chemical compatibility
Bath chemistry and temperature confirmed at quotation
The plate material is chosen for the bath u2014 there is no universal answer
Low level protection
Mandatory float or conductivity cutoff
An immersion heater out of the liquid is a fire, whatever it is potted in
Epoxy Immersion and Tank Heaters are epoxy heating plates. There is no catalogue size and no stocked part number here — the drawing decides the outline and the wattage. What this page gives you instead is everything that constrains the drawing: watt density, temperature, thickness, tolerance, voltage and the certifications the construction is built to.
What Are Epoxy Immersion and Tank Heaters?
Epoxy Immersion and Tank Heaters are epoxy heating plates. They are specified by supply voltage and outline together with the outline drawing, the wattage or the temperature to be held, and what the heater is bonded to — that last one decides the permissible watt density and is the question a quotation cannot skip. The construction is built and tested to UL 499 / IEC 60335 / RoHS.
Construction & Insulation System
A resistance wire or foil element is potted in thermally conductive filled epoxy on an aluminium or stainless plate, cured under vacuum so there are no voids in the heat path. The encapsulant is both the insulation and the seal, and it is also the limit: 150 °C continuous, the lowest ceiling of any construction in this catalog. The element would tolerate three times that and the plate more again — so a design pushing past 150 °C needs a different construction, not a better epoxy.
Watt Density
In free air, with nothing conducting heat away from it, this construction carries 0.3 W/cm². Bonded over its full area to metal that carries the heat off, it carries 2 W/cm². The second figure is not an upgrade of the first — it is a different operating condition, and a heater ordered at 2 W/cm² and then run unbonded fails within minutes. Divide the wattage you need by the area you have before anything else: if the answer is above the free-air figure, either the area grows or the heater gets bonded down.
Typical Applications
Battery module plates, press and laminating platens, plating and anodising tanks, and any flat conduction duty where a flexible heater will not hold its shape and a bare element would not survive the environment.
Specifying the Epoxy Immersion and Tank Heaters
The supplies this construction is most often wound for are 110-120 V AC, 220-240 V AC and 380-415 V AC. Each has its own page, with the resistance and current the wattage works out to at that voltage and what that means for the leads.
Where the environment decides the build rather than the wattage, the insulation pages the ones to read: Filled Epoxy Encapsulation and Aluminium Plate / Extrusion. Each is written to the same headings, so the comparison is like for like.
Specified by the temperature it has to hold: Up to 80 °C and 80 °C to 120 °C. Each page covers the watt density that band allows in free air and bonded down, and the control and over-temperature arrangement that goes with it.
This construction is built and tested to UL 499 and IEC/EN 60335 — worth checking against the standard your own end product is certified under, because a part built to one scope does not automatically satisfy another. For the equipment and duties this construction is actually specified for, see where epoxy immersion and tank heaters are used.
Inside the plant
Manufactured in our own plant
This heater is laid out, wound or etched, laminated, cut, tested and imaged in-house. The stages below are where its resistance tolerance, its temperature uniformity and its insulation integrity are actually decided.
01
Circuit design & layout
The customer outline comes in as a drawing or a DXF, and the element is laid out inside it: conductor gauge from the voltage, path length from the resistance, pitch from the watt density wanted at each part of the surface. Where the load needs more heat at the edges than in the middle, that is decided here, in the geometry, not later with more power.
Calculated resistance and watt density checked against the construction limits before any tooling is cut.
02
Element preparation
Wire-wound elements are wound on a glass carrier at the calculated pitch; etched-foil circuits are photo-imaged and etched from Inconel or copper foil to a trace width held within 0.05 mm. That tolerance is what makes the resistance repeatable from lot to lot, which is what makes the temperature repeatable.
Trace width and element resistance measured before lamination — a circuit out of tolerance is scrapped here, not after it is sealed inside the part.
03
Lamination & vulcanising
The element and its sensor are laid between the insulation and pressed under heat: silicone is vulcanised, polyimide and PET are laminated with a high temperature adhesive, epoxy plates are potted under vacuum so no voids are left anywhere in the heat path. A void is not a cosmetic defect — it is a place the heat cannot leave from, and it becomes the hot spot that ends the part.
Press temperature, pressure and dwell recorded per lot; potted plates checked for voids.
04
Die cutting & leads
The outline is die cut with radiused corners — a die does not cut an inside corner, and a sharp corner in a film is where a tear starts. Leads are crimped or soldered and strain relieved at the exit, and connectors are fitted to the harness drawing so the assembly line never has to solder.
Outline to ±0.5 mm on film, ±1.5 mm on silicone; lead pull-out tested per lot.
Third-party video, selected automatically for this topic. It is not produced by Heating Film and is not a specification source — use the tables on this page for dimensional data.
Frequently Asked Questions
What sizes do Epoxy Immersion and Tank Heaters come in?
There is no size list. Epoxy Immersion and Tank Heaters are cut to your outline, so the size is whatever your drawing says, up to 300 x 800 mm. Larger areas are built as separate zones with their own circuits. Send a dimensioned drawing or a DXF and the quotation comes back against that outline.
How many watts per square centimetre do Epoxy Immersion and Tank Heaters handle?
Two figures, and they are not interchangeable. In free air, with nothing conducting heat away, 0.3 W/cm². Bonded over its full area to metal that carries the heat off, 2 W/cm². A heater ordered at the second figure and then run in the first condition fails within minutes, so the quotation asks what the heater is bonded to before it asks anything else.
How hot can Epoxy Immersion and Tank Heaters run?
150 °C continuously. That limit belongs to the insulation system — Filled Epoxy Encapsulation or Aluminium Plate / Extrusion — not to the element, which would tolerate a good deal more. It is a hard ceiling: above it the insulation degrades, and no derating scheme buys headroom. Past 150 °C the construction has to change rather than be pushed.
What protects Epoxy Immersion and Tank Heaters from overheating?
Nothing in the heater itself — a heater is a resistor and has no opinion about temperature. The protection is a separate part of the design, and on this construction it is normally a bimetal thermostat or a one-shot thermal cutoff fitted inside the insulation, in series with the element. It can be built into the heater at manufacture, which is both cheaper and more reliable than adding it to the assembly afterwards, and it is a different component from the sensor that closes the control loop: the case the cutoff exists for is the loop failing on.
How are Epoxy Immersion and Tank Heaters fitted?
They are bolted through the plate to the load, with the mounting holes machined into the plate before the element is potted.
What voltages are Epoxy Immersion and Tank Heaters available in?
110-120 V AC, 220-240 V AC and 380-415 V AC. The element is wound for the voltage ordered — it is not a switchable range, and running a heater at a voltage other than the one it was wound for changes its power by the square of the ratio. Resistance is held to u00b10.5 mm on the plate, u00b11 mm on the encapsulation.
What is the dielectric strength of Epoxy Immersion and Tank Heaters?
2500 V AC, 1 minute, with insulation resistance above 100 MΩ at 500 V DC measured after the dielectric test. Both are tested on every unit rather than on a sample, because a heater that fails this test in service fails it into whatever it is bonded to.
How do I get a quotation?
Set the outline, size, voltage and power in the builder on this page and send that configuration through, or attach a drawing. The quotation needs six things: the outline, the supply voltage, the power or the temperature you need to hold, what the heater is bonded to, the ambient it works in, and the quantity. With those, a quotation comes back within one business day.
Need a heater quoted?Message our engineers on WhatsApp — send an outline drawing and the supply voltage and get pricing back fast.Start WhatsApp Chat →
This website uses only necessary and functional cookies to operate, secure, and improve basic website performance.
We do not use advertising cookies, Google Analytics, or cross-site tracking technologies.