Process heating fits into an industrial electrical project as an electrical load, a control system and a safety item at the same time: heating cables need a power supply sized for them, protection and earthing that suit them, controls that keep temperatures in range, and installation and testing that match the rest of the electrical scope. Treated as an afterthought, heat tracing becomes a source of overloaded panels, tripped circuits and cold lines. Treated as part of the electrical design, it is routine. This guide from Paklink LLC explains the main types of heating cable, when mineral insulated (MI) cable is the right choice, how to size the electrical supply, and how to control, install and test the system. If your project involves electrical contracting and heat tracing in Dubai, plan both from the start.
In short:
- Process heating keeps pipes, vessels and equipment at the right temperature, and in the UAE it is mostly about temperature maintenance and viscosity control, not freeze protection.
- The cable type depends on the temperature you must reach: self-regulating and constant wattage cables suit moderate temperatures, and MI cable suits very high ones.
- Heating circuits are electrical loads that must be included in the main load calculation, breaker sizing and earth fault protection.
- Good control, dry insulation and documented testing decide whether the system works for years or fails in the first season.
What is process heating in an industrial plant?
Process heating is the use of heat to keep a fluid, a surface or a piece of equipment at a required temperature. In a plant it appears as heated pipelines, tanks, valves, instruments, furnaces and process vessels, and it exists for a few practical reasons:
- Temperature maintenance. Keeping a product at a set temperature as it moves through pipework.
- Viscosity control. Fluids such as heavy oil, bitumen or some chemicals become too thick to pump when they cool.
- Preventing solidification or crystallization. Some products freeze, wax or crystallize if the line falls below a certain temperature.
- Condensation and corrosion control. Warm surfaces stay above the dew point and so stay dry.
- Freeze protection. Preventing water lines and instrument lines from freezing, which matters more in colder regions than in the UAE.
In Dubai and the wider UAE, ambient temperatures rarely threaten freezing, so most heat tracing here is about process temperature maintenance and keeping products flowing.
What is heat tracing, and how does it work?
Electric heat tracing is a system that replaces the heat a pipe or vessel loses to its surroundings, using a heating cable laid along it and covered by thermal insulation. The cable gives off a controlled amount of heat per meter, and the insulation keeps the heat where it is needed.
Heat tracing can be electric or steam-based. Steam tracing runs steam lines alongside process pipes, while electric tracing uses heating cable. Electric systems are popular because they give precise temperature control, need no steam network, are easier to install on small or complex lines and can be monitored electronically.
The relevant standards include IEC 62395 for electrical resistance trace heating systems in industrial and commercial applications, and IEC 60079-30-1 for systems in explosive atmospheres. You can browse these on the IEC website.
What types of electric heating cable are there?
The four main families of heating cable differ in how they produce heat and in the temperatures they can handle. The right one depends on the process temperature, the line length and the environment.
| Cable type | How it behaves | Typical use | Watch out for |
|---|---|---|---|
| Self-regulating | Output rises and falls with the cable’s own temperature, so it can overlap itself safely | Freeze protection and moderate temperature maintenance | Limited temperature range, and high inrush current when started cold |
| Constant wattage | Delivers a fixed output per metre along its length | Process lines with steady heat needs, longer runs | Needs a controller, and must not overlap or touch itself |
| Mineral insulated (MI) | Metal-sheathed cable with a resistance conductor in compacted mineral insulation | Very high temperatures, harsh environments, long life | Requires careful termination and moisture protection |
| Series resistance | A long circuit with a fixed resistance across its length | Very long pipelines | Needs custom design for each circuit |
Paklink’s range covers several of these. It includes self-regulating heating cables, constant wattage heating cables and mineral insulated heating cables, with rated maximum temperatures from about 210°C for the ELSR-H self-regulating cable, through 260°C for constant wattage cable and 400°C for MI cable, up to 600°C for the ELK-MI.
When is mineral insulated (MI) heating cable the right choice?
MI heating cable is the right choice when the process temperature is too high for polymer-insulated cables, or when the conditions are too harsh for them. The construction explains why. An MI cable has a copper or resistance conductor, compacted magnesium oxide insulation around it, and a continuous metal sheath, such as stainless steel or Incoloy, over the top. The metal sheath protects against mechanical damage and chemicals, and the mineral insulation withstands temperatures that would destroy plastic.
Paklink’s ELK-MI mineral insulated heating cable is built this way and is rated for operation up to 600°C. The product page lists these typical applications:
- Furnace and boiler heating
- High-temperature process lines and pipe tracing
- Petrochemical and chemical processing plants
- Metal treatment and heat treatment ovens
- Glass manufacturing and refractory heating
- Power generation, extrusion lines and industrial laboratory heating
When you compare options, these points decide the choice:
| Question | If the answer is yes | Likely choice |
|---|---|---|
| Is the maintained or exposure temperature above the limit of polymer cable? | Polymer insulation would degrade | MI cable |
| Does the cable face mechanical damage or aggressive chemicals? | A metal sheath protects it | MI cable |
| Is a long service life and low maintenance important? | Mineral insulation ages slowly | MI cable |
| Is the line short, low temperature and simple? | MI would be more than needed | Self-regulating or constant wattage |
For in-between temperatures, the range includes a valve and pipe heating cable rated up to 450°C and an MI cable rated up to 400°C. Whichever you choose, confirm the exact rating, sheath material and certification against the product data sheet and your project specification.
How do you design a heat tracing system?
Design starts from the heat the pipe loses, then matches the cable output to that loss with a safety margin. The steps are:
- Define the requirement. The temperature to maintain, the lowest ambient temperature, the fluid and whether the system must also raise the temperature.
- List the items to trace. Pipe length and diameter, valves, flanges, supports, tanks and instruments, all of which lose extra heat.
- Calculate the heat loss per meter. This depends on the temperature difference, the pipe size and the insulation.
- Choose the cable type and output. Pick a cable whose output covers the loss, with a margin, and whose temperature rating suits the process.
- Decide the circuit layout. Split long lines into circuits within the cable’s maximum length.
- Specify controls, sensors and alarms.
- Complete the electrical design. Supply, protection, earthing and cabling.
An illustrative example shows the scale. For a bare calculation of a pipe with cylindrical insulation, heat loss per meter is 2 × π × k × ΔT divided by the natural logarithm of the outer insulation diameter over the pipe diameter, where k is the insulation’s thermal conductivity.
| Input | Value (illustrative) |
|---|---|
| Pipe outer diameter | 60 mm |
| Insulation thickness | 50 mm, so the outer diameter is 160 mm |
| Insulation conductivity (k) | 0.04 W/m·K |
| Maintain temperature minus design ambient (ΔT) | 40°C |
| Heat loss | About 10 W per meter |
| With a 25% safety margin | About 13 W per meter |
The numbers are only an example. Real designs also account for wind, extra loss at valves and supports, and the manufacturer’s design software or tables.
Insulation matters as much as the cable. Wet or damaged insulation can double the heat loss, so the system depends on a dry, intact thermal insulation and weather cladding layer.
What electrical supply and protection does heating need?
Heating circuits are real electrical loads, so they go into the load calculation, the distribution design and the protection design from the start. A useful way to size them is circuit by circuit.
| Step | Calculation | Illustrative result |
|---|---|---|
| Circuit load | Output per metre multiplied by circuit length | 13 W/m × 100 m = 1,300 W |
| Current at 230 V | 1,300 W divided by 230 V | About 5.7 A |
| Breaker | Next standard rating above the current, allowing for starting current | Chosen against the cable maker’s circuit length and breaker tables |
Add the circuits up to get the connected load of the heating system, and include it in the sizing of the main switchboard, the transformer and the supply cables. Heat tracing often runs for long periods, so treat it as a continuous load, and check how many circuits can run at once. If the plant adds a large number of circuits late in the project, the transformer and the main breaker may need to change.
Protection needs particular care:
- Starting current. Self-regulating cables draw more current when cold, so the breaker must allow for the start-up surge on long circuits.
- Earth fault protection. Heating cable circuits normally need ground-fault or earth leakage protection, because damage to the cable or moisture in a termination creates a leakage path. Confirm the required rating with the standard and the project specification.
- Short-circuit and overload protection. Sized to the cable and the circuit length.
- Earthing. The metal sheath and the associated metalwork need a reliable connection to earth.
These circuits normally feed from a dedicated heat tracing panel or a section of a distribution board. Our guide to distribution boards covers sizing, spare ways and short-circuit ratings, all of which apply to a heating panel too.
How are heat tracing circuits controlled and monitored?
Control keeps the temperature in range and the energy use down, while monitoring tells operators when something is wrong. A basic circuit has a temperature sensor, a controller and a switching device. Larger systems add a central controller that watches many circuits.
| Control level | What it does | Best for |
|---|---|---|
| Thermostat control | Switches the circuit on and off at a set temperature | Simple lines and small systems |
| Electronic controller | Controls temperature with a sensor on the pipe or in the ambient air, with alarms | Process lines and critical circuits |
| Multi-circuit control and monitoring | Monitors current, temperature and faults on many circuits, and reports to a control system | Large plants and critical processes |
Good systems alarm on low temperature, high temperature, sensor failure, ground-fault current and loss of current. They connect to the plant’s PLC or SCADA system through standard communication protocols, so heating faults appear on the same screens as other alarms. Paklink supplies related sensors and transmitters and mini PLCs for this kind of control.
How does heat tracing connect to the rest of the electrical scope?
A heat tracing system touches several parts of the electrical design, so it helps to see the connections together:
| Part of the electrical scope | What heat tracing needs from it |
|---|---|
| Main switchgear and transformer | Capacity for the heating load, which is often continuous |
| Distribution boards | A dedicated heat tracing panel with enough circuits, breakers and spare ways |
| Cable containment | Routes for supply cables to junction boxes and circuits, kept away from hot surfaces. |
| Earthing and protection | Earth leakage protection and reliable bonding of sheaths and metalwork |
| Control and monitoring | Sensors, controllers and links to the PLC or SCADA system |
| Power quality | Heating loads are resistive, so they carry little harmonic distortion, but they still count in the load and power factor picture |
| Maintenance | Scheduled tests and inspections of heating circuits |
What changes in hazardous areas?
In areas where flammable gas, vapor or dust may be present, heating cable must be certified for the zone, and the surface temperature must stay below the ignition temperature of the substances present. Equipment is classified by temperature class, which sets the maximum surface temperature it may reach.
This is specialist work. The design must follow the hazardous area standards and the site’s classification drawings, and it needs approved cables, terminations and junction boxes. Paklink’s product page lists the ELK-MI as suitable for hazardous areas, but certification depends on the exact product and zone, so always confirm it against the data sheet and the area classification before you specify.
How do you install, test and commission a heat tracing system?
Installation and testing decide whether the system works as designed. A sound process runs as follows:
- Check the substrate. Surfaces should be clean and free of sharp edges, with piping pressure tested before heating cable goes on.
- Install the cable. Fix it to the pipe as specified, with attention to bend radius, valves, supports and spacing between runs.
- Terminate carefully. Use the correct kits, and keep terminations sealed and dry. This matters most for MI cable, because the mineral insulation absorbs moisture and a wet termination lowers insulation resistance.
- Test before insulation. Measure insulation resistance and the cable’s electrical resistance, and compare them with the manufacturer’s values.
- Install the insulation and cladding, and label the pipe so others know a heating cable is present.
- Test again after insulation. Repeat the insulation resistance test to catch damage done during insulating.
- Commission the controls. Check sensors, set points, alarms and communication links, and record the circuit data.
- Hand over documentation. Circuit lists, test records, as-built drawings and controller settings.
The ELK-MI page describes the cable as trimmable to length on site and friendly to field termination, which can simplify installation. Even so, the termination quality and the test records remain the contractor’s responsibility.
How do you maintain a heat tracing system?
A light but regular routine keeps the system dependable. Typical tasks are:
- Insulation resistance tests on each circuit, compared with the commissioning values
- Checking controller settings, sensors and alarms
- Inspecting insulation, cladding and seals for damage or moisture
- Thermal imaging of terminations and junction boxes
- Testing earth leakage protection
- Recording results so trends show up early
We cover how to build this into a plant-wide routine in our guide to preventive electrical maintenance. Where the plant uses permanent monitoring, the same data can be combined with power quality monitoring to give a fuller picture of electrical health.
What mistakes do heat tracing projects commonly make?
Most heat tracing failures come from decisions made before installation. Seven mistakes appear regularly:
- Adding heating circuits late, after the switchboard and transformer have been sized
- Ignoring starting current on self-regulating circuits, which causes nuisance tripping
- Choosing a cable with too low a temperature rating for the process
- Wet or damaged insulation, which defeats the heat calculation
- Poor terminations, especially on MI cable, where moisture ingress ruins insulation resistance
- No control or alarms, so a failed circuit goes unnoticed until the line freezes, waxes or blocks
- No test records, so there is nothing to compare against when problems start
Planning process heating for your plant?
If you are specifying heat tracing or reviewing the electrical side of an existing system, talk to the team at Paklink LLC about your process temperature, line lengths and supply. You can also explore our heat trace supply and installation services.
Frequently asked questions
What is process heating?
It is the use of heat to keep fluids, pipes, vessels or equipment at a required temperature, for example to maintain viscosity or prevent solidification.
What is heat tracing?
Heat tracing is a system that replaces the heat a pipe or vessel loses, using an electric heating cable or steam line along it, covered by thermal insulation.
What is mineral insulated (MI) heating cable?
It is a heating cable with a metal conductor, compacted mineral insulation and a metal sheath. It handles very high temperatures and harsh conditions that polymer-insulated cables cannot.
What temperature can MI heating cable reach?
It depends on the cable. Paklink’s range includes MI cable rated up to 400°C and the ELK-MI rated up to 600°C. Always check the data sheet for the exact rating and sheath material.
Do heating cables need earth leakage protection?
Yes, heating circuits normally need ground-fault or earth leakage protection. The exact rating comes from the applicable standard and the project specification.
Can heat tracing be used in hazardous areas?
Only with cables, terminations and junction boxes certified for the zone, and with a temperature class suited to the substances present. Specialist design is required.
How do I size the electrical supply for heat tracing?
Calculate each circuit’s load from the cable output and length, add the circuits up, include the total in the main load calculation, and check breakers against the cable maker’s tables, including starting current for self-regulating cables.
