How does self-regulating heat trace work?


Self-regulating heat trace cables are often used to apply heat safely and efficiently for comfort, process, and maintenance purposes. They provide protection against burst water pipes, frozen roofs and gutters, ice and snow formation on ramps, paths, stairs, and many other applications.

For residential and commercial buildings, these systems offer a reliable and long-term solution to expensive damage or operational disturbances. They play such an important but often invisible role in various industries; in this article we will be exploring how self-regulating heat trace works as well as its importance.

First, what is self-regulating heat trace?

In a self-regulating heat trace system, the heat output is influenced by the surface temperature of where the heat trace is fitted. A warmer surface will lower the wattage output whilst a cooler surface will enable more wattage to be produced. Whilst this is a simple difference, understanding it is important when it comes to determining the right heat trace system for your application. A key benefit of self-regulating cable is that it can safely be overlapped on top of itself. This is unlike other forms of heat trace such as constant wattage or MI cable which develop a hot spot and burn out when overlapped or if it comes into contact with itself. Self-regulating cable won’t do that.

How self-regulating heat trace works

Self-regulating heat trace technology works by automatically altering power output in accordance with changes in the temperature that it is connected to. This technology starts on a microscopic level. The innermost part of the cable, typically called the conductive core, is made up of a carbon polymer that reacts to changes in temperature.

When the surface temperature goes down, the core contracts, increasing the total number of electrical paths, and as a result raising the temperature. On the other hand, as the outside temperature goes up, the core expands, lowering the number of electrical paths and reducing the cable’s final power output.

When do you need self-regulating trace heating products?

Even though it is a useful way to counter ice damage, thermal insulation by itself is not enough to offer full protection against pipes freezing up. In addition, pipes aren’t the only things that need protection in winter, cold weather can affect drains, sewers, roofs, gutters, and more.

There are alternatives, but a lot of them don’t have the same level of energy efficiency, safety, ease of installation, and maintenance-free operation that self-regulating heat trace cables have. A self-regulating trace heating system is highly effective in protecting buildings from the dangers of cold weather, whilst offering a range of other advantages too.

How long do heat cables last?

The life expectancy of trace heating cables mostly depends on how much they’re used, but 3-5 years is a common lifespan. Heat trace might carry on putting out heat, but the output can reduce over time, leaving you vulnerable to potential failure. Below are a few ways the lifespan of heat trace systems can be increased:

  • Ensure your insulated jacket is well-fitted and high quality. A loose insulated jacket will increase the required power output and workload of the heat cable. No holes or gaps.
  • Check that heat trace is properly installed over valves, flange pairs, supports, and any other items along the pipe. A heat trace specialist can help with this.
  • Invest in thermostats and controllers. It still needs monitoring even though it is called self-regulating heat trace, as it can’t turn itself on or off.

How can TRM help?

As experienced and professional heat trace specialists, we can design, manufacture, install/train, and control complete heat tracing systems and heating solutions. This will compensate for heat losses on pipes, vessels, equipment, and more, which is essential to ensuring your operations stay efficient and safe no matter the weather and temperature. Contact us today to discuss your heat trace needs and find out how we can help with our full turnkey solutions.

What is electrical heat tracing?

Maintaining or raising the temperature of pipes, instrument impulse lines, and vessels in cold conditions with specialised cables is called electrical trace heating or heat tracing. This type of heat trace is broadly used due to its impressive effects at protecting pipes and other important building elements from freezing. Care should be taken when heating elements are chosen to make sure that they are not possible sources of ignition. There are multiple types of cable available such as mineral insulated and self-limiting. 

Trace heating UK is normally considered in the following conditions: 

  • When there is a risk of pipes freezing. Dead legs or other fluids that are susceptible to freezing are common in cold weather, and trace heating can help prevent this from happening.  
  • Hot water systems typically use trace heating to maintain the temperature of the system. 
  • To keep process temperatures consistent for smooth and efficient running of an industrial plant and equipment. For instance, higher temps make heavy/waxy oils flow better, so trace heating is typically applied to those lines. 

There are a number of considerations involved in the design and installation of electric heat trace cable to make sure the system will work properly during start-up and regular plant operation. The thermostat sensor should be properly located and set at the right temperature. Also, there should be a way of indicating that the cable is working as it should be. 

All pipes, vessels, and impulse lines are at risk of heat loss when their temperatures are greater than the ambient temperature. The rate of heat loss can be reduced by using thermal insulation, but it doesn’t eliminate it completely. Electrical trace heating can help to replace some or all of the heat that is lost from the surface, depending on the desired outcome (prevention of freeze or temperature maintenance).  

A thermostat can be used to turn the heat off when the temperature is below the set point and turn it back on when it is a few degrees above the set point. Alternatively, increasingly common control is supplied from microprocessor-based monitoring and control systems, either stand-alone or within the plant control system. 

There are three main types of heat tracing cables available: 

  • Constant power cables 
  • Constant wattage cables 
  • Self-regulating cables 

Each style of trace heating cable operates differently, and the selection of cable will likely depend on the intended application. 

Constant power cable tracing 

This cable, sometimes known as series resistance, consists of a high-resistance wire insulated and encased in a cover. When used at its voltage, it produces thermal energy from the wire’s resistance. 

A key benefit of constant power trace heating is that is usually inexpensive and can maintain extremely high temperatures (particularly mineral insulated cables) for longer lines. Mineral insulated cables are also useful for sustaining lower temperatures on lines which can get very hot like high temperature steam lines. 

Constant wattage cable tracing 

A constant wattage cable has multiple power zones made by wrapping a heating element around two insulated bus wires. By fusing the element to the conductor wire in notches cut in the insulation, a heating circuit is created along the full length of the cable. There is an internal jacket that separates the bus wires from grounding braid. 

The main advantage of this trace heating method is that the parallel circuitry of the cable allows for precise cutting to the desired length in the field. Another advantage is the ability to attach a constant wattage heating tape using either the jointing kit or the trace heating junction box. 

Self-regulating cable tracing 

Self-regulating cable alters heat output based on the heat loss from the pipework by varying its conductivity. As the pipe’s temperature decreases, the polymer core’s electrical conductivity increases, boosting the cable’s output. However, when the pipe’s temperature increases, its conductivity decreases, resulting in decreased output. 

The cable uses two parallel bus wires which transport electricity but don’t produce significant heat. A semi-conductive polymer containing carbon encases the cables. When heated, it restricts current. The cables are constructed, then exposed to radiation, controlling the carbon content and dosage to make different cables with varied outputs. 

Self-regulating cable offers advantages such as customisable length on-site, improved energy efficiency by reducing output at higher temperatures, and protection from overheating and burning out if mis-wired during installation. This makes them especially advantageous for more hazardous applications. 


We hope you have found this guide on electrical heat tracing useful. If you’re looking for experienced trace heating suppliers, then TRM can help. Our team provide full turn key solutions that will work specifically to the requirements of your building and operations. Contact us today to discuss your trace heating needs.

What is Rock Wool Insulation?

Rock wool insulation comes from a volcanic rock that is melted at a temperature of roughly 1,600C and then spun into wool. The newly created insulation is then bound together using resins and oils, giving the material waterproof qualities too. In this guide, we’ll be looking how rock wool insulation is used in relation to trace heating UK and the advantages of it. 

How is rock wool insulation used? 

Pretty much all the insulation within a building can be done with rock wool, the walls, roof, and floor. Not only does rock wool insulation provide thermal insulation, but it also has many benefits relating to noise and fire too. Therefore, it can work with trace heating cable to help with fire protection and sound insulation as well. This suggests that it doesn’t have an organic breeding ground, meaning rock wool is entirely immune to mould and rot. 

What are the advantages of rock wool? 

Every insulation material has its own set of characteristics and work methods. This means that no one job is the same and you might need to select different insulation materials depending on the project. Below you can see some of the main advantages of rock wool insulation. 

Vapour permeable material 

In comparison to chemical products such as polyurethane foam, rock wool insulation is a vapour permeable material. So, damp can freely move around and evaporate, and the likelihood of damp problems stays minimised. With this is mind it is clear to see why rock wool is so frequently used for cavity wall insulation, as the cavity often touches damp. 

Insulation value doesn’t change 

A lot of insulation materials lose some of their insulation value as time goes by, but this doesn’t apply to rock wool. The initial value of rock wool will not change, so you will always be suitably insulated. 

Rock wool vs glass wool 

Unlike glass wool, rock wool insulation does not cause skin irritation to the same degree, making it easier to have installed. 

Are there any disadvantages to rock wool insulation? 

Some people prefer to go with fibreglass insulation over rock wool and the main reason behind this is the cost. The purchase price of rock wool is normally about 10% higher than fibreglass and other types of insulation. To make the right price comparison, it is best to consider the density of the insulation (quantity of material per cubic metre). Although this can vary widely from producer to producer, which naturally impacts the price and insulation value. 

What is the weight of rock wool insulation? 

The weight of rock wool comes down to the application it is being used for, the categories are: 

  • Around 23kg/m3 in the case of blankets 
  • 30 to 80kg/m3 boards for common application, insulation, or cavities between beams 
  • Approximately 90 to 150kg/m3 for applications under load, roof boards, and floating floors 

Types of rock wool insulation 

Foil faced insulation batts 

Foil faced insulation blankets are used for insulating roofs and stories. They are much cheaper than other types of insulation, but it can be difficult to get the batts into place. These insulation blankets can come in different finishes that will facilitate application onto the beams. 

Standard insulation boards 

Standard rock wool boards are mainly used to insulate cavity walls. They are very easy to install, and the boards can hide irregularities in the masonry. As a result of this, you can be sure that the external wall of the building is suitably insulated. The outside of the rock wool boards are, in the case of cavity walls, covered with a more solid finishing material that is wind and damp resistant. 

If you need help with all things temperature measurement, trace heating, and fireproof wiring, contact our team of expert trace heating suppliers at TRM today. 

Can you use heat trace on PVC pipe?

Trace heating cable can be used on pipes made of plastic, but it’s important to take into account the plastic’s durability and thermal properties first. Plastic is 125 times more resistant to heat than steel, but it is also more vulnerable to damage from high temperatures. The key thing when heating plastic pipes is to use a lower temperature and spread it out as evenly as you can, so all the heat isn’t focused in one place.

It is always beneficial to use electric trace heating products that have an automatic thermostat and control, but this is particularly the case when using heat trace on PVC pipe. An automatic heat trace control can check and control the temperature of the system, alert you to any problems, and turn off the heat cable to avoid any damage.

There is heat cable on the market that is specifically designed for use with plastic pipes, thanks to it being self-regulating and having a limited wattage. Self-regulating heat cables include a conductive core in the middle of two bus wires that become increase in conductivity when they’re cold. This system adds more power to the cold spots and limits it in the warmer parts, which creates a more even heat source.

The manufacturer of the plastic pipe should be able to give you more information regarding the maximum temperature it can withstand and how close the heat cable can be spaced or wrapped onto the pipe to avoid any deterioration. Certain applications might need heat cable to be added to opposite ends of the pipe at a lower temperature to spread the heat more evenly, and to prevent one direct area of focused heat which could seriously impact the pipe.

It is recommended that you put in place a foil material between the pipe and heat cable to stop any direct contact and help to offer better distributed and even heating. If you go down this route, put the heat trace control thermostat directly onto the pipe with no foil over the top of it or between it and the pipe to help achieve a more accurate temperature reading.

To answer the overarching question of this article, yes you can use heat cable on plastic pipes as long as you take care and follow the precautions. These include understanding your pipe’s thermal capabilities, choosing a self-regulating, low wattage heat cable, and using an automatic heat trace control with safety functions. By following these guidelines, you can avoid damaging your heat trace system and extend its lifespan.

How can TRM help?

If you’re looking for help with trace heating UK, our team at TRM can help. As professional and experienced trace heating suppliers, we can explain how an effective trace heating system is used to compensate for heat loss, using an electrical heating part, which is put in physical contact with the surface of pipelines, vessel, tanks, etc.

This will help to ensure your manufacturing is working as it should be by maintaining or increasing temperatures where needed. Contact us today to find out how we can help you with your trace heating and general temperature management in your operations.

What is pipe heat tracing?

What is pipe heat tracing?

Having a pipe heat trace system is essential for cold weather conditions when the liquid that flows through pipes tend to freeze. If freezing occurs within pipes, it can cause damage to the piping system as a whole. In serious cases, the build-up of pressure in pipes can result in cracks, or the pipes could even blow up, causing serious injuries to anyone near to the system. In this article, we’ll be going into detail on what pipe heat tracing is and how it is used.

What is pipe heat tracing?

Pipe heat tracing (also referred to as heat tracing) is often used to make sure fluid, process, or material temperatures within pipes and piping systems are kept above ambient temperatures during static flow conditions as well as offering additional freeze protection in specific applications.

You can design a customised heat trace system for certain applications by choosing the right type of industrial heat trace cable. Also, it’s possible to control the level of heat generation through these wires by altering the wattage of the heat trace cable to work with particular requirements for processing fluid.

How is pipe heat tracing used?

One of the most commonly used applications for electric industrial heat trace products is to avoid the freezing of pipes. Using self-regulating electric heat trace alongside an ambient temperature sensing system is the most cost-effective and efficient way to protect your pipes from freezing.

The system design for electric pipe heat tracing applications will be affected by several factors. These include pipe size/diameter, liquid temperature/heat loss, number of thermal heat sinks in the run (flanges/valves), and type of insulation. This will help to determine the right amount of power necessary for the applications so an efficient heat trace system can be designed and supplied.

The controls in these types of systems can be very complicated, as often they are process critical. In order to manage this effectively, various features can be designed into your system such as real-time temperature data, backup operations (in the event of a failure), system failure notifications, wireless connectivity, and more. Specific allowances need to be made for tracing water for safety showers and fire protection systems. Also, electric heating cable systems are typically used as backup systems when steam is used as the main source of freeze protection.

Maintaining temperature

Heat tracing can be used to maintain a steady temperature in pipes and tanks of any size and in a lot of different applications. Pipes that have thermal protection can keep liquid at a regular temperature whilst being moved to a different process through the pipes. As well as this they can lower tank heating expenses due to the incoming material not forming a thermal drag on the process.

Removable and reusable insulation jackets and blankets

Removable insulation provides cover for valves, flanges, and other fittings in industrial buildings. They are an effective, convenient, and cheaper solution to lowering heat loss and making your overall operations more efficient. Standard pipe and valve insulation line products are designed to fit various sizes, and can be used on pretty much any application that needs thermal processing such as:

  • Valves
  • Pumps
  • Filters and regulators
  • Pressure reducing valves
  • Strainers

As the cold weather starts closing in, it’s important to make sure you’ve got suitable pipe heat tracing in place to avoid frustrating and expensive problems should your pipes freeze over. Contact TRM today to discuss your heat trace needs. Our specialists are on hand to make sure you get industrial heat trace cables and an overall system that works for your operations.

Everything to know about trace heating

What is trace heating? 

Trace heating is when the temperature of pipes and vessels is maintained or increased via specifically engineered cables. Trace heating products exist in response to the winter season when temperatures become very cold and can drop below freezing levels. 

When this happens, businesses often look to trace heating as a solution to prevent their vessels and pipes from freezing during the coldest temperatures. This is when pipes can freeze over which might result in them bursting from the expanding ice applying too much pressure. So, the aim of a trace heating system is to stop frost from forming in water pipes by keeping temperatures at a certain level. 

Also, heat tracing can be applied in processes that need temperature maintenance like insulating steam pipes. Another example is where certain liquids need to be kept at a specific temperature so they can be safely transported. In these cases, heat tracing can still be applied even without cold temperatures. 

How does trace heating work? 

Trace heating is done by connecting specifically engineered cables made from a resistance element to the vessel or pipe. The electric cables then have the job of process temperature maintenance by swapping heat loss with their power output. Ohm’s law dictates that connecting a voltage with a wire or cable will lead to a supply of power, which is then changed into heat energy by the heat tracing system. 

Trace heating cables have two copper conductor wires that are the same length, which forms a heating zone with a resistance filament in position. With a supply of fixed voltage, a consistent wattage is generated which in turn heats up the zone. A thermostat monitors the trace heating cables to make sure that the correct amount of thermal energy is produced so the cable won’t underheat or overheat. 

What are the different types of trace heating UK? 

Series resistance trace heating 

A series resistance heating cable is made up of a high-resistance wire that is usually insulated and enclosed within a protective cover. Thermal energy is created from the resistance of the wire when it is powered at s specific voltage level. The main benefit of a series resistance heating cable is that it often costs less than other options and is capable of maintaining very high temperatures for longer lines. 

Therefore, series resistance trace heating cables are normally made to be a fixed length and can’t be shortened in the field. This is because any break or failure at any point along the line would lead the full cable to fail. So, series resistance trace heating cables are often used for longer pipeline heating procedures. 

However, the circuit still needs to be monitored and controlled as the resistance material could melt because of overheating. Series resistance trace heating is normally put in place when long pipeline process heating is required, for example on the quay side of load pipes on oil refineries and along oil pipelines. 

Constant wattage trace heating 

The design for constant wattage trace heating cables includes a heating element that is wrapped around two insulated, parallel wires. There are several points throughout the trace heating cable that experiences constant wattage. 

A notch is made in the insulation on opposite sides of the conductors. Then a small heating circuit is created by fusing the heating component to the exposed conductor wire and this is continued throughout the entirety of the cable. Next the parallel wires are separated from the grounding braid by an inner jacket. 

A key advantage of constant wattage trace heating, compared to series resistance heating, is that the former can still work even in the event of an issue somewhere on the cable. In addition, the length of the cable can be altered on site thanks to its parallel functionality, this cannot be done with series resistance trace heating. It’s for this reason that a lot of businesses and industries ask heat trace specialists to install constant wattage trace heating, because of the flexibility you get with it. 

Constant wattage trace heating cables always come with a thermostat when installed in order to monitor and regulate the power output of the cable. This is done to stop overheating and burning out, should the cable ever come into contact with itself. 

Self-regulating trace heating 

Self-regulating trace heating cables that can change depending on the temperature. On a basic level, when temperatures drop below a certain limit, the cable resistance will go down as well. However, the resistance of the cable will increase when the temperature goes above the specified level. 

Self-regulating trace heating cables are made from two equal wires encased in a semi-conductive polymer. The polymer is typically made with carbon which stops the current from overflowing at increased temperatures. The carbon inside the polymer can expand or contract to generate different levels of resistance and heat energy output. 

The length of the cables can be altered in the field. Also, the self-limiting capability of the cable enables it to be more energy efficient as it can lower its output at higher temperatures. Thanks to its feature of conserving energy when the temperature goes up, self-regulating cables can help businesses to save money as less power is used. 

Additionally, these cables have better levels of safety which is particularly desirable in hazardous locations. This is because the power output of the cables won’t go above a certain level as output decreases when the temperature increases. So, it’s not possible for the cables to overheat, which could have been dangerous, especially in areas with flammable gases and vapours. 

How can trace heating be applied? 

Freeze protection 

As previously mentioned, trace heating is often used to protect pipes and vessels from freezing by keeping the temperature at a set level above freezing point. This is done by providing heat energy to balance the level of heat lost through conduction. Keep in mind thermal insulation can only slow down the heat loss process, it can’t prevent it from happening completely. So, trace heating is a good solution to heat loss and frost protection. 

Gutter and de-icing roof 

Trace heating cables can be fitted to the roofs and in gutters to avoid the accumulation of ice or snow. Also, the cables function as a draining path for water from the melted ice to move through to stop overflowing in the rooftops and gutters. 

Overflowing can have a negative effect on the structural integrity of buildings as it can lead to water soaking into cracks or joints. Additionally, the extra weight from the gathering of snow or melted ice can cause indentations and depressions on the rooftops and gutters. So, trace heating is key to preventing unwanted water build-up. 


Trace heating helps to lower the chance of cavitation occurring in pipes as heating a liquid makes it thinner and reduces its viscosity. The term cavitation refers to the development of vapour bubbles in a liquid caused by fast changes in pressure.  

Shockwaves are created when the vapour bubbles or cavities in the liquid collapse or implode, which degrades the inside of the pipe over time. Also, cavitation can break up the flow of liquid within the pipes. So, putting heat tracing cables in place will lower the likelihood of cavitation as it helps to reduce the pressure difference in the liquid. 


Thermal insulation doesn’t completely reduce heat loss, so heat tracing is needed for businesses to keep temperatures over a designated level. This is particularly important during the winter season when temperatures can go below freezing levels and frost heaving is likely to happen. 

As professional trace heating suppliers, TRM can help you with your trace heating needs. Contact our team today to discuss your requirements. 



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