What is a heat trace system?

In many industrial and commercial applications, a sufficient drop in temperature can lead to frozen pipes and unintended condensation in steam or compressed air lines. In non-pipe applications where freezing temperatures and precipitation is present the effects can include snow and ice build-up on surfaces and rooftops, leading to potential damage.

Heat trace is a heating technology used to prevent these temperature related issues. Heat tracing can be used to maintain the desired temperature on a pipeline, or to provide freeze protection on buildings, equipment, and other structures.

How do heating cables work?

The cables are fitted directly to pipelines or surfaces that require temperature regulation. Temperature sensing and control equipment ensures the heat trace system maintains the set temperature.

For piping applications, heat trace systems ensure liquid remains within desired temperature parameters, preventing them from freezing in cold weather, and also ensuring that fluids remain at the required temperature for efficient processing.

In commercial and residential applications heat tracing is commonly utilized to address issues with snow and ice accumulation on structures in winter, in addition to the pipe applications already discussed. The goal for roof-top applications is not to completely melt the build-up, but to create a pathway for water drainage. Additionally, heat trace can also be employed to raise temperatures of freezer floors and other similar spaces to prevent damage from thermal expansion.

Heating cables

Self-Regulating Heat Trace Cable

Self-regulating heat trace cables contain a semiconductive polymer core as the heating element rather than a traditional metal heating element.  This semiconductive polymer is extruded over parallel bus wires, and contracts or expands which adjusts its electrical resistance in response to temperature changes. Self-Regulating cables have many advantages over traditional heating cables making them a great choice for many different applications.  Some of those benefits are:

1. Energy Efficiency: Self-Regulating heat trace adjust It’s heat output based on the ambient temperature. When the temperature drops, they produce more heat, and when it rises, they produce less. This ensures that energy is used only when necessary, leading to significant energy savings.
2. Safety: Self-regulating heat trace cables cannot overheat, even if they overlap. This reduces the risk of fire or damage to the system.
3. Ease of Installation: These cables can be cut to length on-site, making them easy to install in various configurations and tight spaces.
4. Longevity and Reliability: Due to their ability to adjust heat output and avoid overheating, self-regulating heat trace systems tend to have a longer lifespan and are considered very reliable.
5. Versatility: They can be used in a wide range of applications, including preventing pipes from freezing, maintaining process temperatures, and protecting roofs and gutters from ice and snow.

Constant Wattage Heat Trace Cable

As the name implies Constant wattage heat trace cables keep a constant wattage along the entire length of cable. The cables are constructed of nichrome wire wrapped around parallel insulated bus wires, connected at alternating intervals to create a network of parallel resistive elements along the length of the cable. 

Constant wattage heat trace does have some disadvantages like not being able to overlap and needing to use a controller.  Both of those situations are a high potential for burn out based on the constant wattage technology.  While there are some disadvantages there are also many advantages which are:

1. Consistent Heat Output: Unlike self-regulating cables, constant wattage cables provide the same amount of heat along their entire length, making them ideal for applications where uniform heating is required.
2. Applications: They are commonly used for process heating, freeze protection, and maintaining the temperature of pipes and vessels. They are particularly useful in commercial plants and large-scale piping projects.
3. Durability: These cables are robust and can handle high temperatures, making them suitable for demanding environments.
4. Installation: They are typically cut to length on-site and can be installed in various configurations to meet specific heating needs.

Industrial Mineral Insulated (MI) Heat Trace Cable

Another type of constant wattage heating cable is Mineral Insulated (MI) heat trace, which consists of one or more metallic heating elements, surrounded by compacted magnesium oxide (MgO), and an Alloy 825 metal sheath. Mineral Insulated (MI) heat trace cables are known for their durability and high performance in extreme conditions. These cables are designed to provide a reliable solution for various industrial applications, especially where high temperatures and power outputs are required. The key features and advantage of Mineral Insulated (MI) heat trace are:

1. High Temperature Resistance: They can withstand temperatures up to 1200°F (648°C) when powered off.
2. Durability: Constructed with a metal sheath and magnesium oxide insulation, these cables are highly resistant to fire, impact, and corrosion.
3. Constant Power Output: Unlike self-regulating cables, MI cables provide a constant power output, which is not affected by temperature variations.
4. Applications: Ideal for freeze protection, high process temperature maintenance, and environments with high exposure temperatures.

The Critical Components of Electrical Heat Tracing Systems

Thanks to their versatility, electrical heat trace systems can cater to a wide array of applications. But what components make up a heat trace system that contribute to this versatility?

1. Heat trace cables – Essential to any system, heating trace cables provide the surface heating needed to maintain or increase temperature. As mentioned earlier, the range of heating cables include self-regulating, constant wattage, or mineral insulated.
2. Temperature controls & monitoring – Controls can vary from basic mechanical thermostats that offer freeze protection to sophisticated industrial heat trace control panels designed for larger applications. Some of these panels feature an HMI (Human-Machine Interface), a user-friendly touchscreen computer that displays various outputs. Additionally, data from monitoring and sensing controls can often be accessed remotely through digitally connected systems, enabling users to view performance data and adjust control settings and alarms.
3. Connection Kits and Accessories - A typical heat trace system requires connection kits to ensure a reliable electrical connection and protect the cables from moisture and other environmental factors.  Most heat trace systems would consist of power connection, splice, and end seal kits.  There are also other components and accessories for mounting as well as tapes to secure the heat trace to the pipe or vessel, ensuring proper heat transfer.
4. Design software – To support the complete design of a team trace system, software allows users to perform calculations and pick the appropriate heat trace model, connection kits, and controls to satisfy their unique application requirements.