Electric Heat Tracing – A Comprehensive Guide

What is Electric Heat Tracing?

Electric heat trace, or surface heating, is the application of heat to an external surface that compensates for heat lost due to changes in temperature in ambient surroundings. In cold or freezing conditions, heat tracing systems help stabilize surface temperatures of pipes or vessels via electric trace heaters to protect the flow of liquids inside and reduce the risk of equipment damage.

Electric trace heaters also maintain process temperatures for substances that can solidify or become overly viscous within a system such that it impedes the progress of critical processes. Freeze protection and temperature maintenance are the most common applications for electric trace heating.

This versatile and powerful thermal technology is used in renewable energy systems, oil and gas processing, petrochemical/chemical processing, power generation, transportation, food and beverage production, environmental monitoring and more.

How Heat Trace Works

There are multiple components within an electric heat trace system that work in concert to make maintaining and adjusting temperatures across even complex systems possible. One key component is the heat trace cable, an electrical element that is fitted along the length of a pipe or other equipment surface. Once the heat cables are securely fixed to the length of the pipe, both are covered with layers of insulation and metal jacketing to prevent heat loss.

A well-designed heat trace system should ensure that the heat trace cable’s input matches the pipe or equipment’s heat loss. Additional factors impacting heat loss include ambient temperature, wind speed and insulation. Carotek offers a large variety of Thermon electric heat trace cables and can help you determine which cables meet your heat tracing needs.

Designing Your Heat Trace System

Assembling an efficient heat trace system that is both economical and suitable for your heating needs can be complicated. There are many elements to consider, such as a wide selection of cable options in various wattage outputs, voltages, and jacket materials, heat sensors and accessories. The process can become complicated quickly.

It is very important to consider specific heat calculations that are necessary to determine the proper cable, wattage and breaker sizes to ensure the system functions properly. Also, sensor placement can be critical for the proper operations in trace heating applications. Carotek can help design the right system to meet your application needs.

Our world-class team of engineers is available to provide the ultimate solution to your heat process needs. We understand that every heat trace project is unique and will work with you to consider which materials and accessories will best serve your specific needs and budget goals. With our highly skilled teams and advanced software, you can be certain that our solutions will meet your needs.

We also partner with Thermon to offer detailed designs with ‘as built’ documentation on any new systems installed. We can help maintain your system to ensure trouble free operation and avoid major upgrades later.

Heat Tracing Expert Consultations and Audits

Protect your plant from costly down time, decreased production, and water damage caused by frozen pipes, instruments and vessels this winter by allowing us to conduct a complete heat trace audit and recommend the options for freeze protection solutions, for both hazardous and non- hazardous areas.

The audit will factor in key considerations to ensure long term reliability of your electric tracing systems. We will help ensure quality and appropriate products are selected that are suitable for lifetime of plant operation (minimum 20 years) in accordance with IEEE benchmark testing. We can provide survey services and detailed reports on the condition of your existing electric heat tracing systems.

Thermon Electric Heating Cables and Systems

Self-Regulating Heating Cables

Self-regulating heat trace cables allow automatic adjustments to heat output in response to the heat loss conditions along the entire circuit. When ambient temperature drops causing heat loss in the equipment, the cable responds by increasing its heat output. When ambient temperature rises and temperatures in the equipment increase, the cable output will decrease. Self-regulating cables can be used for tracing requirements on piping, vessels and equipment as well as commercial applications such as snow and ice melting for tracks, roof, gutter and concrete applications. There are several different types of self-regulating cables that range in maintain temperature from 65°C (150°F) to 200°C (392°F).

Power Limiting Heating Cables

High performance HPT power-limiting heating cables are designed specifically for process temperature maintenance or freeze protection where high maintain temperatures or high temperature exposure is required. A coiled resistor alloy heating element provides the power limiting feature of HPT. This PTC (Positive Temperature Coefficient) characteristic decreases the cable’s power output as the heat-traced product temperature increases and allows the cable to be overlapped during installation. The maximum maintain temperature for HPT cable is 210°C (410°F). Parallel Constant Watt Heating Cables FP cables provide consistent and reliable heat outputs regardless of circuit length and are designed to provide freeze protection or process temperature maintenance to piping, tanks and equipment. Because FP cables are not subject to the inrush current associated with self-regulating heating cables, the need for oversizing power distribution equipment is eliminated. The parallel resistance configuration allows the cable to be cut to length and terminated in the field with easy-to-use Thermon supplied kits. The

Parallel Constant Watt Heating Cables

FP cables provide consistent and reliable heat outputs regardless of circuit length and are designed to provide freeze protection or process temperature maintenance to piping, tanks and equipment. Because FP cables are not subject to the inrush current associated with self-regulating heating cables, the need for oversizing power distribution equipment is eliminated. The parallel resistance configuration allows the cable to be cut to length and terminated in the field with easy-to-use Thermon supplied kits. The maximum maintain temperature for FP cable is 65°C (150°F).

Skin Effect Heat Tracing System

A ThermTrac system provides a cost-effective alternative to conventional resistance heat tracing on long pipelines by eliminating the need for an extensive power distribution system. A pipeline up to 25 kilometers (15 miles) long can be traced from a single power point. The versatility of the system makes it ideal for temperature maintenance, freeze protection and heat up applications. Series Constant Watt Cables Series resistance constant watt heating cables, such as TEK, HTEK and MIQ are used for temperature maintenance or freeze protection along lines where circuit lengths exceed the limitations of parallel resistance heating cables and high maintain temperatures or high temperature exposure is required. High performance HTEK and TEK series cable can be manufactured with prefabricated circuit lengths up to 3658 meters (12,000 ft). Maximum maintain temperature for TEK is 101°C (215°F) and for HETK maintain temperature is 204°C (400°F.) MIQ’s resistance configurations are available to provide tracing for pipes up to 1.6km (1mile). Thermon’s MIQ mineral insulated cables are manufactured using Alloy 825, a high nickel/chromium alloy ideally suited for high temperature service with a maximum maintain temperature of 500°C (932°F.) The circuitry of constant watt series cables provides consistent power output along the entire length of the cable with no voltage drop concerns associated with parallel tracer constructions and can be powered from a single power supply point. These high-performance series resistance constant watt cables can provide tracing for pipes. Electric Heat Thermostats Electric heat thermostats are critical for proper operations in trace heating applications and depending on the required temperature control and requirements for the controller itself, electrical or

Series Constant Watt Cables

Series resistance constant watt heating cables, such as TEK, HTEK and MIQ are used for temperature maintenance or freeze protection along lines where circuit lengths exceed the limitations of parallel resistance heating cables and high maintain temperatures or high temperature exposure is required. High performance HTEK and TEK series cable can be manufactured with prefabricated circuit lengths up to 3658 meters (12,000 ft). Maximum maintain temperature for TEK is 101°C (215°F) and for HETK maintain temperature is 204°C (400°F.)

MIQ’s resistance configurations are available to provide tracing for pipes up to 1.6km (1mile). Thermon’s MIQ mineral insulated cables are manufactured using Alloy 825, a high nickel/chromium alloy ideally suited for high temperature service with a maximum maintain temperature of 500°C (932°F.) The circuitry of constant watt series cables provides consistent power output along the entire length of the cable with no voltage drop concerns associated with parallel tracer constructions and can be powered from a single power supply point. These high-performance series resistance constant watt cables can provide tracing for pipes.

Electric Heat Thermostats

Electric heat thermostats are critical for proper operations in trace heating applications and depending on the required temperature control and requirements for the controller itself, electrical or mechanical thermostat options are available.

An electronic controller uses temperature sensing devices such as RTDs and thermocouples. Electronic controllers are available for field or panel mount applications and provide communication features for remote control and monitoring. Examples of electronic controllers include RTD-100 and TraceNet ECM.

Mechanical thermostats have bulb and capillary style sensors that use expanding fluid to open or close contacts depending on temperature changes. Mechanical thermostats such as E7-25325 are rugged, less expensive than electronic thermostats and do not require any form of control.

Control and Monitoring Systems

Control and monitoring systems play an essential role in heat tracing applications ranging from freeze protecting water lines to maintaining elevated process temperatures. While mechanical thermostats have been used successfully for many heat tracing applications, a more complete control and monitoring solution may be necessary for critical heat tracing applications.

Advancements in technology have made electronic control and monitoring units both more cost effective and more reliable. These systems conserve energy, extend system life, and ensure accurate temperatures are maintained, for reduced operating cost and increased plant reliability.

Performance data, diagnostics and alarms are delivered in real time to management and maintenance teams, accessible from the control room, in the field or remotely from any PC or tablet. Components in the Genesis Network include the Genesis Controller and the Genesis Duo.

The Genesis Controller monitors individual heat trace circuit performance offering a more complete monitoring and control solution for critical heat tracing applications. The Genesis Controller also features selectable control methods for each individual circuit, temperature sensor status identification, programmable “trip” set points, remote alarm acknowledgment and reset capabilities, and more.

The Genesis Duo is a dual-point heat trace temperature monitor and controller with a high temperature limiter. The Duo provides control and monitoring for one or two heat tracing circuits with input from up to two intrinsically safe RTDs per circuit. Native to the Genesis Network, the Duo requires no additional hardware to communicate with Thermon’s state-of-the-art supervisory management platform.

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