Heat trace utilizes electricity and insulation to maintain the temperature of pipes or other vessels, replacing any heat lost to outside temperatures.
A heat tracing system protects pipes and tanks while maintaining ideal temperatures to ensure that users never have to sacrifice efficiency to heat loss.
Powertrace
Powertrace by Powerblanket offers self-regulating trace heat systems that feature a temperature-dependent resistive element housed between two parallel conductors that automatically limit the output according to the surface that it attached.
When the surface temperature increases, the power output of the heat trace decreases, and vice versa. This technology prevents overheating and damage to the protected processes.
Primary applications
Proper heating of liquids at a specific temperature range allows users to transport liquids
Primary applications of heat trace are freeze protection and temperature maintenance. Expansion or freezing of water and other liquids poses a safety concern and can also be damaging to equipment and workers.
Proper heating of liquids at a specific temperature range allows users to transport liquids, maximizing efficiency and simplifying their processes cost-effectively.
What Does A Completed Heat Trace System Look Like?
A heat trace system includes:
- Heat tracing cables (self-regulating heating cables, constant watt cables, or power limiting cables) are applied to piping and tanks, often secured with fiberglass or aluminum.
- A control panel or thermostat.
- A power connection box to connect power from the breaker.
- Ambient temperature sensor.
- Insulation jacket.
- Light indicators to monitor output.
- Cable termination box.
How Do users Install Heat Trace?
While these tips and instructions apply to typical heat trace system installation, refer to manufacturer instructions for product-specific installation instructions.
- Pre-Installation
Ensure that all piping is installed correctly, and is in proper working order
Before installing any electric heat trace, the user must verify the following: first, be sure that the user has selected the correct heat trace and accessories regarding the calculation of heat losses, maximum permissible operating and ambient temperatures, class, and length.
Next, ensure that all piping is installed correctly, is in proper working order, and has been pressure tested.
Wire cutters and an insulation resistance meter
Walk the piping system's length to determine the heating cables' route. The surfaces to which the heat trace will be attached should be free from dirt, rust, and sharp edges or objects. Remove old heat tape and any other combustible materials.
Users will need a pair of wire cutters and an insulation resistance meter with a minimum testing voltage of 500 Vdc and a maximum testing voltage of 2500 Vdc.
Maximum cable circuit length
Take care to determine the maximum cable circuit length allowed for a specific system. Pure Air Controls love to help users with this, so give them a call or check out one of these charts to calculate the total cable heating length.
Once users have confirmed that the heat trace cable is the proper type and output, check for any damage to the cable and test electrical integrity using a merger. The heating cable can be cut to the user’s desired length. Heat trace cable is then combined with termination and splice kits, tee kits, end seals, and other accessories to complete the system.
- Installation
For heat distribution of heat trace on plastic pipes apply aluminum tape to where the trace cables will be laid
Next, payout the cable along the pipe to be traced. Roll the cable out loosely while keeping it near the piping. Doing this will ensure the user has the appropriate amount of cable and account for all components, elbows, loops, and fixtures. Allow excess cable (12-18” per termination is recommended) for splicing, power connections, or any future servicing.
Any adjustments in circuit length will require reconfirmation due to the change in power output, so be sure to cut to the exact desired length. For better heat distribution of heat trace on plastic pipes apply aluminum tape to where the trace cables will be laid.
Heat tracing cable
Begin attaching the heat tracing cable to the pipe on the lower half at a 45° angle (looking at the line straight on, attach a single cable at 4 o’clock and if using an additional cable, at 8 o’clock). Attach the cable using heat or fiberglass tape every 6” to 1’ back toward the power source.
An extra heating cable is required for any flanges, valves, etc. For installation suggestions for placing cable around flanges, valves, or supports, refer to heat tracing cable installation instructions and project designs for the most accurate and task-specific details and information.
Simple thermostat, temperature sensor
Heat trace systems can be controlled with a simple thermostat, or with a temperature sensor like an rtd that provides feedback to a more common PID or PLC-style controller.
These systems will control and adjust the temperature of the heat trace. Additionally, most are equipped with varying types of monitors to assist the user in observing power output.
Cutting a heat-tracing cable
Once the heat trace has been cut and installed on the pipe or tank, carefully follow the instructions
Before cutting the heat tracing cable, ensure that it is fully attached and that appropriate allowances, generally 1’ minimum, have been given for connections and terminations.
Once the heat trace has been cut and installed on the pipe or tank, carefully follow manufacturer instructions for termination. Confirm that the tinned copper overbraid is separated from the two bussbars and that those bussbars are firmly secured into their proper termination points.
Insulation
Proper insulation covering the heat trace cables and the thermostat is an important feature that cannot be forgotten. Additionally, maintaining the integrity and overall well-being of an insulated system is critical.
Before installing insulation, visually check that all cables, splices, and power connections are in working order and free from mechanical damage.
How to Connect Heat Trace Cable?
Before beginning the connection, test the heat trace cable to ensure integrity with a megger of at least 500 Vdc. To do so, connect the positive lead of the megger to the cable’s bus wires and the negative lead of the megger to the cable’s braid.
Again, refer to specific system requirements. Before making any power connections, first, make end and splice connections. Heat trace can be connected to 120V, 208V, 240V, or 277Vac, and to any size breaker.
