This is the first installment in a five part series discussing Heat Tracing.
Heat-tracing systems can be divided into two broad categories, fluid and electric. Fluid heat-tracing systems utilize heating media at elevated temperatures to transfer heat to a pipeline. The fluid is usually contained in a tube or a small pipe attached to the pipe being traced. If steam is the tracing fluid, the condensate is either returned to the boiler or dumped. A number of desirable features made steam the original heat-tracing system of choice to maintain process temperature and provide freeze protection. Steam’s high latent heat from vaporization is ideal for heat-transfer applications. Only a small quantity is required for a large heating load; and it can heat a line quickly, condense at constant temperature, and flow to the point of use without pumping. Steam is universally available and non-toxic.
If an organic heat-transfer fluid is employed, it is returned to a heat exchanger for reheating and recirculation. In general, heating of tracing fluids can be provided by waste heat from a process stream, burning of fossil fuels, steam, or electricity.
Electric heat-tracing systems convert electric power to heat and transfer it to the pipe and its contained fluid. The majority of commercial electric heat-tracing systems in use today are of the resistive type and take the form of cables placed on the pipe. When current flows through the resistive elements, heat is produced in proportion to the square of the current and the resistance of the elements to current flow. Other specialized electric tracing systems make use of impedance, induction, and skin conduction effects to generate and transfer heat.
An Example of Internal Steam Tracing
Click here to see a table listing the operating temperatures, advantages and disadvantages of the different types of heat tracing.
Source: Ankit Chugh, Piping Guide, “Types of Heat Tracing Systems” 2014
Next: More on Steam Tracing vs. Electric Tracing
Harry Woebkenberg, VP Marketing / Jordan Valve Product Manager