![]() ![]() However, the monitoring system still showed lower temperature than were required. Modifications were performed the next summer.Īs shown in Figure 9, more heat tracing was added and an elbow pointing down was installed. I was called to analyze the situation, and advised that more heat tracing was needed and the pipe should point down to prevent snow accumulation. With the large uninsulated pipe exposed, the temperature of the pipe could never be maintained above freezing and eventually, condensate plugged the line. The electronics in the picture are part of a state-of-the-art power-line carrier monitoring system that sends the end-of-pipe temperature back to the Distributed Control System (DCS) in a North Slope of Alaska project. This 1 inch of insulation will also produce a 40☏ temperature difference, which could provide freeze protection in a very low maximum ambient (see Figure 2).įigure 8 shows a 14-inch pipe that was the vent for a large tank (thousands of gallons). A 1-inch pipe will lose 10 watts per foot with no thermal insulation, but will only lose about 1.5 watts per foot with 1 inch of fiberglass thermal insulation. In regard to heat transfer, the first concept one must understand is the value of thermal insulation. Break any one of the legs and the system will not “stand.” Heat Transfer If any one of the legs is compromised, the system may not provide expected performance. One leg is “heating cable quality” (heat trace cable and thermal insulation) the second leg is “engineering quality” (choosing the proper wattage, thermal insulation, ambient temperature, safety factors, etc.) and the final leg is “installation quality,” or the quality of the installation of the piping system and heat tracing system. To make use of a visual symbol, electrical heat tracing is like a stool with 3 legs (see Figure 1). In 1960, about 95% of heat tracing was steam and in 1995, because of improvements in electrical tracing, that number dropped to between 30% and 40% of new installed tracing. This article will mainly focus on electrical heat tracing, the choice of many of new installations in both industrial and commercial projects. In other cases, however, temperature maintenance must be provided by the addition of heat in the form of electrical heaters, steam tubes, or hydronic fluids. Sometimes temperature maintenance can simply be accomplished by installing only thermal insulation. Both freeze protection and process temperature maintenance can indicate the need for heat tracing. It is critical then to have a system in place that would keep the liquids flowing within the pipes at desired temperatures.Ī heat trace system essentially does that and is one of the most reliable ways to control temperatures in the process pipes.A significant number of industrial and commercial piping systems require temperature maintenance. However, for process industries that handle liquids, this phase change is a problem.ĭuring cold weather conditions, liquids are likely to freeze, blocking or restricting the flow within the pipes. How to Design The Perfect Heat Trace SystemĪ liquid has a unique property that allows it to thicken and become solid at lower temperatures. In other words, these traces can automatically regulate the current flow based on the outside temperatures. Modern-day heat traces are made from polymers that are self-regulating. In extreme cases, the pressure build-up within the pipes can lead to cracks, or the pipes might even blow up, causing severe injuries to people working near the processing system.īy using a Chromalox's heat trace system, we can keep the pipes warm even when the surrounding temperatures plummet. As discussed earlier, freezing within the pipes can damage the entire piping system. ![]() Heat trace system is necessary for cold conditions where the liquid flowing within pipes are prone to freezing. ![]() It is also possible to control the amount of heat generation through these cables by varying the wattage of the cable to suit particular processing fluid requirements. You can design a customized heat trace system for a specific process application by selecting the right type of cables for the traces. These paths are made up of a resistive element that heats up when electricity passes through it. A heat trace system is a set of paths lined along pipes or vessels. ![]()
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