![]() ![]() ![]() The cables are manufactured and then irradiated and by varying both the carbon content and the dosage then different tape with different output characteristics can be produced.Īdvantages of self regulating trace heat tape include: This polymer is loaded with carbon as the polymer element heats, it allows less current to flow. They are encased in a semi-conductive polymer. Self regulating tape uses two parallel bus wires which carry electricity but do not create significant heat. As the pipe temperature increases the conductivity reduces and output decreases. As pipe temperature falls the electrical conductivity of the semi-conductive polymer core increases causing the tape to increase output. Self regulating tape adjusts heat output depending on the heat loss from the pipe work by varying its conductivity. Self regulating heating cable is most often called a tape rather than a cable i.e self regulating tape, or even self limiting tape. Another advantage is that constant wattage heating tapes can be joined using either a jointing kit or a trace heating junction box.Īs with constant power cables, constant wattage cables should not be crossed over itself as this can lead to them overheating and eventual burn out.Ĭonstant wattage cable is always installed with a thermostat to control the power output of the cable, making it a very reliable heating source. The major advantage of constant wattage trace heating cable is that this cable can be cut to length in the field due to its parallel circuitry. care needs to be taken during installation that the cable is not crossed over itself as this can lead to the cable overheating and eventual burn out. ![]() a break or failure anywhere along the length of a constant power cable will cause the entire cable to fail, ![]() they are supplied in specific lengths and cannot be shortened in the field, Mineral insulated cables are also good for maintaining lower temperatures on lines which can get extremely hot such as high temperature steam lines.ĭisadvantages of constant power trace heating cables include: The advantage of a constant power heating cable is that it is generally inexpensive and it is able to maintain very high temperatures (especially mineral insulated cables) for longer lines. When powered at its operating voltage, thermal energy is produced from the resistance of the wire. Each type of trace heating cable works differently, and the choice of cable is influenced by intended application.Ĭonstant power heat tracing cable, sometimes referred to as series resistance cable, is made up of a high-resistance wire that is typically insulated and encased in a protective cover. There are three types of heat tracing cables available: constant power cables, constant wattage cables, and self regulating cables. What Types of Trace Heating Cables are Available Without insulation, heat losses are generally too high to be offset by a conventional heat tracing system. The need for properly installed and well-maintained thermal insulation cannot be overemphasised. I Have Heat Tracing - Do I Still Need Insulation? the thermostat energising the heat tracing when temperature falls below the setpoint and de-energises when temperature is a couple of degrees above setpoint, or increasingly common control is supplied from microprocessor-based control and monitoring systems - either stand alone or within the plant control system. freeze prevention, or temperature maintenance.Ĭontrol of the heat supplied can be from a simple on-off thermostat, e.g. The amount of heat replaced depends on what is to be achieved, i.e. Electrical trace heating replaces some, or all, of the heat lost from the surface. The rate of heat loss can be slowed by the use of thermal insulation, but this does not eliminate it. For example, heavy, or waxy oils flow better at higher temperature therefore trace heating is often used on these lines.Įvery pipe, vessel and impulse line is subject to heat loss when its temperature is greater than ambient temperature. to maintain process temperatures for smooth and efficient running of process plant and equipment. Trace heating is often used in hot water systems. to maintain the temperature of a liquid system. Pipes and impulse lines that freeze can rupture therefore trace heating can prevent this. In cold weather this is especially prevelant in dead legs or when there is little or no flow of a fluid susceptible to freezing in a line. when there is a risk of pipes freezing. Heat tracing is usually considered in the following circumstances: In simple terms it the application of a compensating heat source. Electrical Trace Heating System Basics What is Heat Tracing?Įlectrical trace heating, or as it is often called - heat tracing, refers to the process of maintaining or raising the temperature of instrument impulse lines, pipes, and even vessels through specially designed cables. ![]()
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