![]() ![]() ![]() ![]() An electrical heat tracing system consists of heating elements in cables that are applied - along with any necessary fittings and relays - to the outside of components and controlled by thermostats. The end result in that case is the need for emergency repair, increased maintenance costs and unplanned downtime, all of which can negatively affect the user’s bottom line and are generally preventable.Numerous industrial systems depend on electrical heat tracing to keep pipes, vessels and supply lines at the proper temperature for optimal operation. With poor attention to detail during installation, fluids can freeze and lead to abnormal outcomes or - worst case - a catastrophic pipe failure. While the fundamental purpose of heat trace is to protect pipe and instrumentation systems from freezing or to maintain specific process temperatures, the overlying goal is to prevent impacts to normal facility operation. Aluminum tape should always be applied to plastic pipe before the heat trace, to aid in efficient heat transfer. In addition, plastic is a poor thermal conductor. Another is having the heat trace unattached or loosely attached to the pipe, leading to uneven contact or the potential for damage when the insulation is applied. This can include installing the wrong model or an excessive amount of heat trace, which in some cases can melt plastic pipe. There are several other examples of improper installation of heat trace beyond inadequate pipe and device coverage. Addressing these unique situations provides an opportunity for developing standards for the current installation that can become a part of an organizational standard, useful for future expansions. This exercise may even require thermal calculations based on desired maintain temperature, insulation characteristics, and the device shape and total mass. If a unique shape or piece of equipment is identified that is not covered by manufacturer guidelines, it should be discussed with an expert to determine the best approach for applying heat trace. This echoes back to the need for training, discussion and a comprehensive field walk and planning session on the front end. There are certainly a multitude of non-standard devices and shapes that can be encountered during a heat-trace system installation. Poor contact creates the potential for damage when the insulation is applied. Proper installation techniques help ensure the heat trace is appropriately attached to the pipe. What is the best approach for addressing these types of challenges? They often have small-diameter fluid paths that are more prone to freezing than the main pipe. Each of these requires special attention and care when installing heat trace. There are many other unique devices such as filter vessels, air vents, pump heads and pressure transmitters. Utilizing these tables is a best practice for ensuring proper installation and a reliable system.Įlbows, pressure gauges and valves are just a few examples of the types of equipment that may be encountered during installation. For example, one manufacturer’s table recommends installing 4’ of heat trace on an 8” globe valve. When heat tracing valves, most manufacturers have developed a table that recommends specific heat-trace footage based on the valve type and pipe diameter. In addition, some valve types have cavities where material collects outside of the process flow, and the expansion caused by freezing can lead to fluid leaks. ![]() If the material inside a valve body freezes, operation and process control can be affected negatively. In cases where there is an isolation diaphragm below the gauge, the fluid stops at the sensor, so heat trace should be placed to adequately protect the diaphragm.įurthermore, valves typically have significantly more thermal mass than the adjoining pipe, and they deserve special attention during installation. For a wetted gauge where the fluid sensor is inside the gauge behind the display, the heat trace should route around the entire outer circumference of the gauge head. For example, when a pressure gauge is installed in the line, heat trace should be applied in a very specific way. It often is helpful to view the system in terms of where there is standing fluid. ![]()
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