Heat tracing today plays a critical role in the temperature maintenance of a myriad of applications such as pipes, storage tanks and vessels; regulating fluid and gas temperature to ensure optimal flow and stability.
It is highly customisable and available in both electrical and steam options. However, to understand the fundamentals of heat tracing, it’s important to know the differences between electrical heat tracing (EHT) and steam heat tracing which both offer energy and cost savings in its respective applications.
EHT – the safe choice
Throughout its history, EHT has been the safe choice for pipe and equipment heating as it can be regulated to deliver precise outputs. EHT essentially uses an electrical heating element that runs the length of a pipe; this heating element is then used to regulate temperature.
EHT is recommended for use on both metallic and non-metallic, as well as lined piping and process equipment as it is equipped with controls to keep process temperatures within specific limits and conserve energy.
“EHT systems offer a broad range of temperature options; it can be designed for applications with low freeze points right up to very high (800 -1000 degrees Celsius) process maintenance temperatures. EHT can also be installed on short or long pipelines which makes it ideal for large concentrated solar power (CSP) farms and petrochemical plants among many other applications,” explains Giles Maynard, General Manager at eltherm South Africa.
Lastly, the common misconceptions that EHT can’t be installed in Ex areas is false. Like steam tracing, EHT has seen major technological advancements allowing it to be installed anywhere.
Steam Heat Tracing – quick heat up
Steam heat tracing is a great solution in plants where steam is a by-product of various manufacturing techniques.
Simply put, steam heat tracing systems circulate steam around process pipes to heat them. The steam tracing is usually installed by running the steam lines in direct contact with the piping or vessels to be heated. The entire assembly is then insulated to direct the heat into the process fluid.
Says Maynard: “One of the main benefits of steam is that it heats up quickly as the highest rate of heat transfer occurs when the difference between the steam tracing and the piping is the highest. This is particularly beneficial during a plant shutdown.
What to consider
From the above it’s very clear that both EHT and steam heat tracing play an important role in maintaining temperatures. However, EHT does offer less drawbacks and drives down operational expenditure (OPEX).
Explains Maynard: “EHT systems are generally easy and quick to install, use energy efficiently and offer low maintenance costs and can be monitored remotely. Also, many systems today make use of self-regulating cables which optimise the temperature control process.”
“Steam heat tracing is quite cumbersome and time consuming to install and can’t be used on non-metallic pipes. Furthermore, it’s far more expensive to maintain as it makes use of fittings which have a propensity to leak. Overall, steam heat tracing has a much higher OPEX.
“Ultimately there is no cookie cutter solution, each system that requires heat tracing should be evaluated individually. There is no doubt that both EHT and steam heat tracing have an important role to play in the different environments and industries they are developed and designed for. The key is to do proper homework, consult with the experts and install a system that will future proof your investment,” he concludes.