Insulation of a Tank with an Operating Temperature of 40°C


There are various reasons for both isolating and not isolating a hot piece of equipment, and you can find them in the relevant article.


Taking these reasons into account, we will evaluate the case of “insulation of a tank with an operating temperature of 40°C” with technical calculation tables.

The relevant tank has a diameter of 12.22 meters and a height of 13.75 meters, located in an industrial zone near the sea in Kocaeli, Turkey. Generally, insulation of such storage tanks is neglected, and the reasons for this, as detailed in the referenced article, are competence, cost, and potential risks associated with the insulation system. We will evaluate these reasons with technical calculation tables as follows:

Insulation Competence


Since the process is typically the priority in any operation, the personnel are competent in ensuring the reliability of the process. It is not expected to have competent personnel within the operation specifically for insulation needs since the insulation of any equipment or pipeline is considered a secondary element. This approach is reasonable in terms of cost management.

However, providing this competence externally, rather than through employment, is an alternative solution. As seen in the continuation of this article, even for a tank with an operating temperature of 40°C, there are significant cost and environmental impact advantages to having a robust engineering approach for such insulation projects.


Potential Risks of Tank Insulation


In an uninsulated tank, there is no mechanism for corrosion under insulation. However, in this case, we would incur a significant obligation both in terms of cost and environmental impact. Therefore, a robust engineering infrastructure and, different from traditional practices, a high-standard insulation application can minimize potential risks and provide comfort in terms of cost, environmental impact, and process reliability.

Real Cost of Insulation


Contrary to popular belief, insulation cost has never been the top priority parameter for the design and selection of an insulation system in operations. If it were, we would see much more capable and robust insulation systems in all industrial facilities today compared to the existing ones.

A cost analysis was performed for the case of “insulation of a tank with an operating temperature of 40°C,” and all results can be seen in the summary table below:

Before reading this table, it is essential to examine the parameters on which the calculations are based:

  • Only the tank surface is considered in the calculations; a separate table would be needed for details such as the roof, etc.
  • It is assumed that the insulation will be made with 125 kg/m3 rock wool insulation material and 1.0 mm aluminum trapezoidal sheet.
  • Wind speed is assumed to be 1.6 m/s, and the average ambient temperature is 14.7°C. These values are crucial because both ambient temperature and wind speed are significant factors affecting heat loss calculations. It is essential to compile these values from scientific studies or reports published by official authorities. Both ambient temperature and wind speed are crucial factors in heat loss calculations.
  • The relevant tank is assumed to have an operating time of 5,000 hours/year and an economic life of 20 years.
  • Cost calculations include an annual 1.2% interest cost, 1% maintenance cost, and 1% price variation coefficient.
  • The unit energy cost is 0.1489 EUR/kWh, including a 60% efficiency and natural gas as the source. The table compares three different variations:

i. Uninsulated Tank ii. 50 mm Insulation Application This thickness is generally preferred for similar 40°C tank insulation applications. iii. 200 mm Insulation Application The economic thickness value resulting from the calculations. As seen in the table, leaving the tank uninsulated has a significant cost and environmental impact. While an uninsulated tank will cause over 7,000 tons of CO2 emissions throughout its economic life, this value can be reduced to around 200 tons with 50 mm insulation and to about 100 tons with 200 mm insulation.

It does not make sense to base the cost comparison on an uninsulated surface, as there is a significant total cost of around 3.4 million Euros due to substantial heat loss. However, thicknesses of 50 mm and 200 mm insulation will provide a more meaningful comparison. The heat loss generated by the tank throughout its economic life, along with insulation investment and insulation maintenance, will be 289,525 Euros for 50 mm insulation and 183,680 Euros for 200 mm insulation. In other words, choosing optimum economic application over traditional 50 mm insulation can result in a cost advantage of over 100,000 Euros in total. It should be noted that the insulation costs considered in the table are significantly higher (compared to similar applications in Turkey) than traditional insulation practices. This is because a high standard of insulation application is assumed to minimize potential damages caused by the insulation system, including under insulation corrosion mechanisms.

In conclusion, for a tank with an operating temperature of 40°C, equipping it with 200 mm high-standard insulation is the optimum choice both economically and environmentally. Of course, the operation may have different parameters; for example, there may be a much greater sensitivity regarding the risks of the insulation system. In this case, a higher value would be added to the insulation maintenance cost in the calculations, and the results would be interpreted accordingly. In any case, conducting thermal insulation inspections and making optimal insulation system calculations are necessary for any equipment or pipeline above ambient temperature.

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