Details determine success or failure
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Details determine success or failure. A carbon steel pipeline (with a diameter of 38 mm) used for transporting concentrated sulfuric acid in a certain factory experienced an unexpected leak shortly after it was put into use following ten days of maintenance work; upon inspection, it was found to be corroded through. It turns out that the pipeline had a steam tracing pipe. The heat tracing tube came into direct contact with the carbon steel pipe, causing localized overheating of the carbon steel pipe, and differential corrosion occurred in the acidic environment. To prevent direct contact between the carbon steel pipe and the steam tracing pipe, a spacer is placed between them to maintain a certain distance. During this maintenance work, the partition blocks were forgotten to be installed.
Be careful, and you’ll sail safely for years; careful decisions determine success or failure.
98% concentrated sulfuric acid has a freezing point of -0.7°C; heating it with steam makes it highly susceptible to high-temperature corrosion. It is recommended to use electric heating, as it simplifies temperature control and allows for the activation or deactivation of the heating system according to seasonal changes and temperature conditions. This is not just a matter of details, but also a matter of approach
Do stainless steel pipelines and their heat tracing lines also need to be isolated, and are there any relevant standards to guide this? Is it feasible to use carbon steel bolts for stainless steel flanges?
For 98% concentrated sulfuric acid, what temperature range allows the use of carbon steel pipes?