Insulation and heating issues for intermittent transportation of DN900 crude oil buried pipelines
Thread Content
Originally, the crude oil pipelines of DN900 were laid using steam tracing pipe racks; however, due to topographical reasons, it was more appropriate to bury them in some sections, with a burial length of about 60 meters, after which the pipes were placed back on the pipe racks. It is quite troublesome to use steam tracing for buried pipelines with steam traps. This project is located in the coastal area of Fujian, where the lowest temperatures still range in the high teens degrees. Currently, it is planned to use insulation only for buried pipelines, while steam tracing will still be used for overhead pipelines. However, since the crude oil in this project is transported intermittently, it is unclear whether there will be any issues with buried pipelines. Does anyone with relevant experience have any suggestions?
At present, domestic anti-corrosion and insulation pipe manufacturers are all capable of carrying out the tube-in-tube processing with an epoxy powder anti-corrosion layer + insulation layer + protective layer. The main insulation materials used for buried insulated pipelines in China include rigid polyurethane foam plastic, water-repellent silicate pipe shells, glass fiber insulation, and water-repellent rigid rock wool pipe shells. You can check the applicable conditions for these insulation materials based on your specific situation.
Electric heat tracing can be considered; it is generally used for intermittent operation in oil fields.
If the pipeline length is relatively long, skin heating can be used
Could the expert upstairs explain what “skin heating” means? I’ve learned it from you*.
Reply to 4# cy0404020: Thank you. I hope you can explain what \"skin heating\" is”
We are only at a distance of over 60 meters; it’s too short. All other pipelines use steam for heating, while this section relies on electric heating and requires cables to be installed, which isn’t very practical. Moreover, it will cause difficulties in maintenance in the future. The key is that we have a single tube, and circulation cannot be used. We still want to use steam tracing, but we need to dig a pit for steam traps. I hope those with on-site experience can offer some advice.